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Trop. Med. Infect. Dis., Volume 8, Issue 7 (July 2023) – 47 articles

Cover Story (view full-size image): Timely identification, screening and TB preventive therapy (TPT) help in the early diagnosis and prevention of TB among child household contacts of pulmonary tuberculosis patients (PTBP). This cohort study assessed the performance of the TB programme in managing child household contacts (aged <15 years) of PTBP treated in Bishkek, the Kyrgyz Republic. Over 90% of 297 identified child household contacts were screened and active TB was diagnosed in 9%. TPT was initiated in nearly half of those eligible, but in two thirds, it took more than 15 days to initiate TPT. Appreciably, 80% completed TPT. This study from SORT IT on the building operational research capacity of TB programme managers to make evidence-informed decisions recommends that health workers counsel caregivers about the timely initiation of TPT. View this paper
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12 pages, 905 KiB  
Article
Improvement in Infection Prevention and Control Compliance at the Three Tertiary Hospitals of Sierra Leone following an Operational Research Study
Trop. Med. Infect. Dis. 2023, 8(7), 378; https://doi.org/10.3390/tropicalmed8070378 - 24 Jul 2023
Viewed by 1132
Abstract
Implementing infection prevention and control (IPC) programmes in line with the World Health Organization’s (WHO) eight core components has been challenging in Sierra Leone. In 2021, a baseline study found that IPC compliance in three tertiary hospitals was sub-optimal. We aimed to measure [...] Read more.
Implementing infection prevention and control (IPC) programmes in line with the World Health Organization’s (WHO) eight core components has been challenging in Sierra Leone. In 2021, a baseline study found that IPC compliance in three tertiary hospitals was sub-optimal. We aimed to measure the change in IPC compliance and describe recommended actions at these hospitals in 2023. This was a ‘before and after’ observational study using two routine cross-sectional assessments of IPC compliance using the WHO IPC Assessment Framework tool. IPC compliance was graded as inadequate (0–200), basic (201–400), intermediate (401–600), and advanced (601–800). The overall compliance scores for each hospital showed an improvement from ‘Basic’ in 2021 to ‘Intermediate’ in 2023, with a percentage increase in scores of 16.9%, 18.7%, and 26.9% in these hospitals. There was improved compliance in all core components, with the majority in the ‘Intermediate’ level for each hospital IPC programme. Recommended actions including the training of healthcare workers and revision of IPC guidelines were undertaken, but a dedicated IPC budget and healthcare-associated infection surveillance remained as gaps in 2023. Operational research is valuable in monitoring and improving IPC programme implementation. To reach the ‘Advanced’ level, these hospitals should establish a dedicated IPC budget and develop long-term implementation plans. Full article
14 pages, 824 KiB  
Brief Report
One Health Approach in Serosurvey of Toxoplasma gondii in Former Black Slave (Quilombola) Communities in Southern Brazil and Among Their Dogs
Trop. Med. Infect. Dis. 2023, 8(7), 377; https://doi.org/10.3390/tropicalmed8070377 - 24 Jul 2023
Cited by 2 | Viewed by 1081
Abstract
Brazilian quilombos are rural semi-isolated remnant communities of former black slaves and their descendants who traditionally maintained themselves through archaic subsistence livestock and agriculture practices and historically lacked specific public health policies. Although such individuals and their dogs may be exposed to zoonotic [...] Read more.
Brazilian quilombos are rural semi-isolated remnant communities of former black slaves and their descendants who traditionally maintained themselves through archaic subsistence livestock and agriculture practices and historically lacked specific public health policies. Although such individuals and their dogs may be exposed to zoonotic pathogens such as Toxoplasma gondii, no study to date has assessed these human-animal populations together. Populations in four different Brazilian quilombos in southern Brazil were evaluated. Overall, 93/208 people (44.7%) and 63/100 dogs (63.0%) were seropositive for IgG anti-T. gondii antibodies by indirect immunofluorescent antibody test (IFAT), 4/208 (1.9%) human samples seropositive for IgM anti-T. gondii antibodies, with a human-dog seropositivity ratio for IgG of 0.71. Quilombola individuals ingesting game meat were 2.43-fold more likely (95% CI: 1.05–5.9) to be seropositive. No risk factors were associated with seropositivity among dogs, thus suggesting that their exposure to T. gondii was random. Surprisingly, our research group had previously found an inverted human-dog ratio for T. gondii seropositivity of 2.54 in the urban area of a nearby major city. Because consumption of raw/undercooked game meat by quilombola individuals may have contributed to higher exposure, higher overall seroprevalence among dogs may have also indicated interaction with wildlife. Although these dogs may hunt wildlife without their owners’ awareness, the higher dog seropositivity may also be related to feeding from discarded food in the community or backyard livestock animals and drinking surface water contaminated with oocysts. Thus, wildlife cannot be singled out as the reason, and future studies should consider sampling water, soil, wildlife, and livestock tissues, to fully establish the source of infection in dogs herein. Full article
(This article belongs to the Special Issue Recent Advances in Toxoplasma gondii Infection and Toxoplasmosis)
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15 pages, 2199 KiB  
Article
Improvement in Infection Prevention and Control Performance Following Operational Research in Sierra Leone: A Before (2021) and After (2023) Study
Trop. Med. Infect. Dis. 2023, 8(7), 376; https://doi.org/10.3390/tropicalmed8070376 - 23 Jul 2023
Viewed by 1185
Abstract
Introduction: Infection prevention and control (IPC) is crucial to limit health care-associated infections and antimicrobial resistance. An operational research study conducted in Sierra Leone in 2021 reported sub-optimal IPC performance and provided actionable recommendations for improvement. Methods: This was a before-and-after study involving [...] Read more.
Introduction: Infection prevention and control (IPC) is crucial to limit health care-associated infections and antimicrobial resistance. An operational research study conducted in Sierra Leone in 2021 reported sub-optimal IPC performance and provided actionable recommendations for improvement. Methods: This was a before-and-after study involving the national IPC unit and all twelve district-level secondary public hospitals. IPC performance in 2021 (before) and in 2023 (after) was assessed using standardized World Health Organization checklists. IPC performance was graded as: inadequate (0–25%), basic (25.1–50%), intermediate (50.1–75%), and advanced (75.1–100%). Results: The overall IPC performance in the national IPC unit moved from intermediate (58%) to advanced (78%), with improvements in all six core components. Four out of six components achieved advanced levels when compared to the 2021 levels. The median score for hospitals moved from basic (50%) to intermediate (59%), with improvements in six of eight components. Three of four gaps identified in 2021 at the national IPC unit and four of seven at hospitals had been addressed by 2023. Conclusions: The study highlights the role of operational research in informing actions that improved IPC performance. There is a need to embed operational research as part of the routine monitoring of IPC programs. Full article
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19 pages, 6927 KiB  
Article
Anti-Leishmania amazonensis Activity, Cytotoxic Features, and Chemical Profile of Allium sativum (Garlic) Essential Oil
Trop. Med. Infect. Dis. 2023, 8(7), 375; https://doi.org/10.3390/tropicalmed8070375 - 21 Jul 2023
Cited by 1 | Viewed by 1152
Abstract
Human tegumentary leishmaniasis (HTL) is a serious tropical disease caused by Leishmania amazonensis. Developing new leishmanicidal agents can help overcome current treatment challenges, such as drug resistance and toxicity. Essential oils are a source of lipophilic substances with diverse therapeutic properties. This [...] Read more.
Human tegumentary leishmaniasis (HTL) is a serious tropical disease caused by Leishmania amazonensis. Developing new leishmanicidal agents can help overcome current treatment challenges, such as drug resistance and toxicity. Essential oils are a source of lipophilic substances with diverse therapeutic properties. This study aimed to determine the anti-L. amazonensis activity, cytotoxicity, and chemical profile of Allium sativum essential oil (ASEO). The effect of ASEO on parasite and mammalian cells viability was evaluated using resazurin and MTT assays, respectively. The oil’s effect against intracellular amastigotes was also determined. Transmission electron microscopy was used to assess the ultrastructural changes induced by ASEO. In addition, the chemical constituents of ASEO were identified by gas chromatography-mass spectrometry (GC-MS). The cytotoxic potential was evaluated in vitro and in silico. The oil displayed IC50 of 1.76, 3.46, and 3.77 µg/mL against promastigotes, axenic, and intracellular amastigotes, respectively. Photomicrographs of treated parasites showed plasma membrane disruption, increased lipid bodies, and autophagic-like structures. ASEO chemical profiling revealed 1,2,4,6-tetrathiepane (24.84%) and diallyl disulfide (16.75%) as major components. Computational pharmacokinetics and toxicological analysis of ASEO’s major components demonstrated good oral bioavailability and better toxicological endpoints than the reference drugs. Altogether, the results suggest that ASEO could be an alternative drug candidate against HTL. Full article
(This article belongs to the Special Issue Feature Papers in Tropical Medicine and Infectious Disease)
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9 pages, 1118 KiB  
Article
Molecular Characterization of Staphylococcus aureus Complex Isolated from Free-Ranging Long-Tailed Macaques at Kosumpee Forest Park, Maha Sarakham, Thailand
Trop. Med. Infect. Dis. 2023, 8(7), 374; https://doi.org/10.3390/tropicalmed8070374 - 20 Jul 2023
Viewed by 979
Abstract
The Staphylococcus (S.) aureus complex, including methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA), and S. argenteus are bacterial pathogens that are responsible for both human and animal infection. However, insights into the molecular characteristics of MRSA, MSSA, and S. [...] Read more.
The Staphylococcus (S.) aureus complex, including methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA), and S. argenteus are bacterial pathogens that are responsible for both human and animal infection. However, insights into the molecular characteristics of MRSA, MSSA, and S. argenteus carriages in wildlife, especially in long-tailed macaques, rarely have been reported in Thailand. The objective of this study was to assess molecular characterization of MRSA, MSSA, and S. argenteus strains isolated from free-ranging long-tailed macaques (Macaca fascicularis) at Kosumpee Forest Park, Maha Sarakham, Thailand. A total of 21 secondary bacterial isolates (including 14 MRSA, 5 MSSA, and 2 S. argenteus) obtained from the buccal mucosa of 17 macaques were analysed by a Polymerase chain reaction (PCR) to identify several virulence genes, including pvl, tst, hla, hlb clfA, spa (x-region), spa (IgG biding region), and coa. The most prevalent virulence genes were clfA, coa, and the spa IgG biding region which presented in all isolates. These data indicated that MRSA, MSSA, and S. argenteus isolates from the wild macaques at Kosumpee Forest Park possess a unique molecular profile, harbouring high numbers of virulence genes. These findings suggest that wild macaques may potentially serve as carriers for distribution of virulent staphylococcal bacteria in the study area. Full article
(This article belongs to the Special Issue Feature Papers in One Health)
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12 pages, 300 KiB  
Article
Adherence and Toxicity during the Treatment of Latent Tuberculous Infection in a Referral Center in Spain
Trop. Med. Infect. Dis. 2023, 8(7), 373; https://doi.org/10.3390/tropicalmed8070373 - 19 Jul 2023
Cited by 1 | Viewed by 947
Abstract
The screening and treatment of latent tuberculosis infection (LTBI) in countries with a low incidence of TB is a key strategy for the elimination of tuberculosis (TB). However, treatment can result in adverse events (AEs) and have poor adherence. This study aimed to [...] Read more.
The screening and treatment of latent tuberculosis infection (LTBI) in countries with a low incidence of TB is a key strategy for the elimination of tuberculosis (TB). However, treatment can result in adverse events (AEs) and have poor adherence. This study aimed to describe treatment outcomes and AEs for LTBI patients at two departments in Vall d’Hebron University Hospital in Barcelona, Spain. A retrospective study was conducted on all persons treated for LTBI between January 2018 and December 2020. Variables collected included demographics, the reason for LTBI screening and treatment initiation, AEs related to treatment, and treatment outcome. Out of 261 persons who initiated LTBI treatment, 145 (55.6%) were men, with a median age of 42.1 years. The indications for LTBI screening were household contact of a TB case in 96 (36.8%) persons, immunosuppressive treatment in 84 (32.2%), and recently arrived migrants from a country with high TB incidence in 81 (31.0%). Sixty-three (24.1%) persons presented at least one AE during treatment, and seven (2.7%) required definitive discontinuation of treatment. In the multivariate analysis, AE development was more frequent in those who started LTBI treatment due to immunosuppression. Overall, 226 (86.6%) completed treatment successfully. We concluded that LTBI screening and treatment groups had different risks for adverse events and treatment outcomes. Persons receiving immunosuppressive treatment were at higher risk of developing AEs, and recently arrived immigrants from countries with a high incidence of TB had greater LTFU. A person-centered adherence and AE management plan is recommended. Full article
12 pages, 1830 KiB  
Article
Low Prevalence of Schistosoma mekongi Infection and High Prevalence of Other Helminth Infections among Domestic Animals in Southern Lao People’s Democratic Republic
Trop. Med. Infect. Dis. 2023, 8(7), 372; https://doi.org/10.3390/tropicalmed8070372 - 18 Jul 2023
Viewed by 1050
Abstract
The prevalence of Schistosoma mekongi in humans in the Lao People’s Democratic Republic (Lao PDR) has been relatively well monitored and has decreased due to effective interventions such as preventative chemotherapy with mass drug administration of praziquantel and community awareness programs. However, the [...] Read more.
The prevalence of Schistosoma mekongi in humans in the Lao People’s Democratic Republic (Lao PDR) has been relatively well monitored and has decreased due to effective interventions such as preventative chemotherapy with mass drug administration of praziquantel and community awareness programs. However, the prevalence among potential domestic reservoir animals remains broadly unclear, except for a few villages in the endemic area. Therefore, we conducted S. mekongi surveys for the domestic animals that had contact with Mekong River water. We conducted a cross-sectional study of the domestic animals in the seven sentinel villages in the Khong and Mounlapamok Districts of Champasak Province in southern Lao PDR in 2018 by random sampling with a statistically reliable sample size. Stool samples of the five predominant domestic animal species, cattle (n = 160), pig (n = 154), buffalo (n = 149), dog (n = 143), and goat (n = 85), were collected and examined using parasitological FECT method and the LAMP technique. The microscopic analysis did not detect any eggs of S. mekongi in the stool samples of any animal species. However, S. mekongi DNA was detected by the LAMP test in dog stool samples (0.7%; 1/143). On the other hand, the prevalence of other helminths was quite high and heterogeneous among animal species and sentinel sites by the microscopic analysis. These findings suggested that an intervention for S. mekongi infection should focus solely on human populations. However, periodic surveillance for S. mekongi infection among dogs should be conducted to monitor a possible resurgence of S. mekongi infection in the domestic animal population. Full article
(This article belongs to the Special Issue Status and Perspective of Asian Schistosomiasis)
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8 pages, 8422 KiB  
Case Report
Burying Hatchets into Endemic Diagnoses: Disseminated Blastomycosis from a Potentially Novel Occupational Exposure
Trop. Med. Infect. Dis. 2023, 8(7), 371; https://doi.org/10.3390/tropicalmed8070371 - 18 Jul 2023
Viewed by 1014
Abstract
Background: Blastomycosis is an endemic fungal disease predominantly observed in the northern regions of North America. It manifests primarily as pulmonary disease but can also involve dissemination to the skin, bones, and genitourinary tract. Detailed Case Description: We describe a case of a [...] Read more.
Background: Blastomycosis is an endemic fungal disease predominantly observed in the northern regions of North America. It manifests primarily as pulmonary disease but can also involve dissemination to the skin, bones, and genitourinary tract. Detailed Case Description: We describe a case of a patient in Southern California with disseminated blastomycosis following his occupational exposure to decaying wood. The patient was treated with intravenous amphotericin therapy followed by oral itraconazole therapy with full resolution of his symptoms. Conclusions: The patient’s case presentation serves as a reminder regarding Blastomyces infections diagnosed outside of endemic regions and suggests a potential link between blastomycosis and a novel occupational exposure surrounding axe throwing. Full article
(This article belongs to the Special Issue From Bedside to Exposure: Infections of Leisure)
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13 pages, 1093 KiB  
Review
Seroprevalence and Genotype Diversity of Hepatitis C Virus in the Caribbean—A Review
Trop. Med. Infect. Dis. 2023, 8(7), 370; https://doi.org/10.3390/tropicalmed8070370 - 17 Jul 2023
Viewed by 1490
Abstract
Hepatitis C (HCV) continues to present a global public health challenge, with no vaccine available for prevention. Despite the availability of direct-acting antivirals (DAAs) to cure HCV, it remains prevalent in many regions including the Caribbean. As efforts are made to eliminate HCV [...] Read more.
Hepatitis C (HCV) continues to present a global public health challenge, with no vaccine available for prevention. Despite the availability of direct-acting antivirals (DAAs) to cure HCV, it remains prevalent in many regions including the Caribbean. As efforts are made to eliminate HCV from the region, existing barriers, such as the high cost of DAAs and lack of an established database of HCV cases within the Caribbean, must be addressed. This review seeks to assess epidemiologic trends (seroprevalence and genotypic diversity) of HCV in the Caribbean and identify gaps in surveillance of the disease. The literature for the period 1 January 2005 to October 2022 was reviewed to gather country-specific data on HCV across the Caribbean. References were identified through indexed journals accessed through established databases using the following keywords: Caribbean, genotype distribution, and general epidemiologic characteristics. The usage pattern of HCV drugs was determined from information obtained from pharmacists across the Caribbean including Jamaica. The prevalence of HCV in the Caribbean was 1.5%; the region should therefore be considered an area of moderate HCV prevalence. The prevalence of HCV among intravenous drug users (21.9–58.8%), persons living with HIV/AIDS (0.8 to 58.5%), prisoners (32.8–64%), and men who have sex with men (MSM) (0.8–6.9%) was generally higher than in the general population (0.8–2.3%). Genotype 1 (83%) was most prevalent followed by genotypes 2 (7.2%) and 3 (2.1%), respectively. Less than 50% of countries in the Caribbean have reliable or well-curated surveillance data on HCV. Drugs currently being used for treatment of HCV infections across the Caribbean include Epclusa (sofosbuvir/velpatasvir) and Harvoni (ledipasvir/sofosbuvir). Some of these drugs are only available in the private sector and are sourced externally whenever needed. While trends point to a potentially higher prevalence of HCV, it will require well-designed random surveys to obtain better estimates of the infection seroprevalence, supported by strong public health laboratory systems. DAAs that are pan-genotypic should translate into treatments that are affordable, accessible, and available to improve cure rates and reduce the HCV burden in the population. Full article
(This article belongs to the Section Infectious Diseases)
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14 pages, 1462 KiB  
Article
Comparing Additionality of Tuberculosis Cases Using GeneXpert or Smear-Based Active TB Case-Finding Strategies among Social Contacts of Index Cases in Nepal
Trop. Med. Infect. Dis. 2023, 8(7), 369; https://doi.org/10.3390/tropicalmed8070369 - 17 Jul 2023
Cited by 1 | Viewed by 1833
Abstract
This study compares the yield and additionality of community-based active tuberculosis (TB) active case-finding strategies using either smear microscopy or GeneXpert as the TB diagnostic test. Active case-finding strategies screened social contacts of index cases and high-risk groups in four districts of Nepal [...] Read more.
This study compares the yield and additionality of community-based active tuberculosis (TB) active case-finding strategies using either smear microscopy or GeneXpert as the TB diagnostic test. Active case-finding strategies screened social contacts of index cases and high-risk groups in four districts of Nepal in July 2017–2019. Two districts (Chitwan and Dhanusha) applied GeneXpert testing and two districts (Makwanpur and Mahotarri) used smear microscopy. Two control districts implemented standard national TB program activities. Districts implementing GeneXpert testing screened 23,657 people for TB, tested 17,114 and diagnosed 764 TB cases, producing a yield of 4.5%. Districts implementing smear microscopy screened 19,961 people for TB, tested 13,285 and diagnosed 437 cases, producing a yield of 3.3%. The screening numbers required were 31 for GeneXpert and 45.7 for smear districts. The test numbers required were 22.4 and 30.4 for GeneXpert and smear. Using the TB REACH additionality method, social contact tracing for TB through GeneXpert testing contributed to a 20% (3958/3322) increase in district-level TB notifications, smear microscopy 12.4% (3146/2798), and −0.5% (2553/2566) for control districts. Therefore, social contact tracing of TB index cases using GeneXpert testing should be implemented throughout Nepal within the TB FREE initiative to close the notification gap and accelerate progress toward END TB strategy targets. Full article
(This article belongs to the Section Infectious Diseases)
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11 pages, 1433 KiB  
Article
Microscopic and Molecular Identification of Cyclospora cayetanensis and Cystoisospora belli in HIV-Infected People in Tabriz, Northwest of Iran
Trop. Med. Infect. Dis. 2023, 8(7), 368; https://doi.org/10.3390/tropicalmed8070368 - 17 Jul 2023
Viewed by 1030
Abstract
Opportunistic pathogens such as Cryptosporidium, Cystoisospora belli, and Cyclospora cayetanensis cause various gastrointestinal and non-digestive disorders in people with HIV/AIDS. These symptoms are especially severe in HIV-infected people who have a CD4+ count of less than 200 cells/mL. This study aimed [...] Read more.
Opportunistic pathogens such as Cryptosporidium, Cystoisospora belli, and Cyclospora cayetanensis cause various gastrointestinal and non-digestive disorders in people with HIV/AIDS. These symptoms are especially severe in HIV-infected people who have a CD4+ count of less than 200 cells/mL. This study aimed to determine the prevalence of C. belli and C. cayetanensis infections among people living with HIV in Tabriz, northwest of Iran. This descriptive study was performed on 137 people with HIV who had been referred to behavioral disease counseling centers in Tabriz. Then, after receiving written consent, fecal samples were collected and evaluated for the detection of parasitic infections using direct methods and modified acid fast staining, as well as polymerase chain reaction (PCR).From the 137 fecal samples collected (98 males and 39 females, between 20 and 40 years old), 1.5% were positive for C. cayetanensis and 2.9% were positive for C. belli. Due to the prevalence of C. cayetanensis and C. belli in people with HIV in Tabriz, essential measures, including personal hygiene training for infection control and prevention, seem necessary. Full article
(This article belongs to the Section Neglected and Emerging Tropical Diseases)
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10 pages, 509 KiB  
Article
Evaluation of Omnigene-Sputum for Preservation of Sputum Samples for Diagnosis of Mycobacterium tuberculosis
Trop. Med. Infect. Dis. 2023, 8(7), 367; https://doi.org/10.3390/tropicalmed8070367 - 17 Jul 2023
Viewed by 946
Abstract
In several low-income countries, the transport of sputa could take up to one week to reach the laboratories, resulting in increased contamination rates and a loss of growth. The aim of this study was to evaluate the effect of the OMNIgene-SPUTUM in preserving [...] Read more.
In several low-income countries, the transport of sputa could take up to one week to reach the laboratories, resulting in increased contamination rates and a loss of growth. The aim of this study was to evaluate the effect of the OMNIgene-SPUTUM in preserving Mycobacterium tuberculosis on sputum samples simulating three hypothetical scenarios for conservation and/or decontamination: (1) sputum was mixed with OMN and conserved at room temperature for five days and then processed for culture (OMN); (2) sputum cultures followed the routine standing operating procedure at day 0 (STD); and (3) sputum samples were kept at room temperature for five days and mixed with the standard decontamination reagent (SDT5) and then processed for culture. The positivity rate based on smear microscopy was 36.4%, 29.1%, and 27.3% for STD, STD5, and OMN, respectively. The proportion of positive results by liquid culture (MGIT) was 39.1% (43/110) for STD, 26.4% (29/110) for STD5, and 20.0% for OMN (22/110). The overall concordance of liquid culture results was 51.8% (57/110): 37.3% (41/110) for negative results, 11.8% (13/110) for MTBC growth, and 2.7% (3/110) for contaminated results. The OMN arm showed better performance in solid culture than in liquid culture, with a notable reduction in contaminated results. Full article
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3 pages, 191 KiB  
Editorial
Geospatial Health (GeoHealth): Current Trends, Methods, and Applications
Trop. Med. Infect. Dis. 2023, 8(7), 366; https://doi.org/10.3390/tropicalmed8070366 - 17 Jul 2023
Viewed by 1290
Abstract
As an emerging field, Geospatial Health (GeoHealth) integrates geospatial technologies, (spatial) epidemiology, and health services/resource allocations (health accessibility), with a focus to fight the burden of diseases [...] Full article
11 pages, 951 KiB  
Review
Chikungunya Virus Diagnosis: A Review of Current Antigen Detection Methods
Trop. Med. Infect. Dis. 2023, 8(7), 365; https://doi.org/10.3390/tropicalmed8070365 - 17 Jul 2023
Viewed by 3837
Abstract
Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV). CHIKV is expanding at an alarming rate, potentially spreading and establishing endemicity in new areas where competent vectors are present. The dramatic spread of CHIKV in recent years highlights the urgent [...] Read more.
Chikungunya is a mosquito-borne viral disease caused by the chikungunya virus (CHIKV). CHIKV is expanding at an alarming rate, potentially spreading and establishing endemicity in new areas where competent vectors are present. The dramatic spread of CHIKV in recent years highlights the urgent need to take precautionary measures and investigate options for control. It is crucial in developing nations where diagnostic tools are limited, and symptoms are similar to other prevalent diseases such as malaria and dengue. The most reliable method for diagnosing chikungunya virus is viral gene detection by RT-PCR. Alternative methods like detecting human antibody and viral antigen can also be used, especially in areas where resources are limited. In this review, we summarize the limited data on antigen detection immunoassays. We further explain the essential structural elements of the virus to help comprehend the scientific concepts underlying the testing methods, as well as future methods and diagnostic approaches under investigation. Full article
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27 pages, 3836 KiB  
Article
Legionnaires’ Disease in Occupational Settings: A Cross-Sectional Study from Northeastern Italy (2019)
Trop. Med. Infect. Dis. 2023, 8(7), 364; https://doi.org/10.3390/tropicalmed8070364 - 16 Jul 2023
Cited by 1 | Viewed by 1097
Abstract
In Italy, Legionnaires’ Disease (LD) causes >1000 hospital admissions per year, with a lethality rate of 5 to 10%. Occupational exposures could reasonably explain a substantial share of total cases, but the role of Occupational Physicians (OPs) in management and prevention of LD [...] Read more.
In Italy, Legionnaires’ Disease (LD) causes >1000 hospital admissions per year, with a lethality rate of 5 to 10%. Occupational exposures could reasonably explain a substantial share of total cases, but the role of Occupational Physicians (OPs) in management and prevention of LD has been scarcely investigated. The present survey therefore evaluates the knowledge, attitudes and practices (KAP) regarding LD from a convenience sample of Italian OPs, focusing on their participation in preventive interventions. A total of 165 OPs were recruited through a training event (Parma, Northeastern Italy, 2019), and completed a specifically designed structured questionnaire. The association between reported participation in preventive interventions and individual factors was analyzed using a binary logistic regression model, calculating corresponding multivariable Odds Ratio (aOR). Overall, participants exhibited satisfactory knowledge of the clinical and diagnostic aspects of LD, while substantial uncertainties were associated epidemiological factors (i.e., notification rate and lethality). Although the majority of participating OPs reportedly assisted at least one hospital (26.7%) and/or a nursing home (42.4%) and/or a wastewater treatment plant, only 41.8% reportedly contributed to the risk assessment for LD and 18.8% promoted specifically designed preventive measures. Working as OPs in nursing homes (aOR 8.732; 95% Confidence Intervals [95%CI] 2.991 to 25.487) and wastewater treatment plants (aOR 8.710; 95%CI 2.844 to 26.668) was associated with participation in the risk assessment for LD, while the promotion of preventive practice was associated with working as an OP in hospitals (aOR 6.792; 95%CI 2.026 to 22.764) and wastewater treatment plants (aOR 4.464, 95%CI 1.363 to 14.619). In other words, the effective participation of the OP in the implementation of preventive measures appears uncommon and is limited to certain occupational settings. Collectively, these results highlight the importance of tailoring specifically designed information campaigns aimed to raise the involvement of OPs in the prevention of LD in occupational settings other than healthcare. Full article
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15 pages, 3885 KiB  
Article
Impacts on Human Movement in Australian Cities Related to the COVID-19 Pandemic
Trop. Med. Infect. Dis. 2023, 8(7), 363; https://doi.org/10.3390/tropicalmed8070363 - 14 Jul 2023
Viewed by 1075
Abstract
No studies have yet examined high-resolution shifts in the spatial patterns of human movement in Australia throughout 2020 and 2021, a period coincident with the repeated enactment and removal of varied governmental restrictions aimed at reducing community transmission of SARS-CoV-2. We compared overlapping [...] Read more.
No studies have yet examined high-resolution shifts in the spatial patterns of human movement in Australia throughout 2020 and 2021, a period coincident with the repeated enactment and removal of varied governmental restrictions aimed at reducing community transmission of SARS-CoV-2. We compared overlapping timeseries of COVID-19 pandemic-related restrictions, epidemiological data on cases and vaccination rates, and high-resolution human movement data to characterize population-level responses to the pandemic in Australian cities. We found that restrictions on human movement and/or mandatory business closures reduced the average population-level weekly movement volumes in cities, as measured by aggregated travel time, by almost half. Of the movements that continued to occur, long movements reduced more dramatically than short movements, likely indicating that people stayed closer to home. We also found that the repeated lockdowns did not reduce their impact on human movement, but the effect of the restrictions on human movement waned as the duration of restrictions increased. Lastly, we found that after restrictions ceased, the subsequent surge in SARS-CoV-2 transmission coincided with a substantial, non-mandated drop in human movement volume. These findings have implications for public health policy makers when faced with anticipating responses to restrictions during future emergency situations. Full article
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11 pages, 3927 KiB  
Article
Risk Stratification to Guide Prevention and Control Strategies for Arboviruses Transmitted by Aedes aegypti
Trop. Med. Infect. Dis. 2023, 8(7), 362; https://doi.org/10.3390/tropicalmed8070362 - 14 Jul 2023
Viewed by 1133
Abstract
Strategies for the prevention of arboviral diseases transmitted by Aedes aegypti have traditionally focused on vector control. This remains the same to this day, despite a lack of documented evidence on its efficacy due to a lack of coverage and sustainability. The continuous [...] Read more.
Strategies for the prevention of arboviral diseases transmitted by Aedes aegypti have traditionally focused on vector control. This remains the same to this day, despite a lack of documented evidence on its efficacy due to a lack of coverage and sustainability. The continuous growth of urban areas and generally unplanned urbanization, which favor the presence of Ae. aegypti, demand resources, both material and human, as well as logistics to effectively lower the population’s risk of infection. These considerations have motivated the development of tools to identify areas with a recurrent concentration of arboviral cases during an outbreak to be able to prioritize preventive actions and optimize available resources. This study explores the existence of spatial patterns of dengue incidence in the locality of Tartagal, in northeastern Argentina, during the outbreaks that occurred between 2010 and 2020. Approximately half (50.8%) of the cases recorded during this period were concentrated in 35.9% of the urban area. Additionally, an important overlap was found between hotspot areas of dengue and chikungunya (Kendall’s W = 0.92; p-value < 0.001) during the 2016 outbreak. Moreover, 65.9% of the cases recorded in 2022 were geolocalized within the hotspot areas detected between 2010 and 2020. These results can be used to generate a risk map to implement timely preventive control strategies that prioritize these areas to reduce their vulnerability while optimizing the available resources and increasing the scope of action. Full article
(This article belongs to the Special Issue Surveillance and Control of Mosquito-Borne Diseases)
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9 pages, 261 KiB  
Article
HCV Co-Infection and Its Genotypic Distribution in HIV-Infected Patients in Nepalese Population
Trop. Med. Infect. Dis. 2023, 8(7), 361; https://doi.org/10.3390/tropicalmed8070361 - 13 Jul 2023
Viewed by 1094
Abstract
Hepatitis C Virus (HCV) co-infection and its genotypic distribution in people living with Human Immunodeficiency Virus (HIV) show global inconsistency. Therefore, the present study aimed to investigate the prevalence and genotypic distribution patterns of HCV, along with viral load, in people living with [...] Read more.
Hepatitis C Virus (HCV) co-infection and its genotypic distribution in people living with Human Immunodeficiency Virus (HIV) show global inconsistency. Therefore, the present study aimed to investigate the prevalence and genotypic distribution patterns of HCV, along with viral load, in people living with HIV. This cross-sectional study was conducted at SRL Diagnostics Nepal, Pvt. Ltd. in 203 HIV-seropositive patients attending the Tribhuvan University Teaching Hospital (TUTH), Maharajgunj, Kathmandu, Nepal from October 2021 to May 2022. The viral load and HCV genotypes were estimated from RNA extracted from the blood sample (plasma) of PLHIV by using a standard Q-PCR protocol. HCV infection was considered as a core variable, whereas covariates used for this study were duration of HIV infection, age, sex, and ART regimen. Out of total 203 PLHIV, the estimated prevalence of HCV co-infection was 115 (56.6%). Male gender was a unique characteristic associated with a high prevalence of HCV co-infection compared to females. The HCV viral load among PLHIV ranged from 34 to 3,000,000 IU/mL. Among HCV co-infected PLHIV, 56 (48.69%) had a low level of HCV viral load. Interestingly, only 3 (2.6%) patients had an HCV viral load higher than 3,000,000 IU/mL. Diverse HCV genotypes were found in the population, including genotypes 1, 1a, 3a, 5a, and 6. However, genotype 3 was the most prevalent HCV variant among HCV-co-infected PLHIV, with a distribution of 36 (61.1%) and viral load ranging from 34 to 3000 IU/mL. HCV co-infection is frequent in the Nepalese population of people living with HIV, particularly due to HCV genotypic variant 3. The findings of this study could be useful for the management and clearance of the HCV co-infection in PLHIV, aiming to provide a good quality of life. Full article
19 pages, 10581 KiB  
Review
What Do You Need to Know before Studying Chagas Disease? A Beginner’s Guide
Trop. Med. Infect. Dis. 2023, 8(7), 360; https://doi.org/10.3390/tropicalmed8070360 - 10 Jul 2023
Cited by 4 | Viewed by 2506
Abstract
Chagas disease is one of the most important tropical infections in the world and mainly affects poor people. The causative agent is the hemoflagellate protozoan Trypanosoma cruzi, which circulates among insect vectors and mammals throughout the Americas. A large body of research [...] Read more.
Chagas disease is one of the most important tropical infections in the world and mainly affects poor people. The causative agent is the hemoflagellate protozoan Trypanosoma cruzi, which circulates among insect vectors and mammals throughout the Americas. A large body of research on Chagas disease has shown the complexity of this zoonosis, and controlling it remains a challenge for public health systems. Although knowledge of Chagas disease has advanced greatly, there are still many gaps, and it is necessary to continue generating basic and applied research to create more effective control strategies. The aim of this review is to provide up-to-date information on the components of Chagas disease and highlight current trends in research. We hope that this review will be a starting point for beginners and facilitate the search for more specific information. Full article
(This article belongs to the Special Issue Advances in Chagas Disease Control)
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8 pages, 625 KiB  
Communication
Seropositivity of Anti-Toxoplasma gondii and Anti-Neospora caninum Antibodies in Cattle Intended for Human Consumption in an Amazonian Area of North Brazil
Trop. Med. Infect. Dis. 2023, 8(7), 359; https://doi.org/10.3390/tropicalmed8070359 - 10 Jul 2023
Viewed by 875
Abstract
Toxoplasma gondii and Neospora caninum are obligate intracellular intestinal coccidia distributed worldwide, and are causative agents of toxoplasmosis and neosporosis, respectively. The aim of this study was to evaluate the prevalence of anti-T. gondii and anti-N. caninum antibodies and the factors [...] Read more.
Toxoplasma gondii and Neospora caninum are obligate intracellular intestinal coccidia distributed worldwide, and are causative agents of toxoplasmosis and neosporosis, respectively. The aim of this study was to evaluate the prevalence of anti-T. gondii and anti-N. caninum antibodies and the factors associated with infections in beef cattle intended for human consumption in an Amazonian area of North Brazil. We collected blood samples of 387 cattle from 50 herds located in different municipalities of the State of Rondônia. An epidemiological questionnaire was distributed to farmers, with regard to nutritional, sanitary and reproductive herd management. The samples were identified, refrigerated and sent for serological analyses via IFAT (Immunofluorescent Antibody Test). Among the 387 analyzed animals, 91 (23.5%; CI 95%: 18.8–27.2) were positive for anti-T. gondii antibodies, with titers varying from 1:64 (75.8%) to 1:512 (2.2%). For anti-N. caninum antibodies, only four animals (1%; CI 95%: 0–2.7) were positive, with titers ranging from 1:400 (50%) to 1:1600 (25%). We observed a significant rate of anti-T. gondii antibodies in the variables “pure breed” and “contact with free-range chickens” (p < 0.2). There were no risk factors associated with the presence of anti-T. gondii or anti-N. caninum antibodies. In conclusion, there was a high prevalence of anti-T. gondii antibodies in beef cattle intended for human consumption in the State of Rondônia, Brazil, and a low prevalence of anti-N. caninum antibodies. Longitudinal studies can better elucidate the cause of these prevalence levels and how they could be better prevented and controlled. Full article
(This article belongs to the Section Infectious Diseases)
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12 pages, 557 KiB  
Review
Overlapping Infection by Strongyloides spp. and Cytomegalovirus in the Immunocompromised Host: A Comprehensive Review of the Literature
Trop. Med. Infect. Dis. 2023, 8(7), 358; https://doi.org/10.3390/tropicalmed8070358 - 10 Jul 2023
Cited by 2 | Viewed by 1186
Abstract
Strongyloides and cytomegalovirus co-infections are rarely reported, even though they are distinguished by high morbidity and mortality, especially in immunocompromised hosts. We narratively reviewed the literature on reported cases of Strongyloides and CMV co-infections in immunosuppressed patients. Most cases occurred in males with [...] Read more.
Strongyloides and cytomegalovirus co-infections are rarely reported, even though they are distinguished by high morbidity and mortality, especially in immunocompromised hosts. We narratively reviewed the literature on reported cases of Strongyloides and CMV co-infections in immunosuppressed patients. Most cases occurred in males with a median age of 47 (IQR, 37–59). Strongyloides/CMV co-infections occurred among immunocompromised hosts, especially in solid organ transplants and hematological or rheumatological diseases. Most of the patients underwent a course of steroid treatment before the diagnosis of co-infections. Other common immunomodulatory agents were tacrolimus and mycophenolate. The first clinical manifestations of co-infections were mainly gastrointestinal, followed by respiratory symptoms. CMV was, in most patients, co-infected with an isolated reactivation, although Strongyloides manifested especially as hyperinfection syndrome. Ganciclovir and ivermectin are the mainstays of CMV and Strongyloides treatment. However, the treatment mortality reported in this narrative review is around 52.4%. Interestingly secondary bacterial infections are common in CMV/Strongyloides-infected patients. Full article
(This article belongs to the Section Infectious Diseases)
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10 pages, 1509 KiB  
Brief Report
Influence of Testosterone in Neglected Tropical Diseases: Clinical Aspects in Leprosy and In Vitro Experiments in Leishmaniasis
Trop. Med. Infect. Dis. 2023, 8(7), 357; https://doi.org/10.3390/tropicalmed8070357 - 10 Jul 2023
Viewed by 1146
Abstract
Neglected tropical diseases encompass a group of chronic and debilitating infectious diseases that primarily affect marginalized populations. Among these diseases, leprosy and leishmaniasis are endemic in numerous countries and can result in severe and disfiguring manifestations. Although there have been reports indicating a [...] Read more.
Neglected tropical diseases encompass a group of chronic and debilitating infectious diseases that primarily affect marginalized populations. Among these diseases, leprosy and leishmaniasis are endemic in numerous countries and can result in severe and disfiguring manifestations. Although there have been reports indicating a higher incidence of leprosy and leishmaniasis in males, the underlying factors contributing to this observation remain unclear. Therefore, the objective of this study was to examine both clinical and experimental evidence regarding the role of testosterone in leprosy and leishmaniasis. A prospective clinical study was conducted to compare the clinical forms of leprosy and assess circulating testosterone levels. Additionally, the impact of testosterone on Leishmania amazonensis-infected macrophages was evaluated in vitro. The findings demonstrated that serum testosterone levels were higher in women with leprosy than in the control group, irrespective of the multi- or pauci-bacillary form of the disease. However, no differences in testosterone levels were observed in men when comparing leprosy patients and controls. Interestingly, increasing doses of testosterone in macrophages infected with L. amazonensis resulted in a higher proportion of infected cells, decreased CD40 expression on the cell surface, elevated expression of SOCS1, and decreased expression of IRF5. These findings provide biological evidence to support the influence of testosterone on intracellular infections, though the interpretation of clinical evidence remains limited. Full article
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15 pages, 6621 KiB  
Article
One Health Approach to Leptospirosis: Human–Dog Seroprevalence Associated to Socioeconomic and Environmental Risk Factors in Brazil over a 20-Year Period (2001–2020)
Trop. Med. Infect. Dis. 2023, 8(7), 356; https://doi.org/10.3390/tropicalmed8070356 - 07 Jul 2023
Cited by 2 | Viewed by 1198
Abstract
Despite being considered a neglected, re-emerging and the most widespread zoonotic disease worldwide, human-dog leptospirosis has not been subjected to One Health approach, and neither were its socioeconomic and environmental risk factors, as well as concomitant spatial analysis over time. Accordingly, notified human [...] Read more.
Despite being considered a neglected, re-emerging and the most widespread zoonotic disease worldwide, human-dog leptospirosis has not been subjected to One Health approach, and neither were its socioeconomic and environmental risk factors, as well as concomitant spatial analysis over time. Accordingly, notified human leptospirosis cases, incidence rate and urban hotspot areas, in addition to a systematic review of dog leptospirosis cases, were performed nationwide from 2001 to 2020 in Brazil. Data on Gross Domestic Product (GDP), flooding and study areas were also assessed and tabulated. Human–dog leptospirosis cases were simultaneously mapped with overlapping flooding areas, along with the main circulant serovars. Comparative outcome has shown that dogs may be exposed similarly to humans, becoming important sentinels and/or reservoirs for human leptospirosis in larger geographic areas. Moreover, the study herein can help in the decision and implementation of public policies in Brazil and may serve as a model for other tropical countries worldwide. Full article
(This article belongs to the Special Issue Feature Papers in One Health)
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14 pages, 2511 KiB  
Article
Potent In Vitro and In Vivo Effects of Stachys lavandulifolia Methanolic Extract against Toxoplasma gondii Infection
Trop. Med. Infect. Dis. 2023, 8(7), 355; https://doi.org/10.3390/tropicalmed8070355 - 05 Jul 2023
Viewed by 1374
Abstract
The present study aimed to evaluate the in vitro, in vivo, and safety of Stachys lavandulifolia Vahl. methanolic extract (SLME) against acute toxoplasmosis caused by Toxoplasma gondii RH strain in mice. Methods: MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to evaluate the in vitro effect [...] Read more.
The present study aimed to evaluate the in vitro, in vivo, and safety of Stachys lavandulifolia Vahl. methanolic extract (SLME) against acute toxoplasmosis caused by Toxoplasma gondii RH strain in mice. Methods: MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to evaluate the in vitro effect of the SLME on T. gondii tachyzoites. Totally, 72 male BALB/c mice (40 mice for in vivo evaluation of SLME and 32 mice for its toxicity effects on liver and kidney serum enzymes) were used for the present investigation. At first, 40 mice were orally pre-treated with the SLME at doses of 25, 50, and 75 mg/kg/day for two weeks. Mice were checked daily, and the rate of survival and the mean number of tachyzoites were recorded. Liver lipid peroxidation (LPO) and nitric oxide (NO) levels, the effects on kidney and liver function, as well as the expression level of the proinflammatory cytokines such as interleukin-1β (IL-1β) and interferon-γ (IFN-γ), were studied by the quantitative real-time PCR. Flow cytometry analysis was performed on the effects of SLME on the detection of apoptotic and necrotic cells in T. gondii tachyzoites. Results: The SLME at the concentrations 75 and 150 µg/mL completely killed the tachyzoites after 2 hr of incubation. SLME at 25, 50, and 75 mg/kg/day increased the survival rate of infected mice by the sixth, seventh, and eighth days, respectively. SLME also significantly (p < 0.05) decreased the LPO and NO levels and upregulated the IL-1β and IFN-γ mRNA gene expression levels, whereas no considerable change was observed in the serum level of kidney and liver enzymes. Flow cytometry analysis revealed the prompted early and late apoptosis after exposure to T. gondii tachyzoites with various concentrations of SLME. Conclusion: We found the relevant in vitro anti-Toxoplasma effects of SLME against T. gondii. Moreover, the results confirmed the promising in vivo prophylactic effects of SLME. SLME provokes the innate immune system, induces apoptosis, modulates the proinflammatory cytokines, and inhibits hepatic injury in infected mice. With all these descriptions, further surveys are required to support these findings and elucidate this plant’s possible mechanisms of action. Full article
(This article belongs to the Special Issue Drug Discovery in the Treatment of Microbial and Parasitic Diseases)
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9 pages, 1077 KiB  
Brief Report
In Vitro Drug Susceptibility of a Leishmania (Leishmania) infantum Isolate from a Visceral Leishmaniasis Pediatric Patient after Multiple Relapses
Trop. Med. Infect. Dis. 2023, 8(7), 354; https://doi.org/10.3390/tropicalmed8070354 - 04 Jul 2023
Viewed by 1393
Abstract
The parasitic protozoan Leishmania (Leishmania) infantum is the etiological agent of human visceral leishmaniasis in South America, an infectious disease associated with malnutrition, anemia, and hepatosplenomegaly. In Brazil alone, around 2700 cases are reported each year. Treatment failure can occur as a result [...] Read more.
The parasitic protozoan Leishmania (Leishmania) infantum is the etiological agent of human visceral leishmaniasis in South America, an infectious disease associated with malnutrition, anemia, and hepatosplenomegaly. In Brazil alone, around 2700 cases are reported each year. Treatment failure can occur as a result of drug, host, and/or parasite-related factors. Here, we isolated a Leishmania species from a pediatric patient with visceral leishmaniasis that did not respond to chemotherapy, experiencing a total of nine therapeutic relapses and undergoing a splenectomy. The parasite was confirmed as L. (L.) infantum after sequencing of the ribosomal DNA internal transcribed spacer, and the clinical isolate, in both promastigote and amastigote forms, was submitted to in vitro susceptibility assays with all the drugs currently used in the chemotherapy of leishmaniasis. The isolate was susceptible to meglumine antimoniate, amphotericin B, pentamidine, miltefosine, and paromomycin, similarly to another strain of this species that had previously been characterized. These findings indicate that the multiples relapses observed in this pediatric patient were not due to a decrease in the drug susceptibility of this isolate; therefore, immunophysiological aspects of the patient should be further investigated to understand the basis of treatment failure in this case. Full article
(This article belongs to the Special Issue Emerging Topics in Leishmaniasis Research)
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24 pages, 2473 KiB  
Review
Knobs, Adhesion, and Severe Falciparum Malaria
Trop. Med. Infect. Dis. 2023, 8(7), 353; https://doi.org/10.3390/tropicalmed8070353 - 04 Jul 2023
Cited by 2 | Viewed by 1966
Abstract
Plasmodium falciparum can cause a severe disease with high mortality. A major factor contributing to the increased virulence of P. falciparum, as compared to other human malarial parasites, is the sequestration of infected erythrocytes in the capillary beds of organs and tissues. [...] Read more.
Plasmodium falciparum can cause a severe disease with high mortality. A major factor contributing to the increased virulence of P. falciparum, as compared to other human malarial parasites, is the sequestration of infected erythrocytes in the capillary beds of organs and tissues. This sequestration is due to the cytoadherence of infected erythrocytes to endothelial cells. Cytoadherence is primarily mediated by a parasite protein expressed on the surface of the infected erythrocyte called P. falciparum erythrocyte membrane protein-1 (PfEMP1). PfEMP1 is embedded in electron-dense protuberances on the surface of the infected erythrocytes called knobs. These knobs are assembled on the erythrocyte membrane via exported parasite proteins, and the knobs function as focal points for the cytoadherence of infected erythrocytes to endothelial cells. PfEMP1 is a member of the var gene family, and there are approximately 60 antigenically distinct PfEMP1 alleles per parasite genome. Var gene expression exhibits allelic exclusion, with only a single allele being expressed by an individual parasite. This results in sequential waves of antigenically distinct infected erythrocytes and this antigenic variation allows the parasite to establish long-term chronic infections. A wide range of endothelial cell receptors can bind to the various PfEMP1 alleles, and thus, antigenic variation also results in a change in the cytoadherence phenotype. The cytoadherence phenotype may result in infected erythrocytes sequestering in different tissues and this difference in sequestration may explain the wide range of possible clinical manifestations associated with severe falciparum malaria. Full article
(This article belongs to the Special Issue Emerging Insights in Pathogenesis of Infectious Protozoa and Algae)
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24 pages, 1470 KiB  
Article
Modelling Differential Diagnosis of Febrile Diseases with Fuzzy Cognitive Map
Trop. Med. Infect. Dis. 2023, 8(7), 352; https://doi.org/10.3390/tropicalmed8070352 - 03 Jul 2023
Cited by 2 | Viewed by 1216
Abstract
The report of the World Health Organization (WHO) about the poor accessibility of people living in low-to-middle-income countries to medical facilities and personnel has been a concern to both professionals and nonprofessionals in healthcare. This poor accessibility has led to high morbidity and [...] Read more.
The report of the World Health Organization (WHO) about the poor accessibility of people living in low-to-middle-income countries to medical facilities and personnel has been a concern to both professionals and nonprofessionals in healthcare. This poor accessibility has led to high morbidity and mortality rates in tropical regions, especially when such a disease presents itself with confusable symptoms that are not easily differentiable by inexperienced doctors, such as those found in febrile diseases. This prompted the development of the fuzzy cognitive map (FCM) model to serve as a decision-support tool for medical health workers in the diagnosis of febrile diseases. With 2465 datasets gathered from four states in the febrile diseases-prone regions in Nigeria with the aid of 60 medical doctors, 10 of those doctors helped in weighting and fuzzifying the symptoms, which were used to generate the FCM model. Results obtained from computations to predict diagnosis results for the 2465 patients, and those diagnosed by the physicians on the field, showed an average of 87% accuracy for the 11 febrile diseases used in the study. The number of comorbidities of diseases with varying degrees of severity for most patients in the study also covary strongly with those found by the physicians in the field. Full article
(This article belongs to the Section Infectious Diseases)
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9 pages, 909 KiB  
Communication
Assessing the Relationship between Annual Surface Temperature Changes and the Burden of Dengue: Implications for Climate Change and Global Health Outcomes
Trop. Med. Infect. Dis. 2023, 8(7), 351; https://doi.org/10.3390/tropicalmed8070351 - 02 Jul 2023
Viewed by 1763
Abstract
Dengue fever remains a significant global health concern, imposing a substantial burden on public health systems worldwide. Recent studies have suggested that climate change, specifically the increase in surface temperatures associated with global warming, may impact the transmission dynamics of dengue. This study [...] Read more.
Dengue fever remains a significant global health concern, imposing a substantial burden on public health systems worldwide. Recent studies have suggested that climate change, specifically the increase in surface temperatures associated with global warming, may impact the transmission dynamics of dengue. This study aimed to assess the relationship between annual surface temperature changes from 1961 to 2019 and the burden of dengue in 185 countries. The dengue burden was evaluated for 2019 using disability-adjusted life years (DALYs) and the annual rate of change (ARC) in DALY rates assessed from 1990 to 2019. A cross-sectional and ecological analysis was conducted using two publicly available datasets. Regression coefficients (β) and 95% confidence intervals (CI) were used to examine the relationship between annual surface temperature changes and the burden of dengue. The results revealed a significant negative relationship between mean surface temperatures and DALY rates in 2019 (β = −16.9, 95% CI −26.9 to −6.8). Similarly, a significant negative relationship was observed between the temperature variable and the ARC (β = −0.99, 95% CI −1.66 to −0.32). These findings suggest that as temperatures continue to rise, the burden of dengue may globally decrease. The ecology of the vector and variations in seasons, precipitation patterns, and humidity levels may partially contribute to this phenomenon. Our study contributes to the expanding body of evidence regarding the potential implications of climate change for dengue dynamics. It emphasizes the critical importance of addressing climate change as a determinant of global health outcomes. Full article
(This article belongs to the Section Infectious Diseases)
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10 pages, 404 KiB  
Article
Comparison of Xpert MTB/RIF Ultra Results of Stool and Sputum in Children with Presumptive Tuberculosis in Southern Ethiopia
Trop. Med. Infect. Dis. 2023, 8(7), 350; https://doi.org/10.3390/tropicalmed8070350 - 30 Jun 2023
Viewed by 1835
Abstract
The introduction of stool as a readily obtainable sample and the recently developed simple one-step (SOS) stool processing method on Xpert MTB/RIF Ultra (Xpert Ultra) offer an opportunity for TB diagnosis in children. We conducted this study in secondary health facilities in Ethiopia, [...] Read more.
The introduction of stool as a readily obtainable sample and the recently developed simple one-step (SOS) stool processing method on Xpert MTB/RIF Ultra (Xpert Ultra) offer an opportunity for TB diagnosis in children. We conducted this study in secondary health facilities in Ethiopia, which are the first-level referral facilities for childhood TB diagnosis and treatment, with the aim to determine if stool-based TB diagnosis can be performed with a reasonable level of concordance with sputum tests using Xpert MTB/RIF Ultra. Eligible children 0–14 years old with presumptive pulmonary TB were asked to provide stools in addition to routinely requested sputum samples. We determined the level of agreement between the stool and sputum test results. Of the 373 children included in the study, 61% were <5 years of age and 56% were male. Thirty-six children (9.7%) were diagnosed with TB, and all started treatment. The rate of concordance between stool and sputum was high, with a kappa value of 0.83 (p < 0.001). There were more Xpert Ultra positive results on stool (n = 27 (7.2%)) than on sputum/NGA (n = 23 (6.2%)). Laboratories in secondary hospitals can perform stool-based TB diagnosis in children, with high concordance between stool and sputum test results reaffirming the applicability of the SOS stool method. Full article
12 pages, 3889 KiB  
Article
Spatiotemporal Patterns of the Omicron Wave of COVID-19 in the United States
Trop. Med. Infect. Dis. 2023, 8(7), 349; https://doi.org/10.3390/tropicalmed8070349 - 30 Jun 2023
Cited by 1 | Viewed by 997
Abstract
COVID-19 has undergone multiple mutations, with the Omicron variant proving to be highly contagious and rapidly spreading across many countries. The United States was severely hit by the Omicron variant. However, it was still unclear how Omicron transferred across the United States. Here, [...] Read more.
COVID-19 has undergone multiple mutations, with the Omicron variant proving to be highly contagious and rapidly spreading across many countries. The United States was severely hit by the Omicron variant. However, it was still unclear how Omicron transferred across the United States. Here, we collected daily COVID-19 cases and deaths in each county from 1 December 2021 to 28 February 2022 as the Omicron wave. We adopted space-time scan statistics, the Hoover index, and trajectories of the epicenter to quantify spatiotemporal patterns of the Omicron wave of COVID-19. The results showed that the highest and earliest cluster was located in the Northeast. The Hoover index for both cases and deaths exhibited phases of rapid decline, slow decline, and relative stability, indicating a rapid spread of the Omicron wave across the country. The Hoover index for deaths was consistently higher than that for cases. The epicenter of cases and deaths shifted from the west to the east, then southwest. Nevertheless, cases were more widespread than deaths, with a lag in mortality data. This study uncovers the spatiotemporal patterns of Omicron transmission in the United States, and its underlying mechanisms deserve further exploration. Full article
(This article belongs to the Special Issue Spatial and Spatiotemporal Analysis of Infectious Diseases)
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