Rocky Mountain Spotted Fever Mimicking Multisystem Inflammatory Syndrome in Hospitalized Children, Sonora, Mexico.

We describe 5 children who had Rocky Mountain spotted fever (RMSF) and manifested clinical symptoms similar to multisystem inflammatory syndrome in Sonora, Mexico, where RMSF is hyperendemic. Physicians should consider RMSF in differential diagnoses of hospitalized patients with multisystem inflammatory syndrome to prevent illness and death caused by rickettsial disease.

Neurological manifestation of Brazilian spotted fever in childhood.

Rocky Mountain Spotted Fever is a rickettsial disease caused by the bacteria Rickettsia rickettsii. In Brazil, the disease is known as Brazilian spotted fever (BSF), being the most significant tick-borne disease in the country. Among the affected patients, only 5% of cases occur in children aged one to nine years. Typical symptoms of the disease are fever, rash, headache and digestive symptoms. Neurological manifestations such as seizures, aphasia and hemiparesis have been described in few patients. This study aimed to describe the case of an infant diagnosed with BSF who presented severe signs of neurological manifestation.

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.

An impedimetric immunosensor for diagnosis of Brazilian spotted fever in blood plasma.

Brazilian spotted fever (BSF) is a serious disease of medical importance due to its rapid evolution and high lethality. The effectiveness of the treatment mainly depends on the rapid diagnosis, which is currently performed by indirect immunofluorescence and PCR tests, which require high costs and laboratory structure. In order to propose an alternative methodology, we sought to develop an impedimetric immunosensor (IM) based on the immobilization of specific IgY antibodies for IgG anti Rickettsia rickettsii, using blood plasma from capybara (Hydrochoerus hydrochaeris), for characterization, validation and applications of the ready IM. IM selectivity was observed when comparing capybara reagent IgG (IgGcr) readings with non-reagent IgG (IgGnr). A reagent IgG calibration curve was obtained, from which the limits of detection (LOD) and quantification (LOQ) of 1.3 ng mL-1 and 4.4 ng mL-1 were calculated, respectively. The accuracy tests showed that different concentrations of IgGcr showed a maximum deviation of 20.0%, with CI between 90.00% and 95.00%. Intermediate precision tests showed a relative standard deviation of 2.09% for researcher 1 and 2.61% for researcher 2, and the F test showed no significant difference between the recovery values found between the two analysts, since Fcal 1.56 < 5.05 and P-value 0.48 > 0, 05. Therefore, an impedimetric immunosensor was developed to detect anti BSF IgG in capybara blood plasma, which greatly contributes to the improvement of diagnostic tests, cost reduction and ease of execution.

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

Nota informativa N. 6/2023 - SES/GEVEDT: orientações sobre solicitação, avaliação e distribuição do medicamento doxiciclina 100 mg comprimido solúvel para os casos suspeitos de febre maculosa / Information note N. 6/2023 - SES/GEVEDT: guidance on requesting, evaluating and distributing the drug doxycycline 100 mg soluble tablet for suspected cases of spotted fever

Nota informativa com orientações sobre solicitação, avaliação e distribuição do medicamento doxiciclina para os casos suspeitos de febre maculosa no Estado de Goiás

Informative note with guidance on requesting, evaluating and distributing the drug doxycycline for suspected cases of spotted fever in the State of Goiás

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.

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.

Knowledge, Attitudes, and Practices on Rocky Mountain Spotted Fever among Physicians in a Highly Endemic Region-Mexicali, Mexico.

Rocky Mountain spotted fever (RMSF) is a potentially fatal tickborne disease caused by the bacterium, Rickettsia rickettsii and transmitted primarily by the brown dog tick (Rhipicephalus sanguineus) in the southwestern United States and Mexico. RMSF can be rapidly fatal if not treated early with doxycycline, making healthcare worker awareness and education critical to reduce morbidity and mortality. During 2008-2019, Mexicali experienced a RMSF epidemic with 779 confirmed cases, and an 11-year case-fatality rate of 18% (N = 140). A cross-sectional study was conducted with 290 physicians and physicians-in-training across 12 medical facilities in Mexicali. They were asked to complete a 23-item questionnaire to assess knowledge, attitudes, and practices for clinical, epidemiologic, and preventive aspects of RMSF. Half of participants were female, the largest age group was aged 25 to 44 (47%), and median time in practice was 6 years (interquartile rate: 1-21.5). Less than half (48%) surveyed were confident where diagnostic testing could be performed, and two-thirds did not regularly order serology (67%) or molecular diagnostic (66%) tests for RMSF when a patient presented with fever. Sixty-four percent knew doxycycline as first-line treatment of children < 8 years with suspected RMSF. When comparing healthcare workers with < 6 years of experience to those with ≥ 6 years, more experience was associated with greater confidence in where to have diagnostic testing performed (prevalence odds ratio [prevalence odds ratios [pOR]] = 2.3; P = 0.004), and frequency of ordering laboratory tests (serology, pOR = 3.3; P = 0.002; polymerase chain reaction, pOR = 3.9; P = 0.001). Continued education, including information on diagnostic testing is key to reducing morbidity and mortality from RMSF.

Clinical features of patients with Rocky Mountain spotted fever, dengue and chikungunya infection.

INTRODUCTION: Clinical distinction between arbovirus infections and those caused by rickettsia is crucial to initiate appropriate medical treatment. OBJECTIVE: To compare the differences between Rocky Mountain spotted fever (RMSF) and other vector-borne diseases (dengue and chikungunya) with similar clinical presentation, and to identify data that could aid rapid diagnosis of these diseases. METHODS: We evaluated sociodemographic, clinical and laboratory data of 399 patients from five hospitals and clinics of Sonora, Mexico, between 2004 and 2016, with laboratory-confirmed diagnosis of RMSF, dengue, or chikungunya. RESULTS: The RMSF group had the highest lethality (49/63 deaths, 77.8 %), followed by the chikungunya group (3/161, 1.9 %) and the dengue group (3/161, 1.9 %). Clinical differences included the presence of rash, edema, and pruritus; in addition, differences in multiple biomarkers such as platelets, hemoglobin, indirect bilirubin, and serum sodium levels were documented. CONCLUSION: Rash on the palms and soles, edema and absence of pruritus, together with high levels of direct bilirubin and severe thrombocytopenia could be useful indicators to differentiate patients at RMSF advanced stages from those with dengue and chikungunya.

INTRODUCCIÓN: La distinción clínica entre infecciones arbovirales y las provocadas por rickettsias es crucial para iniciar el tratamiento médico apropiado. OBJETIVO: Comparar las diferencias entre fiebre manchada de las montañas rocosas (FMMR) y otras enfermedades transmitidas por vector (dengue y chikungunya) con presentación clínica similar e identificar los datos que pudieran ayudar al diagnóstico rápido de esas enfermedades. MÉTODOS: Se evaluaron datos sociodemográficos, clínicos y de laboratorio de 399 pacientes de cinco hospitales y clínicas en Sonora, México, entre 2004 y 2016, con el diagnóstico confirmado por laboratorio de FMMR, dengue o chikungunya. RESULTADOS: El grupo con FMMR presentó la mayor letalidad (49/63 muertes, 77.8 %), seguido por el de chikungunya (3/161, 1.9 %) y el de dengue (3/161, 1.9 %). Las diferencias clínicas consistieron en la presencia de exantema, edema y prurito; además, se documentaron diferencias en múltiples biomarcadores como plaquetas, hemoglobina, bilirrubina indirecta y niveles de sodio sérico. CONCLUSIÓN: El exantema en palmas y plantas, edema y ausencia de prurito, aunados a niveles altos de bilirrubina directa y trombocitopenia severa pudieran ser indicadores útiles para diferenciar a pacientes con FMMR en etapas avanzadas de aquellos con dengue y chikungunya.

Serological evidence of Rickettsia in horses from a semi-arid Brazilian region.

Brazilian spotted fever (BSF) is a common tick-borne disease caused by Rickettsia rickettsii. Horses are the primary hosts of the main vector, Amblyomma sculptum, and are considered efficient sentinels for circulation of Rickettsia. Therefore, the aim of this study was to detect antibodies reactive to R. rickettsii antigens in horses from a non-endemic area in the north-central region of Bahia state, Brazil. Blood samples and ticks were collected from 70 horses from the municipalities of Senhor do Bonfim, Antônio Gonçalves, Pindobaçu, and Campo Formoso. The sera obtained were tested by an indirect immunofluorescence assay to detect anti-Rickettsia antibodies. Overall, 5.7% (4/70) of the horses reacted to R. rickettsii antigens. Ticks were collected from 18.6% (13/70) of the horses and were identified as A. sculptum and Dermacentor nitens. Despite being a non-endemic area, seropositive animals were identified in our study, suggesting circulation of rickettsial agents in the region. This is the first serological survey of this agent in horses from the north-central region of Bahia, and further studies are needed to understand the epidemiology of BSF in these locations.

Características clínicas de los pacientes con fiebre manchada de las Montañas Rocosas, infección por dengue y chikungunya / Clinical features of patients with Rocky Mountain spotted fever, dengue and chikungunya infection

Resumen Introducción: La distinción clínica entre infecciones arbovirales y las provocadas por rickettsias es crucial para iniciar el tratamiento médico apropiado. Objetivo: Comparar las diferencias entre fiebre manchada de las Montañas Rocosas (FMMR) y otras enfermedades transmitidas por vector (dengue y chikungunya) con presentación clínica similar e identificar los datos que pudieran ayudar al diagnóstico rápido de esas enfermedades. Métodos: Se evaluaron datos sociodemográficos, clínicos y de laboratorio de 399 pacientes de cinco hospitales y clínicas en Sonora, México, entre 2004 y 2016, con el diagnóstico confirmado por laboratorio de FMMR, dengue o chikungunya. Resultados: El grupo con FMMR presentó la mayor letalidad (49/63 muertes, 77.8 %), seguido por el de chikungunya (3/161, 1.9 %) y el de dengue (3/161, 1.9 %). Las diferencias clínicas consistieron en la presencia de exantema, edema y prurito; además, se documentaron diferencias en múltiples biomarcadores como plaquetas, hemoglobina, bilirrubina indirecta y niveles de sodio sérico. Conclusión: El exantema en palmas y plantas, edema y ausencia de prurito, aunados a niveles altos de bilirrubina directa y trombocitopenia severa pudieran ser indicadores útiles para diferenciar a pacientes con FMMR en etapas avanzadas de aquellos con dengue y chikungunya.

Abstract Introduction: Clinical distinction between arbovirus infections and those caused by rickettsia is crucial to initiate appropriate medical treatment. Objective: To compare the differences between Rocky Mountain spotted fever (RMSF) and other vector-borne diseases (dengue and chikungunya) with similar clinical presentation, and to identify data that could aid rapid diagnosis of these diseases. Methods: Sociodemographic, clinical and laboratory data of 399 patients from five hospitals and clinics of Sonora, Mexico, with laboratory-confirmed diagnosis of RMSF, dengue, or chikungunya between 2004 and 2016 were evaluated. Results: The RMSF group had the highest lethality (49/63 deaths, 77.8 %), followed by the chikungunya group (3/161, 1.9 %) and the dengue group (3/161, 1.9 %). Clinical differences included the presence of rash, edema, and pruritus; in addition, differences in multiple biomarkers such as platelets, hemoglobin, indirect bilirubin, and serum sodium levels were documented. Conclusion: Rash on the palms and soles, edema and absence of pruritus, together with high levels of direct bilirubin and severe thrombocytopenia could be useful indicators to differentiate patients at RMSF advanced stages from those with dengue and chikungunya.

Serological evidence of Rickettsia in horses from a semi-arid Brazilian region / Evidência sorológica de Rickettsia em cavalos da região semiárida do Brasil

Abstract Brazilian spotted fever (BSF) is a common tick-borne disease caused by Rickettsia rickettsii. Horses are the primary hosts of the main vector, Amblyomma sculptum, and are considered efficient sentinels for circulation of Rickettsia. Therefore, the aim of this study was to detect antibodies reactive to R. rickettsii antigens in horses from a non-endemic area in the north-central region of Bahia state, Brazil. Blood samples and ticks were collected from 70 horses from the municipalities of Senhor do Bonfim, Antônio Gonçalves, Pindobaçu, and Campo Formoso. The sera obtained were tested by an indirect immunofluorescence assay to detect anti-Rickettsia antibodies. Overall, 5.7% (4/70) of the horses reacted to R. rickettsii antigens. Ticks were collected from 18.6% (13/70) of the horses and were identified as A. sculptum and Dermacentor nitens. Despite being a non-endemic area, seropositive animals were identified in our study, suggesting circulation of rickettsial agents in the region. This is the first serological survey of this agent in horses from the north-central region of Bahia, and further studies are needed to understand the epidemiology of BSF in these locations.

Resumo A Febre Maculosa Brasileira (FMB) é uma importante zoonose causada por Rickettsia rickettsii, sendo seu vetor o Amblyomma sculptum. Cavalos são os principais hospedeiros desse carrapato e considerados sentinelas eficientes para detectar a circulação de Rickettsia. O objetivo deste estudo foi detectar anticorpos reativos a antígenos de R. rickettsii em cavalos de uma área não-endêmica na região Centro-Norte da Bahia, Brasil. Foram coletadas amostras de sangue e carrapatos de 70 cavalos nos municípios de Senhor do Bonfim, Antônio Gonçalves, Pindobaçu e Campo Formoso. Os soros obtidos foram testados pela reação de imunofluorescência indireta para detectar anticorpos anti-Rickettsia. No geral, 5,7% (4/70) dos cavalos reagiram sorologicamente para antígenos de R. rickettsii. Os carrapatos foram coletados em 18,6% (13/70) dos cavalos e foram identificados como A. sculptum e Dermacentor nitens. Embora seja uma área não endêmica, foram observados animais soropositivos, sugerindo a circulação de riquétsias na região estudada. Este é o primeiro estudo de levantamento sorológico desse agente em cavalos do Centro-Norte da Bahia. São necessários mais estudos para compreender a epidemiologia da FMB nesses locais.

Rickettsial infection in equids, opossums and ticks in the municipality of Monte Mor, state of São Paulo, Brazil.

The aim of this study was to investigate rickettsial infection in equids, opossums and ticks in the municipality of Monte Mor, a place where a Brazilian spotted fever case occurred in 2005. In addition, characteristics possibly associated with seropositivity in horses were analyzed. Serum samples from horses, mules and opossums (Didelphis albiventris) were subjected to indirect immunofluorescence assay (IFA) against Rickettsia rickettsii. The ticks collected from the animals were identified and Amblyomma sculptum ticks from the equids were tested using PCR for Rickettsia spp. Anti-R. rickettsii antibodies were detected in 22.6% (14/62) of the horses, none of the mules and 21.7% (5/23) of the opossums. Among the variables analyzed, only age > 12 years showed a statistically significant association with seropositivity among horses. All of the 166 A. sculptum ticks tested using PCR were negative. The results showed that rickettsiae of the spotted fever group was circulating in the municipality of Monte Mor when the samples were collected and indicate a need for surveillance of Brazilian spotted fever in this region.

Typhus Group Rickettsiosis, Brazilian Amazon.

Rickettsia rickettsii infection is the only rickettsiosis included in the list of reportable diseases in Brazil, where typhus group rickettsioses, mainly murine typhus, have been underreported. We report a case of typhus group rickettsiosis with unique ecologic particularities in a patient from the Brazilian Amazon, where, to our knowledge, rickettsioses have not been reported.

Needlestick-Associated Rocky Mountain Spotted Fever, Brazil.

We report a fatal case of Rocky Mountain spotted fever (RMSF) in a man in Brazil without recent history of tick bites or environmental exposure. He received an accidental needlestick while working as a nurse. The nurse and his patient died. Both cases were confirmed as RMSF by molecular methods.

Spotted fever group rickettsial infection in dogs and their ticks from domesticwildlife interface areas in southeastern Brazil / Infecção por rickettsias do Grupo da Febre Maculosa em cães e carrapatos de áreas de interface doméstico-silvestre no sudeste Brasileiro

Rickettsia rickettsii is the causative agent of Brazilian spotted fever (BSF), for which humans and dogs are both susceptible. Dogs are sentinels in serological surveys, however, canine disease is rarely reported. Therefore, we aimed to evaluate natural infection by spotted fever group (SFG) Rickettsia spp. in dogs and ticks collected from domiciles close to forest fragments, featuring domesticwildlife interface areas. Samples from 115 dogs and 135 ixodids were assessed by polymerase chain reactions (PCR) targeting the gltA gene for Rickettsia spp. and the ompA gene for the SFG rickettsial species. One dog (0.87%; 1/115) was positive for R. rickettsii. This dog presented nonspecific laboratory and clinical abnormalities (thrombocytopenia, hyperproteinemia, lymph node enlargement, emaciation, anorexia, and lethargy). Rickettsia parkeri was identified in 2.96% (4/135) of the ticks (Amblyomma sculptum, A. aureolatum, and Rhipicephalus sanguineus). This study confirmed the presence of SFG bacteria in non-endemic and preserved locations, where domestic and wild populations interact. We reinforce the fact that the dog is susceptible to natural R. rickettsii infection. Although this is a rare finding, preventive measures should be taken against BSF in the studied areas. Finally, R. parkeri infection is possibly being demonstrated in A. sculptum for the first time.(AU)

Rickettsia rickettsii é o agente causador da Febre Maculosa Brasileira (FMB), doença na qual humanos e cães são susceptíveis. Os cães são sentinelas nos inquéritos sorológicos, contudo, a doença canina é raramente descrita. Assim sendo, objetivou-se avaliar a infecção natural por Rickettsia spp. do Grupo da Febre Maculosa (GFM) em cães e carrapatos obtidos de domicílios próximos a fragmentos de mata, caracterizando áreas de interface domésticosilvestre. Amostras de 115 cães e 135 ixodídeos foram avaliadas pela reação em cadeia da polimerase (PCR) tendo como alvo o gene gltA de Rickettsia spp. e o gene ompA das espécies do GFM. Um cão (0,87%; 1/115) foi positivo para R. rickettsii. Este animal apresentou alterações clínicas e laboratoriais inespecíficas (trombocitopenia, hiperproteinemia, linfonodos edemaciados, emagrecimento, anorexia e letargia). Rickettsia parkeri foi identificada em 2,96% (4/135) dos carrapatos (Amblyomma sculptum, A. aureolatum e Rhipicephalus sanguineus). Este estudo confirmou a presença de bactérias do GFM em locais preservados e não endêmicos, onde populações domésticas e silvestres interagem. Reforçamos o fato do cão ser susceptível à infecção natural por R. rickettsii. Embora este seja um achado raro, medidas preventivas devem ser tomadas contra a FMB nas áreas estudadas. Em última análise, a infecção por R. parkeri possivelmente está sendo demonstrada pela primeira vez em A. sculptum.(AU)