Apathy in the elderly: an atypical manifestation of spotted fever rickettsioses

Apathy denotes a lack of motivation, enthusiasm, feelings, or concern. Decreased daily functions and cognitive impairment are other features. In the elderly, these manifestations are overlooked and attributed to ageing or associated comorbidities. Spotted fever group rickettsial (SFG) infections are endemic in the Central Hills of Sri Lanka. We observed occult SFG infection as a treatable cause of apathy in the elderly. We studied patients with apathy admitted to the Teaching Hospital, Peradeniya (THP), Sri Lanka, during 2018 & 2019. The diagnosis was confirmed by indirect immunofluorescence assay (IFA-IgG) rising titers. There were 12 patients aged 64 to 85 years, of whom eight were female. The duration of illness ranged from 5 days to 5 months, with a median of 3 weeks. The presenting symptoms were feverish feeling (66·7%), headache (58·3%), gastrointestinal disturbances (66·7%), changing sleep pattern (100%) and cognitive disturbance (100%). A discrete, maculo-papular, erythematous rash on the limbs was observed in 3 (25%) patients. All had a faint rash on the insole, mild facial puffiness, and mild ankle swelling with pain. Treatment primarily included doxycycline or chloramphenicol. Apathy is a treatable atypical manifestation of rickettsial infections in the elderly and requires strong clinical suspicion and exclusion of other causes. Early recognition of symptoms and further examination for occult clinical features of rickettsial infection helps in diagnosis.