Characterization of rickettsia rickettsii in a case of Fatal Brazilian spotted fever in the city of Rio de Janeiro, Brazil

Abstract

A lethal case of Brazilian spotted fever (BSF) is presented. Clinical features were initially of gastrointestinal involvement and evolved with progression to septic shock, meningoencephalitis and death on the 6 th day of illness. Indirect immunofluorescence assay (IFA) for spotted fever group rickettsia (SFGR) was non-reactive. Diagnosis was confirmed by the polymerase chain reaction (PCR) and the nucleotide sequencing of a fragment of the ompA gene showed 100% homology to Rickettsia rickettsii. BSF has not been reported in the city of Rio de Janeiro in the last three decades, and the present description should alert the clinicians to its presence in urban Rio de Janeiro, and to the differential diagnosis with dengue fever, gastroenteritis, leptospirosis and bacterial septic shock, among others. Key-Words: Brazilian spotted fever, spotted fever group rickettsia, Rickettsia rickettsii, lethal case, Rio de Janeiro city, indirect immunofluorescence, polymerase chain reaction, central nervous system involvement.Brazilian spotted fever (BSF) is a systemic disease caused by Rickettsia rickettsii, a bacterium transmitted by the horse tick Amblyomma cajennense. It is endemic in the Southeast of Brazil (Rio de Janeiro, São Paulo, Minas Gerais and Espírito Santo states) and affects exposed children and adults [1][2][3][4]. Case presentation mimics several conditions which are endemic in the area, such as dengue fever, leptospirosis, gastroenteritis, meningococcal meningits and severe sepsis [1][2][3][4]. This paper reports a fatal case of BSF, occurring in July, in the metropolitan area of Rio de Janeiro, with prominent sepsis, rash and neurological and cerebrospinal fluid (CSF) findings. Case ReportA 48 year-old white male presented, six days prior to hospital admission, with acute onset of high-grade fever, myalgia, headache, nausea, vomiting and diarrhea. He was a heavy smoker, but past medical history was otherwise unremarkable. He sought medical attention and was treated symptomatically. Two days later his symptoms persisted and he developed jaundice: he was given sulfamethoxazole-trimethoprim and was sent home. The following day he sought the Emergency ward because of hematemesis and melena; he was oliguric. He was transferred to an infectious diseases reference hospital with the presumptive diagnosis of leptospirosis. He was a porter in the north area of Rio de Janeiro, and had frequent contact with rodents. He had been bitten by ticks in Campo Grande (west area of Rio Janeiro) two weeks previously, while visiting his brother, who was a horse cart driver. On arrival he was jaundiced, in deep coma with no neck stiffness, systolic blood pressure was 60 mmHg, heart rate =128 bpm, and a generalized purpuric rash was noted. He was intubated, mechanically ventilated, given rapid intravenous fluid, noradrenaline, ceftriaxone, oxacillin and chloramphenicol. Myoclonus was observed, and two hours after admission he presented a generalized tonic-clonic seizure. Initial investigation showed leukocytosis (18,200 cells/mm 3 , di...

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Fatal Brazilian spotless fever caused by Rickettsia rickettsii in a dark-skinned patient

“…Described for the first time in 1929, Brazilian spotted fever (BSF) is caused by Rickettsia rickettsii and is considered the most important spotted fever group rickettsiosis (SFGR) in Brazil [1][2][3][4][5][6] . Since 2001, when national compulsory notification was implemented, the number of notified BSF cases has increased and in the last 10 years, more than 735 confirmed cases have been reported, with a mean mortality of 28% (Brazilian Ministry of Health, 2009).…”

Survey for Tick-Borne Zoonoses in the State of Espirito Santo, Southeastern Brazil

“…[3][4][5][6][7][8] Lyme disease-like syndrome is an emerging clinical entity that has been described in Brazil, and imitates the clinical manifestations of the classical Lyme disease from the northern hemisphere. However, no spirochetes have been identified in Brazilian patients and ticks, despite exhaustive use of molecular and microbiological assays on clinical samples.…”