Journal Description
Tropical Medicine and Infectious Disease
Tropical Medicine and Infectious Disease
is an international, scientific, peer-reviewed, open access journal of tropical medicine and infectious disease published quarterly online by MDPI. It is the official journal of the Australasian College of Tropical Medicine (ACTM) and its Joint Faculties of Travel Medicine and Expedition and Wilderness Medicine.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, ESCI (Web of Science), PubMed, PMC, Embase, and many other databases.
- Journal Rank: CiteScore - Q2 (Public Health, Environmental and Occupational Health)
- Rapid Publication: manuscripts are peer-reviewed and a first decision provided to authors approximately 16.1 days after submission; acceptance to publication is undertaken in 4.6 days (median values for papers published in this journal in the first half of 2021).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Latest Articles
A Randomised Controlled Trial of Ice to Reduce the Pain of Immunisation—The ICE Trial
Trop. Med. Infect. Dis. 2021, 6(3), 158; https://doi.org/10.3390/tropicalmed6030158 (registering DOI) - 28 Aug 2021
Abstract
►
Show Figures
Background and objectives: vaccine injections are a common cause of iatrogenic pain and anxiety, contributing to non-compliance with scheduled vaccinations. With injection-related pain being recognised as a barrier to vaccination uptake in both adults and children, it is important to investigate strategies to
[...] Read more.
Background and objectives: vaccine injections are a common cause of iatrogenic pain and anxiety, contributing to non-compliance with scheduled vaccinations. With injection-related pain being recognised as a barrier to vaccination uptake in both adults and children, it is important to investigate strategies to effectively reduce immunisation pain. This prospective randomised controlled trial investigated the effects of applying an ice pack on vaccine-related pain in adults. Methods: medical students receiving the flu vaccination were randomised to receive an ice pack (intervention) or placebo cold pack (control) at the injection site for 30 s prior to needle insertion. Immediate post-vaccination pain (VAS) and adverse reactions in the proceeding 24 h were recorded. Results: pain scores between the intervention (n = 19) and control groups (n = 16) were not statistically significant (intervention: median pain VAS = 7.00, IQR = 18; control: median pain VAS = 11, IQR = 14 (p = 0.26). There were no significant differences in the number of adverse events between the two groups (site pain p = 0.18; localised swelling (p = 0.67); bruising p = 0.09; erythema p = 0.46). Discussion: ice did not reduce vaccination-related pain compared to cold packs. COVID-19 related restrictions impacted participant recruitment, rendering the study insufficiently powered to draw conclusions about the results.
Full article
Open AccessArticle
Knowledge of Antimalarials and Health Seeking Behaviour of Households in Case of Suspected Malaria in Democratic Republic of the Congo
by
, , , , , , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 157; https://doi.org/10.3390/tropicalmed6030157 - 26 Aug 2021
Abstract
(1) Background: The Democratic Republic of the Congo (DRC) is heavily affected by malaria despite availability of effective treatments. Ignorance and unrecommended behaviour toward a suspected malaria case in households may contribute to this problem. (2) Method: In communities of one rural and
[...] Read more.
(1) Background: The Democratic Republic of the Congo (DRC) is heavily affected by malaria despite availability of effective treatments. Ignorance and unrecommended behaviour toward a suspected malaria case in households may contribute to this problem. (2) Method: In communities of one rural and one urban Health Centres in each of the 11 previous provinces of DRC, all households with a case of malaria in the 15 days prior to the survey were selected. The patient or caregiver (responder) were interviewed. Logistic regression was used to assess predictors of knowledge of recommended antimalarials and adequate behaviour in case of suspected malaria. (3) Results: 1732 households participated; about 62% (1060/1721) of the responders were informed about antimalarials, 70.1% (742/1059) knew the recommended antimalarials and 58.6% (995/1699) resorted to self-medication. Predictors of knowledge of antimalarials were education to secondary school or university, information from media and smaller households. Predictors of good behaviour were Catholic religion and smaller households. Receiving information from Community Health Workers (CHWs) failed to be determinants of knowledge or adequate behaviour. (4) Conclusion: malaria control in DRC is hampered by ignorance and non-adherence to national recommendations. These aspects are influenced by unsuccessful communication, size of households and level of education.
Full article
(This article belongs to the Special Issue Malaria Elimination: Managing Implementation of the Interventions for Success)
Open AccessCase Report
Double Trouble: Dengue Followed by COVID-19 Infection Acquired in Two Different Regions: A Doctor’s Case Report and Spatial Distribution of Cases in Presidente Prudente, São Paulo, Brazil
by
, , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 156; https://doi.org/10.3390/tropicalmed6030156 - 25 Aug 2021
Abstract
Co-epidemics of COVID-19 and dengue in dengue-endemic countries represent a serious public health concern. In Brazil, São Paulo state ranks first for cases and deaths from COVID-19, and dengue is endemic in most regions of the country. In 2020, an outbreak of dengue
[...] Read more.
Co-epidemics of COVID-19 and dengue in dengue-endemic countries represent a serious public health concern. In Brazil, São Paulo state ranks first for cases and deaths from COVID-19, and dengue is endemic in most regions of the country. In 2020, an outbreak of dengue occurred in western São Paulo. We determined the spatiotemporal distribution of dengue in the context of COVID-19 cases in Presidente Prudente, a mid-sized city in western São Paulo. To illustrate the burden of both infections, a case report of a doctor and his family, infected with dengue and COVID-19, is presented. There were three clusters of dengue and COVID-19 in the periphery. A dengue cluster was found in a region where there were no corresponding COVID-19 cases. Meanwhile, there were COVID-19 clusters where dengue activity was lower. In 2020, the COVID-19 epidemic emerged when dengue reached its seasonal peak, resulting in a simultaneous outbreak of both diseases. Lower rates of dengue were found in the city compared with 2019, and the fear of patients with mild dengue symptoms about remaining in hospital and acquiring COVID-19 infection may be the main cause. Simultaneous spatial clusters of dengue and COVID-19 in environmentally and socioeconomically vulnerable areas can guide public health authorities in intensive interventions to improve clinical diagnosis, epidemiological surveillance, and management of both diseases. The patient and his family were first infected with dengue and he then carried COVID-19 to his family, reinforcing the risk of health care workers spreading the virus to the community. We highlight the epidemiological significance of presenting a case report and spatial analysis of COVID-19 in the same study in the context of a dengue outbreak.
Full article
(This article belongs to the Special Issue Spatial Epidemiology of Vector-Borne Diseases)
►▼
Show Figures

Figure 1
Open AccessArticle
Cross-Neutralisation of Novel Bombali Virus by Ebola Virus Antibodies and Convalescent Plasma Using an Optimised Pseudotype-Based Neutralisation Assay
by
, , , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 155; https://doi.org/10.3390/tropicalmed6030155 (registering DOI) - 25 Aug 2021
Abstract
Ebolaviruses continue to pose a significant outbreak threat, and while Ebola virus (EBOV)-specific vaccines and antivirals have been licensed, efforts to develop candidates offering broad species cross-protection are continuing. The use of pseudotyped virus in place of live virus is recognised as an
[...] Read more.
Ebolaviruses continue to pose a significant outbreak threat, and while Ebola virus (EBOV)-specific vaccines and antivirals have been licensed, efforts to develop candidates offering broad species cross-protection are continuing. The use of pseudotyped virus in place of live virus is recognised as an alternative, safer, high-throughput platform to evaluate anti-ebolavirus antibodies towards their development, yet it requires optimisation. Here, we have shown that the target cell line impacts neutralisation assay results and cannot be selected purely based on permissiveness. In expanding the platform to incorporate each of the ebolavirus species envelope glycoprotein, allowing a comprehensive assessment of cross-neutralisation, we found that the recently discovered Bombali virus has a point mutation in the receptor-binding domain which prevents entry into a hamster cell line and, importantly, shows that this virus can be cross-neutralised by EBOV antibodies and convalescent plasma.
Full article
(This article belongs to the Special Issue Ebola: Preparedness and Response)
►▼
Show Figures

Figure 1
Open AccessArticle
Impact of COVID-19 on Tuberculosis Case Detection and Treatment Outcomes in Sierra Leone
by
, , , , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 154; https://doi.org/10.3390/tropicalmed6030154 - 19 Aug 2021
Abstract
The COVID-19 pandemic has adversely affected tuberculosis (TB) care delivery in high burden countries. We therefore conducted a retrospective study to assess the impact of COVID-19 on TB case detection and treatment outcomes at the Chest Clinic at Connaught Hospital in Freetown, Sierra
[...] Read more.
The COVID-19 pandemic has adversely affected tuberculosis (TB) care delivery in high burden countries. We therefore conducted a retrospective study to assess the impact of COVID-19 on TB case detection and treatment outcomes at the Chest Clinic at Connaught Hospital in Freetown, Sierra Leone. Overall, 2300 presumptive cases were tested during the first three quarters of 2020 (intra-COVID-19) versus 2636 in 2019 (baseline), representing a 12.7% decline. Testing declined by 25% in women, 20% in children and 81% in community-initiated referrals. Notwithstanding, laboratory-confirmed TB cases increased by 37.0% and treatment success rate was higher in 2020 (55.6% vs. 46.7%, p = 0.002). Multivariate logistic regression analysis found that age < 55 years (aOR 1.74, 95% CI (1.80, 2.56); p = 0.005), new diagnosis (aOR 1.69, 95% CI (1.16, 2.47); p = 0.007), pulmonary TB (aOR 3.17, 95% CI (1.67, 6.04); p < 0.001), HIV negative status (aOR 1.60, 95%CI (1.24, 2.06); p < 0.001) and self-administration of anti-TB drugs through monthly dispensing versus directly observed therapy (DOT) (aOR 1.56, 95% CI (1.21, 2.03); p = 0.001) independently predicted treatment success. These findings may have policy implications for DOTS in this setting and suggest that more resources are needed to reverse the negative impact of the COVID-19 pandemic on TB program activities in Sierra Leone.
Full article
(This article belongs to the Special Issue Assessing, Understanding and Mitigating the Impact of COVID-19 on TB Prevention, Care and Control)
►▼
Show Figures

Figure 1
Open AccessReview
Onchocerciasis Fingerprints in the Geriatric Population: Does Host Immunity Play a Role?
by
, , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 153; https://doi.org/10.3390/tropicalmed6030153 - 19 Aug 2021
Abstract
One of the most debilitating consequences of aging is the progressive decline in immune function, known as immunosenescence. This phenomenon is characterized by a shift in T-cell phenotypes, with a manifest decrease of naive T-cells—dealing with newly encountered antigens—and a concomitant accumulation of
[...] Read more.
One of the most debilitating consequences of aging is the progressive decline in immune function, known as immunosenescence. This phenomenon is characterized by a shift in T-cell phenotypes, with a manifest decrease of naive T-cells—dealing with newly encountered antigens—and a concomitant accumulation of senescent and regulatory T-cells, leading to a greater risk of morbidity and mortality in older subjects. Additionally, with aging, several studies have unequivocally revealed an increase in the prevalence of onchocerciasis infection. Most lymphatic complications, skin and eye lesions due to onchocerciasis are more frequent among the elderly population. While the reasons for increased susceptibility to onchocerciasis with age are likely to be multi-factorial, age-associated immune dysfunction could play a key role in the onset and progression of the disease. On the other hand, there is a growing consensus that infection with onchocerciasis may evoke deleterious effects on the host’s immunity and exacerbate immune dysfunction. Indeed, Onchocerca volvulus has been reported to counteract the immune responses of the host through molecular mimicry by impairing T-cell activation and interfering with the processing of antigens. Moreover, reports indicate impaired cellular and humoral immune responses even to non-parasite antigens in onchocerciasis patients. This diminished protective response may intensify the immunosenescence outcomes, with a consequent vulnerability of those affected to additional diseases. Taken together, this review is aimed at contributing to a better understanding of the immunological and potential pathological mechanisms of onchocerciasis in the older population.
Full article
(This article belongs to the Special Issue Viral-Host Metabolic Interactions)
Open AccessCase Report
A Cluster of Dengue Cases in Travelers: A Clinical Series from Thailand
by
, , , , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 152; https://doi.org/10.3390/tropicalmed6030152 - 14 Aug 2021
Abstract
Dengue is an overlooked tropical disease for which billions of people are at risk. The disease, caused by a Flavivirus with four distinct serotypes, is transmitted primarily by urban Aedes mosquito species. The infection leads to a spectrum of clinical manifestations, with the
[...] Read more.
Dengue is an overlooked tropical disease for which billions of people are at risk. The disease, caused by a Flavivirus with four distinct serotypes, is transmitted primarily by urban Aedes mosquito species. The infection leads to a spectrum of clinical manifestations, with the majority being asymptomatic. Primary dengue fever and, to a greater extent, a subsequent infection with a different serotype is associated with increased severity. Increased global travel and recreational tourism expose individuals naïve to the dengue viruses, the most common arboviral infections among travelers. We describe a cluster of possible primary acute dengue infections in a group of 12 individuals who presented to Bangkok Hospital for Tropical Diseases in 2017. Infection was confirmed by dengue NS1 antigen and multiplex real-time RT-PCR. Nine individuals required hospitalization, and four developed dengue warning signs. Leukocytes, neutrophils, and platelets declined towards defervescence and were negatively correlated with day of illness. Six clinical isolates were identified as dengue serotype-1, with 100% nucleotide identity suggesting that these patients were infected with the same virus.
Full article
(This article belongs to the Special Issue Epidemiology of Dengue: Past, Present and Future (Volume II))
►▼
Show Figures

Figure 1
Open AccessArticle
An Autochthonous Outbreak of the SARS-CoV-2 P.1 Variant of Concern in Southern Italy, April 2021
by
, , , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 151; https://doi.org/10.3390/tropicalmed6030151 - 12 Aug 2021
Abstract
The SARS-CoV-2 P.1 variant of concern (VOC) was first identified in Brazil and is now spreading in European countries. It is characterized by the E484K mutation in the receptor-binding domain, which could contribute to the evasion from neutralizing antibodies. In Italy, this variant
[...] Read more.
The SARS-CoV-2 P.1 variant of concern (VOC) was first identified in Brazil and is now spreading in European countries. It is characterized by the E484K mutation in the receptor-binding domain, which could contribute to the evasion from neutralizing antibodies. In Italy, this variant was first identified in January 2021. Here, we report an autochthonous outbreak of SARS-CoV-2 P.1 variant infections in southern Italy in subjects who had not travelled to endemic areas or outside the Apulia region. The outbreak involved seven subjects, three of whom had received a COVID-19 vaccine (one had received two doses and two had received one dose). Four patients had a mild clinical presentation. Laboratory investigations of nasopharyngeal swabs revealed that all strains were S-gene target failure-negative and molecular tests revealed they were the P.1 variant. Whole-genome sequencing confirmed that five subjects were infected with closely related strains classified as the P.1 lineage. The circulation of VOCs highlights the importance of strictly monitoring the spread of SARS-CoV-2 variants through genomic surveillance and of investigating local outbreaks. Furthermore, public health measures including social distancing, screening, and quarantine for travelers are key tools to slow down the viral transmission and to contain and mitigate the impact of VOC diffusion, and rapid scaling-up of vaccination is crucial to avoid a possible new epidemic wave.
Full article
(This article belongs to the Special Issue COVID-19: Current Status and Future Prospects)
►▼
Show Figures

Figure 1
Open AccessArticle
The Effect of HBV/HCV in Response to HAART in HIV Patients after 12 Months in Kumba Health District in the South West Region of Cameroon
by
, , , and
Trop. Med. Infect. Dis. 2021, 6(3), 150; https://doi.org/10.3390/tropicalmed6030150 - 10 Aug 2021
Abstract
Hepatitis B (HBV) and C (HCV) are two among the numerous forms of infections whose clinical degeneration, morbidity–mortality and low immune responsiveness in people living with human immunodeficiency virus (HIV) are highly evident. Co-infection of HIV with HBV and HCV has been associated
[...] Read more.
Hepatitis B (HBV) and C (HCV) are two among the numerous forms of infections whose clinical degeneration, morbidity–mortality and low immune responsiveness in people living with human immunodeficiency virus (HIV) are highly evident. Co-infection of HIV with HBV and HCV has been associated with reduced survival, increased risk of progression to liver diseases and increased risk of hepatotoxicity associated with antiretroviral therapy (ARV). We carried out biochemical, immunological, virological and clinical analysis of hepatitis B and C positive HIV patients as well as some HIV positive individuals receiving antiretroviral therapy in Kumba Health District to evaluate the immune response to the ARV therapy and identified risk factors associated with the treatment outcomes. A total of 52 HIV patients, 36 HIV/HBV and 12 HIV/HCV patients were involved in this study. We performed CD4 counts, viral load test, analyzed ALAT/ASAT, albumin, bilirubin, and creatinine and measured the weights of HIV patients, HIV/HBV and HIV/HCV enrolled for not more than one year in Kumba Health District. The results were analyzed to evaluate the immune response and possible risk factors associated with the treatment outcomes. The mean increase in weight in participants of all groups over 12 months (17.12 kg) was greater than the mean increase in CD4 (8.92 cell/mm3). However, the mean decrease in viral loads over a 12 months was also very high (1035.17 copies/mL). There was a significant change in the mean values from baseline for all the three variables (p < 0.0001). HIV disease outcomes following HAART (high active antiretroviral therapy) do not appear to be adversely affected by HBV or HCV co-infection, except for slightly poorer CD4 count responses in HIV/HCV co-infected patients. Concerning the renal and liver functions, all the biomarkers witnessed a decrease in patients of all groups in response to HAART over time, with a more rapid decrease in mono-infected patients as compared with those co-infected with HBV but the case was contrary for those co-infected with HCV. Co-infection with HBV or HCV was relatively common among HIV infected participants in Kumba Health District. There were differences in response to HAART between the mono-infected compared with the co-infected, taking into consideration the weight, CD4 count, and viral load. In addition, there was also a variation in the different biomarkers of liver and renal function between mono-infected and co-infected patients.
Full article
(This article belongs to the Special Issue Control of Viral Hepatitis)
Open AccessArticle
Blood Lead Levels and Subsequence Risk of Malaria in the African Population: A Systematic Review and Meta-Analysis
by
and
Trop. Med. Infect. Dis. 2021, 6(3), 149; https://doi.org/10.3390/tropicalmed6030149 - 08 Aug 2021
Abstract
Previous epidemiological studies showed that blood lead level (BLL) was associated with malaria infection and severity. Therefore, the present study aimed to qualitatively and quantitatively synthesize the evidence on the association between BLL and risk of malaria infection and severity using the systematic
[...] Read more.
Previous epidemiological studies showed that blood lead level (BLL) was associated with malaria infection and severity. Therefore, the present study aimed to qualitatively and quantitatively synthesize the evidence on the association between BLL and risk of malaria infection and severity using the systematic review and meta-analysis approach. Potentially relevant studies were identified from three databases using a combination of search terms. The quality of the included studies was assessed using the checklist for the cross-sectional studies developed by the Joanna Briggs Institute. The qualitative synthesis of the risk or odds of malaria infection in patients with BLL was performed as the outcome of each included study could not be pooled. The pooled mean BLL and prevalence of malaria infection of the included studies was estimated using a random-effect model. The heterogeneity of the outcomes among the included studies was assessed using the Cochran Q test and I2 statistics. The subgroup analysis of the study sites and participants was performed to explore the source(s) of heterogeneity of the outcomes. Publication bias was assessed in the case of more than 10 studies used for pooling of the same outcome. Among 114 potentially relevant studies identified from the databases, 6 eligible studies were included for qualitative and quantitative syntheses. The results showed that the pooled mean BLLs were 7.33 μg/dL in children (95% confidence interval (95%CI), 4.08–10.58; I2, 98.2%), 7.94 μg/dL in children with BLL > 45 mg/dL before chelation (95%CI, 7.87–8.01), 7.41 μg/dL in infants (95%CI, 7.34–7.48 μg/dL), 9.20 μg/dL in children with malaria (95%CI, 9.16–9.24 μg/ dL), and 36.37 μg/dL in pregnant women (95%CI, 34.43–38.31 μg/dL). The prevalence rates of malaria among participants (2381 participants, 803 malaria-positive patients) were 53% in children (95%CI, 50–57%; I2, 99.8%), 24% in children with BLL > 45 mg/dL before chelation (95%CI, 21–27%), 12% in infants (95%CI, 8–18%), and 21% in pregnant women (95%CI, 18–26%). The subgroup analysis of countries demonstrated that the prevalence rates of malaria among participants was 17% in Benin (95%CI, 13–21%; I2, 98.8%) and 36% in Nigeria (95%CI, 10–63%; I2, 99.4%). BLL associated with decreased risk of malaria was demonstrated by two studies conducted in Benin and Nigeria, while BLL associated with increased risk of malaria was demonstrated by a study conducted in Nigeria. BLL was associated with the risk of severe malaria, involving severe neurological features and severe anemia. In conclusion, the present systematic review and meta-analysis determined the current status of the studies on BLL and risk of malaria in African countries. Further studies are needed to investigate the impact of BLL on patients with malaria to help the clinician determine the risk of severity, such as the development of neurological features or severe anemia, among patients exposed to lead.
Full article
(This article belongs to the Special Issue Occupational and Work-Related Diseases in Developing/Tropical Countries)
►▼
Show Figures

Figure 1
Open AccessReview
Tuberculosis in Adolescents and Young Adults: Emerging Data on TB Transmission and Prevention among Vulnerable Young People
Trop. Med. Infect. Dis. 2021, 6(3), 148; https://doi.org/10.3390/tropicalmed6030148 - 05 Aug 2021
Abstract
Adolescents and young adults (AYA, ages 10–24 years) comprise a uniquely important but understudied population in global efforts to end tuberculosis (TB), the leading infectious cause of death by a single agent worldwide prior to the COVID-19 pandemic. While TB prevention and care
[...] Read more.
Adolescents and young adults (AYA, ages 10–24 years) comprise a uniquely important but understudied population in global efforts to end tuberculosis (TB), the leading infectious cause of death by a single agent worldwide prior to the COVID-19 pandemic. While TB prevention and care strategies often overlook AYA by grouping them with either children or adults, AYA have particular physiologic, developmental, and social characteristics that require dedicated approaches. This review describes current evidence on the prevention and control of TB among AYA, including approaches to TB screening, dynamics of TB transmission among AYA, and management challenges within the context of unique developmental needs. Challenges are considered for vulnerable groups of AYA such as migrants and refugees; AYA experiencing homelessness, incarceration, or substance use; and AYA living with HIV. We outline areas for needed research and implementation strategies to address TB among AYA globally.
Full article
(This article belongs to the Special Issue Infection Prevention and Control: Practical and Educational Advances)
►▼
Show Figures

Figure 1
Open AccessReview
A Review of the Environmental Trigger and Transmission Components for Prediction of Cholera
Trop. Med. Infect. Dis. 2021, 6(3), 147; https://doi.org/10.3390/tropicalmed6030147 - 05 Aug 2021
Abstract
Climate variables influence the occurrence, growth, and distribution of Vibrio cholerae in the aquatic environment. Together with socio-economic factors, these variables affect the incidence and intensity of cholera outbreaks. The current pandemic of cholera began in the 1960s, and millions of cholera cases
[...] Read more.
Climate variables influence the occurrence, growth, and distribution of Vibrio cholerae in the aquatic environment. Together with socio-economic factors, these variables affect the incidence and intensity of cholera outbreaks. The current pandemic of cholera began in the 1960s, and millions of cholera cases are reported each year globally. Hence, cholera remains a significant health challenge, notably where human vulnerability intersects with changes in hydrological and environmental processes. Cholera outbreaks may be epidemic or endemic, the mode of which is governed by trigger and transmission components that control the outbreak and spread of the disease, respectively. Traditional cholera risk assessment models, namely compartmental susceptible-exposed-infected-recovered (SEIR) type models, have been used to determine the predictive spread of cholera through the fecal–oral route in human populations. However, these models often fail to capture modes of infection via indirect routes, such as pathogen movement in the environment and heterogeneities relevant to disease transmission. Conversely, other models that rely solely on variability of selected environmental factors (i.e., examine only triggers) have accomplished real-time outbreak prediction but fail to capture the transmission of cholera within impacted populations. Since the mode of cholera outbreaks can transition from epidemic to endemic, a comprehensive transmission model is needed to achieve timely and reliable prediction with respect to quantitative environmental risk. Here, we discuss progression of the trigger module associated with both epidemic and endemic cholera, in the context of the autochthonous aquatic nature of the causative agent of cholera, V. cholerae, as well as disease prediction.
Full article
(This article belongs to the Special Issue Cholera Control in 2021: Bioecology, Immunology, Current and Future Vaccines and Treatment Options)
►▼
Show Figures

Figure 1
Open AccessArticle
Assessment of the Biosafety and Biosecurity in the Reference Veterinary Laboratory of Parakou in Benin
by
, , , and
Trop. Med. Infect. Dis. 2021, 6(3), 146; https://doi.org/10.3390/tropicalmed6030146 - 04 Aug 2021
Abstract
Optimal biosafety and biosecurity are major requirements of global health security. This study assessed the biorisk management in the reference veterinary laboratory of Parakou (Benin). The study was cross-sectional, descriptive, and evaluative. The non-probability sampling method with the reasoned choice was used. The
[...] Read more.
Optimal biosafety and biosecurity are major requirements of global health security. This study assessed the biorisk management in the reference veterinary laboratory of Parakou (Benin). The study was cross-sectional, descriptive, and evaluative. The non-probability sampling method with the reasoned choice was used. The Food and Agriculture Organization laboratory mapping tool-safety was used to collect information from the laboratory team. Group discussion, working environment observation, and document exploitation were the data collection techniques. The biorisk management was rated good if the average indicator of the laboratory reached at least 80%. Otherwise, the biorisk management was rated insufficient. The overall laboratory biosafety and biosecurity score was insufficient (42.4%). Per area, the scores were 26.7% for engineering, 33.3% for administration, 53.8% for personal protective equipment, and 62.3% for the operational. There was no area or category score that reached 80%. Containment, waste disposal, and personal protective equipment disposal were the best performing categories with a score above 60%. The laboratory has no biosafety and accident prevention program. Its premises require renovation. The standard operating procedures for biosafety are not yet finalized, and the training mechanism is not optimal. Therefore, strong advocacy and implementation of a biorisk management improvement plan appear as urgent corrective actions which are required to help the reference veterinary laboratory of Parakou in its task to protect the livestock and, ultimately, the people of Benin from dangerous diseases and emerging pathogens.
Full article
(This article belongs to the Special Issue Tropical Laboratory Safety Including Biosafety)
►▼
Show Figures

Figure 1
Open AccessArticle
Spatial and Temporal Patterns of Ross River Virus in Queensland, 2001–2020
Trop. Med. Infect. Dis. 2021, 6(3), 145; https://doi.org/10.3390/tropicalmed6030145 - 03 Aug 2021
Abstract
Ross River virus (RRV), the most common human arbovirus infection in Australia, causes significant morbidity and substantial medical costs. About half of Australian cases occur in Queensland. We describe the spatial and temporal patterns of RRV disease in Queensland over the past two
[...] Read more.
Ross River virus (RRV), the most common human arbovirus infection in Australia, causes significant morbidity and substantial medical costs. About half of Australian cases occur in Queensland. We describe the spatial and temporal patterns of RRV disease in Queensland over the past two decades. RRV notifications, human population data, and weather data from 2001 to 2020 were analysed by the Statistical Area Level 2 (SA2) area. Spatial interpolation or linear extrapolation were used for missing weather values and the estimated population in 2020, respectively. Notifications and incidence rates were analysed through space and time. During the study period, there were 43,699 notifications in Queensland. The highest annual number of notifications was recorded in 2015 (6182), followed by 2020 (3160). The average annual incidence rate was 5 per 10,000 people and the peak period for RRV notifications was March to May. Generally, SA2 areas in northern Queensland had higher numbers of notifications and higher incidence rates than SA2 areas in southern Queensland. The SA2 areas with high incidence rates were in east coastal areas and western Queensland. The timely prediction may aid disease prevention and routine vector control programs, and RRV management plans are important for these areas.
Full article
(This article belongs to the Special Issue Spatial Epidemiology of Vector-Borne Diseases)
►▼
Show Figures

Figure 1
Open AccessArticle
A Case of Trauma-Induced Falciformispora lignatilis Eumycetoma in a Renal Transplant Recipient
by
, , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 144; https://doi.org/10.3390/tropicalmed6030144 - 03 Aug 2021
Abstract
►▼
Show Figures
Mycetoma is a chronic, granulomatous, subcutaneous infection caused by several species of fungi and soil-inhabiting bacteria, and is divided into eumycetoma and actinomycetoma, respectively. Endemicity is described with worldwide distribution within the “mycetoma belt”; however, the global burden is ill-defined. Mycetoma is rare
[...] Read more.
Mycetoma is a chronic, granulomatous, subcutaneous infection caused by several species of fungi and soil-inhabiting bacteria, and is divided into eumycetoma and actinomycetoma, respectively. Endemicity is described with worldwide distribution within the “mycetoma belt”; however, the global burden is ill-defined. Mycetoma is rare in Australia, with only a few published case reports. Over time, the breadth of eumycetoma pathogens has expanded with local epidemiology accounting for variations in regional prevalence. Direct inoculation of pathogens typically heralds the triad of subcutaneous mass, sinus formation and discharging grains. We describe a case of eumycetoma in a 48-year-old male Filipino renal transplant recipient who presented with a painless slow-growing elbow lesion. Ultrasonography revealed two ovoid masses and surgical excision ensued. Histopathology revealed necrotising granulomata with numerous chestnut-brown thick-walled cells, septate hyphae, and occasional grains. On suspicion of localised chromoblastomycosis, the isolate was sent to a reference laboratory which identified the fungus as Falciformispora lignatilis, an organism not hitherto associated with human infection. Amongst the solid organ transplant cohort, similar atypical presentations have been described. Clinicians need to consider eumycetoma where an epidemiological link with the tropics exists, especially in atypical presentations in transplant recipients, including absent preceding trauma.
Full article

Figure 1
Open AccessReview
Observational Characterization of the Ecological and Environmental Features Associated with the Presence of Oropouche Virus and the Primary Vector Culicoides paraenesis: Data Synthesis and Systematic Review
Trop. Med. Infect. Dis. 2021, 6(3), 143; https://doi.org/10.3390/tropicalmed6030143 - 02 Aug 2021
Abstract
►▼
Show Figures
Oropouche virus (OROV), a member of the Orthobunyavirus genus, is an arthropod-borne virus (arbovirus) and is the etiologic agent of human and animal disease. The primary vector of OROV is presumed to be the biting midge, Culicoides paraenesis, though Culex quinquefasciatus, Cq.
[...] Read more.
Oropouche virus (OROV), a member of the Orthobunyavirus genus, is an arthropod-borne virus (arbovirus) and is the etiologic agent of human and animal disease. The primary vector of OROV is presumed to be the biting midge, Culicoides paraenesis, though Culex quinquefasciatus, Cq. venezuelensis, and Aedes serratus mosquitoes are considered secondary vectors. The objective of this systematic review is to characterize locations where OROV and/or its primary vector have been detected. Synthesis of known data through review of published literature regarding OROV and vectors was carried out through two independent searches: one search targeted to OROV, and another targeted towards the primary vector. A total of 911 records were returned, but only 90 (9.9%) articles satisfied all inclusion criteria. When locations were characterized, some common features were noted more frequently than others, though no one characteristic was significantly associated with presence of OROV using a logistic classification model. In a separate correlation analysis, vector presence was significantly correlated only with the presence of restingas. The lack of significant relationships is likely due to the paucity of data regarding OROV and its eco-epidemiology and highlights the importance of continued focus on characterizing this and other neglected tropical diseases.
Full article

Figure 1
Open AccessArticle
Newly Diagnosed Diabetes in Patients with COVID-19: Different Types and Short-Term Outcomes
by
, , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 142; https://doi.org/10.3390/tropicalmed6030142 - 02 Aug 2021
Abstract
A great global concern is currently focused on the coronavirus disease 2019 (COVID-19) pandemic and its associated morbidities. The goal of this study was to determine the frequency of newly diagnosed diabetes mellitus (DM) and its different types among COVID-19 patients, and to
[...] Read more.
A great global concern is currently focused on the coronavirus disease 2019 (COVID-19) pandemic and its associated morbidities. The goal of this study was to determine the frequency of newly diagnosed diabetes mellitus (DM) and its different types among COVID-19 patients, and to check the glycemic control in diabetic cases for three months. After excluding known cases of DM, 570 patients with confirmed COVID-19 were studied. All participants were classified as non-diabetic or newly discovered diabetic. According to hemoglobin A1c (HbA1c) and fasting insulin, newly discovered diabetic patients were further classified into pre-existing DM, new-onset type 1 DM, and new-onset type 2 DM. Glycemic control was monitored for three months in newly diagnosed diabetic patients. DM was diagnosed in 77 patients (13.5%); 12 (2.1%) with pre-existing DM, 7 (1.2%) with new-onset type 1 DM, and 58 (10.2%) with new-onset type 2 DM. Significantly higher rates of severe infection and mortality (p < 0.001 and p = 0.046) were evident among diabetic patients. Among survived diabetic patients (n = 63), hyperglycemia and the need for anti-diabetic treatment persisted in 73% of them for three months. COVID-19 was associated with a new-onset of DM in 11.4% of all participants and expression of pre-existing DM in 2.1% of all participants, both being associated with severe infection. COVID-19 patients with newly diagnosed diabetes had high risk of mortality. New-onset DM persisted for at least three months in more than two-thirds of cases.
Full article
(This article belongs to the Special Issue COVID-19: Current Status and Future Prospects)
►▼
Show Figures

Figure 1
Open AccessArticle
Analytical Estimation of Data-Motivated Time-Dependent Disease Transmission Rate: An Application to Ebola and Selected Public Health Problems
Trop. Med. Infect. Dis. 2021, 6(3), 141; https://doi.org/10.3390/tropicalmed6030141 - 31 Jul 2021
Abstract
Obtaining reasonable estimates for transmission rates from observed data is a challenge when using mathematical models to study the dynamics of ?infectious? diseases, like Ebola. Most models assume the transmission rate of a contagion either does not vary over time or change in
[...] Read more.
Obtaining reasonable estimates for transmission rates from observed data is a challenge when using mathematical models to study the dynamics of ?infectious? diseases, like Ebola. Most models assume the transmission rate of a contagion either does not vary over time or change in a fixed pre-determined adhoc ways. However, these rates do vary during an outbreak due to multitude of factors such as environmental conditions, social behaviors, and public-health interventions deployed to control the disease, which are in-part guided by changing size of an outbreak. We derive analytical estimates of time-dependent transmission rate for an epidemic in terms of either incidence or prevalence using a standard mathematical SIR-type epidemic model. We illustrate applicability of our method by applying data on various public health problems, including infectious diseases (Ebola, SARS, and Leishmaniasis) and social issues (obesity and alcohol drinking) to compute transmission rates over time. We show that time-dependent transmission rate estimates can have a large variation, depending on the type of available data and other epidemiological parameters. Time-dependent estimation of transmission rates captures the dynamics of the problem better and can be utilized to understand disease progression more accurately.
Full article
(This article belongs to the Special Issue Ebola: Preparedness and Response)
►▼
Show Figures

Figure 1
Open AccessReview
Emerging Trends in the West Nile Virus Epidemiology in Croatia in the ‘One Health’ Context, 2011–2020
by
, , , , , , , , , , , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 140; https://doi.org/10.3390/tropicalmed6030140 - 24 Jul 2021
Abstract
West Nile virus (WNV) is one of the most widely distributed (re-)emerging arboviruses. In Croatia, acute WNV infections as well as seropositivity were detected in humans, horses, birds and poultry. Although serologic evidence of WNV human infections dates back to the 1970s, no
[...] Read more.
West Nile virus (WNV) is one of the most widely distributed (re-)emerging arboviruses. In Croatia, acute WNV infections as well as seropositivity were detected in humans, horses, birds and poultry. Although serologic evidence of WNV human infections dates back to the 1970s, no clinical cases were reported until 2012. WNV outbreaks, as well as sporadic infections, were continuously recorded in continental Croatian counties from 2012 to 2018. In addition, acute asymptomatic infections (IgM antibodies) in horses have been regularly notified in continental regions since 2012, while seropositive horses (seroprevalence rates 3.7–21.4%) were detected in both continental and coastal regions. Moreover, WNV seropositivity in poultry (1.8–22.9%) was reported from 2013 to 2020. During the largest WNV outbreak in 2018, WNV RNA was detected for the first time in two dead goshawks (Accipiter gentilis) from the same aviary in North-West Croatia, while WNV antibodies were found in one buzzard (Butteo butteo) from the same region. In addition, WNV RNA was detected in a dead blackbird (Turdus merula) at the Croatian littoral. The phylogenetic analysis of 11 strains detected in urine samples of patients with neuroinvasive disease and 1 strain detected in a goshawk showed circulation of WNV lineage 2. Thus far, WNV has not been detected in mosquitoes in Croatia.
Full article
(This article belongs to the Special Issue West Nile Infection)
►▼
Show Figures

Figure 1
Open AccessArticle
Estimation of Potential HIV Transmission Risk in Recent Anal Intercourse Events among Men Who Have Sex with Men and Transgender Women in Bali, Indonesia
by
, , , , and
Trop. Med. Infect. Dis. 2021, 6(3), 139; https://doi.org/10.3390/tropicalmed6030139 - 22 Jul 2021
Abstract
In recent years, prevalence of Human Immunodeficiency Virus (HIV) has increased substantially in Bali, Indonesia, in men who have sex with men (MSM) and transgender women, known locally as ‘waria’. There are limited behavioural data in this population. We conducted a behavioural survey
[...] Read more.
In recent years, prevalence of Human Immunodeficiency Virus (HIV) has increased substantially in Bali, Indonesia, in men who have sex with men (MSM) and transgender women, known locally as ‘waria’. There are limited behavioural data in this population. We conducted a behavioural survey of MSM/waria in Bali in March–April 2018. Respondents were primarily recruited by HIV outreach workers. Respondents reported details about anal intercourse events with their last male/waria romantic partner and/or last male/waria casual partner (respondents could report on both if relevant). Statistical significance was tested with generalised estimating equations. Among 709 participants, median age was 27 (interquartile range = 24–31), and 92.1% were male and 7.9% were waria. One-third were born in Bali. Overall, 85.9% had ever had an HIV test; 55.1% reported being HIV-negative, 15.0% HIV-positive, and 30.0% had unknown serostatus. Most (86.5%) reported sex with men, 9.5% with waria, and 20.0% with women in the previous 6 months. Respondents described 703 anal intercourse events (397/306 with romantic/casual partners, respectively; 191 reported on both). Over half (56.5%) of the events were protected by condoms and 7.3% by biomedical prevention (2.6% by PrEP in either partner, 4.7% by HIV treatments in either partner). Thus, 36.3% of events involved unprotected condomless anal intercourse (40.8%/30.4% in romantic/casual partners, respectively). In multivariate analysis, unprotected condomless anal intercourse events were associated with romantic partners (p < 0.001), being born in Bali (p = 0.002), lower education (p = 0.013), believing that withdrawal before ejaculation is effective (p < 0.001), liking to use withdrawal (p = 0.021), and not liking condoms (p < 0.001). One-quarter of events had potentially reduced HIV transmission risk through non-condom-based risk reduction strategies, while 11.1% had no potential risk reduction. Events presenting the highest potential risk of HIV transmission were more commonly reported by respondents born in Bali.
Full article
(This article belongs to the Special Issue HIV and Co-Infections: Old and New Challenges)
►▼
Show Figures

Figure 1
Highly Accessed Articles
Latest Books
E-Mail Alert
News
Topics
Topic in
Life, Atmosphere, TropicalMed
Climate Change and Infectious Disease
Editor-in-Chief: Bernardino RocaDeadline: 5 November 2021
Topic in
TropicalMed, Microorganisms, Pathogens
Zoonoses in Tropical Countries
Editor-in-Chief: Johanna LindahlDeadline: 30 November 2021
Topic in
TropicalMed, Pathogens
Novel Therapeutic Strategies against Leishmania and TrypanosomaEditor-in-Chief: André Luis Souza dos SantosDeadline: 31 January 2022
Conferences
Special Issues
Special Issue in
TropicalMed
Occupational and Work-Related Diseases in Developing/Tropical Countries
Guest Editor: Ngatu Roger NlanduDeadline: 1 September 2021
Special Issue in
TropicalMed
West Nile Infection
Guest Editor: Maddalena PeghinDeadline: 1 October 2021
Special Issue in
TropicalMed
Viral-Host Metabolic Interactions
Guest Editors: Kuan Rong Chan, Yaw Shin Ooi, Yie Hou Lee, Eugenia Ong ZiyingDeadline: 20 October 2021
Special Issue in
TropicalMed
Infection Prevention and Control: Practical and Educational Advances
Guest Editors: Constantinos Tsioutis, Spyridon KarageorgosDeadline: 1 November 2021


