Short Report: First Outbreak of Atlantic Rainforest Spotted Fever in North-Eastern of Brazil-Clinical Features and Eco-Epidemiological Investigation.
Gabriel Nunes de Oliveira, Ruan Carvalho Passos, Ricardo Siqueira Bovendorp et al.
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Case in brief
Three people developed illness after tick bites while entering Atlantic Forest areas in Ilhéus, Bahia, between March 11 and April 4, 2025. Symptoms began 7–10 days after exposure and included an enlarging inoculation eschar, rash, regional lymphadenopathy, fever, myalgia, and prostration. Rickettsia parkeri strain Atlantic rainforest DNA was detected in eschar samples from all three; two patients also showed IgG seroconversion. All responded to doxycycline. Investigators collected immature Amblyomma ovale ticks from wild rodents at the exposure sites, supporting the local eco-epidemiological context.
What made this case unusual
The cases constitute the first reported cluster of Atlantic rainforest spotted fever in Brazil, with all three confirmed by molecular analysis.
Diagnostic / clinical pearl
After tick exposure in an Atlantic Forest area, an enlarging inoculation eschar with fever and rash should prompt consideration of Atlantic rainforest spotted fever; eschar material can provide molecular confirmation.
Why it matters
The cluster supports transmission potential in southern Bahia and the authors identify the area as endemic for the disease.