Neurological manifestations of Kyasanur Forest disease: a retrospective cohort study from South India

BACKGROUND: Kyasanur Forest disease (KFD) is a viral zoonotic disease where patients present with febrile illness and haemorrhagic manifestations in the first phase. In a small fraction of patients, the fever may be biphasic. This study aimed to describe the neurological manifestations of patients with KFD in the first and second phases of the illness. METHODS: This is a retrospective cohort study of 297 patients admitted with a molecular diagnosis of KFD from December 2018 to December 2020. The case records of these patients were reviewed for evidence of neurological involvement. RESULTS: A total of 34 (11.5%) patients in the first phase and 16 (36.4%) patients in the second phase had neurological involvement. Altered sensorium, seizures and focal infarcts were common in the first phase, while cerebellar signs and leptomeningeal enhancement were common in the second phase. CONCLUSIONS: Neurological involvement is seen in both phases of KFD. While in the first phase it is a result of possible encephalitis/encephalopathy, the second phase involvement is possibly due to postinfectious cerebellitis or meningitis.