Retrospective analysis of clinical information in Crimean-Congo haemorrhagic fever patients: 2014-2015, India

BACKGROUND & OBJECTIVES: Differential diagnosis of Crimean-Congo haemorrhagic fever (CCHF) from other acute febrile illnesses with haemorrhagic manifestation is challenging in India. Nosocomial infection is a significant mode of transmission due to exposure of healthcare workers to blood and body fluids of infected patients. Being a risk group 4 virus, laboratory confirmation of infection is not widely available. In such a situation, early identification of potential CCHF patients would be useful in limiting the spread of the disease. The objective of this study was to retrospectively analyse clinical and laboratory findings of CCHF patients that might be useful in early detection of a CCHF case in limited resource settings. METHODS: Retrospective analysis of clinical and laboratory data of patients suspected to have CCHF referred for diagnosis from Gujarat and Rajasthan States of India (2014-2015) was done. Samples were tested using CCHF-specific real time reverse transcription (RT)-PCR and IgM ELISA. RESULTS: Among the 69 patients referred, 21 were laboratory confirmed CCHF cases of whom nine had a history of occupational exposure. No clustering of cases was noted. Platelet count cut-off for detection of positive cases by receiver operating characteristic curve was 21.5×10([9])/l with sensitivity 82.4 per cent and specificity 82.1 per cent. Melaena was a significant clinical presentation in confirmed positive CCHF patients. INTERPRETATION & CONCLUSIONS: The study findings suggest that in endemic areas thrombocytopenia and melaena may be early indicators of CCHF. Further studies are needed to confirm these findings.