Neurological manifestation of Brazilian spotted fever in childhood

ABSTRACT 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.

A confirmed case of macrophage activation syndrome secondary to spotted fever rickettsiosis: Response to immunomodulation in a pediatric patient in northeastern, Mexico

An 8-year-old girl with a rash and high-grade fever for 6 days arrived at the emergency room. She had an erythematous macular rash on the face, trunk, arms, and legs. Further interrogation called attention to the presence of close contact with stray dogs. Her town had been recognized as a site of a rickettsiosis outbreak in the past year. Spotted fever rickettsiosis was suspected, and doxycycline treatment was initiated. Macrophage activation syndrome (MAS) secondary to Rickettsia rickettsii infection was diagnosed according to the Hemophagocytic lymphohistiocytosis and EULAR/PRINTO/PRES 2016 criteria. As there are no clear guidelines on the treatment of MAS secondary to R. rickettsii. the course of action taken by the pediatric intensive care unit team was to avoid disseminated intravascular coagulopathy and treat MAS, both life-threatening conditions. Directed therapy with high doses of methylprednisolone and intravenous immunoglobulin therapy was initiated. The patient recovered, regaining her functional state before the illness. Few articles have described the association between MAS and rickettsiosis, an illness with high mortality, which makes it paramount to detect and treat promptly.

Rickettsiosis de fiebre manchada. Estudio de casos notificados en un hospital pediátrico de segundo nivel en el noreste de México, 2012-2022 / Spotted fever rickettsioses. Study of cases reported in a secondary care pediatric hospital of northeastern Mexico, 2012-2022

Resumen Antecedentes: La rickettsiosis de fiebre manchada es una enfermedad grave y con alta tasa de letalidad si no se identifica oportunamente. Objetivo: Describir las características de los pacientes hospitalizados por rickettsiosis de fiebre manchada, así como los factores de riesgo asociados a mal pronóstico. Material y métodos: Se recabaron los datos del expediente clínico de pacientes hospitalizados entre agosto de 2012 y julio de 2022. Las variables se analizaron mediante prueba U de Mann-Whitney, prueba exacta de Fisher y regresión logística univariada y multivariada. Resultados: Se analizaron 26 pacientes, en quienes se identificó una mortalidad de 57.6 %. En la comparación entre grupos, el número de plaquetas fue menor en los no supervivientes (16.0 × 103/µL versus 25.9 × 103/µL, p = 0.031). El porcentaje de pacientes supervivientes que recibieron tratamiento más de 72 horas después del inicio de la fiebre fue 45.5 % (cinco pacientes) versus 86.7 % de los no supervivientes (13 pacientes), p = 0.034. Recibir tratamiento después de 72 horas del inicio de la fiebre incrementó 7.09 veces la probabilidad de desenlace fatal (RM = 8.09, IC 95 % = 1.1-55.8, p = 0.034). Conclusiones: Iniciar tratamiento adecuado posterior a 72 horas del inicio de la fiebre podría ser un factor de riesgo de mortalidad, de ahí que la importancia del diagnóstico oportuno y tratamiento adecuado de esta enfermedad.

Abstract Background: Spotted fever rickettsiosis is a serious disease with a high mortality rate if not timely detected. Objective: To describe the characteristics of patients hospitalized for spotted fever rickettsiosis, as well as the risk factors associated with poor prognosis. Material and methods: Data from medical records of patients hospitalized between August 2012 and July 2022 were collected. Variables were analyzed using Mann-Whitney's U-test, Fisher's exact test, and univariate or multivariate logistic regression analysis. Results: Twenty-six patients were analyzed, among which a mortality of 57.6% was identified. In the between-group comparison, platelet count was lower in non-survivors (16.0 × 103/µL vs. 25.9 × 103/µL, p = 0.031). The percentage of surviving patients who received treatment more than 72 hours after fever onset was 45.5% (five patients) vs. 86.7% of non-survivors (13 patients) (p = 0.034). Receiving treatment 72 hours after fever onset increased by 7.09 times the probability of a fatal outcome (OR = 8.09, 95% CI = 1.1-55.8, p = 0.034). Conclusions: Starting adequate treatment 72 hours after the onset of fever may be an important risk factor for mortality, hence the importance of timely diagnosis and appropriate treatment of this disease.

Caso autóctono de rickettsiosis por Rickettsia parkeri en la Selva Paranaense, Misiones, Argentina / Autochthonous Rickettsia parkeri rickettsiosis in the Paranaense Forest, Misiones, Argentina

Resumen Se informa un caso autóctono de rickettsiosis por Rickettsia parkeri, ocurrido en junio del 2018 en la zona selvática del Parque Provincial Urugua-í, Misiones, Argentina, región sin registros previos de esta enfermedad en humanos. Se describen los aspectos epidemiológicos, ecológicos, clínicos y de laboratorio necesarios para el diagnóstico oportuno y el tratamiento adecuado. Se resalta el hecho de considerar a las rickettsiosis como diagnóstico diferencial ante un paciente con síndrome febril agudo exantemático; el antecedente epidemiológico de exposición al vector característico de la región, garrapatas del género Amblyomma, es un elemento fundamental.

Abstract We report an autochthonous case of Rickettsia parkeri rickettsiosis occurred in June 2018 in a forested area of the Urugua-í Provincial Park, Misiones, Argentina. No previous records of this disease in humans have been previously reported in this region. The epidemiological, ecological, clinical, and laboratory features required for a proper diagnosis and adequate treatment are described here. The fact of considering rickettsiosis as a differential diagnosis in a patient with exanthematic acute febrile syndrome is highlighted, being the epidemiological history of exposure to the vector (ticks of the genus Amblyomma) an essential element.

Monitoring Weil–Felix test in epidemic retinitis

Purpose: The objective was to study the positivity of the Weil–Felix test (WFT) in epidemic retinitis (ER) during the course of the disease. Methods: This is a retrospective, observational case series of patients diagnosed with ER and presented to a tertiary eye care hospital in south India. Patients with positive WFT at the presentation, and who underwent a follow?up WFT during or after the resolution of ER were studied from September 2019 to March 2022. Patient’s demographics, timings of clinical presentation and resolution, and investigation details with a special focus on WFT positivity and its duration were noted. Results: Sixteen patients were studied. Patients presented after 5 weeks of the fever (range: 2?12 weeks, median: 4). After 1?2 months, WFT was still positive in eight patients (50%). Only in one patient titers increased after 1 month, while in others, the titers decreased (n = 11) or remained the same (n = 4). Repeated tests in those patients (n = 6) after 3?4 months turned negative. Resolution of ER was seen at 1.35 months (range: 1?3 months) after the presentation. The mean duration for WFT to turn negative was 2 months from the presentation (range: 1?4 months) or 3.2 months of the fever (range: 1.5?6 months). Conclusion: In contrast to the reported physician’s observation of increasing titers of WFT after rickettsial fever, ophthalmologists may observe decreasing WFT titers in ER. The clinical resolution of ER may precede the normalization of WFT. Follow?up WFT titers should be studied in larger series in confirmed cases of rickettsial?ER to validate the affordable and readily available WFT in India

A story of a lone star tick: an imported case of Amblyomma americanum (Linnaeus, 1758) infected with Rickettsia amblyommatis that parasitized a US traveler returning to Mexico

ABSTRACT In this study, we report the presence of a female Amblyomma americanum tick attached to a former resident of the East Coast of the United States who moved to Mexico city. The amplification and sequencing of gene fragments of the 16S-rDNA and cytochrome c oxidase subunit 1 corroborated the identification of the species of the tick. Additionally, the presence of DNA of Rickettsia amblyommatis was confirmed. This work is the first report of an exotic tick of the genus Amblyomma in a traveler from the US to Mexico and represents the second record of an imported tick attached to humans in Mexico.

Clinical and epidemiological analysis of 18 cases of Japanese spotted fever in Zigui County / 中华检验医学杂志

Objective:The epidemiological and clinical characteristics of 18 cases of Japanese spotted fever (JSF) in Zigui County were analyzed in order to improve the prevention and treatment of JSF.Methods:This is a case series analysis. The epidemiological and clinical data, laboratory tests and imaging characteristics of 18 JSF cases with median age of 60 years (54, 68) identified by The People′s Hospital of Zigui from April 2021 to August 2022 were collected and analyzed retrospectively.Results:Most (17/18) of the patients were farmers and all had a field exposure history. The patient′s onset was from April to October. Spring and autumn were the seasons with the highest incidence of JSF. The first symptoms of patients were high fever, headache, and fatigue. Of the 18 cases, 15 had a rash and 12 presented an eschar and 3 had neither rash nor eschar. In addition, 10 of 18 cases experienced edema of both lower extremities, and 3 got disturbance of consciousness. Laboratory tests found that 15 patients had abnormal white blood cells and 11 patients had decreased platelets. C-reactive protein, procalcitonin, D-dimer, lactate dehydrogenase, and alpha-hydroxybutyrate dehydrogenase were elevated in all patients; 13 patients with elevated alanine aminotransferase, 14 patients with elevated aspartate transamination. Kidney damage caused by Rickettsia japonica infection showed by abnormal proteinuria in 11 of the patients. Conclusions:The most common clinical manifestations of JSF are non-specific indications such as high fever, chills, fatigue, headache. The eschar and rash, which are the main features of Rickettsia infection, are not present in all patients, resulting delay of diagnosis or misdiagnosis. Medical workers should be more alert to rickettsial infections in patients with fever of unknown origin, especially in seasons of high incidence of spotted fever. Early diagnosis and correct antibiotic treatment shall be given according to the patient′s clinical manifestations, laboratory results and imaging test to control disease progression.

Early diagnostic value of mNGS for 15 cases with critical rickettsial disease in Hainan / 中华检验医学杂志

Objective:To explore the clinical utility of metagenomic next-generation sequencing (mNGS) for patients with critically ill atypical rickettsial infections in the early diagnosis and therapy.Methods:From Jan 2020 to Aug 2022, clinical features, blood biochemical results, imaging data and mNGS results in patients with unexplained critical illnesses were collected and analyzed retrospectively. Fisher's exact test was used to compare the positive rate of mNGS and weil felix reaction.Results:All 15 patients with rickettsial disease had fever, 12 cases had headache, but only 3 had a typical rash or scab of diagnostic significance, 6 had septic shock and all had multi-organ dysfunction; blood mNGS tests were positive in 15 cases, of which 10 had Orientia tsutsugamushi detected in their blood and the remaining five had Rickettsia moschata detected in their blood. The positive rate of mNGS was significantly higher than that of the weil felix reaction (15/15 vs 0, P<0.001). All patients were given doxycycline and other treatments after diagnosis, of which 14 improved and were discharged, and one died 1 week after discharge due to critical condition and abandonment of treatment. Conclusion:mNGS can improve the detection rate of atypical rickettsiae in patients with negative routine test results, which can provide valuable reference basis for early diagnosis and early anti-infection treatment of patients with critical rickettsial disease.

Historical geographic overlap of human rickettsiosis with animal reservoirs in Juiz de Fora, Minas Gerais, Brazil / Sobreposição geográfica histórica da riquetsiose humana com reservatórios animais em Juiz de Fora, Minas Gerais, Brasil

Background and objectives: we investigated the existence of a historical geographic overlap between the location of spotted fever group rickettsiosis human cases, a disease caused by the gram-negative bacterium Rickettsia sp., and that of mammalian reservoirs, specifically domestic horses and capybaras, in the urban perimeter of the city of Juiz de Fora, Minas Gerais, Brazil. Methods: cases of human rickettsiosis that occurred during a period of 17 years (2003-2020) were geolocated and the distribution of cases in time and geographic space was assessed using 1st and 2nd order geospatial association indicators. We also analyzed the overlap between the locations of human rickettsiosis cases and the area of occurrence of domestic horses and capybaras. Results: men were diagnosed more often than women, but a large proportion of affected women died. The results indicate an aggregation of human rickettsiosis cases in time (cases tend to occur close to each other at each epidemic event) and in geographic space (cases are concentrated in a specific geographic region of the urban perimeter). Human cases seem to be more associated with city regions with: i) higher local frequency of domestic horses and not capybaras; ii) lower rates of family development. Conclusion: it is suggested that, in the local epidemiological scenario, domestic horses appear to be the main sources of the rickettsia infecting humans, not capybaras.(AU)

Justificativa e objetivos: foi investigada a existência de uma sobreposição geográfica histórica entre a localização dos casos de riquetsiose humana do grupo da febre maculosa, um grupo de doenças causadas pela bactéria Gram-negativa Rickettsia sp., e dos reservatórios mamíferos, especificamente cavalos domésticos e capivaras, no perímetro urbano do município de Juiz de Fora, Minas Gerais, Brasil. Métodos: foram geolocalizados os casos de riquetsiose humana ocorridos durante um período de 17 anos (2003-2020), sendo avaliada a distribuição dos casos no tempo e espaço geográfico através de indicadores de associação geoespacial de 1a e 2a ordem. Também analisamos a superposição dos locais dos casos de riquetsiose humana com a área de ocorrência de cavalos domésticos e capivaras. Resultados: homens foram diagnosticados mais frequentemente que as mulheres, mas grande proporção das mulheres acometidas faleceu. Os resultados indicam uma agregação dos casos de riquetsiose humana no tempo (os casos tendem a ocorrer próximos entre si a cada evento epidêmico) e no espaço geográfico (os casos se concentram em uma região geográfica específica do perímetro urbano). Os casos humanos aparentam ser mais associados às regiões da cidade com: i) maior frequência local de cavalos domésticos e não das capivaras; ii) menores índices de desenvolvimento familiar. Conclusão: sugere-se que, no cenário epidemiológico local, são os cavalos domésticos que aparentam ser as principais fontes da riquétsia infectando os humanos, não as capivaras.(AU)

Justificación y objetivos: investigamos la existencia de una superposición geográfica histórica entre la localización de casos de rickettsiosis exantemáticas humana, enfermedad causada por la bacteria gramnegativa Rickettsia sp., y la de mamíferos reservorios, específicamente caballos domésticos y capibaras, en el perímetro urbano de la ciudad de Juiz de Fora, Minas Gerais, Brasil. Métodos: se geolocalizaron los casos de rickettsiosis humana ocurridos durante un período de 17 años (2003-2020), y se evaluó la distribución de casos en el tiempo y espacio geográfico utilizando indicadores de asociación geoespacial de 1er y 2do orden. También analizamos la superposición entre las ubicaciones de los casos de rickettsiosis humana y el área de ocurrencia de los caballos domésticos y capibaras. Resultados: los hombres fueron diagnosticados con más frecuencia que las mujeres, pero una gran proporción de mujeres afectadas fallecieron. Los resultados indican una agregación de casos de rickettsiosis humana en el tiempo (los casos tienden a ocurrir cerca uno del otro en cada evento epidémico) y en el espacio geográfico (los casos se concentran en una región geográfica específica del perímetro urbano). Los casos humanos parecen estar más asociados con regiones urbanas con: i) mayor frecuencia local de caballos domésticos y no de capibaras; ii) menores tasas de desarrollo familiar. Conclusión: se sugiere que, en el escenario epidemiológico local, los caballos domésticos parecen ser las principales fuentes de la rickettsia que infecta a los humanos, no los capibaras.(AU)

A rare case of scrub typhus vasculitis presenting as acute coronary syndrome diagnosed by skin manifestations

A 48-year-old diabetic man presented with complaints of acute onset chest heaviness with palpitations, anxiety and headache. He had raised troponin-T level and electrocardiogram showed ST elevation myocardial infarction. There was a prior history of fever of 4 days duration with associated abdominal pain. He later developed skin rash and neurological symptoms following admission to the hospital. Dermatological examination revealed purpura and a livedo-like rash. Investigations revealed deranged liver and renal function tests and positive serological tests for scrub typhus. Coronary angiography revealed no evidence of atherosclerosis or any other pathology. He was therefore diagnosed as a case of scrub typhus-induced vasculitis with coronary manifestations and was managed with oral doxycycline. Scrub typhus presenting like an acute coronary syndrome has been reported very rarely previously. In addition, patient had gastrointestinal, central nervous system and hematological involvement which added to the rarity of the case.

Rickettsiosis: La importancia de realizar un diagnóstico precoz y manejo temprano / Rickettsiosis: The importance of making an early diagnosis and early management

La rickettsia es una bacteria transmitida por vectores como la garrapata, piojos, ácaros entre otros. El ser humano es un hospedero accidental, la rickettsia se transmite al ser humano por medio de la saliva de la garrapata infectada inoculando la bacteria a la piel. Existen diferentes especies de rickettsia, la especie más importante en América es la Rickettsia rickettsii, reportándose casos en diferentes partes del mundo. Esta enfermedad se caracteriza por un daño al endotelio de los vasos sanguíneos de pequeño calibre, ocasionando lesiones en piel, a nivel pulmonar, cerebral y renal principalmente. Sus manifestaciones clínicas iniciales son inespecíficas y se pueden confundir con otras enfermedades por lo cual una historia clínica detallada es lo que nos puede llevar a una sospecha diagnóstica temprana. Esta patología se considera una enfermedad reemergente, debido a que en muchos lugares existe un subregistro de la misma, esto como resultado de una falta de sospecha clínica y aplicación de medidas de prevención. En Panamá desde los años 1950 se diagnosticaron los primeros casos. En este año en curso (2021), se diagnosticaron dos casos pediátricos en el Hospital del Niño Dr. José Renan Esquivel, los cuales serán objetos de revisión en este artículo.

Rickettsia are bacteria transmitted by vectors such as ticks, lice, mites. The human being is an accidental host, the rickettsia is transmitted to the human being through the saliva of the infected tick inoculating the bacteria to the skin. There are different species of Rickettsia, the most important species in America is Rickettsia rickettsii. This disease is characterized by damage to the endothelium of small caliber blood vessels, causing lesions mainly in the skin, lung, brain, and kidney. Its initial clinical manifestations are nonspecific and can be confused with other diseases, which is why a detailed clinical history is what can lead us to an early diagnostic. This disease is considered a reemerging disease in spite of having a wide distribution and knowledge of the disease due to lack of suspicion and prevention. In Panama, the first cases were diagnosed in the 1950s and this year 2021 two cases were diagnosed in children at the Hospital del Niño Dr. José Renán Esquivel.

Occurrence of tick-borne pathogens in dogs in a coastal region of the state of Ceará, northeastern Brazil / Ocorrência de patógenos transmitidos por carrapatos em cães em uma região litorânea do estado do Ceará, nordeste do Brasil

Abstract The aim of this study was to determine the occurrence of tick-borne pathogens (Ehrlichia canis, Babesia vogeli, Hepatozoon spp. and Rickettsia spp.) in dogs in Vila de Jericoacoara, coastal region of Ceará, Brazil. Blood samples were collected from 153 animals and analyzed using molecular and serological methods. Sixty animals were found to be infected or exposed to at least one of the pathogens studied. Babesia vogeli was the most prevalent pathogen (15%), followed by E. canis (13.7%) and Hepatozoon spp. (11.8%), which was identified as Hepatozoon canis through sequencing. Twenty dogs (13%) were seroreactive to Rickettsia spp. Rhipicephalus sanguineus sensu lato was observed on 11.8% of the animals. There were associations between age (< 3 years old) and positivity for B. vogeli, and between habitation (stray dogs) and positivity for H. canis. There were also associations between anemia and infection with H. canis, and between leukopenia and exposure to Rickettsia spp. No association was detected between clinical alterations and infection with or exposure to the pathogens studied. The results confirmed that pathogens of veterinary importance are circulating in northeastern Brazil and showed that dogs are exposed to Rickettsia species with zoonotic potential, thus indicating a need for vector control measures.

Resumo O objetivo deste estudo foi determinar a ocorrência de patógenos transmitidos por carrapatos (Ehrlichia canis, Babesia vogeli, Hepatozoon spp. e Rickettsia spp.) em cães na Vila de Jericoacoara, região costeira do Ceará, Brasil. Amostras de sangue foram coletadas de 153 animais e analisadas por métodos moleculares e sorológicos. Sessenta animais foram encontrados infectados ou expostos a pelo menos a um dos patógenos estudados. Babesia vogeli foi o patógeno mais prevalente (15%), seguido por E. canis (13,7%) e Hepatozoon spp. (11,8%), que foi identificado como Hepatozoon canis por sequenciamento. Vinte cães (13%) foram sororreativos à Rickettsia spp. Rhipicephalus sanguineus sensu lato foi observado em 11,8% dos animais. Houve associações entre idade (<3 anos) e positividade para B. vogeli, e entre habitação (cães de rua) e positividade para H. canis. Também houve associações entre anemia e infecção por H. canis, e entre leucopenia e exposição a Rickettsia spp. Não foi detectada associação entre alterações clínicas e infecção ou exposição aos patógenos estudados. Os resultados confirmaram que patógenos de importância veterinária estão circulando no nordeste do Brasil e mostraram que cães estão expostos a espécies de Rickettsia com potencial zoonótico, indicando a necessidade de medidas de controle do vetor.

A new focus of spotted fever caused by Rickettsia parkeri in Brazil

ABSTRACT Spotted fever (SF) is a tick-borne zoonosis caused by bacteria of the genus Rickettsia . The disease varies in severity from mild clinical forms to severe cases. In Brazil, Rickettsia rickettsii SF is the most serious rickettsiosis and can result in death if not diagnosed and treated at the onset of symptoms. The SF mild form is caused by Rickettsia parkeri strain Atlantic Rainforest, and this etiological agent has been reported in the South, Southeast and Northeast regions of the country, in areas of preserved or little antropized Atlantic Rainforest. Amblyomma ovale is the proven vector and dogs are the hosts associated with the bioagent cycle. During a SF case investigation in Paraty municipality, Rio de Janeiro State, an Atlantic Rainforest biome area in Southeastern Brazil, the human pathogen R. parkeri strain Atlantic Rainforest was detected by PCR in a sample of human skin inoculation eschar and in a female A. ovale tick collected from a dog. These results expand the known area of occurrence of this mild form rickettsiosis in Brazil. In addition, the results of the present study indicate the importance of implementing programs to control canine ectoparasites and to raise awareness of the risks of infection, signs and symptoms of SF caused by R. parkeri strain Atlantic Rainforest.

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

ABSTRACT 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.

Serological exposure of spotted fever group Rickettsia in capybaras (Hydrochoerus hydrochaeris) from urban parks in Campo Grande, Brazilian Midwest

ABSTRACT Background: Rickettsia of the spotted fever group (SFG) has been reported in ticks and domestic animals in Campo Grande (CG), Midwest Brazil. Methods: We searched for Rickettsia in the SFG in capybaras and their ticks in an urban park in the CG. Results: The seropositivity rate was 88.2% (15/17). Although 87.7% of the capybaras sampled showed infestations with Amblyomma sculptum, A. dubitatum, and Amblyomma spp., no molecular results were detected in ticks. Conclusions: Since Rickettsia from the SFG circulates among capybaras in the urban parks of Campo Grande, this large rodent species should be monitored within the One Health Agenda.

Rickettsia conorii infection with fatal complication

ABSTRACT Rickettsial diseases (RD) are a group of endotheliotropic infectious diseases caused by different species of genera Rickettsia. RD are not an uncommon disease and may be misdiagnosed during the evaluation of acute febrile illness due to a lack of reliable serological marker and diagnostic culture methods. Clinical manifestation of RD varies from febrile illness with rashes and myalgia to fatal complications such as shock and respiratory failure. We describe a case of a young male who presented initially with acute febrile illness, followed by shock and respiratory failure, and unfortunately succumbed to death. A post-mortem examination showed histological features of endotheliotropic infection, such as interstitial / perivascular edema in various organs and noncardiogenic pulmonary edema (suggesting increased vascular permeability) and evidence of vasculitis in the lung, liver, and intestines. Molecular studies performed from lung, liver, and kidney tissue confirm the diagnosis of spotted fever group rickettsial disease due to Rickettsia conorii.

Seroprevalence of rickettsial infection in northern Cyprus: A study among hunters

@#This study was conducted to investigate rickettsial seropositivity among hunters, a high-risk population for tick-borne diseases in northern Cyprus. Serum samples were collected from 300 hunters from different locations during the 2017-2018 hunting season (November 2017 - February 2018). The samples were analyzed by indirect immunofluorescence assay (IFA) using slides coated with Rickettsia slovaca, a species belonging to the spotted fever group (SFG). During the sample collection, a questionnaire was also applied to evaluate possible risk factors for rickettsial seropositivity. Of the 300 serum samples, six (2.0%) were found to be IgG-positive with a titer of 1:64. While all seropositive individuals were male, the statistical analysis revealed no significant association of gender with rickettsial seropositivity (p=1.000). Other factors including age (p=0.414), residential places of the participants (p=0.347), hunting years (p=0.694) or hunting abroad (p=1.000) did not significantly affect the IgG positivity. Also, no statistical correlation was found between a history of an arthropod (tick, louse, or flea) bite and rickettsial seropositivity (p=1.000). To our knowledge, this is the first study that demonstrates rickettsial seropositivity among human population in northern Cyprus. Our study suggests that awareness should be raised among the people especially involved in outdoor activities such as hunting, and control programs should be implemented to prevent possible rickettsiosis cases. Further serological studies using other Rickettsia spp. antigens, as well as molecular studies that search for Rickettsia spp. in humans, animals and arthropods are needed to obtain more comprehensive data on rickettsiosis in northern Cyprus.

A new record of Rickettsia japonica in ticks infesting a Burmese ferret-badger in Thailand

@#Ticks are important vectors of arthropod-borne diseases and they can transmit a wide variety of zoonotic pathogens to humans, domestic and wild animals. Rickettsia japonica is a member of SFG rickettsiae causing Japanese spotted fever (JSF) and can transmit to humans via infected ticks. In this study, we report the first case of Rickettsia japonica in Haemaphysalis hystricis tick collected from a roadkill Burmese ferret-badger (Melogale personata) in Loei province, northeastern Thailand. According to the DNA sequences and phylogenetic analyses of the outer membrane protein A and B genes (ompA and ompB), the detected R. japonica was identical to those found in JSF patients in Korea, Japan, and China, and closely related to Rickettsia detected by ompA in a tick from Thailand. Further study on the prevalence of R. japonica and diversity of mammalian reservoir hosts will be useful to gain a better understanding of JSF epidemiology.

Investigation on the infection of spotted fever group Rickettsiae and Rickettsia mooseri of wild rodents in the field of plague foci in Western Yunnan / 中华地方病学杂志

Objective:To investigate the infection of spotted fever group Rickettsiae (SFGR) and Rickettsia mooseri ( R.mooseri) of wild rodents in the field of plague foci in Western Yunnan. Methods:The DNA of liver samples of 2 512 wild rodents captured from the plague foci in Lianghe County, Jianchuan County and Yulong County in Western Yunnan from 2015 to 2016 was extracted by magnetic bead method, and the heat shock protein groEL gene primers were used for nested PCR amplification. Gene sequence splicing and Blast homology comparison were performed using DNAStar 7.1 software and GenBank of the National Center for Biotechnology Information (NCBI) of the United States, respectively, and DNAStar 7.1 and MEGA 6.0 softwares were used to construct phylogenetic trees.Results:The wild rodents infected with SFGR were Mus pahari, Rattus steini, Crocidura attenuata and Suncus murinus (one for each), with a total infection rate of 0.16% (4/2 512); no R.mooseri infection was detected. The SFGR infection rates of wild rodents in the plague foci of Lianghe County and Jianchuan County were 0.49% (3/611) and 0.10% (1/1 029), respectively; no SFGR infection was detected in the wild rodents in the plague foci of Yulong County. The homology analysis showed that the homology between SFGR positive samples and reference sequences was 95.45%-100.00%; some of the groEL gene sequences were highly similar among the four positive samples, and the homology was 89.60%-97.40%. Sequence evolution analysis showed that the sequences of three SFGR positive samples from the plague focus in Lianghe County were clustered in the same branch, and the homology reached 94.40%-97.40%; one positive sample sequence from the plague focus in Jianchuan County was clustered in one branch. Conclusion:SFGR infection rate of wild rodents in the field of plague foci in Western Yunnan is low, and no R.mooseri infection is found.