Use of mass-participation outdoor events to assess human exposure to tickborne pathogens

Mapping the public health threat of tickborne pathogens requires quantification of not only the density of infected host-seeking ticks but also the rate of human exposure to these ticks. To efficiently sample a high number of persons in a short time, we used a mass-participation outdoor event. In June 2014, we sampled ≈500 persons competing in a 2-day mountain marathon run across predominantly tick-infested habitat in Scotland. From the number of tick bites recorded and prevalence of tick infection with Borrelia burgdoferi sensu lato and B. miyamotoi, we quantified the frequency of competitor exposure to the pathogens. Mass-participation outdoor events have the potential to serve as excellent windows for epidemiologic study of tickborne pathogens; their concerted use should improve spatial and temporal mapping of human exposure to infected ticks

B. burgdorferi infekcija u krpeljma uklonjenih sa ljudi i prisustvo antitela protiv borelija kod pacijenata infestiranih krpeljima

The primary objectives of this study were (1) to determine the presence of Borrelia burgdorferi infection in ticks removed from patients for the purpose of singling out sites with increased risk of Lyme borreliosis, and (2) to determine the presence of IgM and/or IgG antibodies against B. burgdorferi sensu lato (s. l.) complex in sera of patients who had ticks removed. From 108 ticks removed from patients, all were examined zoologically and a sub-sample of 91 ticks was tested using PCR analysis to determine the presence of DNA indicating B. burgdorferi infection. To detect anti-Borrelia IgM and/ or IgG antibodies in 61 patients bitten by ticks, we used line recombinant immunoblot test. The most common tick identified was Ixodes ricinus. B. burgdorferi s. l. was present in 37 of 91 tested ticks (40.7%). Seroconversion against B. burgdorferi s. l. antigen was detected in 12 of 61 patients (19.7%). Most of the infected ticks were from the province of Vojvodina (11 municipalities), with the city of Novi Sad proving to be the site with the highest number of infected ticks, 6 in total.Glavni cilj ove studije je bio da se ispita prisustvo B. burgdorferi infekcije u krpeljma uklonjenih sa pacijenata radi utvđivanja lokaliteta sa povećanim rizikom za obolevanje od lajm borelioze, kao i ispitivanje prisustva IgM i/ili IgG antitela usmerenih protiv B. burgdorferi s. l. kompleksa u serumu pacijenata infestiranih krpeljima. Sa pacijenata je prikupljeno i zoološki ispitano 108 krpelja. PCR analiza krpelja korišc'ena je za utvrđivanje prisustva B. burgdorferi s. l. kompleks kod 91 krpelja od ukupnih 108. Za otkrivanje IgM i/ili IgG antitela protiv B. burgdorferi s. l. korišćeni su linijski rekombinantni imunoblot testovi. Najčešc'i identifikovani krpelj je Ixodes ricinus. B. burgdorferi s. l. je bila prisutna u 37 od 91 testiranog krpelja (40,7%). Prisustvo IgM/IgG antitela protiv B. burgdorferi s. l. otkriveno je kod 12 od 61 pacijenta (19,7%). Najviše inficiarnih krpelja je sa teritorije AP Vojvodine (11 opština), gde je urbani deo Novog Sada lokalitet sa najvećim brojem inficiranih krpelja - 6

Occupational Lyme Disease: A Systematic Review and Meta-Analysis

Lyme disease (LD) can have significant consequences for the health of workers. The frequency of infection can be estimated by using prevalence and incidence data on antibodies against Borrelia Burgdoferi (BB). A systematic search of studies published in English between 2002 and 2021 and a meta-analysis were conducted in PubMed/Medline, Web of Science, Scopus, and Google Scholar databases. Out of a total of 1125 studies retrieved, 35 articles were included in the systematic review. Overall, in these studies, outdoor workers showed a 20.5% BB seroprevalence rate. Meta-analysis, performed on 15 studies (3932 subjects), revealed a significantly increased risk in outdoor activities (OR 1.93 95%CI 1.15–3.23), with medium-level heterogeneity (I2 = 69.2%), and non-significant publication bias. The estimated OR in forestry and agricultural workers was 2.36 (CI95% 1.28; 4.34) in comparison with the controls, while a non-significant increase in risk (OR = 1.05, CI95% 0.28; 3.88) was found in the remaining categories of workers (veterinarians, animal breeders, soldiers). The estimated pooled risk was significantly higher in the studies published until 2010 (OR 3.03 95% CI 1.39–6.61), while in more recent studies the odds became non-significant (OR 1.08 95% CI 0.63–1.85). The promotion of awareness campaigns targeting outdoor workers in endemic areas, and the implementation of local programs aimed at controlling range expansion of vectors, are key strategies for protecting workers

Linking human tick bite risk with tick abundance in the environment: a novel approach to quantify tick bite risk using orienteers in Scotland

The rate that people are bitten by ticks is critical in determining the risk of tick-borne infections but is rarely quantified accurately. Often tick abundance in the environment is used as a proxy for tick bite risk, but the relationship with risk is poorly understood. We used a novel citizen science approach to measure tick bite rate in orienteers, to assess the relationship between tick abundance and tick bite risk and to identify risk factors for tick bites. Eleven orienteering events were attended in Scotland between August 2018 and September 2019. The number of tick bites in orienteers, and the time and distance of activity were collected using an online questionnaire. Tick abundance in the same areas used for the orienteering events was estimated by surveying ticks on ground vegetation using blanket drags. Among orienteers, mean incidence was 409 tick bites per 1,000 person-hours. Tick abundance and tick bite rate were strongly correlated, indicating that data from questing tick surveys is a useful proxy for the risk of human tick bites. Tick bite rate was better explained by the activity duration than distance covered and was higher in orienteers that ran earlier in the day, exposed to higher temperatures and in woodland habitats. This study highlights the value of the citizen science approach used, which crucially included submission of activity reports both with and without ticks, to generate robust data on tick bite rate. Accurately measuring tick bite rate and understanding environmental factors that influence it are essential in mitigating the risk of tick-borne diseases

An investigation on permethrin-treated military uniforms against diurnal mosquitoes under field conditions

Background: Military forces are exposed to mosquito bites because of their duties. In addition to the nuisance caused by mosquito bites, they are the vector of some vector-borne diseases in many countries of the world. Impregnation of military uniforms with permethrin is one of the most effective methods of protecting military personnel. The purpose of this study was to evaluate the effect of permethrin-impregnated uniforms against diurnal mosquitoes under field conditions.Methods:  In this study, one of the most common uniforms used in the Iranian military was treated by permethrin (0.125 mg. permethrin ai/cm2) and evaluated against the natural population of day-biting mosquitoes, in the rural area with Eight participants, three of them put on the treated uniforms and the other one of them wore the untreated uniforms and Four officers were also appointed as collectors.Results: The average number of bites in those who wore untreated uniforms (control) was 1.8/min/person (107.8/hr), while it was 0.16 (9.83/hr) for treated uniforms. The protection of treated uniforms was about 91%. The knockdown rate for Culex and Aedes mosquitoes was 95.92% and 94.44%, respectively. The mortality rate in Culex was 98.59% and 98.61% in Aedes mosquitoes when exposed to treated uniforms.Conclusion: In this study, military uniforms impregnated with permethrin showed significant protection against the bites of Culex and Aedes mosquitoes. This intervention can be used to protect military personnel from the bites of Culex and Aedes these mosquitoes and to reduce the diseases transmitted by these mosquitoes.Keywords: Permethrin; Military uniforms; Impregnation; Mosquitoe

Trends Parasitol

In the United States, the blacklegged tick, Ixodes scapularis, is a vector of seven human pathogens, including those causing Lyme disease, anaplasmosis, babesiosis, Borrelia miyamotoi disease, Powassan virus disease, and ehrlichiosis associated with Ehrlichia muris eauclarensis. In addition to an accelerated rate of discovery of I. scapularis-borne pathogens over the past two decades, the geographic range of the tick, and incidence and range of I. scapularis-borne disease cases, have increased. Despite knowledge of when and where humans are most at risk of exposure to infected ticks, control of I. scapularis-borne diseases remains a challenge. Human vaccines are not available, and we lack solid evidence for other prevention and control methods to reduce human disease. The way forward is discussed.CC999999/ImCDC/Intramural CDC HHS/United States2018-10-01T00:00:00Z29336985PMC5879012vault:2772

Unexpected Risks for Campers and Hikers: Tick-Borne Infections

Introduction: Camping and hiking are popular worldwide recreational activities. All age groups, elderly or young, immunocompetent or immunosupressive people may engage in these activities. During these activities, individuals may get injured or be exposed to pathogens. There is also a strong possibility of experiencing mosquito, lice, or tick bites, bee stings, or being bitten by scorpions, snakes, rodents, wild or feral animals. This study reviewed the current literature regarding tick-borne infections encountered during recreational activities.Methods: PubMed and the Web of Science databases were searched for the keywords “campers,” “hikers,” and “tick borne infections.” Major reviews, research papers, and case series on campers and hikers were reviewed, and current articles for tick-borne infections were selected and summarized.Results: People who engage in recreational activities are potentially at risk for infection from environmental sources. A group of important vector-borne diseases is tick-borne infections, the major agents of which are Babesia spp., Borrelia spp., Rickettsia spp., Ehrlichia spp., Francisella tularensis, Coxiella burnetii, Crimen-Congo Hemorrhagic Fever (CCHF), and Tick-Borne Encephalitis (TBE) viruses. These infections have a widespread geographical distribution.Conclusion: Participating in outdoor recreational activities is increasing all over the world. While partaking in these activities, humans are frequently exposed to ticks and are potentially at risk for infection. To prevent infection, public and medical awareness is necessary