Suspected human anthrax outbreak investigation in a tribal village of Koraput, India, 2021.

Background: Odisha is a state in India endemic to anthrax disease with frequent reports of suspected animal cases. A suspected outbreak of anthrax in humans was reported on 24 October 2021 at Tukum village in Koraput district of Odisha, India after a bullock was found dead and consumed by the locals on 17 October 2021. Methods: This extended outbreak investigation was carried out through house-to-house active surveillance from 24 October to 2 November 2021 in the Koraput district. Eschar skin swabs from wounds were collected and processed at District Public Health Laboratory, Koraput, and analyzed in Indian Council of Medical Research-Regional Medical Research Centre, Bhubaneswar for molecular confirmation. Samples from bone, soil, and dried meat were collected from the contaminated sites and were transported to Animal Diseases Research Institute, Cuttack for confirmation. Results: Four suspected cases of human anthrax were identified who had handled and consumed dead bullock meat, among which one human had died later. The attack rate of the persons at risk in the village was calculated to be 1.23%. However, no Conclusion: Investigation revealed that a suspected anthrax cluster outbreak was due to butchering/de-skinning and consumption of the anthrax-infected dead animal. The presence of bacilli in human samples could not be confirmed due to the intake of antibiotics before the collection of sample. This finding highlighted the importance of sample collection at a suitable time and a possible need for one health approach for better coordination among the different responsible departments.