An investigation of an anthrax outbreak in Makoni District Ward 22 and 23 in Zimbabwe

Abstract

Background : The first official clinical case of human anthrax case was made at Makoni District Medical Office on the 19 th of December 2013. This followed cattle deaths which were confirmed in the laboratory to be due to anthrax. We report the clinical characteristics, distribution of anthrax cases (place and time), risk factors for contracting the disease, environmental assessment, district preparedness and response and outbreak prevention and control measures. Methods: We conducted an outbreak investigation with the design of a 1:1 unmatched case-control study. Data were collected using a structured questionnaire. Environmental assessment, district preparedness and response and outbreak prevention and control measures were assessed using checklists through observations and key informant interviews. Data were analyzed using Stata-16. Bivariate analysis was performed to identify risk factors for contracting anthrax. Results: Thirty-seven cases (37) and 37 controls were interviewed. All the cases had cutaneous anthrax with commonest site of eschar being the hand (43%). Most of the cases (89%) were managed according to national guidelines. Eating meat from a from a cattle slaughtered due unknown illness or died alone [OR = 7.00 , 95%CI(2.06-23.82], skinning [OR = 5.04, 95%CI(1.77-14.36)], cutting meat [OR = 5.32, 95%CI(1.91-14.77)], cooking meat [OR = 3.42, 95%CI(1.32-8.91.)], source of from other villagers [vs butchery, OR = 14.85, 95%CI(2.79-79.06)], cuts during cutting meat or skinning cattle [OR = 3.50, 95% CI(1.18-10.51)], belonging to a religion which permits eating meat from a from a cattle slaughtered due unknown illness or died alone [OR = 6.29, 95%CI(1.85-21.39)] were associated with contracting anthrax. Having heard of anthrax before was protective against contracting anthrax [OR = 0.35, 95%CI (0.13-0.93)]. The district was ill-equipped and delay to respond to the outbreak. Conclusion: The anthrax outbreak resulted from contact with and consumption of infected cattle meat. The district delayed and was not prepared to control the outbreak. However, the outbreak was controlled through cattle vaccination; health education and awareness campaigns. The district should strengthen its emergence preparedness and response capacity, revive zoonotic committees, conduct awareness campaign during the high-risk period and improve the surveillance of anthrax during high risk periods.