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Diseases transmitted by ticks have been an important health problem all over the world. Brazilian Spotted Fever (BSF) stands for a serious epidemiological concern due to the high mortality rates pointed out. Capybaras are commonly incriminated as possible reservoirs in the BSF transmission cycle. In the last decades the numbers of these animals raised sharply and they have invaded human areas. They intensify the contact between ticks and humans beings. This study aim is to contribute to the possible role performed for this rodent in the BSF epidemiology in some areas located in Campinas region, São Paulo. Cabybaras infected by rickettsiae of BSF group were studied through the analysis of the frequencies of BSF-group rickettisae antibodies titer = 64 by indirect immunofluorescence test (IFA), and data from human cases epidemiological surveillance. The serum frequency positiveness varied greatly according to areas where animals were captured. However it was found serum positiviness only in the areas where human cases of BSF were reported. These findings suggest the capybara may be seen as sentinel animal. Due to presence of serological cross reactivity between microorganisms belonging to SF group, the results must be interpreted carefully and additional methods to distinguish pathogenic rickettsiae are required in our country. Doenças transmitidas por carrapatos vêm sendo um importante problema de saúde pública no mundo. A Febre Maculosa Brasileira (FMB) representa um sério risco epidemiológico devido às altas taxas de letalidade apresentadas. As capivaras são freqüentemente incriminadas como possíveis reservatórios no ciclo de transmissão da FMB. Nas últimas décadas o número desses animais cresceu intensamente e eles invadiram os espaços humanos. As capivaras intensificam o contato entre carrapatos e seres humanos na medida em que se apresentam muito infestadas por estes parasitos. O objetivo deste estudo é contribuir para o conhecimento do possível papel desempenhado por este roedor na epidemiologia da FMB em algumas áreas da região de Campinas, SP. Foi estudada a infecção das capivaras por rickettsias do grupo da FMB, por meio da análise das freqüências de anticorpos contra este grupo, nestes animais, e dados da vigilância epidemiológica de casos humanos. A freqüência desses anticorpos variou amplamente entre as localidades, entretanto, só foram encontrados soros com anticorpos com titulagem =64 naquelas onde havia notificação de casos humanos. Estes achados sugerem que a capivara poderá ser um animal sentinela. No entanto, devido à ocorrência de reação cruzada entre os microorganismos do grupo de FM estes resultados devem ser interpretados com cautela e são necessários métodos capazes de distinguir rickettsias patogênicas.

Entrevistas com 25 proprietários de rebanhos com produção diária acima de 500 litros de leite, sorteados da listagem da cooperativa de Passos/MG/Brasil, foram aplicadas para caracterizar suas percepções sobre a biologia do Boophilus microplus e suas atitudes no controle de carrapatos. A maioria desses produtores tem pelo menos o ensino médio completo e está na atividade há mais de dez anos. Os prejuízos biológicos produzidos pelos carrapatos são bem percebidos por eles; porém, não demonstraram conhecimento sobre a biologia do B. microplus e as desvantagens dos banhos carrapaticidas, principalmente com relação aos riscos toxicológicos. Esses produtores realizam controle de carrapatos sem critérios técnicos e com alta freqüência, baseando-se na avaliação subjetiva da infestação nos animais. Isto favorece o estabelecimento da resistência aos acaricidas e demonstra que a transferência de tecnologia sobre controle de carrapatos para o setor pecuário é falha. Twenty five dairy farms were randomly chosen from all farms producing more than 500 liters of milk/ day in Passos, MG, Brazil. The owners were interviewed to characterize their perceptions about the biology of B. microplus and their attitudes towards tick control. Most of the producers have a college degree and more than six year-experience in the activity. The biological damages caused by ticks are perceived by the farmers. Their tick control is performed without technical criteria and they did not show a proper knowledge on the biology of B. microplus nor on the toxicological risks of acaricides application. The results reveal a gap between the technology and farmers, favoring tick resistance to acaricides.

The emergence and reemergence of a serious infectious disease are often associated with a high case-fatality rate because of misdiagnosis and inappropriate or delayed treatment. The current reemergence of spotted fever rickettsiosis caused by Rickettsia rickettsii in Brazil has resulted in a high proportion of fatal cases. We describe two familial clusters of Brazilian spotted fever in the state of Minas Gerais, involving six children 9 months to 15 years of age; five died. Immunohistochemical investigation of tissues obtained at necropsy of a child in each location, Novo Cruzeiro and Coronel Fabriciano municipalities, established the diagnosis by demonstration of disseminated endothelial infection with spotted fever group rickettsiae. The diagnosis in the two fatal cases from Coronel Fabriciano and the surviving patient from Novo Cruzeiro was further supported by immunofluorescence serologic tests.

In June 2000, suspected cases of Brazilian spotted fever (BSF) occurred in Coronel Fabriciano Municipality, Minas Gerais State, Brazil. Pooled fleas collected near two fatal cases contained rickettsial DNA. The nucleotide sequence alignment of the 391-bp segment of the 17-kDa protein gene showed that the products were identical to each other and to the R. felis 17-kDa gene, confirming circulation of R. felis in Brazil.

Brazilian spotted fever is the most common rickettsiosis in Brazil, most prevalent in the States of São Paulo and Minas Gerais. The aim of this study was to describe the epidemiological characteristics of Brazilian spotted fever in Minas Gerais from 2000 to 2008. Of the 132 cases of Brazilian spotted fever, 53 patients died, representing a case-fatality rate of 40.2%. Males predominated, with 78.8% of confirmed cases, and median age was 26.5 years. Absence of rash was associated with increased risk of death (p = 0.005). Greater Metropolitan Belo Horizonte, Rio Doce Valley, and Zona da Mata accounted for 70.6% of the cases, which occurred mainly from May to November. There was an increase in the number of cases, which could suggest an expansion of the disease, but probably resulted from an increase in the health system's diagnostic capacity and sensitivity. Despite this improvement, the case-fatality rate remains high and with no apparent tendency to decrease, thus indicating the need for improved prevention and patient care. A febre maculosa brasileira é a rickettsiose mais comum do território nacional, com maior importância nos estados de São Paulo e Minas Gerais. O objetivo deste estudo foi descrever os aspectos epidemiológicos dos casos de febre maculosa brasileira ocorridos em Minas Gerais no período de 2000 a 2008. Dos 132 casos confirmados, 53 evoluíram para óbito, representando uma letalidade de 40,2%. O sexo masculino foi o mais acometido com 78,8% dos casos confirmados, e mediana de idade de 26,5 anos. Entre os fatores de risco determinantes do óbito, a ausência de exantema apresentou associação significativa (p = 0,005). A Região Metropolitana de Belo Horizonte, o Vale do Rio Doce e a Zona da Mata responderam por 70,6% dos casos, que ocorreram principalmente entre os meses de maio e novembro. Houve crescimento no número de casos, que apesar de sugerir expansão da doença, provavelmente decorreu do aumento da capacidade diagnóstica e sensibilidade do sistema de saúde. Apesar dessa melhora, a letalidade permaneceu alta e sem tendências à diminuição, o que implica a necessidade de medidas preventivas e assistenciais.

The authors describe their work in the Americas in Rickettsia felis cases in humans and the presence of Rickettsia felis in vectors.

We revisited a Brazilian spotted fever focal area in Minas Gerais state, Brazil, in 2002, and performed a serologic survey in dogs and cats. The results of this survey are compared with the survey made 10 years before. The possible efficacy of vector control measures adopted in this area and the role of dogs and horses as sentinels of infection by Rickettsia are discussed.

Brazilian spotted fever (BSF) rickettsiosis is the most common and recognized of the human rickettsioses in Brazil. It is difficult to establish the diagnosis of human rickettsiosis infection by routine microbiologic methods, creating a false idea that Rickettsia and Ehrlichia infections are rare and without importance. New tick-borne diseases, like Human Granulocytic Anaplasmosis (HGA) and Human Monocytic Ehrlichiosis (HME), have been described in many countries. These diseases can present symptoms similar to rickettsioses of the spotted fever group, and they are transmitted by ixodid ticks. The first two suspected cases of human ehrlichiosis in Brazil were first considered to be cases of BSF. The differential diagnosis was made at the Minas Gerais Rickettsiosis Public Health Laboratory. The clinical and laboratory findings, with positive serology for the HME agent, indicated suspected cases of human ehrlichioses in Brazil.

Depois da descoberta e caracterização inicial da Rickettsia felis em 1992 por Azad e cols, e à descrição subseqüente do primeiro caso de infecção humana em 1994, houveram duas comunicações de rickettsioses causadas por Rickettsia felis na América Latina. A primeira foi feita por Zavala-Velazquez e cols em 2000 no México. Em 2001, Raoult e cols descreveram a ocorrência de dois casos humanos de rickettsiose por Rickettsia felis no Brasil. Na presente discussão, esses dois artigos foram comparados, e depois da descrição dos principais sinais e sintomas, conclui-se que outros estudos são necessários, com a participação de um maior número de pacientes, para se estabelecer a verdadeira freqüência dos sinais clínicos e sintomas presentes nas rickettsioses por Rickettsia felis. After the discovery and initial characterization of Rickettsia felis in 1992 by Azad and cols, and the subsequent first description of a human case of infection in 1994, there have been two communications of human rickettsiosis cases caused by Rickettsia felis in Latin America. The first one was published in 2000 by Zavala-Velazquez and cols in Mexico. In 2001 Raoult and cols described the occurrence of two human cases of Rickettsia felis rickettsiosis in Brazil. In the present discussion these two articles were compared and after the description of the principal signs and symptoms, it was concluded that more studies are needed with descriptions of a greater number of patients to establish the true frequency of the clinical signs and symptoms present in Rickettsia felis rickettsiosis.

We report cases of spotted fever rickettsiosis in Coronel Fabriciano Municipality of Minas Gerais State, Brazil. The cases occurred in May and June of 2000. During this period there were two deaths among children from an area named Pedreira in a periurban area of this municipality. In a boy who died with clinical manifestations of Brazilian spotted fever, a necropsy revealed the presence of a spotted fever group Rickettsia. The serological results confirm the difficulty in the differential diagnosis of patients with symptoms of rickettsial diseases. São reportados casos de rickettsioses do grupo das febres maculosas no município de Coronel Fabriciano, Estado de Minas Gerais, Brasil. Os casos ocorreram nos meses de maio e junho de 2000. Durante este período, ocorreram dois óbitos em crianças procedentes de uma área peri-urbana conhecida como Pedreira no município de Coronel Fabriciano. Em um menino, que faleceu com manifestações clínicas da febre maculosa brasileira, à necropsia foi revelada a presença de Rickettsia do grupo das febres maculosas. Os resultados sorológicos confirmaram a dificuldade no diagnóstico diferencial de pacientes com sintomas de doenças rickettsiais.

O trabalho descreve um inquérito sorológico para rickettsioses em escolares e cães de Novo Cruzeiro, Minas Gerais, Brasil, em 1998. Trezentos e trinta e um escolares pertenciam a uma área endêmica e 142 a uma área não endêmica do município. Trinta e nove (10,1%) soros foram reativos à Reação de Imunofluorescência Indireta (RIFI) para Rickettsia rickettsii no título de 1:64, sendo que dentre esses reativos, 35 eram de estudantes de escolas de área endêmica. Dentre os 73 cães analisados quanto à presença de anticorpos anti R. rickettsii, anti Ehrlichia chaffeensis e anti Ehrlichia canis à RIFI no título de 1:64, 3 (4,11%), 11 (15,07%) e 13 (17,81%) desses animais foram reativos respectivamente aos antígenos testados. Conclui-se que, a sororeatividade para R. rickettsii em indivíduos sadios sem história prévia de febre maculosa brasileira, uma doença marcante por sua alta letalidade, e a presença de sororeatividade para Ehrlichia com potencial patogênico para o homem em cães, nos leva a indagar sobre a transmissão ao homem de outras espécies da família Rickettsiae na área estudada. This article describes a serological survey for rickettsiosis in the county of Novo Cruzeiro, Minas Gerais State, Brazil, in 1998, testing schoolchildren and dogs. Sera included 331 samples from schoolchildren from an endemic area and 142 samples from schoolchildren from a non-endemic area in the county. All children examined were healthy and had not reported clinical symptoms of Brazilian spotted fever prior to the serological survey. Some 35 children in the endemic area were reactive to Rickettsia rickettsii by indirect fluorescent antibody (IFA) with a titer of 1:64, corresponding to 10.6%. Sera from 73 dogs were tested, showing seroreactivity (IFA 1:64) to Rickettsia rickettsi, Ehrlichia chaffeensis, and Ehrlichia canis in 3 (4.11%), 11 (15.07%), and 13 (17.81%), respectively. The results in schoolchildren and the presence of canine seroreactivity to Ehrlichia species that are potentially pathogenic to humans suggests the risk of transmission of other Rickettsiae in the study area.

Brazilian spotted fever (BSF) is the most important and frequent rickettsial disease in Brazil. A fatal case of BSF is reported in a 32-year-old black man, who died of irreversible shock after five days of fever, severe headache and abdominal pain with no rash. Spleen, kidney and heart samples collected at autopsy were positive for Rickettsia rickettsii by PCR and sequencing. The authors emphasize the need for a high index of diagnostic suspicion for spotted fever in black patients. Absence of a skin rash should not dissuade clinicians from considering the possibility of BSF and initiating empirical therapy.

During the last 20 years, Brazilian spotted fever (BSF) has been the most common rickettsiosis and had the highest case–fatality ratio of any rickettsiosis in Brazil [1]. In Minas Gerais, many cases were described in the 1930s and 1940s, but no reports of BSF cases appeared in the medical literature during the decades of the 1950s, 1960s and 1970s. In the 1980s an epidemic form appeared in rural and peri-urban areas, predominantly in the valleys of Jequitinhonha, Mucuri and Rio Doce [2]. One of the objectives of this study was to understand the status of the BSF vectors and hosts in an area of low endemicity. The city of Santa Cruz do Escalvado, located in the Piranga Valley, Minas Gerais, Brazil (Table. 1), which is considered to be an old focus for BSF, was chosen. The first cases in this area occurred in 1985, with few cases after this date [3]. Table 1 Percentage of seroreactivity to rickettsiae by IFA at a titre of 1:64 in animals collected in Santa Cruz do Escalvado, Minas Gerais, Brazil MATERIALS AND METHODS The capture of wild animals and the serological survey were carried out in Santa Cruz do Escalvado every 3 months during the period from May 2005 to March 2006 in partnership with professionals of the National Foundation of Health (FUNASA). During the visits, traps to catch rodents (a total of 100 traps/collection) and opossums (a total of 20 traps/collection) were placed in nearby dwellings, including garages, sheds, stockpiles of food, plantations of corn, bamboo thickets, waste deposits and near the homes. Those samples were evaluated by indirect immunofluorescence reaction (IFA) using antigen obtained in Sao Paulo University for spotted fever group (SFG) rickettsiae (Rickettsia rickettsii, R. parkeri, R. felis and R. amblyommii) and Rickettsia bellii. Serum samples were tested at a dilution of 1:64 using the CDC protocol [4]. We captured wild vertebrates including rodents Rattus rattus (33), Nectomys squamipes (35) and Oryzomys subfalus (12) and opossums Didelphis aurita (14). From the 184 animals captured, we collected blood samples from 166 animals, as well as from 37 horses and 53 dogs. The rodents were caught around their common habitats. The species R. rattus was captured mainly in bunkers and warehouses. The species N. squamipes and O. subflavus were captured mainly in cultivated fields and woods. The 14 D. aurita opossums were captured in areas close to houses and also in thickets of bamboo.

The authors describe cases of Brazilian spotted fever (BSF) diagnosed in Minas Gerais state, Brazil, by the Minas Gerais Public Health Laboratory, Ezequiel Dias Foundation from 1995 to 2004. In addition they present three cases of human Rickettsia felis rickettsiosis from Minas Gerais diagnosed in France in 1999, and the first two suspected cases of human monocytic ehrlichiosis (HME) diagnosed in Ezequiel Dias Foundation in 2001. In both cases a differential diagnose was made with BSF.