A descriptive study of 63 patients with rickettsial infections: reasons for delay in the diagnosis

Abstract

BACKGROUND: Most patients with rickettsial infections present to hospital as cases of "febrile illness of unknown origin". The delay in diagnosis may result in severe complications. Objectives: To determine reasons for the delay in diagnosis of rickettsial infections. DESIGN, SETTING AND METHODS: Patients admitted to the University Medical Unit, Colombo North Teaching Hospital, Ragama from November 2004 and diagnosed as having rickettsial infections and junior medical staff (JMS) were interviewed retrospectively to find possible reasons for delay in diagnosis. RESULTS: 63 patients [31 males; mean age 36 years (SD:12.2)] were recruited. (39 and 24 were later confirmed for Orientia tsutsugamushi, R. conorii infection byiFA titre >1:128) The mean duration of illness on admission was 9 days (SD:2.2). Clinical features on admission were fever 63(100%), headache 56(89%), lymphadenopathy 42(67%), eschar 42(67%), rash 12(19%), hepatomegaly 22(34%), splenomegaly 17(26%), deafness 6(9%), and tinnitus 8(12%). All 49 patients who could recall pre¬admission medication said they had not been given anti-rickettsial antibiotics. Interview of JMS (after-admission) showed that rickettsial infections were not considered in the differential diagnosis of 38(60%) patients. The other 25 were examined for an eschar: missed in 10(40%), detected in 9(36%) but not interpreted correctly in 7 of the 9 (63%). Rash was detected in all 12 patients who had it, but diagnosis was not considered in 10(83%). CONCLUSION: The main reasons for the delay in diagnosis seem to be lack of awareness of the high prevalence of rickettsial infections and poor knowledge of clinical features among junior medical staff.