Risk factors for contracting anthrax in Kuwirirana ward, Gokwe North, Zimbabwe

NT Gombe, BMM Nkomo, A Chadambuka, G Shambira, M Tshimanga

Abstract

Background: A report of an anthrax outbreak was received at Gokwe district hospital from the Veterinary department on the 23rd January 2007. This study was therefore conducted to determine risk factors for contracting anthrax amongst residents of Kuwirirana ward.

Methods: We conducted a 1:1 unmatched case control study. A case was any person in Kuwirirana ward who developed a disease which manifested by itching of the affected area, followed by a painful lesion which became papular, then vesiculated and eventually developed into a depressed black eschar from 12 January to 20 February 2007. A control was a person resident of Kuwirirana ward without such diagnosis during the same period.

Results: Thirty-seven cases and 37 controls were interviewed. On univariate analysis, eating contaminated meat (OR = 7.7, 95% CI 2-29.8), belonging to a household with cattle deaths (OR= 9.7, 95% CI 2.9-33), assisting with skinning anthrax infected carcasses (OR= 5.4(95% CI 1.7-17), assisting with meat preparation for drying (OR = 5(95%CI 1.9-13.9), assisting with cutting contaminated meat (OR = 4.8(95% CI 1.7-13.2), having cuts or wounds during skinning (OR = 19.5, 95% CI 2.4-159) and belonging to a village with cattle deaths (OR = 6.5(95%CI 1.3-32) were significantly associated with anthrax.

Conclusion: Anthrax in Kuwirirana resulted from contact with and consumption of anthrax infected carcasses. We recommend that the district hold regular zoonotic committee meetings and conduct awareness campaign for the community and carry out annual cattle vaccinations.

Key Words: Zimbabwe, Gokwe, Outbreak, Anthrax, Bacillus anthracis