Research

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10 pages, 1405 KiB

Open AccessArticle

Epidemics of Crimean-Congo Hemorrhagic Fever (CCHF) in Sudan between 2010 and 2020

by Ayman Ahmed, Yousif Ali, Bashir Salim, Isabelle Dietrich and Jakob Zinsstag

Microorganisms 2022, 10(5), 928; https://doi.org/10.3390/microorganisms10050928 - 28 Apr 2022

Cited by 10 | Viewed by 2657

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic arboviral disease that poses a great threat to global health in the Old World, and it is endemic in Europe, Asia, and Africa, including Sudan. In this retrospective study, we reviewed previous epidemiological reports about the [...] Read more.

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic arboviral disease that poses a great threat to global health in the Old World, and it is endemic in Europe, Asia, and Africa, including Sudan. In this retrospective study, we reviewed previous epidemiological reports about the major epidemics of CCHF throughout Sudan between 2010 and 2020. During these epidemics, the infection of humans with Crimean-Congo hemorrhagic fever virus (CCHFV), the causative agent of CCHF, was diagnosed using qRT-PCR. We have identified 88 cases of CCHF, including 13 fatalities reported during five epidemics that occurred in 2010, 2011, 2015, 2019, and 2020. The two epidemics in 2010 and 2011 were by far the largest, with 51 and 27 cases reported, respectively. The majority of cases (78%) were reported in the endemic region of Kordofan. Here, we document that the first emergence of CCHFV in the Darfur region, West Sudan, occurred in 2010. We were not able to investigate outbreak dynamics through phylogenetic analysis due to the limited diagnostic capacity and the lack of sequencing services in the country. These findings call for establishing a genomic-based integrated One Health surveillance and response system for the early preparedness, prevention, and control of CCHF in the country. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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11 pages, 702 KiB

Open AccessArticle

Assessing Tick-Borne Disease Risk and Surveillance: Toward a Multi-Modal Approach to Diagnostic Positioning and Prediction

by Chris Brooks, Connie L. McNeely, Sarah P. Maxwell and Kevin C. Thomas

Microorganisms 2022, 10(4), 832; https://doi.org/10.3390/microorganisms10040832 - 18 Apr 2022

Cited by 4 | Viewed by 2231

Abstract

The true extent of tick-borne disease (TBD) incidence and risk among humans is largely unknown, posing significant public health challenges. This study offers an exploratory analysis of a multimodal dataset and is part of a larger ongoing project to determine if entomological data, [...] Read more.

The true extent of tick-borne disease (TBD) incidence and risk among humans is largely unknown, posing significant public health challenges. This study offers an exploratory analysis of a multimodal dataset and is part of a larger ongoing project to determine if entomological data, canine serological reports, self-reported human tick bite encounters (TBEs), and/or associated TBD diagnoses can serve as proxies for human disease risk. Focusing on the United States (U.S.), it characterizes self-reported TBD diagnoses (specifically, anaplasmosis, ehrlichiosis, and Lyme disease), co-infections, and their frequency and distribution across U.S. counties in relation to the presence of other factors related to TBD risk. Survey data was used to construct a list of TBEs localizable to individual U.S. counties. National data regarding these counties—namely the presence of official Lyme Disease (LD) case reports from the Centers for Disease Control and Prevention, as well as the tick vectors I. scapularis and I. pacificus within a given county—were then linked with survey-reported TBEs, tabulated by diagnosis (including co-infections), to determine the distribution of county-level endpoints across diagnostic categories. In addition, data on the presence of positive serological diagnostic tests conducted in canines were considered due to their potential utility as a proxy for TBD and TBE risk. The final dataset contained 249 TBEs localized to a total of 144 counties across 30 states. Diagnostic categories included respondents with LD (n = 70) and those with anaplasmosis and ehrlichiosis diagnoses and co-infections (n < 20 per diagnostic category). TBEs also were indicated by respondents who did not report TBD diagnoses, with some indicating uncertainty. The distribution of respondent-reported TBEs varied between canine TBDs, with LD-positive respondents reporting noticeably larger proportions of TBEs in counties with canine LD and smaller proportions in counties with canine anaplasmosis, compared to respondents without an LD diagnosis; a notional logistic regression suggests these differences may be significant (canine LD: Odds Ratio [OR] = 6.04, p = 0.026) (canine anaplasmosis: OR = 0.50, p = 0.095). These results suggest that certain widely available diagnostic TBD data in animals (in this case, domesticated dogs) may be sensitive to differences in human TBD risk factors and thus may have utility as proxies in future research. In the absence of an available standardized, unified, and national TBD database, such proxies, along with relevant surveys and reports, may provide a much-needed working solution for scientists and clinicians studying TBDs. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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12 pages, 1420 KiB

Open AccessArticle

Prevalence of Borrelia burgdorferi Sensu Lato in Ixodes ricinus Ticks Collected from Kaylaka Park in Pleven, Bulgaria

by Alexander Blazhev, Iskren Stanilov, Lyuba Dineva Miteva, Milena Atanasova, Svetla Blazheva and Spaska Stanilova

Microorganisms 2022, 10(4), 772; https://doi.org/10.3390/microorganisms10040772 - 03 Apr 2022

Cited by 4 | Viewed by 1976

Abstract

We aimed to determine the presence and distribution of Borrelia burgdorferi sensu lato (s.l.) in Ixodes ricinus ticks collected from urbanized and wild areas in Kaylaka Park (Bulgaria). A total of 546 ticks were collected over three years (2017–2019). The presence of Borrelia [...] Read more.

We aimed to determine the presence and distribution of Borrelia burgdorferi sensu lato (s.l.) in Ixodes ricinus ticks collected from urbanized and wild areas in Kaylaka Park (Bulgaria). A total of 546 ticks were collected over three years (2017–2019). The presence of Borrelia in 334 of the collected I. ricinus was detected by dark-field microscopy (DFM) and two nested PCRs (nPCR) targeting the borrelial 5S-23S rRNA intergenic spacer and Flagellin B (FlaB) gene. DFM was performed on a total of 215 ticks, of which 86 (40%) were positive. PCR was performed on 153 of the ticks. In total, 42.5% of the 5S-23S rRNA intergenic spacer and 49% of FlaB were positive. Considering as positive any single tick in which Borrelia sp. was detected regardless of the used method, the infection rate reached 37% (10/27) in the nymphs and 48.5% (149/307) in the adults (48.7% (77/158) females, 48.3% (72/149) males). The incidence of B. burgdorferi infection in I. ricinus did not differ statistically significantly between female, male, and nymph. This study provides evidence that Lyme disease spirochetes are present in various regions of Kaylaka Park with extremely high prevalence in their vectors. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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13 pages, 1243 KiB

Open AccessArticle

Tick-Borne Encephalitis Risk Increases with Dog Ownership, Frequent Walks, and Gardening: A Case-Control Study in Germany 2018–2020

by Teresa Marie Nygren, Antonia Pilic, Merle Margarete Böhmer, Christiane Wagner-Wiening, Ole Wichmann, Thomas Harder and Wiebke Hellenbrand

Microorganisms 2022, 10(4), 690; https://doi.org/10.3390/microorganisms10040690 - 23 Mar 2022

Cited by 5 | Viewed by 2192

Abstract

In Germany, tick-borne encephalitis (TBE) infections mainly occur in southern regions. Despite recent increases in incidence, TBE vaccination coverage remains low, necessitating additional preventive strategies against TBE. Our case-control study in Southern Germany from 2018 to 2020 mapped knowledge/application of tick-protective strategies and [...] Read more.

In Germany, tick-borne encephalitis (TBE) infections mainly occur in southern regions. Despite recent increases in incidence, TBE vaccination coverage remains low, necessitating additional preventive strategies against TBE. Our case-control study in Southern Germany from 2018 to 2020 mapped knowledge/application of tick-protective strategies and identified TBE risk factors. We calculated odds ratios (OR), with 95% confidence intervals (CI). We interviewed 581 cases and 975 matched controls. Most participants recalled lifetime tick bites, mainly while walking, gardening, or hiking. However, only 45% of cases noticed ticks during exposure time; another 12% reported unpasteurized milk intake. While tick-protection knowledge was satisfactory, application lagged behind. Risk factors included dog ownership (OR = 2.45, 95% CI: 1.85–3.24), walks ≥ 4×/week (OR = 2.11, 95% CI: 1.42–3.12), gardening ≥ 4×/week (OR = 1.83, 95% CI: 1.11–3.02), and garden proximity < 250 m of forests (OR = 2.54, 95% CI: 1.82–3.56). Applying ≥2 tick-protective strategies (OR = 0.52, 95% CI: 0.40–0.68) and keeping lawns mowed (OR = 0.63, 95% CI: 0.43–0.91) were inversely associated with TBE. In 2020 (likely pandemic-related), cases reported significantly more walks than previously, potentially explaining the record high case numbers. Our findings provide guidance on targets for TBE prevention. Persons with gardens near forests, frequent outdoor activities, or dogs could particularly benefit from targeted information, including on vaccination and preventing tick bites. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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13 pages, 1036 KiB

Open AccessArticle

Molecular Detection and Characterization of Babesia and Theileria in Cattle and Water Buffaloes from Southern Luzon, Philippines

by Ian Cary B. Prado, Larry Xerxes B. Capuno, Jr., Princess DLP. Collera, Aaron Paul D. Cabralda, Kristina Andrea S. De Ramos, John Michael G. Bernardo, Billy P. Divina, Tatsunori Masatani, Tetsuya Tanaka and Remil L. Galay

Microorganisms 2022, 10(4), 678; https://doi.org/10.3390/microorganisms10040678 - 22 Mar 2022

Cited by 7 | Viewed by 3208

Abstract

Babesia and Theileria are tick-borne protozoan parasites that can cause significant economic losses in the cattle industry. This study aimed to contribute to the limited epidemiological data on Theileria orientalis as well as Babesia bigemina and B. bovis in large ruminants in the [...] Read more.

Babesia and Theileria are tick-borne protozoan parasites that can cause significant economic losses in the cattle industry. This study aimed to contribute to the limited epidemiological data on Theileria orientalis as well as Babesia bigemina and B. bovis in large ruminants in the Philippines. Blood samples of 412 cattle and 108 water buffalo collected from four provinces in Southern Luzon, Philippines, were initially tested for the 18S rRNA gene of piroplasms through nested PCR. Positive samples were further subjected to species-specific PCR. The 18s rRNA of piroplasms was detected in 123 (29.9%) cattle and three (2.8%) water buffaloes. Theileria orientalis was found to be the most common piroplasm in cattle with a detection rate of 17.5%, followed by Babesia bovis and B. bigemina. Co-infections were also observed. Two water buffaloes were found infected with B. bovis, while one was positive for B. bigemina. The phylogenetic tree for B. bovis showed clustering of the isolates in two clades together with isolates from other countries, and a third separate clade. Meanwhile, the T. orientalis isolates in this study were distributed in three clades together with reported isolates from other countries. This study confirms the presence of T. orientalis in the Philippines and reports the genetic diversity of B. bovis and T. orientalis. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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15 pages, 2003 KiB

Open AccessArticle

Geo-Spatial Characteristics of 567 Places of Tick-Borne Encephalitis Infection in Southern Germany, 2018–2020

by Amelie M. Friedsam, Oliver J. Brady, Antonia Pilic, Gerhard Dobler, Wiebke Hellenbrand and Teresa M. Nygren

Microorganisms 2022, 10(3), 643; https://doi.org/10.3390/microorganisms10030643 - 17 Mar 2022

Cited by 7 | Viewed by 2185

Abstract

Tick-borne encephalitis (TBE) is a growing public health problem with increasing incidence and expanding risk areas. Improved prevention requires better understanding of the spatial distribution and ecological determinants of TBE transmission. However, a TBE risk map at sub-district level is still missing for [...] Read more.

Tick-borne encephalitis (TBE) is a growing public health problem with increasing incidence and expanding risk areas. Improved prevention requires better understanding of the spatial distribution and ecological determinants of TBE transmission. However, a TBE risk map at sub-district level is still missing for Germany. We investigated the distribution and geo-spatial characteristics of 567 self-reported places of probable TBE infection (POI) from 359 cases notified in 2018–2020 in the study area of Bavaria and Baden-Wuerttemberg, compared to 41 confirmed TBE foci and 1701 random comparator places. We built an ecological niche model to interpolate TBE risk to the entire study area. POI were distributed heterogeneously at sub-district level, as predicted probabilities varied markedly across regions (range 0–93%). POI were spatially associated with abiotic, biotic, and anthropogenic geo-spatial characteristics, including summer precipitation, population density, and annual frost days. The model performed with 69% sensitivity and 63% specificity at an optimised probability threshold (0.28) and an area under the curve of 0.73. We observed high predictive probabilities in small-scale areas, consistent with the known circulation of the TBE virus in spatially restricted microfoci. Supported by further field work, our findings may help identify new TBE foci. Our fine-grained risk map could supplement targeted prevention in risk areas. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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12 pages, 1552 KiB

Open AccessArticle

Epidemiological Surveillance of Lyme Borreliosis in Bavaria, Germany, 2013–2020

by Merle Margarete Böhmer, Katharina Ens, Stefanie Böhm, Susanne Heinzinger and Volker Fingerle

Microorganisms 2021, 9(9), 1872; https://doi.org/10.3390/microorganisms9091872 - 03 Sep 2021

Cited by 10 | Viewed by 2831

Abstract

Lyme borreliosis (LB) is the most common tick-borne disease in Germany. Mandatory notification of acute LB manifestations (erythema migrans (EM), neuroborreliosis (NB), and Lyme arthritis (LA)) was implemented in Bavaria on 1 March 2013. We aimed to describe the epidemiological situation and to [...] Read more.

Lyme borreliosis (LB) is the most common tick-borne disease in Germany. Mandatory notification of acute LB manifestations (erythema migrans (EM), neuroborreliosis (NB), and Lyme arthritis (LA)) was implemented in Bavaria on 1 March 2013. We aimed to describe the epidemiological situation and to identify LB risk areas and populations. Therefore, we analyzed LB cases notified from March 2013 to December 2020 and calculated incidence (cases/100,000 inhabitants) by time, place, and person. Overall, 35,458 cases were reported during the study period (EM: 96.7%; NB: 1.7%; LA: 1.8%). The average incidence was 34.3/100,000, but annual incidence varied substantially (2015: 23.2; 2020: 47.4). Marked regional differences at the district level were observed (annual average incidence range: 4–154/100,000). The Bavarian Forest and parts of Franconia were identified as high-risk regions. Additionally, high risk for LB was found in 5–9-year-old males and in 60–69-year-old females. The first group also had the highest risk of a severe disease course. We were able to identify areas and populations in Bavaria with an increased LB risk, thereby providing a basis for targeted measures to prevent LB. Since LB vaccination is currently not available, such measures should comprise (i) avoiding tick bites, (ii) removing ticks rapidly after a bite, and (iii) treating LB early/adequately. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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Review

Jump to: Research

16 pages, 1448 KiB

Open AccessReview

Recommendations to Improve Tick-Borne Encephalitis Surveillance and Vaccine Uptake in Europe

by Michael Kunze, Pavle Banović, Petra Bogovič, Violeta Briciu, Rok Čivljak, Gerhard Dobler, Adriana Hristea, Jana Kerlik, Suvi Kuivanen, Jan Kynčl, Anne-Mette Lebech, Lars Lindquist, Iwona Paradowska-Stankiewicz, Srđan Roglić, Dita Smíšková, Franc Strle, Olli Vapalahti, Nenad Vranješ, Nataliya Vynograd, Joanna Maria Zajkowska, Andreas Pilz, Andreas Palmborg and Wilhelm Erber Show full author list Hide full author list

Microorganisms 2022, 10(7), 1283; https://doi.org/10.3390/microorganisms10071283 - 24 Jun 2022

Cited by 29 | Viewed by 3316

Abstract

There has been an increase in reported TBE cases in Europe since 2015, reaching a peak in some countries in 2020, highlighting the need for better management of TBE risk in Europe. TBE surveillance is currently limited, in part, due to varying diagnostic [...] Read more.

There has been an increase in reported TBE cases in Europe since 2015, reaching a peak in some countries in 2020, highlighting the need for better management of TBE risk in Europe. TBE surveillance is currently limited, in part, due to varying diagnostic guidelines, access to testing, and awareness of TBE. Consequently, TBE prevalence is underestimated and vaccination recommendations inadequate. TBE vaccine uptake is unsatisfactory in many TBE-endemic European countries. This review summarizes the findings of a scientific workshop of experts to improve TBE surveillance and vaccine uptake in Europe. Strategies to improve TBE surveillance and vaccine uptake should focus on: aligning diagnostic criteria and testing across Europe; expanding current vaccine recommendations and reducing their complexity; and increasing public education of the potential risks posed by TBEV infection. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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21 pages, 2982 KiB

Open AccessReview

The Role of Ticks in the Emergence of Borrelia burgdorferi as a Zoonotic Pathogen and Its Vector Control: A Global Systemic Review

by Sabir Hussain, Abrar Hussain, Umair Aziz, Baolin Song, Jehan Zeb, David George, Jun Li and Olivier Sparagano

Microorganisms 2021, 9(12), 2412; https://doi.org/10.3390/microorganisms9122412 - 23 Nov 2021

Cited by 13 | Viewed by 2816

Abstract

Ticks are widely distributed across the globe, serving as hosts for numerous pathogens that make them major contributors to zoonotic parasitosis. Borrelia burgdorferi is a bacterial species that causes an emerging zoonotic tick-borne disease known as Lyme borreliosis. The role of ticks in [...] Read more.

Ticks are widely distributed across the globe, serving as hosts for numerous pathogens that make them major contributors to zoonotic parasitosis. Borrelia burgdorferi is a bacterial species that causes an emerging zoonotic tick-borne disease known as Lyme borreliosis. The role of ticks in the transmission of this pathogen was explored in this study. According to this systematic review, undertaken according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 19 tick species are known to carry Borrelia burgdorferi, with more than half of the recorded cases in the last two decades related to Ixodes ricinus and Ixodes scapularis ticks. Forty-six studies from four continents, Europe, North America, Asia, and Africa, reported this pathogen in ticks collected from vegetation, animals, and humans. This study highlights an increasing distribution of tick-associated Borrelia burgdorferi, likely driven by accelerated tick population increases in response to climate change coupled with tick dispersal via migratory birds. This updated catalogue helps in compiling all tick species responsible for the transmission of B. burgdorferi across the globe. Gaps in research exist on Borrelia burgdorferi in continents such as Asia and Africa, and in considering environmentally friendly vector control strategies in Europe and North America. Full article

(This article belongs to the Special Issue Epidemiology, Surveillance and Prevention of Tick-Borne Diseases)

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