Antibodies for Rickettsia spp. in patients with negative serology for dengue virus, leptospirosis, and meningococcal disease in municipalities of São Paulo State, Brazil.

INTRODUCTION: Brazilian spotted fever is an infectious disease with a high mortality rate if not treated early. Differential diagnosis is difficult, as the first clinical signs are non-specific and can be confused with other diseases. The aim of the study was to investigate evidence of infection with Rickettsia rickettsii and Rickettsia parkeri in negative sera samples, collected in 2014, from patients with suspected leptospirosis, dengue fever, and meningococcal disease in Atibaia and Bragança Paulista municipalities of the State of São Paulo. METHODS: The samples stored at the Institute Adolfo Lutz in Campinas were tested using an indirect immunofluorescence assay (IFA) with IgG and IgM against R. rickettsii and R. parkeri. Real-time polymerase chain reaction (PCR) testing was performed for the sera samples of patients who died (n = 3), those with initial suspicion of meningococcal disease (n = 6), and those with positive IFA results. RESULTS: Of 258 samples from Bragança Paulista, 4 (1.6%) were positive, with IgG titers of 1:64 and 1:128 against R. rickettsii and R. parkeri, respectively. Of 155 samples from Atibaia, 2 (1.3%) were positive, with IgG titers of 1:64 and 1:128 against R. rickettsii and R. parkeri, respectively. No sample showed positive PCR results. CONCLUSIONS: This serological investigation suggests there is evidence of exposure to Rickettsia spp. in residents of areas that have environmental conditions favorable to the spread of bacteria, in which Brazilian spotted fever incidence was not previously confirmed.

Antibodies for Rickettsia spp. in patients with negative serology for dengue virus, leptospirosis, and meningococcal disease in municipalities of São Paulo State, Brazil

Abstract INTRODUCTION Brazilian spotted fever is an infectious disease with a high mortality rate if not treated early. Differential diagnosis is difficult, as the first clinical signs are non-specific and can be confused with other diseases. The aim of the study was to investigate evidence of infection with Rickettsia rickettsii and Rickettsia parkeri in negative sera samples, collected in 2014, from patients with suspected leptospirosis, dengue fever, and meningococcal disease in Atibaia and Bragança Paulista municipalities of the State of São Paulo. METHODS The samples stored at the Institute Adolfo Lutz in Campinas were tested using an indirect immunofluorescence assay (IFA) with IgG and IgM against R. rickettsii and R. parkeri. Real-time polymerase chain reaction (PCR) testing was performed for the sera samples of patients who died (n = 3), those with initial suspicion of meningococcal disease (n = 6), and those with positive IFA results. RESULTS Of 258 samples from Bragança Paulista, 4 (1.6%) were positive, with IgG titers of 1:64 and 1:128 against R. rickettsii and R. parkeri, respectively. Of 155 samples from Atibaia, 2 (1.3%) were positive, with IgG titers of 1:64 and 1:128 against R. rickettsii and R. parkeri, respectively. No sample showed positive PCR results. CONCLUSIONS This serological investigation suggests there is evidence of exposure to Rickettsia spp. in residents of areas that have environmental conditions favorable to the spread of bacteria, in which Brazilian spotted fever incidence was not previously confirmed.

Importância de Rattus norvegicus capturados no Município de São Paulo, SP, Brasil, como hospedeiros paratênicos de Toxocara canis (Ascaroidea, Nematoda) / Importance of Rattus norvegicus as parathenic hosts to Toxocara canis (Ascaroidea, Nematoda) in Sao Paulo, SP, Brazil

Analisaram-se os soros de 121 exemplares de Rattus noruetricus capturados no município de São Paulo, através de reação de hemaglutinação passiva, para pesquisar a presença de anticorpos anti-Toxocara, com a finalidade de avaliar o potencial destes roedores como hospedeiros paratênicos de Toxooara canis. Considerando como positivos os soros cujo título foi igualou superior a 1:20, em 28 ratos (23,120/0) revelaram-se anticorpos anti-Toxocara, indicando que é freqüente a infecção destes animais por T. canis em nosso meio e a possibilidade de atuarem estes murídeos como hospedeiros paratênicos para o nematóide (AU).