Rickettsial retinitis—an Indian perspective

BACKGROUND Though rickettsiosis is common in India, there is paucity of rickettsial retinitis (RR) reports from India. Moreover, rickettsial sub-types and their association with retinitis have not been studied. We are reporting a case series of presumed RR with their course of the disease, visual outcome, and association with rickettsial sub-type based on Weil-Felix test. FINDINGS This is a retrospective study of 19 eyes of 10 patients presented to a single institution. Cases diagnosed with presumed RR were identified from our database from March 2006 to October 2014 and studied retrospectively for patient's demography, clinical presentation, and treatment. Patients with history of fever, retinitis, and a positive Weil-Felix test and a negative chikungunya and dengue serology were diagnosed as presumed rickettsial uveitis. One patient was diagnosed to have epidemic typhus, and four were diagnosed to have Indian tick typhus. Nine patients had bilateral presentation. One patient had history of dog tick bite, and four patients had skin rashes. All the patients presented between 2 and 4 weeks after a fever. CONCLUSIONS Retinitis on posterior pole with recent history of fever with or without skin rash and a positive Weil-Felix test may suggest a rickettsial etiology. Its ocular manifestation could be an immune response to recent systemic rickettsial infection. Indian tick typhus and epidemic typhus could be the common sub-types seen in our population. Although it has aggressive presentation, it has a good visual prognosis.