Tick Season Research Articles

Parasiticide use and obesity in dogs with sudden acquired retinal degeneration syndrome.

To investigate parasiticide use and describe signalment features in patients with sudden acquired retinal degeneration syndrome (SARDS). Retrospective case-control study of dogs with (n = 71) and without (136) SARDS. Parasiticide use, presentation season, weight, body condition, and signalment were compared between dogs diagnosed with SARDS and the reference population by use of descriptive statistics and logistic regression. Animals with SARDS were at a 5.99 times higher odds of having previously used imidacloprid (95% CI, 1.6 to 22.2; P = .003). However, time of last imidocloprid administration was > 6 years prior to diagnosis in 6 SARDS-affected individuals and 15, 26, or 42 months before diagnosis (n = 1 each). No other class of parasiticide had a significant association with SARDS. Seasonal variation was observed with a negative association identified between incidence of SARDS and tick season (October to January; P < .001). Overweight and obese dogs were 4.42 (95% CI, 1.9 to 10.4) and 4.96 (95% CI, 2.1 to 11.6) times more likely to have SARDS (P ≤ .001). History of polyphagia or weight gain was not associated with an increased likelihood of being overweight or obese within the SARDS-affected population (P > .108). While a statistically significant association was found between imidacloprid use and SARDS, this is unlikely to be clinically significant given the lack of a temporal association, sparse exposure numbers, and low point estimate of the OR. A positive association between being overweight or obese and a diagnosis of SARDS was found independent of polyphagia and weight gain, suggesting that it may be a risk factor for the development of SARDS.

The prevalence of pathogens in ticks collected from humans in Belgium, 2021, versus 2017

BackgroundTicks carry a variety of microorganisms, some of which are pathogenic to humans. The human risk of tick-borne diseases depends on, among others, the prevalence of pathogens in ticks biting humans. To follow-up on this prevalence over time, a Belgian study from 2017 was repeated in 2021.MethodsDuring the tick season 2021, citizens were invited to have ticks removed from their skin, send them and fill in a short questionnaire on an existing citizen science platform for the notification of tick bites (TekenNet). Ticks were morphologically identified to species and life stage level and screened using multiplex qPCR targeting, among others, Borrelia burgdorferi (sensu lato), Anaplasma phagocytophilum, Borrelia miyamotoi, Neoehrlichia mikurensis, Babesia spp., Rickettsia helvetica and tick-borne encephalitis virus (TBEV). The same methodology as in 2017 was used.ResultsIn 2021, the same tick species as in 2017 were identified in similar proportions; of 1094 ticks, 98.7% were Ixodes ricinus, 0.8% Ixodes hexagonus and 0.5% Dermacentor reticulatus. A total of 928 nymphs and adults could be screened for the presence of pathogens. Borrelia burgdorferi (s.l.) was detected in 9.9% (95% CI 8.2–12.0%), which is significantly lower than the prevalence of 13.9% (95% CI 12.2–15.7%) in 2017 (P = 0.004). The prevalences of A. phagocytophilum (4.7%; 95% CI 3.5–6.3%) and R. helvetica (13.3%; 95% CI 11.2–15.6%) in 2021 were significantly higher compared to 2017 (1.8%; 95% CI 1.3–2.7% and 6.8%; 95% CI 5.6–8.2% respectively) (P < 0.001 for both). For the other pathogens tested, no statistical differences compared to 2017 were found, with prevalences ranging between 1.5 and 2.9% in 2021. Rickettsia raoultii was again found in D. reticulatus ticks (n = 3/5 in 2021). Similar to 2017, no TBEV was detected in the ticks. Co-infections were found in 5.1% of ticks. When combining co-infection occurrence in 2017 and 2021, a positive correlation was observed between B. burgdorferi (s.l.) and N. mikurensis and B. burgdorferi (s.l.) and B. miyamotoi (P < 0.001 for both).ConclusionsAlthough the 2021 prevalences fell within expectations, differences were found compared to 2017. Further research to understand the explanations behind these differences is needed.Graphical

Risk factors for nonidiopathic and idiopathic facial nerve palsies: findings of a retrospective study

BackgroundIdiopathic (IF) and nonidiopathic facial (NIF) nerve palsies are the most common forms of peripheral facial nerve palsies. Various risk factors for IF palsies, such as weather, have been explored, but such associations are sparse for NIF palsies, and it remains unclear whether certain diagnostic procedures, such as contrast agent-enhanced cerebral magnetic resonance imaging (cMRI), are helpful in the differential diagnosis of NIF vs. IF.MethodsIn this retrospective, monocentric study over a five-year period, the medical reports of 343 patients with peripheral facial nerve palsy were analysed based on aetiology, sociodemographic factors, cardiovascular risk factors, consultation time, diagnostic procedures such as cMRI, and laboratory results. We also investigated whether weather conditions and German Google Trends data were associated with the occurrence of NIF. To assess the importance of doctors’ clinical opinions, the documented anamneses and clinical examination reports were presented and rated in a blinded fashion by five neurology residents to assess the likelihood of NIF.ResultsA total of 254 patients (74%) had IF, and 89 patients (26%) had NIF. The most common aetiology among the NIF patients was the varicella zoster virus (VZV, 45%). Among the factors analysed, efflorescence (odds ratio (OR) 17.3) and rater agreement (OR 5.3) had the highest associations with NIF. The day of consultation (Friday, OR 3.6) and the cMRI findings of contrast enhancement of the facial nerve (OR 2.3) were also risk factors associated with NIF. In contrast, the local weather, Google Trends data, and cardiovascular risk factors were not associated with NIF.ConclusionThe findings of this retrospective study highlight the importance of patient history and careful inspections to identify skin lesions for the differential diagnosis of acute facial nerve palsy. Special caution is advised for hospital physicians during the tick season, as a surge in NIF cases can lead to a concomitant increase in IF cases, making it challenging to choose adequate diagnostic methods.

An Overview of Tick-Borne Encephalitis Epidemiology in Endemic Regions of Continental Croatia, 2017-2023.

Tick-borne encephalitis (TBE) represents an important public health problem in Europe. We analyzed the epidemiology of TBE based on data from humans, animals, and Ixodes ricinus ticks in endemic regions of continental Croatia. In the period from 2017 to 2023, cerebrospinal fluid (CSF) and serum samples of 684 patients with neuroinvasive diseases, 2240 horse serum samples, and 300 sheep serum samples were tested for TBEV. In addition, 8751 I. ricinus ticks were collected. CSF samples were tested using RT-PCR. Serological tests (serum, CSF) were performed using commercial ELISA, with confirmation of cross-reactive samples by a virus neutralization test. Eighty-four autochthonous human TBEV cases were confirmed. The majority of patients were in the age group of 40-69 years (58.3%) with a male predominance (70.2%). TBE showed a bimodal seasonality with a large peak in April-August and a small one in October-November. In addition to humans, TBEV IgG antibodies were found in 12.2% of horses and 9.7% of sheep. Seasonal tick abundance corresponds to the reported number of human infections. Continental Croatia is still an active natural focus of TBE. Continuous monitoring of infections in humans, sentinel animals, and ticks is needed for the implementation of preventive measures.

Tick Season

Tick Season

Molecular identification of cattle ticks in the Greater Accra Region of Ghana: a high occurrence of Rhipicephalus microplus.

Ticks are competent vectors of a wide range of pathogens. They are of veterinary and public health importance as they affect both animal and human health. Transhumance and the transboundary movements of cattle within the West African Sub-region have facilitated the spread of ticks which threatens the introduction of invasive species. Currently, Rhipicephalus microplus have been identified in the Upper East Region of Ghana which could mean a wider distribution of the species across the country due to livestock trade. This study focused on three sites in the Greater Accra Region, which serves as the gateway to receiving most of the cattle transported from the northern regions of Ghana. Ticks were sampled from August 2022 in the wet season to January 2023 in the dry season. Three tick genera were identified: Amblyomma (19.5%), Hyalomma (1.1%), and Rhipicephalus (79.3%) from the 1,489 feeding ticks collected from cattle. Furthermore, Rhipicephalus microplus, Hyalomma rufipes and Amblyomma variegatum were identified molecularly using primers that target the mitochondrial COI gene. There was a significant association between the tick species and seasons (p < 0.001). Finding R. microplus in this study indicates the extent of the spread of this invasive tick species in Ghana and highlights the need for efficient surveillance systems and control measures within the country.

Outdoor recreation, tick borne encephalitis incidence and seasonality in Finland, Norway and Sweden during the COVID-19 pandemic (2020/2021)

ABSTRACTDuring the pandemic outdoor activities were encouraged to mitigate transmission risk while providing safe spaces for social interactions. Human behaviour, which may favour or disfavour, contact rates between questing ticks and humans, is a key factor impacting tick-borne encephalitis (TBE) incidence.We analyzed annual and weekly TBE cases in Finland, Norway and Sweden from 2010 to 2021 to assess trend, seasonality, and discuss changes in human tick exposure imposed by COVID-19. We compared the pre-pandemic incidence (2010–2019) with the pandemic incidence (2020–2021) by fitting a generalized linear model (GLM) to incidence data.Pre-pandemic incidence was 1.0, 0.29 and 2.8 for Finland, Norway and Sweden, respectively, compared to incidence of 2.2, 1.0 and 3.9 during the pandemic years. However, there was an increasing trend for all countries across the whole study period. Therefore, we predicted the number of cases in 2020/2021 based on a model fitted to the annual cases in 2010–2019. The incidences during the pandemic were 1.3 times higher for Finland, 1.7 times higher for Norway and no difference for Sweden. When social restrictions were enforced to curb the spread of SARS-CoV-2 there were profound changes in outdoor recreational behavior. Future consideration of public health interventions that promote outdoor activities may increase exposure to vector-borne diseases.

Field efficacy of fluralaner (Bravecto® chewable tablets) for preventing Babesia canis infection transmitted by Dermacentor reticulatus ticks to dogs

BackgroundThe isoxazoline fluralaner is effective for prevention of Babesia canis transmission from infected Dermacentor reticulatus ticks to dogs for 84 days in a controlled environment. This study was designed to evaluate the effectiveness of fluralaner chewable tablets for sustained prevention of B. canis infection of dogs in endemic areas under natural conditions.MethodsIn Europe, privately owned, clinically healthy pet dogs were enrolled and randomized either to receive fluralaner at 25–56 mg/kg (Bravecto® chewable tablets) on days 0 and 84, or to remain untreated during the D. reticulatus season. Blood samples were collected to evaluate B. canis exposure: on days 0 and 21 (exposure before day 0), during the study and at the end of the tick season (dogs suspected of having become infected after day 0). Efficacy was determined by the percentage reduction in B. canis transmission risk based on the difference in B. canis-positive tests in fluralaner-treated dogs compared with untreated dogs. In addition, ticks collected at monthly intervals throughout the study were identified to species level and females tested for B. canis DNA.ResultsA total of 152 dogs were enrolled in the study, although nine dogs were excluded because they tested positive for B. canis DNA or antibodies within 21 days after enrollment. During the study period, no fluralaner-treated dog became positive for B. canis, resulting in calculated efficacy of 100%. However, babesiosis infection was diagnosed in five untreated control dogs (Fisher’s exact test, left-sided, P = 0.0312). Tick analyses revealed that one sample collected in Hungary was infected with B. canis.ConclusionOral administration of Bravecto chewable tablets at the recommended dosage to dogs completely prevented B. canis transmission under field conditions in an endemic area for 12 weeks.Graphical

Cattle co-infection patterns by hemopathogens and their phylogenetic analysis during the tick season in Constantine and Mila, Northeast Algeria.

Tropical theileriosis, babesiosis, and anaplasmosis are the most dominant tick-borne infections in North Africa where they cause significant economic losses in ruminants' industry. The aim of the present work was to study infections and co-infection patterns in 66 cattle with clinical signs of piroplasmosis and/or anaplasmosis in two localities, Beni Hamidene and Grarem Gouga, districts of Constantine and Mila (Northeast of Algeria), respectively. This study was conducted between early May and late September during four years 2017, 2018, 2020, and 2021. PCR showed that the most frequent pathogen in cattle with clinical signs of piroplasmosis and/or anaplasmosis was Theileria annulata (66/66; 100%) followed by Babesia bovis (21/66; 31.8%), Anaplasma marginale (15/66; 22.7%), and Babesia bigemina (3/66; 4.5%) (p < 0.001). Giemsa-stained blood smears examinations revealed that 66.7% (44/66); 10.6% (7/66); and 9.1% (6/66) of cattle were infected by T. annulata, Babesia spp., and A. marginale, respectively (p < 0.001). PCR revealed seven co-infection patterns: T. annulata/A. marginale (15/66; 22.7%), T. annulata/B. bovis (21/66; 31.8%), T. annulata/B. bigemina (3/66; 4.5%), T. annulata/A. marginale/B. bovis (7/66; 10.6%), T. annulata/B. bovis/B. bigemina (2/66; 3%), T. annulata/A. marginale/B. bigemina (1/66; 1.5%), and T. annulata/A. marginale/B. bigemina/B. bovis (1/66; 1.5%). Phylogenetic analyses showed that T. annulata Tams1 and B. bigemina gp45 sequences were identical to isolates from Mauritania and South Africa, respectively. The three A. marginale amplicons obtained herein had 99.63 to 99.88% similarity between them. This study provides data that can be used to improve control programs targeting these cattle hemopathogens.

Movement ecology of exotic nilgai antelope: A threat to the re‐emergence of cattle fever ticks in the southern USA

AbstractWildlife plays an important role in the emergence of livestock diseases, and their movements can complicate disease management efforts. One of the most significant vector‐borne diseases of livestock worldwide is bovine babesiosis, spread by cattle fever ticks (CFTs; Rhipicephalus [=Boophilus] microplus and Rhipicephalus [=Boophilus] annulatus). Although CFTs were eradicated from the United States by 1943, bovine babesiosis and CFTs are prevalent in México. Recently, management of CFTs in the Texas–México region has been complicated by the presence of free‐ranging, exotic nilgai antelope (Boselaphus tragocamelus). Nilgai are abundant in this region and are competent hosts for CFTs. The goal of this study was to better understand nilgai movements and space use to inform CFT treatment strategies. We analyzed hourly locations from 40 GPS‐collared nilgai in Cameron County, TX, USA, from April 2019 to September 2020. We assigned each nilgai a movement behavior using the net squared displacement metric. We estimated nilgai home range sizes at different temporal scales (monthly, seasonally, and overall) using Brownian bridge movement models. We observed movement patterns consistent with residency (52.5%), seasonal movers (17.5%), dispersal (5%), and unclassified (25%). Resident nilgai had an average maximum axial distance of 7.8 km, while two young females made separate dispersal movements of about 40 km within a year. Overall, nilgai had large and highly variable home ranges: annual median home range estimate for females was 563 ha (range = 105–1545 ha), and for males, it was 937 ha (range = 221–1602 ha). Peak nilgai movements occurred during crepuscular hours, and median hourly movement for females was 57 m/h, and for males, it was 66 m/h. Nilgai home ranges and long‐distance movements have the potential to overlap multiple ranches, as the typical ranch size in South Texas ranges from 250 to 6000 ha. Resident nilgai were more likely to maintain local infestations of CFT. Dispersal events took place during peak tick season, demonstrating the potential for nilgai to aid in the spread of CFT. Understanding these behaviors will help the CFT Eradication Program develop more efficacious treatment strategies to treat infestations in nilgai.

Molecular epidemiology of Theileria species in ticks and its potential threat to livestock in the Republic of Korea

The purpose of this study was to investigate molecular epidemiology of Theileria spp. in ticks in Korea and assess their potential threat from wildlife animals to domestic animals. A total of 21152 hard ticks were collected from Chungcheong and Jeolla provinces of Korea from March to October 2021. Tick species were identified by microscopy and Theileria spp. were screened by nested PCR targeting 18S rRNA. Haemaphysalis spp. were the most abundant tick species, followed by H. longicornis, H. flava, Amblyomma testudinarium, and Ixodes nipponensis. Of the collected ticks, 6914 ticks (541 pools) were screened, and PCR showed 211 positive pools (39.0%; MIR: 3.05). The PCR and phylogenetic analysis identified two Theileria species, T. luwenshuni and Theileria sp., with T. luwenshuni (162/211, 76.78%; MIR: 2.34) being more abundant than Theileria sp. (36/211, 17.06%; MIR: 0.52); co-infection of the two species were noted (13/211, 6.16%; MIR: 0.19). Among the tick species, H. longicornis, especially nymphs, showed the highest prevalence. Regarding season, the highest prevalence was observed in May. Considering the tick and Theileria species identified in this study, H. longicornis nymph and cervine play a critical role in maintaining Theileria spp. in Korea and could be a potential threat to domestic animals, including deer and goats. In addition, there are significant correlations among tick distribution, region, season, and prevalence of Theileria.

Assessing the spatial and temporal patterns and risk factors for acquisition of Ixodes spp. by companion animals across Canada

Climatic and land use changes have contributed to substantial changes in the abundance, distribution, and activity patterns of ticks in Canada, which have led to an increased risk of tick bites and tick-borne pathogen exposure for companion animals. The objectives of this study were to describe current spatial and temporal patterns of Ixodes spp. on companion animals in Canada and explore the association between tick bites and dog and cat demographic factors. Ticks were collected for one year (April 2019 – March 2020) from 94 veterinary clinics. Included with each submission was a short questionnaire containing owner-reported information on travel history, date of removal and suspected location of tick acquisition, and animal-specific demographic factors. Ticks were identified morphologically using a stereomicroscope, standard keys, and through PCR analyses. Mixed effect multivariable logistic regression models were built to explore the association between an Ixodes scapularis bite and animal demographic factors; veterinary clinic was included as a random effect. Approximately 2300 submissions were received from clinics across Canada, totalling 4425 ticks. The most common Ixodes spp. was I. scapularis (n = 2168), followed by Ixodes pacificus (n = 172) and Ixodes cookei (n = 155). Ixodes scapularis were well distributed in regions across central and eastern Canada. Ixodes cookei was found in eastern Canada, with the greatest numbers from Quebec and New Brunswick. Ixodes pacificus submissions were restricted to British Columbia. Across eastern Canada, dogs of the herding, mixed breed (large and small), sporting, working, terrier, and toy breed groups, and spayed cats were all found to have higher odds of acquiring I. scapularis, compared to other tick species. For the dog model, significant interactions were found between predictor variables age and sex. Regional information on tick distribution, seasonality, and risk factors for acquisition contribute to evidence-based veterinary practices for tick and tick-borne disease control in Canada.

Mapping and monitoring tick (Acari, Ixodida) distribution, seasonality, and host associations in the United Kingdom between 2017 and 2020.

Tick-borne disease risk is intrinsically linked to the distribution of tick vector species. To assess risk and anticipate disease emergence, an understanding of tick distribution, host associations, and seasonality is needed. This can be achieved, to some extent, using passive surveillance supported by engagement with the public, animal health, and public health experts. The Tick Surveillance Scheme (TSS) collects data and maps tick distribution across the United Kingdom (UK). Between 2017 and 2020, 3720 tick records were received and 39 tick species were detected. Most records were acquired in the UK, with a subset associated with recent overseas travel. The dominant UK acquired species was Ixodes ricinus (Ixodida: Ixodidae, Linnaeus), the main vector of Lyme borreliosis. Records peaked during May and June, highlighting a key risk period for tick bites. Other key UK species were detected, including Dermacentor reticulatus (Ixodida: Ixodidae, Fabricius) and Haemaphysalis punctata (Ixodida: Ixodidae, Canestrini & Fanzago) as well as several rarer species that may present novel tick-borne disease risk to humans and other animals. Updated tick distribution maps highlight areas in the UK where tick exposure has occurred. There is evidence of increasing human tick exposure over time, including during the COVID-19 pandemic, but seasonal patterns remain unchanged.

Movement of Ixodes pacificus and Dermacentor occidentalis (Acari: Ixodidae) adult ticks in chaparral under natural conditions in Northern California, U.S.A.

The movement of Ixodes pacificus and Dermacentor occidentalis adult ticks down a hill slope under natural conditions was investigated using the mark-release-recapture (MRR) method. We evaluated the movement of host-seeking adult ticks down a hill slope to determine if ticks travel downhill from an uphill area to trail margins below. During the tick seasons in 2016-2018, the ticks were collected by flagging, marked with paint, released at a predetermined location, and recaptured by weekly flagging. Of the 188 female and 114 male I. pacificus marked and released 30 m above the trail in 2016, 11 (5.8%) females and one (0.9%) male were recaptured at the trail. In 2017, of the 71 female and 52 male I. pacificus, none were recaptured. In 2018, nine (3.6%) female and one (0.4%) male I. pacificus were recaptured of the 247 female and 287 males marked and released. Fifteen (18.5%) female and six (7.3%) male D. occidentalis were recaptured of the 81 females and 82 males marked and released in 2017. The trail deterred further movement with only 0.6% of I. pacificus and 8.3% of D. occidentalis recaptured on the opposite side of the trail. This study demonstrated that some I. pacificus and D. occidentalis adults found along the uphill side of trails may have originated from an area 30 m from the trail margin, some travelling at a rate of 1.6-1.9 m/day under natural conditions in chaparral.

“Leopards do not change their spots:” tick borne disease symptomology case report

BackgroundHuman Monocytic Ehrlichiosis is caused by infection with the bacteria Ehrlichia chaffeensis through the bite of an infected lone star tick (Amblyomma americanum). Patients infected with Human Monocytic Ehrlichiosis often present with symptoms including fever, headache, myalgia, and occasionally a macular rash. The presence of other endemic tick-borne diseases with similar symptoms, such as Rocky Mountain Spotted Fever, complicate the diagnosis of Human Monocytic Ehrlichiosis.Case presentationA patient developed a fever, diffuse myalgia, headache, and a non-productive cough 5 days after a fishing trip in late May in central North Carolina. Over the course of the illness the patient’s symptoms worsened, with arthralgia, bilateral lower extremity erythema and edema, and a developing bilateral rash on the palms. With testing that revealed elevated liver enzymes, a potential for recent tick exposure (e.g., fishing trip), presentation during tick season, and the development of a rash, Rocky Mountain Spotted Fever and Human Monocytic Ehrlichiosis were considered. The patient was prescribed a seven-day course of oral doxycycline and cefalexin, which would provide coverage from Rickettsia, Ehrlichia and gram-positive bacteria typically responsible for cellulitis. Many of the patient’s symptoms resolved or improved, although the right shoulder remained painful to active movement. The patient was prescribed another seven-day course of doxycycline due to his perceived incomplete response to the first course. Approximately 5 weeks after symptom onset (D0 + 36), the patient followed up with a provider for convalescent testing and counseling. Convalescent Ehrlichia and Rickettsia serological tests were ordered. The acute Ehrlichia serology and acute Rickettsia serology were originally non-reactive with both titers measured at < 1:64. Convalescent serology, ordered 28 days after the acute sample collection, showed a greater than four-fold increase in the Ehrlichia IgG titer (1:256), satisfying clinical and laboratory case definitions for ehrlichiosis. In follow-up, 3 weeks later (D0 + 57), the patient reported that most of his pain had subsided, though he still occasionally got shooting nerve pain when exercising.ConclusionThis case of Human Monocytic Ehrlichiosis in North Carolina exemplifies the need for a knowledge of spatial epidemiological patterns and clinical manifestations in the diagnosis of tick-borne diseases.

The impact of climatic factors on tick-related hospital visits and borreliosis incidence rates in European Russia.

Tick-borne diseases are among the challenges associated with warming climate. Many studies predict, and already note, expansion of ticks’ habitats to the north, bringing previously non-endemic diseases, such as borreliosis and encephalitis, to the new areas. In addition, higher temperatures accelerate phases of ticks’ development in areas where ticks have established populations. Earlier works have shown that meteorological parameters, such as temperature and humidity influence ticks’ survival and define their areas of habitat. Here, we study the link between climatic parameters and tick-related hospital visits as well as borreliosis incidence rates focusing on European Russia. We have used yearly incidence rates of borreliosis spanning a period of 20 years (1997-2016) and weekly tick-related hospital visits spanning two years (2018-2019). We identify regions in Russia characterized by similar dynamics of incidence rates and dominating tick species. For each cluster, we find a set of climatic parameters that are significantly correlated with the incidence rates, though a linear regression approach using exclusively climatic parameters to incidence prediction was less than 50% effective. On a weekly timescale, we find correlations of different climatic parameters with hospital visits. Finally, we trained two long short-term memory neural network models to project the tick-related hospital visits until the end of the century, under the RCP8.5 climate scenario, and present our findings in the evolution of the tick season length for different regions in Russia. Our results show that the regions with an expected increase in both tick season length and borreliosis incidence rates are located in the southern forested areas of European Russia. Oppositely, our projections suggest no prolongation of the tick season length in the northern areas with already established tick population.

Monitoring Trends in Distribution and Seasonality of Medically Important Ticks in North America Using Online Crowdsourced Records from iNaturalist.

Simple SummaryAn increasing number of cases of tick-borne diseases are being reported across North America and in new areas. This has been linked to the spread of ticks, primarily the blacklegged tick Ixodes scapularis and the lone star tick Amblyomma americanum, into new geographical regions. Tick surveillance systems have played an important role in monitoring the changing distributions of these ticks and have benefitted greatly from including data collected by members of the public through citizen or community science projects. Enlisting the help of community scientists is an economical way to collect large amounts of data over a wide geographical area, and participants can also benefit by receiving information relevant to their tick encounter, for example regarding tick-borne disease symptoms. This study examined tick observations from the online image-based biological recording platform iNaturalist to evaluate its use as an extra tool to collect information on expanding tick distributions. The distribution and seasonality of iNaturalist tick observations were found to accurately represent those of the studied species and identified potential new areas of tick expansion. Free-to-access iNaturalist data is a highly cost-effective method to support existing tick surveillance strategies to aid preparedness and response in emerging areas of tick establishment.Recent increases in the incidence and geographic range of tick-borne diseases in North America are linked to the range expansion of medically important tick species, including Ixodes scapularis, Amblyomma americanum, and Amblyomma maculatum. Passive tick surveillance programs have been highly successful in collecting information on tick distribution, seasonality, host-biting activity, and pathogen infection prevalence. These have demonstrated the power of citizen or community science participation to collect country-wide, epidemiologically relevant data in a resource-efficient manner. This study examined tick observations from the online image-based biological recording platform iNaturalist to evaluate its use as an effective tool for monitoring the distributions of A. americanum, A. maculatum, I. scapularis, and Dermacentor in the United States and Canada. The distribution and seasonality of iNaturalist tick observations were found to accurately represent those of the studied species. County-level iNaturalist tick occurrence data showed good agreement with other data sources in documented areas of I. scapularis and A. americanum establishment, and highlighted numerous previously unreported counties with iNaturalist observations of these species. This study supports the use of iNaturalist data as a highly cost-effective passive tick surveillance method that can complement existing surveillance strategies to update tick distributions and identify new areas of tick establishment.

Management of Pediatric Lyme Disease: Updates From 2020 Lyme Guidelines.

Management of Pediatric Lyme Disease: Updates From 2020 Lyme Guidelines.

Rickettsiosis subcommittee report to the tick-borne disease working group

Tick-borne rickettsial infections are serious, common, and difficult to diagnose. Among the most important factors leading to failure to diagnose and treat tick-borne rickettsioses effectively is a lack of consideration of the potential diagnosis by primary caregivers and emergency department physicians in patients presenting with undifferentiated acute febrile illness during tick season. This situation exists because of insufficient primary and continuing medical education of medical students, primary care and emergency medicine residents, and practicing physicians regarding tick-borne rickettsioses specific to the region where they practice. Delayed initiation of treatment with an appropriate antibiotic is associated with adverse outcomes including increased rates of hospitalization, admission to an intensive care unit, and mortality. The earliest symptoms are nonspecific, consisting of fever, headache, myalgias, and nausea and/or vomiting. Laboratory abnormalities are typically absent at this time when the therapeutic response to an appropriate antibiotic would be optimal. There is a mistaken idea among a substantial portion of physicians that the best antibiotic available, doxycycline, should not be administered to children 8 years of age or younger or during pregnancy. For all of the above reasons, there is unnecessary morbidity and mortality caused by tick-borne rickettsioses. This report proposes measures to address these critical issues regarding tick-borne rickettsioses.

Merozoites of Theileria orientalis buffeli reduce the parasitaemia of T. orientalis ikeda following tick challenge

Theileria orientalis is a tick-borne protozoal parasite causing anaemia and death in susceptible cattle. This investigation aimed to confirm whether immunisation with the “benign” buffeli genotype of T. orientalis could reduce the parasitaemia of the virulent ikeda genotype. Calves were inoculated intravenously or subcutaneously with bovine blood containing merozoites of T. orientalis buffeli and when recipients became positive by PCR, they and control calves were challenged with unfed nymphs of Haemaphysalis longicornis ticks infected as larvae with T. orientalis ikeda. All calves became positive for the challenge within 12 days after tick application. In the immunised calves, the first wave of parasitaemia with T. orientalis ikeda from 4 to 6 weeks was reduced significantly by >80 % before the parasite burden declined into the carrier state by 9 weeks. The parasitaemias in two calves which exhibited low infections with T. orientalis ikeda shortly after arrival, were also significantly reduced after tick challenge. The results confirm the previous studies on immunity to T. sergenti in Japan, and field experience with theileriosis in endemic zones where the carrier state appears to prevent clinical disease despite repeated, seasonal tick infestations with virulent genotypes of the parasite. This method offers a means to reduce the severity of the first wave of theilerial parasitaemia after tick challenge and possibly recover associated production losses.