Rickettsial infection in animals and Brazilian spotted fever endemicity.
We compared the rickettsial infection status of Amblyomma cajennense ticks, humans, dogs, and horses in both Brazilian spotted fever (BSF)-endemic and -nonendemic areas in the state of Sao Paulo, Brazil. Most of the horses and few dogs from BSF-endemic areas had serologic titers against Rickettsia rickettsii antigens. In contrast, no dogs or horses from BSF-nonendemic areas had serologic titers against R. rickettsii antigens, although they were continually exposed to A. cajennense ticks. All human serum samples and ticks from both areas were negative by serologic assay and polymerase chain reaction, respectively. Our results indicate that surveys of horse serum are a useful method of BSF surveillance in areas where humans are exposed to A. cajennense ticks. In addition, we successfully performed experimental infection of A. cajennense ticks with R. parkeri.
Sangioni
Luis A
LA
University of São Paulo, São, São Paulo, Brazil.
Horta
Maurício C
MC
Vianna
Manoella C B
MC
Gennari
Solange M
SM
Soares
Rodrigo M
RM
Galvão
Márcio A M
MA
Schumaker
Teresinha T S
TT
Ferreira
Fernando
F
Vidotto
Odilon
O
Labruna
Marcelo B
MB
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001938:Brazil / Q000453:epidemiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004285:Dogs; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006736:Horses; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D012282:Rickettsia Infections / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D012284:Rickettsia rickettsii / Q000235:genetics / Q000254:growth & development*; D012424:Rural Population; D013984:Tick Infestations / Q000382:microbiology; D013987:Ticks / Q000382:microbiology*
D000907:Antibodies, Bacterial; D004269:DNA, Bacterial