Antibodies for Rickettsia spp. in patients with negative serology for dengue virus, leptospirosis, and meningococcal disease in municipalities of São Paulo State, Brazil.
BACKGROUND
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.
Programa de Pós-Graduação Stricto Sensu Saúde Coletiva-Epidemiologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
Juliana Anacleto Cabral
JA
Prata
Superintendência de Controle de Endemias, Mogi-Guaçu, São Paulo, Brazil.
Celso Eduardo de
CE
Souza
Departamento de Doenças de Notificação Compulsória, Hospital das Clínicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
Rodrigo Nogueira
RN
Angerami
Laboratório de Sorologia, Instituto Adolfo Lutz, Campinas, São Paulo Brazil.
Taíse Marongio Cotrim de Moraes
TM
Barbosa
Laboratório de Riquétsias, Centro de Virologia, Instituto Adolfo Lutz, São Paulo, São Paulo, Brazil.
Fabiana Cristina Pereira Dos
FC
Santos
Laboratório de Riquétsias, Centro de Virologia, Instituto Adolfo Lutz, São Paulo, São Paulo, Brazil.
Silvia
S
Colombo
Laboratório de Sorologia, Instituto Adolfo Lutz, Campinas, São Paulo Brazil.
Vânia Martins Fontes Del
VM
Guercio
Programa de Pós-Graduação Stricto Sensu Saúde Coletiva-Epidemiologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.
Maria Rita
MR
Donalísio
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D001938:Brazil / Q000453:epidemiology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood* / Q000276:immunology; D008297:Male; D015995:Prevalence; D012281:Rickettsia / Q000145:classification / Q000276:immunology*; D012282:Rickettsia Infections / Q000175:diagnosis / Q000453:epidemiology*; D016036:Seroepidemiologic Studies
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007075:Immunoglobulin M