A case series of spotted fever rickettsiosis with neurological manifestations in Sri Lanka

Abstract

BACKGROUND: Spotted fever group (SFG) rickettsial infections are increasingly detected in Sri Lanka. We describe 17 patients with SFG who developed neurological manifestations. METHODS: The cases were studied prospectively from 2008 at the Teaching Hospital, Peradeniya. An immunofluorescent antibody assay (IFA) was used to confirm the diagnosis. RESULTS: All had an IFA IgG titer ranging from 1/64 to 1/4096 and a positive IFA IgM titer against Rickettsia conorii antigen; in 10 (59%) cases the IgG titers were ≥ 1/256 (definitive cases). The median age of the patients was 62 years (range 26-82 years); 10 were male and seven female. The median duration of fever was 12 days (range 4-35 days). Neurological manifestations on admission were drowsiness or confusion in 14 (82%) and a semi-comatose state in three (18%). Rigidity of the limbs occurred in 14 (82%), bradykinesia and resting tremors in 12 (71%), which persisted after defervescence, neck stiffness in seven (42%), weakness of the limbs in five (29%), deafness in two (12%), and stupor in three (18%). Electroencephalograms in three (18%) showed generalized slow waves. Cerebrospinal fluid examination showed a cellular reaction, predominantly lymphocytes, in three cases. Two patients died (fatality rate 12%). CONCLUSION: We have documented for the first time the neurological features of SFG rickettsioses in the Central Province, Sri Lanka. These were predominantly extrapyramidal features in patients of older age.