Prevalence of antibodies to spotted fever group rickettsiae in humans and domestic animals in a Brazilian spotted fever-endemic area in the state of São Paulo, Brazil: serologic evidence for infection by Rickettsia rickettsii and another spotted fever group Rickettsia.
In serum samples obtained from all the healthy humans, horses, dogs, and donkeys present on three farms in the Pedreira Municipality, an endemic area for Brazilian spotted fever, an indirect immunofluorescence assay (IFA) detected antibodies against Rickettsia rickettsii in 17 (77.3%) horses, 5 (31.3%) dogs (titers ranging from 64 to 4,048), and none of 4 donkeys or 50 humans. Five canine and eight equine sera with high antibody titers to R. rickettsii were also tested by IFA against R. bellii, R. akari, and R. africae antigens. Sera from two horses and two dogs that showed similar high antibody titers against two rickettsial antigens were evaluated after cross-absorption. Sera from seven horses and two dogs contained antibodies specific for R. rickettsii, and one dog serum had antibodies against a Rickettsia species very closely related to R. africae. The latter may have been caused by infection with the recently identified COOPERI strain.
Horta
Maurício C
MC
Faculty of Veterinary Medicine, and Department of Parasitology, University of São Paulo, São Paulo, Brazil.
Labruna
Marcelo B
MB
Sangioni
Luis A
LA
Vianna
Manoella C B
MC
Gennari
Solange M
SM
Galvão
Márcio A M
MA
Mafra
Claudio L
CL
Vidotto
Odilon
O
Schumaker
Teresinha T S
TT
Walker
David H
DH
D000818:Animals; D000829:Animals, Domestic / Q000382:microbiology*; D000907:Antibodies, Bacterial / Q000097:blood*; D001938:Brazil / Q000453:epidemiology; D004285:Dogs; D019353:Endemic Diseases; D005455:Fluorescent Antibody Technique; D006736:Horses; D006801:Humans; D015995:Prevalence; D012282:Rickettsia Infections / Q000453:epidemiology* / Q000382:microbiology / Q000662:veterinary; D012284:Rickettsia rickettsii / Q000276:immunology*; D012373:Rocky Mountain Spotted Fever / Q000097:blood / Q000453:epidemiology* / Q000382:microbiology; D016036:Seroepidemiologic Studies
D000907:Antibodies, Bacterial