Comparative ecological analysis and predictive modeling of tick-borne pathogens.

Tick-borne diseases constitute the predominant vector-borne health threat in North America. Recent observations have noted a significant expansion in the range of the black-legged tick (Ixodes scapularis Say, Acari: Ixodidae), alongside a rise in the incidence of diseases caused by its transmitted pathogens: Borrelia burgdorferi Johnson (Spirochaetales: Spirochaetaceae), Babesia microti Starcovici (Piroplasmida: Babesiidae), and Anaplasma phagocytophilium Zhu (Rickettsiales: Anaplasmataceae), the causative agents of Lyme disease, babesiosis, and anaplasmosis, respectively. Prior research identified environmental features that influence the ecological dynamics of I. scapularis and B. burgdorferi that can be used to predict the distribution and abundance of these organisms, and thus Lyme disease risk. In contrast, there is a paucity of research into the environmental determinants of B. microti and A. phagocytophilium. Here, we use over a decade of surveillance data to model the impact of environmental features on the infection prevalence of these increasingly common human pathogens in ticks across New York State (NYS). Our findings reveal a consistent northward and westward expansion of B. microti in NYS from 2009 to 2019, while the range of A. phagocytophilum varied at fine spatial scales. We constructed biogeographic models using data from over 650 site-year visits and encompassing more than 250 environmental variables to accurately forecast infection prevalence for each pathogen to a future year that was not included in model training. Several environmental features were identified to have divergent effects on the pathogens, revealing potential ecological differences governing their distribution and abundance. These validated biogeographic models have applicability for disease prevention efforts.

Evidence of Human Bourbon Virus Infections, North Carolina, USA.

Bourbon virus is a tickborne virus that can cause human disease. Cases have been reported in Kansas, Oklahoma, and Missouri, USA. We identified Bourbon virus-specific neutralizing antibodies in patients from North Carolina. Bourbon virus infections are likely more common than previously thought, highlighting the need for improved diagnostics and surveillance.

Exploring midgut expression dynamics: longitudinal transcriptomic analysis of adult female Amblyomma americanum midgut and comparative insights with other hard tick species.

Background: Female ticks remain attached to their host for multiple days to complete a blood meal. This prolonged feeding period is accompanied by a significant increase in the tick's size and body weight, paralleled by noteworthy changes to the tick midgut. While the midgut is recognized for its established role in blood storage and processing, its importance extends to playing a crucial role in the acquisition, survival, and proliferation of pathogens. Despite this, our overall understanding of tick midgut biology is limited. Results: We conducted a comprehensive longitudinal transcriptome analysis of the midgut in adult female A. americanum ticks across various feeding stages, including unfed, slow-feeding, and rapid-feeding phases. Our analysis revealed 15,599 putative DNA coding sequences (CDS) classified within 26 functional groups. Dimensional and differential expression analysis highlighted the dynamic transcriptional changes in the tick midgut as feeding progresses, particularly during the initial period of feeding and the transition from the slow-feeding to the rapid-feeding phase. Additionally, we performed an orthology analysis comparing our dataset with midgut transcriptomes from other hard ticks, such as Ixodes scapularis and Rhipicephalus microplus. This comparison allowed us to identify transcripts commonly expressed during different feeding phases across these three species. Conclusion: Our findings provide a detailed temporal resolution of numerous metabolic pathways in A. americanum, emphasizing the dynamic transcriptional changes occurring in the tick midgut throughout the feeding process. Furthermore, we identified conserved transcripts across three different tick species that exhibit similar expression patterns. This knowledge has significant implications for future research aimed at deciphering the physiological pathways relevant within the tick midgut. It also offers potential avenues for developing control methods that target multiple tick species.

Anaplasma platys and Rickettsia massiliae in Rhipicephalus sanguineus sensu stricto ticks collected on dogs in the Patagonian region of Argentina.

The aim of this study was to examine the presence of tick-borne rickettsial bacteria in Rhipicephalus sanguineus sensu stricto ticks collected from dogs in the Patagonian region of Argentina. Fourteen stray dogs from Valcheta, Río Negro province, Argentina were examined for the presence of R. sanguineus s.s. ticks. Ninety ticks were collected and identified to species level. DNA was extracted and analysed by conventional PCR assays for the presence of tick-borne bacteria belonging to the genera Anaplasma, Ehrlichia and Rickettsia. Thirty-three tick pools were tested by different PCR assays of which 3 were positive for Anaplasmataceae bacteria. From the 3 Anaplasmataceae positive samples, 2 partial 16S rDNA sequences were generated and belonging to Anaplasma platys, the causative agent of canine cyclic thrombocytopenia. Two tick samples were positive in Rickettsia specific PCR assays and were identified by phylogenetic analysis as Rickettsia massiliae, a member of the spotted fever group rickettsiae. The results of this study demonstrate the molecular detection of 2 rickettsial bacteria in R. sanguineus s.s. in a region of Argentina where no data were available so far.

First molecular diagnosis of the human pathogen Rickettsia raoultii and other spotted fever group rickettsiae in Sudanese ixodid ticks from domestic ruminants.

BACKGROUND: Rickettsial infections are often neglected and poorly recognized by physicians in many tropical and subtropical regions. Despite a number of recent reports describing rickettsial diseases in new locations and the discovery of new rickettsiae, medical science and research have largely neglected the diagnosis and antimicrobial treatment of rickettsial infections in subtropical and tropical areas; thus, much remains to be discovered. This study aimed to detect and characterize spotted fever group (SFG) rickettsiae in ixodid ticks infesting domestic ruminants in Khartoum State. METHODS: Polymerase chain reaction targeting both genes that encode for citrate synthase (gltA) and outer membrane protein (ompA) was performed for the presence of SFG rickettsia followed by sequence and phylogenetic analysis. RESULTS: Of the 202 ticks examined for the presence of SFG rickettsia, gltA gene was detected in 4 samples (2%). Furthermore, gltA-positive samples were used to amplify the ompA gene, in which only two samples yielded positive results. Sequence and phylogenetic analysis of the positive samples revealed four different species of SFG rickettsiae: Rickettsia aeschlimannii, Rickettsia rhipicephali, Rickettsia massiliae and Rickettsia raoultii. CONCLUSIONS: These results indicated the presence of SFG rickettsia in Sudanese ticks. This also indicates that humans have an opportunity to acquire these infections. It is important to keep in mind the need for careful consideration of rickettsial infections in individuals with a fever of unknown origin.

Unveiling Misconceptions among Small-Scale Farmers Regarding Ticks and Tick-Borne Diseases in Balochistan, Pakistan.

Ticks and tick-borne diseases (TBDs) pose potential health threats to small-scale farmers of grazing animals in the upper highlands of Balochistan, Pakistan. This study was conducted based on a questionnaire survey involving 153 farmers of grazing animals in seven districts to access their knowledge, attitudes, and practices regarding ticks and TBDs. Odds ratios and 95% confidence intervals, based on Fisher's test, were used to assess risk factors for determining preventive measures. The findings revealed a low level of knowledge among the participants. For instance, there was a lack of awareness of the effects of climate change and the economic impact of ticks on animal health. The essential precautions, such as the non-indiscriminate use of acaricides, wearing dark-colored clothing, and limiting children's interaction with grazing animals, were often overlooked. However, the farmers had a positive attitude towards tick control, but they mostly relied on the knowledge of local communities. The neglect of such measures places these farmers and their children at risk of contracting TBDs. This study also indicates minimal involvement from the government in educating farmers and controlling ticks. The role of stakeholders, including the government, non-governmental organizations, veterinary doctors, and local farmer communities, is crucial to address these issues and to implement effective training programs that address misconceptions about ticks and TBDs. Overall, this study highlights the importance of implementing awareness and education programs to address the misconceptions about ticks and TBDs among farmers.

Associations between Ornithodoros spp. Ticks and Mojave Desert Tortoises (Gopherus agassizii) Obtained from Health Assessment Documents.

Soft ticks in the genus Ornithodoros occur throughout the Mojave Desert in southern Nevada, southeastern California, and parts of southwestern Utah and northwestern Arizona, USA, and are frequently observed parasitizing Mojave desert tortoises (Gopherus agassizii). However, limited research exists examining the relationship between ticks and desert tortoises. Mojave desert tortoises are listed as threatened by the US Fish and Wildlife Service, and as such, their populations are monitored and individual tortoise health is routinely assessed. These health assessments document the presence and abundance of ticks present on tortoises, but detailed examination of the relationship between ticks and tortoise health has been lacking. This study analyzed the relationship between tick presence and desert tortoise health assessments as a function of season, location, age (adult vs. juvenile), foraging behavior, evidence of clinical signs of disease, body condition score, and sex. Our results indicate that more ticks were found on tortoises in the summer than in any other season. Ticks were observed more frequently on captive tortoises versus wild tortoises, and more ticks were likely to be present on adult tortoises than on juveniles. Ticks were also more likely to be observed on tortoises that lacked evidence of foraging and on tortoises with observed clinical signs of disease. These findings provide valuable insights into the biology of ticks in relation to tortoises that may be useful for management of both captive and free-living threatened tortoise populations where ticks are detected. Our study also may improve understanding of potential tick-borne disease dynamics in the Mojave desert tortoise habitat, including Borrelia sp. carried by Ornithodoros ticks, which cause tick-borne relapsing fever in people.

Molecular detection of lumpy skin disease virus in naturally infected cattle and buffaloes: unveiling the role of tick vectors in disease spread.

Lumpy skin disease (LSD) is a viral disease that affects cattle and buffaloes in Egypt, causing considerable economic losses in the animal sector. This study aimed to investigate the recent outbreak of LSDV in cattle and buffaloes and evaluate the potential role of the hard tick Rhipicephalus annulatus in their transmission through isolation and molecular characterization by multiplex PCR (mPCR) and real-time quantitative PCR (rt-qPCR) assays. A total of 50 skin biopsies (cattle n = 30, buffaloes n = 20), 110 nasal swabs (cattle n = 76, buffaloes n = 44), and 129 blood samples (cattle n = 84, buffaloes n = 45) were collected. In addition, 145 hard ticks of different stages were collected from cattle and buffaloes of different breeds and ages in different governorates in Egypt from November 2021 to June 2022. Multiplex PCR and real-time quantitative PCR (rt-qPCR) assays based on SYBR Green and targets (P32, VP32, G protein, and viral fusion protein) were used. We identified positive results in 17 out of 30 cattle skin biopsies (56.6%), 1 out of 7 buffalo skin scabs (14.3%), and 5 out of 45 buffalo blood samples (11.11%) using mPCR and RT-qPCR methods. We successfully isolated LSDV from hard ticks and cattle infested with ticks and exhibited characteristic signs of LSD on the chorioallantois membrane (CAM) of specific pathogen-free embryonated chicken eggs (SPF-ECE). The isolates were confirmed by multiplex PCR and RT-qPCR. The cyclic threshold (Ct) with correlation-slandered curve values of rt-qPCR ranging from 10.2 to 36.5 showed the amount of LSDV-DNA in different samples. The study's findings demonstrated the widespread circulation of LSDV in both cattle and buffaloes in Egypt and provided strong evidence that hard ticks R. annulatus play a role in the transmission of LSDV in susceptible animals.

Short Communication: Anaplasma phagocytophilum and Babesia spp. in ixodid ticks infesting red foxes (Vulpes vulpes) in Great Britain.

Red foxes (Vulpes vulpes) are found throughout the United Kingdom (UK), and can reach high population densities in urban areas. They are often infested with ticks which may carry tick-borne pathogens, leading to a risk of transmission to domestic animals and humans. This study investigated the prevalence of tick-borne pathogens in ticks sourced from red fox carcasses across Great Britain between 2018 and 2022. Tick species were identified using morphological keys and molecular barcoding, followed by specific pathogen testing using PCR. In total, 227 ticks were collected from 93 foxes. Pooling (n = 2) was undertaken for unengorged nymphs from the same tick species and fox host, with 203 homogenates tested in total (24 pools and 179 individual ticks). Ixodes hexagonus was the most abundant tick species sampled (73 %), of which 59 % were nymphs and 41 % were females. Less common were Ixodes ricinus (12 %) and Ixodes canisuga (15 %), the majority of which were females (73 % and 91 %, respectively). One Ixodes sp. larva was identified. Babesia DNA was identified in seven individual ticks and once in pooled ticks (n = 2); seven detections were in I. hexagonus and one in I. canisuga, with an overall detection rate of 7 % (95 % CI: 6 - 8 %). Sequence analysis confirmed that all Babesia detections in I. hexagonus were Babesia vulpes, with detection of Babesia Badger Type A in I. canisuga. Screening for Anaplasma phagocytophilum DNA through amplification of the msp2 gene yielded an overall detection rate of 4 % (detected in I. hexagonus only). Louping ill virus was not detected by qRT-PCR in any tick RNA tested. The majority of pathogen detections were in ticks from red foxes in rural areas of the UK, although a small number of Babesia detections were in ticks collected from semi-rural or urban red foxes. Additionally, B. vulpes was detected in GB red fox tissues, suggesting a potential role as a reservoir host. This study confirms the detection of tick-borne pathogens in ticks infesting UK red foxes and highlights the involvement of GB tick species in animal or human disease transmission.

Giant Erythema in a Child with Lyme Disease.

Herein we report a case of Lyme borreliosis in a pediatric patient, highlighting the diagnostic challenges associated with this condition. An 11-year-old girl was admitted with high fever, headaches, abdominal pain, and a progressing rash. Initial symptoms included small rashes that vanished with antihistamine treatment, but maculopapular rashes later emerged on the trunk and limbs, prompting further investigation. Differential diagnosis included toxic erythema, Stevens-Johnson syndrome, and Lyme borreliosis. Despite no reported tick bite and initial doubt due to the season, Lyme borreliosis was confirmed by serologic testing, diagnosing the patient with early disseminated Lyme disease. The diagnostic complexity was increased by the rash's atypical presentation - large, homogeneous papular rashes. This case emphasizes the necessity for physicians to adeptly gather detailed histories and employ thorough, up-to-date diagnostic methods. Effective correlation of clinical findings with laboratory results and ongoing patient observation proved critical for an accurate diagnosis. This report underscores the importance of recognizing atypical presentations of Lyme borreliosis in children and the need for careful differential diagnosis.

We report the case of a 11-year-old girl diagnosed with Lyme disease, caused by tick bites that are often painless and hard to detect. This makes diagnosis challenging, especially in children. Her illness began with a small rash that disappeared with treatment. Over a few days, she developed a high fever, headaches, abdominal pain, and extensive rashes on her body. Initially, we considered other conditions like toxic erythema. However, new rashes kept appearing, prompting reconsideration. Despite no known tick bite, Lyme disease was suspected. A blood test confirmed Lyme disease, and she was treated with the antibiotic doxycycline. She improved significantly within 10 days, and no new rashes appeared after 2 weeks. This case highlights the need to consider Lyme disease even without a known tick bite. It underscores the importance of careful observation, detailed patient histories, and thorough testing to accurately diagnose and treat this disease in children.

Prevalence of and potential risk factors for multiple resistance to acaricides in Rhipicephalus (Boophilus) microplus ticks: A survey in the state of Rio Grande Do Sul, Brazil.

The cattle tick Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Ixodida, Ixodidae) is responsible for significant economic losses in bovine production in tropical and subtropical regions worldwide. Control of this tick predominantly involves the use of chemical acaricides; however, their indiscriminate use has led to the selection of resistant populations. A survey on tick populations was conducted in the state of Rio Grande do Sul, in Brazil, to assess the prevalence of multiple resistance to acaricides in cattle farms. Additionally, questionnaires were administered to identify potential risk factors associated with multiple resistance to acaricides. In total, 176 farms with a bovine population of ≥40 cattle were randomly assigned for tick sampling. The resistance to six acaricidal compounds was investigated by bioassays. A larval packet test was performed for amitraz, chlorpyrifos, cypermethrin, fipronil and ivermectin. Fluazuron was screened using an adult immersion test. Multiple resistance to acaricides (i.e., resistance to three or more compounds) was detected in 173 samples, representing 98% of the total samples. Among these samples, 125 (71%) showed resistance to all six compounds tested. Additionally, we classified the resistance intensity into four levels (I to IV) based on the quartile distribution of the bioassay data. Ten samples (6%) showed high and very high levels (III and IV) of resistance to all six compounds tested. Three variables were significantly associated with multiple resistance to the six acaricides tested: (i) use of injectable acaricides to control ticks, (ii) application of more than five acaricide treatments per year, and (iii) farms with larger herds (≥232 animals). These results regarding widespread resistance and the emergence of multiple resistance to acaricides ticks are alarming and highlight the significant challenge of tick control in southern Brazil.

O carrapato bovino Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Ixodida, Ixodidae) é responsável por significativas perdas econômicas na bovinocultura nas regiões tropicais e subtropicais do mundo. O controle deste carrapato é predominantemente realizado através do uso de carrapaticidas químicos; entretanto, o uso indiscriminado tem selecionado populações resistentes. Um inquérito em populações de carrapato foi conduzido no Rio Grande do Sul, Brasil, para identificar a prevalência de multirresistência a carrapaticidas em propriedades rurais. Além disso, questionários foram aplicados para determinar os potenciais fatores de risco associados à multirresistência a carrapaticidas. No total, 176 propriedades rurais com mais de ≥40 bovinos foram amostradas aleatoriamente. A resistência a seis classes de carrapaticidas foi investigada por bioensaios. O teste de pacote de larvas foi realizado para amitraz, clorpirifós, cipermetrina, fipronil e ivermectina. Fluazuron foi testado usando Teste de Imersão de carrapatos adultos. Multirresistência a carrapaticidas (resistência a três ou mais carrapaticidas) foi detectada em 173 amostras, representando 98% do total de amostras. Entre essas amostras, 125 (71%) apresentaram resistência aos seis carrapaticidas testados. Ademais, a intensidade de resistência foi classificada em quatro níveis (I a IV) baseada na distribuição de quartis dos dados dos bioensaios. Dez amostras (6%) apresentaram alto e muito alto nível de resistência (III e IV) aos seis carrapaticidas testados. Três variáveis foram significativamente associadas à multirresistência aos seis carrapaticidas testados: (i) uso de formulações injetáveis para controle de carrapato, (ii) aplicação de mais de cinco tratamentos carrapaticidas ao ano e (iii) propriedades com grande número de animais (≥232 bovinos). Esses resultados evidenciam que a disseminação da resistência e a emergência de populações de carrapatos multirresistentes é alarmante e destaca o desafio do controle de carrapatos no sul do Brasil.

Comprehensive analysis of the global impact and distribution of tick paralysis, a deadly neurological yet fully reversible condition.

SUMMARYTick paralysis is a potentially fatal condition caused by neurotoxins secreted by the salivary glands of certain ticks. Documented cases have been reported worldwide, predominantly in the United States, Canada, and Australia, with additional reports from Europe and Africa. This condition also affects animals, leading to significant economic losses and adverse impacts on animal health and welfare. To date, 75 tick species, mostly hard ticks, have been identified as capable of causing this life-threatening condition. Due to symptom overlap with other conditions, accurate diagnosis of tick paralysis is crucial to avoid misdiagnosis, which could result in adverse patient outcomes. This review provides a comprehensive analysis of the current literature on tick paralysis, including the implicated tick species, global distribution, tick toxins, molecular pathogenesis, clinical manifestations, diagnosis, treatment, control, and prevention. Enhancing awareness among medical and veterinary professionals is critical for improving the management of tick paralysis and its health impacts on both humans and animals.

Conceptual Framework for Community-Based Prevention of Brown Dog Tick-Associated Rocky Mountain Spotted Fever.

Rocky Mountain spotted fever (RMSF) is a severe tickborne disease that can reach epidemic proportions in communities with certain social and ecologic risk factors. In some areas, the case-fatality rate of brown dog tick-associated RMSF is up to 50%. Because of the spread of brown dog tick-associated RMSF in the southwestern United States and northern Mexico, the disease has the potential to emerge and become endemic in other communities that have large populations of free-roaming dogs, brown dog ticks, limited resources, and low provider awareness of the disease. By using a One Health approach, interdisciplinary teams can identify communities at risk and prevent severe or fatal RMSF in humans before cases occur. We have developed a conceptual framework for RMSF prevention to enable communities to identify their RMSF risk level and implement prevention and control strategies.

Transmission of Severe Fever with Thrombocytopenia Syndrome Virus to Human from Nonindigenous Tick Host, Japan.

We report a human case of severe fever with thrombocytopenia syndrome virus infection transmitted by a tick, confirmed by viral identification. Haemaphysalis aborensis, a tick species not native to Japan that has been observed to transmit the virus to humans, is now recognized as a potential vector of this virus in Japan.

Exploring the longitudinal expression dynamics of midguts in adult female Amblyomma americanum ticks.

BACKGROUND: Female ticks remain attached to their host for multiple days to complete a blood meal. This prolonged feeding period is accompanied by a significant increase in the tick's size and body weight, paralleled by noteworthy changes to the tick midgut. While the midgut is recognized for its established role in blood storage and processing, its importance extends to playing a crucial role in the acquisition, survival, and proliferation of pathogens. Despite this, our overall understanding of tick midgut biology is limited. RESULTS: Our transcriptome analysis identified 15,599 putative DNA coding sequences (CDS), which were classified into 26 functional groups. Dimensional and differential expression analyses revealed four primary transcriptional profiles corresponding to unfed, slow-feeding, transitory (from slow- to rapid-feeding), and rapid-feeding stages. Additionally, comparing the current dataset with previously deposited transcriptome from other tick species allowed the identification of commonly expressed transcripts across different feeding stages. CONCLUSION: Our findings provide a detailed temporal resolution of numerous metabolic pathways in the midgut of A. americanum adult females throughout the feeding process, highlighting the dynamic transcriptional regulation of the tick's midgut as feeding progresses. Furthermore, we identified conserved transcripts across three different tick species that exhibit similar expression patterns. This knowledge not only enhances our understanding of the physiological processes within the tick midgut but also opens up potential avenues for developing control methods that target multiple tick species.

Baggio-Yoshinari Syndrome: A Report of Five Cases.

Compared to classic Lyme disease (LD), Baggio-Yoshinari syndrome (BYS) has the following distinctive characteristics: it is transmitted in the Amazon area and Northeast, Central-West, Southeast, and South regions of Brazil by hard ticks, notably Amblyomma cajannense or Rhipicefalus sp. The absence of Ixodes sp. ticks in areas at risk of BYS in Brazil is probably the main reason for the disease's differences from LD in the United States, Europe, and Asia. Biodiversity and climate probably favor the formation of atypical pleomorphic Borrelias, which have not yet been cultivated or isolated. Clinically, the first manifestation of BYS is the erythema migrans as in the classic forms of Lyme disease, but BYS is distinguished from LD by its prolonged clinical evolution, with a high frequency of relapses and the appearance of autoimmune manifestations. Prevalent symptoms are headache and erythema nodosum. Five clinical cases of BYS in patients who contracted the disease in the Brazilian Amazon rainforest are described here. This syndrome should be considered among differential diagnoses in patients bitten by ticks in Brazil who present with erythema migrans and/or headache. It is important to pursue an early diagnosis because symptoms respond well to antibiotics in the early stages; if treatment is started late, a chronic course with articular and neurological sequelae can be detected.

Camelpox Virus in Western Kazakhstan: Assessment of the Role of Local Fauna as Reservoirs of Infection.

This article investigates the role of local fauna in Western Kazakhstan as potential reservoirs of the camelpox virus (CMLV). The study emphasizes analyzing possible sources and transmission pathways of the virus using polymerase chain reaction (PCR) and serological methods, including virus neutralization tests and enzyme-linked immunosorbent assays (ELISA). Samples were collected from both young and adult camels, as well as rodents, ticks and blood-sucking insects in the Mangystau and Atyrau regions. The PCR results revealed the absence of viral DNA in rodents, ticks and blood-sucking insects; also, the ELISA test did not detect specific antibodies in rodents. These findings suggest that these groups of fauna likely do not play a significant role in the maintenance and spread of CMLV. Consequently, the primary sources of transmission are likely other factors, potentially including the camels themselves. The study's results indicate the need to reassess current hypotheses regarding infection reservoirs and to explore alternative sources to enhance strategies for the control and prevention of the camelpox virus.

Efficacy of Rotational Grazing on the Control of Rhipicephalus microplus Infesting Calves in Humid Tropical Conditions.

Grazing management through pasture rotation has been mentioned as a viable alternative for the control of Rhipicephalus microplus; however, there is limited information on rotational grazing at field level. The objectives of this research were (1) to evaluate the effect of rotational grazing with 30 and 45 days of pasture rest and continuous grazing (without rest) on R. microplus tick loads in Brahman heifers and its most common crosses with Holstein; (2) to know the parasite dynamics of R. microplus under the three grazing systems in the humid tropics of Mexico; and (3) to determine the effect of the treatments on the characteristics of the pastures (availability of forage biomass, plant height, and soil cover). The experiment was carried out for 1 year from April 2022 to March 2023, with three grazing treatments: Treatments 1 and 2 considered rotational grazing with 30 (RT30) and 45 days of rest (RT45), respectively, and Treatment 3 as continuous grazing (CT00). Thirty calves from 8 to 12 months of initial age were distributed in each treatment (n = 10). Every 14 days, the number of engorged and semiengorged female ticks in cattle was determined. Concomitantly, the region's temperature, relative humidity, and rainfall were recorded, as well as the agronomic characteristics of the pasture. Rotational grazing animals with 30 days of rest had the highest number of ticks, while grazing animals with 45 days of rest had the least. Tick load dynamics among groups did not correlate with climatic variables (p > 0.05). The height and grass cover presented significant changes due to grazing (p < 0.05), which could influence the tick cycle by the exposure of the soil, modifying the microclimatic conditions and consequently harming the survival and development of R. microplus in the evaluated systems. The negative effect of rotational grazing on the nonparasitic phase of R. microplus deserves further studies.

Crimean Congo hemorrhagic fever virus exposure among febrile patients, cattle herders, and cattle herds in Cameroon.

PROBLEM ADDRESSED: Crimean Congo hemorrhagic fever (CCHF) is a tick-borne disease with high fatality rates and an expansive geographic distribution, yet disease prevalence data in Cameroon is lacking. OBJECTIVE: This study aimed to determine CCHF virus (CCHFV) seroprevalence and tick distribution among cattle herders and febrile patients in West and Centre Cameroon. METHODS AND APPROACH: Two cross-sectional serological studies of human and cattle were conducted from October to December 2021 and from June to July 2022, which included the collection of ticks. Enzyme-linked immunosorbent assay (ELISA) were used to detect anti-CCHFV antibodies, while a knowledge, attitudes, and practice (KAP) survey assessed tick and tickborne disease related knowledge and behaviors among herders. Tick identification used morphological keys. RESULTS: The KAP survey showed adequate tick knowledge (94.5 %) among herders but poor understanding of disease transmission, with favorable attitudes towards tick control (24.7 %) but inadequate implementation. Rhipicephalus annulatus (64.1 %) predominated among the 1,296 ticks collected during each rainy season. Among cattle, 27.4 % were seropositive, and seropositivity was associated with specific villages, cattle age (>4 years), and female sex. Herders had a 17.8 % seroprevalence, while febrile patients had 8.3 %, with higher rates in those >20 years old for both groups. Self-reported tick removal by herders after contact and grazing may increase CCHFV exposure. CONCLUSIONS: This study confirms CCHFV circulation in rural West Cameroon and unexpected exposure risk in Yaounde, highlighting the need for active entomological surveillance and preventive measures in transhumance and cattle market activities. Establishing an occupation-based surveillance system can help identify CCHFV hotspots to prevent outbreaks.

Molecular detection of Ehrlichia spp., Anaplasma spp., and Bartonella spp. in dogs treated at a veterinary teaching clinic in Peru.

In recent years, vector-borne diseases have become widespread throughout the world and affect the health of humans and domestic animals. These diseases spread to areas where their primary vectors, fleas and ticks, thrive, particularly in tropical and subtropical climate regions, providing ideal conditions for their proliferation. The growing closeness between people and their pets increases the likelihood of bites from these ectoparasites, which represents a latent zoonotic risk. Therefore, the objective of the study was to determine the presence of Anaplasma spp., Ehrlichia spp., and Bartonella spp. in dogs treated at the Small Animal Clinic of the Faculty of Veterinary Medicine of the Universidad Nacional Mayor de San Marcos, located in Lima, Peru. Blood samples from 214 dogs were molecularly analyzed for hemopathogen detection. The results revealed prevalences of 2.6 % (6/214) for Anaplasma platys, 5.14 % (11/214) for Ehrlichia canis, and 0.46 % (1/214) for Bartonella rochalimae. No statistically significant relationship was found between the animal infection and the age, sex, breed, presence of fleas (Ctenocephalides felis) and ticks (Rhipicephalus sanguineus), and locality. This study reported molecularly for the first time the presence of A. platys, E. canis, and B. rochalimae in dogs from Lima city, and demonstrates the occurrence of zoonotic pathogens in pets treated at the veterinary clinic.