Factors associated with the confirmation and death for Brazilian spotted fever in an important endemic area of the State of São Paulo, 2007-2021.

BACKGROUND: We evaluated the predictive factors for case confirmation and death from Brazilian spotted fever in an endemic area of Southeastern Brazil. METHODS: A cross-sectional study was conducted. All suspected cases reported between 2007 and 2021 were analyzed using two logistic regression models. RESULTS: 60 cases were confirmed. Male sex, age group of 40-59 years, tick parasitism, presence of capybaras or horses, exanthema and hospitalization were positively associated with confirmation. Death was associated with a longer period between first symptom-hospitalization and shorter treatment. CONCLUSIONS: Complete clinical evaluation and information on risk exposure are key to early suspicion, diagnosis, treatment and prevention of deaths.

Rocky Mountain spotted fever is a neglected tropical disease in Latin America.

Rocky Mountain spotted fever (RMSF), a severe and extraordinarily lethal infectious disease, has emerged as a widespread public health crisis among predominantly vulnerable populations in several countries of Latin America, particularly evident in northern Mexico. Historically, RMSF has gained less attention than many other tropical infectious diseases, resulting in insufficient allocations of resources and development of capabilities for its prevention and control in endemic regions. We argue that RMSF fulfills accepted criteria for a neglected tropical disease (NTD). The relative neglect of RMSF in most Latin American countries contributes to disparities in morbidity and mortality witnessed in this region. By recognizing RMSF as an NTD, an increased public policy interest, equitable and more appropriate allocation of resources, scientific interest, and social participation can ameliorate the impact of this potentially treatable disease, particularly in vulnerable populations.

Tick-Borne Illnesses in Emergency and Wilderness Medicine.

This review highlights the causative organisms, clinical features, diagnosis, and treatment of the most common tick-borne illnesses in the United States, including Lyme disease, Rocky Mountain spotted fever, anaplasmosis, ehrlichiosis, tularemia, Powassan virus, and alpha-gal syndrome. Tick bite prevention strategies and some basic tick removal recommendations are also provided.

Evaluating the circulation of Ehrlichia canis and Rickettsia spp. in domestic dogs from a semiarid region in Brazil.

Tick-borne diseases are important for animal and human health, because they can cause death if not diagnosed and treated early. Canine monocytic ehrlichiosis (CME) can cause high morbidity in dog populations. Rocky Mountain Spotted Fever (RMSF) is among the most virulent infectious in humans; dogs are also susceptible to infection. The aims of this study were to evaluate the presence of Ehrlichia canis and Rickettsia spp. infections in domestic dogs, and to identify tick species parasitizing dogs among urban areas of two municipalities (Sobral and Alcântaras) in the Ceará State, Northeastern Brazil. A total of 208 domiciled dogs was sampled. After clinical evaluation, blood samples and ticks were collected and submitted to Real-Time Polymerase Chain Reaction (RT-PCR) targeting E. canis DNA. Serum samples were screened by Indirect Immunofluorescence Assays (IFA) for antibodies against different strains of Rickettsia spp. previously recognized in Brazil. The results of this study indicate the molecular detection of E. canis in the state of Ceará, Brazil, where the proportion of canine infection in Sobral (9.9%) was higher than in Alcântaras (5.6%). Rhipicephalus sanguineus sensu lato was the prevalent tick species infesting the dogs in both municipalities (43.5 and 53.3%, respectively). Our serological results indicate that dogs of the study area were at low risk of exposure to these tick-borne Rickettsia spp. of the spotted fever group. Our study offers epidemiological data of these diseases to better understanding Rickettsiales epidemic and enzootic cycles in the Brazilian semiarid region, improving prevention and control measures.

Newly Recognized Spotted Fever Group Rickettsia as Cause of Severe Rocky Mountain Spotted Fever-Like Illness, Northern California, USA.

The incidence of spotted fever group (SFG) rickettsioses in the United States has tripled since 2010. Rocky Mountain spotted fever, the most severe SFG rickettsiosis, is caused by Rickettsia rickettsii. The lack of species-specific confirmatory testing obfuscates the relative contribution of R. rickettsii and other SFG Rickettsia to this increase. We report a newly recognized rickettsial pathogen, Rickettsia sp. CA6269, as the cause of severe Rocky Mountain spotted fever-like illness in 2 case-patients residing in northern California. Multilocus sequence typing supported the recognition of this pathogen as a novel Rickettsia genotype most closely related to R. rickettsii. Cross-reactivity observed for an established molecular diagnostic test indicated that Rickettsia sp. CA6269 might be misidentified as R. rickettsii. We developed a Rickettsia sp. CA6269-specific real-time PCR to help resolve this diagnostic challenge and better characterize the spectrum of clinical disease and ecologic epidemiology of this pathogen.

Roaming Dogs, Intense Brown Dog Tick Infestation, and Emerging Rocky Mountain Spotted Fever in Tijuana, México.

A two decades-long epidemic of Rocky Mountain spotted fever in northern México reached the U.S. border city of Tijuana in 2021. Cases were near the city periphery in marginalized areas, some lacking infrastructure such as streets or utilities. We worked in the three census areas where human cases were reported and in 12 additional control Áreas Geoestadisticas Básicas. There were dogs, the primary tick host and Rickettsia rickettsii reservoir, in 76% of homes, with 2.2 owned dogs per home on average, approximately equal numbers of roaming dogs were seen, and 46.2% of owned dogs were allowed to roam in the street. Sixty-eight percent of people had heard of Rocky Mountain spotted fever (RMSF), and 35% self-reported tick infestation, including 19% of homes without dogs. Ticks appeared to move among houses of adjacent neighbors. Of 191 examined dogs, 61.8% were tick-infested, with 6-fold increased odds if they were allowed to roam. Although no dogs were Rickettsia polymerase chain reaction-positive, we found one R. rickettsii- and 11 Rickettsia massiliae-infected ticks. The rickettsial IgG seroprevalence by immunofluorescence antibody assay was 76.4%, associated with unhealthy body condition, adults, dogs with >10 ticks, more dogs being seen in the area, and dogs being permitted in the street. Insufficient medical and canine management resources have contributed to a case fatality rate of RMSF that has exceeded 50% in areas. High canine seroprevalence suggests risks to people and dogs; unfortunately, herd immunity is impeded by high turnover in the canine population owing to the birth of puppies and high death rates. Binational One Health workers should monitor disease spread, enact canine population management and tick eradication, and provide prevention, diagnostic, and treatment support.

Five human pathogens detected by tick surveillance in New York City parks, 2014-2015.

A total of 2,504 ticks of 5 species (Ixodes scapularis, Dermacentor variabilis, Amblyomma americanum, Haemaphysalis leporispalustris, and H. longicornis) were collected over 2 yr (2014-2015) in New York City parks. Specimens were collected via tick-dragging, identified to species, and tested for pathogens of human diseases. The causative agents of 5 human diseases (Lyme borreliosis, ehrlichiosis, babesiosis, anaplasmosis, and Rocky Mountain spotted fever) were detected in a subset of samples. Results of this surveillance effort further illustrate that risk of tick-borne disease is considerable even in parks located adjacent to densely populated areas.

The four most frequently diagnosed vector-borne diseases among service member and non-service member beneficiaries in the geographic combatant commands, 2010-2022.

Vector-borne diseases (VBDs) may pose an increased risk for U.S. service members during recurring military training exercises, operations, and response missions, in addition to residence in endemic regions within and outside the continental U.S. Prior MSMR reports address VBD surveillance, described by surveillance data for 23 reportable medical events (RMEs), among active duty and reserve component service members. This report covers a 13-year surveillance period, from January 2010 to December 2022, and provides linear trends of selected VBDs among Armed Forces service and non-service member beneficiaries diagnosed at installations within the Northern Command (NORTHCOM), Africa Command (AFRICOM), Central Command (CENTCOM), European Command (EUCOM), Indo-Pacific Command (INDOPACOM), or Southern Command (SOUTHCOM). Trends of only the 4 mostfrequently reported VBDs were evaluated, as Lyme disease, malaria, Rocky Mountain Spotted Fever (RMSF), and dengue fever comprised 90% (n=5,199) of all 23 VBDs (n=5,750) among Military Health System (MHS) beneficiaries documented as RMEs during the surveillance period.

Case Report: Fatal Rickettsiosis in Pregnancy.

Rocky Mountain spotted fever (RMSF) is a tick-borne infection caused by Rickettsia rickettsii. We present a series of two cases of pregnant patients who showed up at the emergency room of a hospital in Nuevo León, Mexico. Both patients lived in environments where R. rickettsii is endemic and they presented with several days of symptoms, including fever. Both patients developed a rash and had stillbirths during their hospital stay. Treatment with doxycycline was delayed, with fatal results in both patients. Diagnosis of RMSF was confirmed via polymerase chain reaction assay postmortem. The need to link epidemiological clues with clinical data is critical in the diagnosis and early treatment of RMSF to prevent maternal deaths.

Predicting the global potential distribution of two major vectors of Rocky Mountain Spotted Fever under conditions of global climate change.

Rocky Mountain spotted fever is a tick-borne disease that is highly dangerous but often overlooked by the public. To prevent the spread of the disease, it is important to understand the distribution patterns of its vectors' suitable areas. This study aims to explore the potential global suitability of areas for the vectors of Rocky Mountain spotted fever, including Dermacentor variabilis and Amblyomma cajennense under both historical and future climate scenarios. The study also seeks to investigate the impact of climatic factors on the distribution patterns of these vectors. Data on species distribution were downloaded from the Global Biodiversity Information Facility, Web of Science and PubMed database. The climatic variables were downloaded from WorldClim Global Climate Database. The Maximum Entropy Model was used to evaluate the contribution of monthly precipitation, monthly maximum temperature, monthly minimum temperature, elevation, and nineteen other climatic variables to vector survival, as well as to predict the suitable area for the vectors. We found that D. variabilis is distributed in North America, while A. cajennense is mainly distributed in South America, but all other continents except Antarctica have a suitable distribution. D. variabilis is more likely to survive in temperate regions, and A. cajennense is more likely to survive in tropical zones. D. variabilis is more sensitive to temperature, whereas A. cajennense is sensitive to both temperature and precipitation, and A. cajennense prefers tropical regions with hot and humid characteristics. The high suitable areas of both vectors were almost expanded in the ssp5-8.5 scenario, but not so much in the ssp1-2.6 scenario. Highly suitable areas with vectors survival should be strengthened with additional testing to prevent related diseases from occurring, and other highly suitable areas should be alert for entry and exit monitoring to prevent invasion and colonization of vectors.

Optimal control of a tick population with a view to control of Rocky Mountain Spotted Fever.

In some regions of the Americas, domestic dogs are the host for the tick vector Rhipicephalus sanguineus, and spread the tick-borne pathogen Rickettsia rickettsii, which causes Rocky Mountain Spotted Fever (RMSF) in humans. Interventions are carried out against the vector via dog collars and acaricidal wall treatments. This paper investigates the optimal control of acaricidal wall treatments, using a prior model for populations and disease transmission developed for this particular vector, host, and pathogen. It is modified with a death term during questing stages reflecting the cost of control and level of coverage. In the presence of the control, the percentage of dogs and ticks infected with Ri. rickettsii decreases in a short period and remains suppressed for a longer period, including after treatment is discontinued. Risk of RMSF infection declines by 90% during this time. In the absence of re-application, infected tick and dog populations rebound, indicating the eventual need for repeated treatment.

POTENTIAL SHARED DISEASE RISK AMONG DOGS AND COYOTES (CANIS LATRANS) EXEMPLIFIED BY THE ECOLOGY OF RICKETTSIOSIS IN A ROCKY MOUNTAIN SPOTTED FEVER-EPIDEMIC REGION IN NORTHERN MEXICO.

Rocky Mountain spotted fever (RMSF), caused by the bacterium Rickettsia rickettsii, is a re-emerging tick-borne zoonosis in North America, with hundreds of human fatalities in multiple outbreaks in northern Mexico and the southwestern US in the past few decades. Free-roaming dogs are key because they are reservoirs for the pathogen and the main hosts of the brown dog tick (Rhipicephalus sanguineus), which vectors RMSF in this region. Because coyotes (Canis latrans) can be infected with R. rickettsii and infested with Rh. sanguineus, we hypothesized that space sharing among dogs and coyotes could enhance disease risks. In summer 2021, we captured and sampled 11 coyotes at two sites in Baja California, Mexico, near population centers with human cases of RMSF, and fitted seven individuals with GPS logging collars. We also tested tissue samples, sera, and ectoparasites for DNA of R. rickettsii with PCR and used serology to detect antibodies to R. rickettsii. Finally, we deployed an array of cameras to document dog-coyote interactions. Mean home range size was 40.37 km2. Both GPS and camera data showed considerable home range overlap both between individual coyotes and between coyotes and dogs. Coyotes were active in areas where dogs occur including the domestic interface surrounding human settlements. Although none of our samples were positive for R. rickettsii on PCR, 72.7% (8/11) of the samples were seropositive with titers ≥64. Our data confirm shared space use and risk of shared parasites and disease between coyotes and dogs.

Serologic Testing for Rocky Mountain Spotted Fever in a Low-Incidence Region.

BACKGROUND: Tick-borne diseases have grown in incidence over recent decades. As a result, diagnostic testing has become more common, often performed as broad antibody-based panels for multiple tick-transmitted pathogens. Rocky Mountain spotted fever (RMSF) is rare in our region yet may cause severe morbidity, leading to diagnostic screening in low-risk patients. We sought to describe trends in RMSF diagnostic testing, rate of IgG seropositivity, and clinical features of those tested. METHODS: We performed a retrospective chart review of patients ≤21 years old undergoing testing for RMSF and/or with an ICD-9/10 code for RMSF. Patients were categorized by infection likelihood based on clinical and laboratory criteria adapted from Centers for Disease Control and Prevention's (CDC) case definition of spotted fever rickettsioses. Clinical data were collected and analyzed with descriptive statistics. RESULTS: One hundred and seventy patients were included. 5.8% met CDC criteria for rickettsial infection, 6.5% had an elevated IgG titer but lacked suggestive symptoms, and 87.6% had a negative IgG titer. Many patients tested were unlikely to have RMSF, including 50% lacking fever, 20% lacking any RMSF "classic triad" symptoms, 13% without acute illness, and 22% tested during months with low tick activity. Convalescent serology was performed in 7.6% of patients and none underwent Rickettsia rickettsii polymerase chain reaction (PCR) testing. CONCLUSIONS: Diagnostic testing was frequently performed in patients unlikely to have RMSF. We identified many opportunities for improving test utilization. Reserving testing for those with higher pretest probability, performing convalescent serology, and utilizing PCR may improve the accuracy of RMSF diagnosis and reduce clinical challenges stemming from inappropriate testing.

Alerta epidemiológico: alerta acerca do registro de casos de febre maculosa no Estado de São Paulo / Epidemiological alert: alert about the record of cases of spotted fever in the State of São Paulo

Alerta emitido pela Coordenação de Zoonoses da Gerência de Vigilância Epidemiológica de Doenças Transmissíveis (GVEDT) e o Centro de Informações Estratégicas e Resposta em Vigilância (CIEVS Goiás) da Gerência de Emergências em Saúde Pública (GESP) da Superintendência de Vigilância em Saúde (SUVISA) com o objetivo de alertar os profissionais de saúde quanto aos sinais e sintomas devido aos casos recentes de febre maculosa (FM) registrados no estado de São Paulo

Alert issued by the Zoonoses Coordination of the Communicable Diseases Epidemiological Surveillance Management (GVEDT) and the Center for Strategic Information and Surveillance Response (CIEVS Goiás) of the Public Health Emergencies Management (GESP) of the Health Surveillance Superintendence (SUVISA) in order to alert health professionals about the signs and symptoms due to recent cases of spotted fever (FM) registered in the state of São Paulo

First molecular evidence of Wolbachia occurrence in Amblyomma sculptum (Acari: Ixodidae).

As the main vector for the bacterium Rickettsia rickettsii in Brazil, the tick Amblyomma sculptum is a parasite of great public health importance in this country. Wolbachia is an endosymbiont bacterium highly widespread among invertebrates and because of its impact on its hosts' biology, form a powerful alternative for pests and disease control. The aim of this study was to investigate the occurrence of this bacterium in A. sculptum. For this, 187 adult ticks collected in two municipalities in the interior of the state of São Paulo, Brazil, were analyzed using molecular techniques and bioinformatics tools. A total of 15 ticks were positive for the presence of Wolbachia. Phylogenetic analysis on the 16S rRNA gene indicated that the Wolbachia DNA sequences obtained in this investigation belonged to different clades, probably in supergroups B and F. This was the first study to report the occurrence of Wolbachia in A. sculptum and it enriches knowledge about the susceptibility of ticks to this bacterium. Now that we know that Wolbachia can be found in A. sculptum, the objective for a next study must be to investigate Wolbachia's possible origin in this tick.

Clinical manifestations of Rickettsia rickettsii in a familial outbreak in Panama.

We report an isolated outbreak of Rickettsia rickettsii in the Ngäbe-Buglé indigenous region, located 750 m (tropical wet) above sea level, in a jungle and mountainous area of Western Panama. Seven members of a family were infected simultaneously, resulting in four deaths. Family outbreaks have been previously described and are responsible for 4-8% of the cases described [1-4]. The simultaneous onset of symptoms in the affected population group is extremely unusual [1,5], but it should not dissuade the clinician from considering the possibility of Rickettsia rickettsii infection.

Avaliação de tecnologia educacional sobre febre maculosa: ensaio clínico randomizado / Evaluation of educational technology on spotted fever: randomized clinical trial

O objetivo geral desse estudo foi avaliar a eficácia de um Laboratório Interativo versus uma Aula Expositiva para aquisição de conhecimento cognitivo sobre Febre Maculosa (FM) em alunos do ensino médio e profissionalizante de duas cidades brasileiras de região endêmica. Para alcançá-lo, foi preciso identificar o conhecimento prévio da população, desenvolver uma intervenção (metodológico) e testá-la (ensaio clínico), o que resultou na elaboração de quatro artigos e um relatório científico. O primeiro artigo se trata de um estudo metodológico, em que foi apresentado o percurso da construção, bem como o processo de validação de aparência, conteúdo e semântica. Os resultados da validação mostraram um índice de validade de conteúdo superior a 0,8 para a grande maioria das variáveis e o Laboratório Interativo foi avaliado de forma positiva pelos participantes do estudo. O segundo artigo, também estudo metodológico, teve como objetivo construir e validar um questionário de avaliação cognitiva, chamado de Quiz, para avaliar o conhecimento dos participantes antes e após a participação no Laboratório Interativo. Este Quiz alcançou concordância satisfatória entre os juízes e população alvo, o que garante ser um instrumento adequado para o processo de avaliação sobre a temática investigada. O terceiro artigo foi uma revisão integrativa da literatura, que sintetizou e interpretou estudos sobre as ações de educação em saúde sobre FM. Realizaram-se buscas sistemáticas em seis bases de dados, complementadas por buscas manuais. A amostra final foi composta por cinco artigos, analisados segundo os preceitos da análise de conteúdo dedutiva. Esta revisão permitiu identificar que, apesar das discussões sobre educação em saúde em FM serem de relevância mundial para a Saúde, ainda há uma escassez de trabalhos voltados integralmente para esta prática. O quarto artigo foi referente a avaliação do Laboratório Interativo sobre FM, tratando-se de um ensaio clínico randomizado. Participaram do estudo 458 alunos divididos em quatro grupos: Grupo Intervenção da cidade A que participou do Laboratório Interativo, Grupo Comparação da cidade A que participou da Aula Expositiva (alunos área da saúde); Grupo Intervenção da cidade B que participou do Laboratório Interativo e Grupo Comparação da cidade B que não participou de nenhuma Atividade (alunos de diversos cursos). O conhecimento dos alunos foi avaliado antes e após a intervenção com aplicação do Quiz sobre FM. Os resultados referentes a comparação intergrupos mostrou que os alunos que participaram do Laboratório Interativo apresentaram melhora no conhecimento na maioria das variáveis em comparação aos outros grupos, embora o conhecimento também tenha aumentado no Grupo Comparação-Aula Expositiva. Na comparação intragrupos, os alunos que participaram do Laboratório Interativo apresentaram um ganho significativo de conhecimento em comparação aos alunos que participaram da Aula Expositiva, e bem maior que àqueles que não participaram de nenhuma atividade. Por fim, buscando auxiliar a promoção em saúde em relação a doença FM, compreendemos a importância de elaborar uma Tecnologia Educacional em formato audiovisual. Assim, foi construído um conjunto de quatro vídeos educativos sobre FM para estudantes de 6 a 12 anos, acompanhado de manual pedagógico ao professor/educador. Trata-se de um recurso educativo para ser utilizado em sala de aula, com intuito que o tema seja trabalhado de forma transversal nas escolas para facilitar a construção do conhecimento e fortalecer o empoderamento dos alunos frente as suas decisões em saúde. Tomados em conjunto, os resultados obtidos nesta Tese mostram a urgência de ações voltados para esta temática, evidenciando o pioneirismo e inovação do estudo. Desta maneira, além de contribuir com a literatura, esse trabalho atende a uma demanda social ao elaborar um recurso educativo que contempla as necessidades de saúde de um grupo, mais especificamente, uma população que vive em região considerada endêmica para FM.

The overall objective of this study was to evaluate the effectiveness of an Interactive Laboratory versus an Expository Classroom in acquiring cognitive knowledge about Rocky Mountain Spotted Fever (RMSF) in high school and technical College students from two Brazilian cities in an endemic region. To achieve this, it was necessary to identify the population's prior knowledge, develop an intervention (methodological) and test it (clinical trial), which resulted in four articles and a scientific report. The first article is a methodological study, in which the path of the construction was presented, as well as the process of appearance, content, and semantic validation. The validation results showed a content validity index greater than 0.8 for the vast majority of the variables and the Interactive Lab was rated positively by the study participants. The second paper, also a methodological study, aimed to construct and validate a cognitive assessment questionnaire, called a RMSF Quiz, to assess the knowledge of participants before and after participating in the Interactive Lab. This Quiz achieved satisfactory agreement between the judges and the target population, which guarantees that it is an adequate instrument for the evaluation process on the investigated theme. The third article was an integrative literature review, which synthesized and interpreted studies on health education actions on RMSF. Systematic searches were performed in six databases, complemented by manual searches. The final sample was composed of five articles, analyzed according to the precepts of deductive content analysis. This review allowed us to identify that, despite the fact that discussions about health education in RMSF are of worldwide relevance for Health, there is still a scarcity of studies integrally focused on this practice. The fourth article was a randomized clinical trial evaluating the RMSF Interactive Lab. The study included 458 students divided into four groups: Intervention Group from city A that participated in the Interactive Lab; Comparison Group from city A that participated in the Lecture Class (health students); Intervention Group from city B that participated in the Interactive Lab; and Comparison Group from city B that did not participate in any Activity (students from various courses). The students' knowledge was evaluated before and after the intervention with the application of the RMSF Quiz. The results of the intergroup comparison showed that the students who participated in the Interactive Lab had improved knowledge in most variables compared to the other groups, although knowledge also increased in the Comparison Group - Lecture Class. In the intra-group comparison, the students who participated in the Interactive Lab showed a significant gain in knowledge compared to the students who participated in the Lecture Class, and much greater than those who did not participate in any activity. Finally, in order to help promote health to RMSF, we realized the importance of developing an Educational Technology in audiovisual format. Thus, a set of four educational videos on RMSF for students aged 6 to 12 years, accompanied by a pedagogical manual for the teacher/educator, was built. It is an educational resource to be used in the classroom, so that the theme can be worked in a transversal way in schools to facilitate the construction of knowledge and strengthen the students' empowerment in their health decisions. Taken together, the results obtained in this Thesis show the urgency of actions focused on this theme, evidencing the pioneering and innovation of the study. Thus, in addition to contributing to the literature, this work meets a social demand by developing an educational resource that addresses the health needs of a group, more specifically, a population living in a region considered endemic for RMSF.

Tick-borne pathogens detected in sheltered dogs during an epidemic of Rocky Mountain spotted fever, a One Health challenge.

OBJECTIVE: To assess exposure to and infection with 3 pathogens (Rickettsia rickettsii, Anaplasma platys, and Ehrlichia canis) vectored by brown dog ticks (Rhipicephalus sanguineus) in sheltered dogs at the western US-Mexico border. ANIMALS: 239 dogs in shelters in San Diego and Imperial counties, US, and Mexicali and Tijuana, Mexico. PROCEDURES: Each dog had blood drawn and basic demographic data collected. PCR was performed to determine active infection with Rickettsia spp, E canis, and A platys. Serology was performed to determine exposure to Rickettsia, Anaplasma, and Ehrlichia species. RESULTS: 2 of 78 (2.6%) dogs sampled in Tijuana were actively infected with R rickettsii. A single brown dog tick collected from a dog in Tijuana was PCR-positive for R rickettsii. Infection with E canis and A platys ranged across shelters from 0% to 27% and 0% to 33%, respectively. Dogs in all 4 locations demonstrated exposure to all 3 pathogens, though Rickettsia and Ehrlichia seropositivity was highest in Mexicali (81% and 49%, respectively) and Anaplasma seropositivity was highest in Tijuana (45%). CLINICAL RELEVANCE: While infection and exposure were highest in sheltered dogs in the southern locations, dogs in all locations demonstrated exposure to all pathogens, demonstrating the potential for emergence and spread of zoonotic pathogens with significant public health consequences in southern California and northern Baja California. In addition, veterinarians and shelter staff should be aware that Ehrlichia or Anaplasma infection may co-occur with Rocky Mountain spotted fever, which is a human health risk.

Fatal Brazilian spotted fever in a healthy military man during field training in Rio de Janeiro city, southeastern Brazil.

Brazilian spotted fever, a zoonotic disease transmitted by ticks, is caused by Rickettsia rickettsii. We report a fulminant case of this zoonosis in a healthy 46-year-old military man in the urban region of Rio de Janeiro city, in October, 2021. Ticks and capybaras (Amblyomma sculptum, Hydrochoerus hydrochaeris, respectively) were identified in the military fields, pointing to the participation of this large synanthropic rodent, recognized as an efficient amplifier host of Rickettsia rickettsii in Brazil. As the military population is considered a risk group for spotted fever, it is necessary to alert health professionals to the importance of the early detection of the disease and its adequate management, mainly in populations that are particularly at risk of exposure to ticks, in order to avoid fatal outcomes.