Human Cutaneous Anthrax Outbreak Associated with Livestock Contact, Georgia, 2012: a Case-Control Study
Edit original node
Background: Georgia’s National Centers for Disease Control (NCDC) registered increased human cutaneous anthrax in 2011-2012 (81, 143 respectively) compared to 2009-2010 (43, 27, respectively). We investigated to detect infection source and implement control measures.
Methods: We conducted a 1:2 matched case-control study in two high incidence regions, Kvemo Kartli, [KK] and Kakheti [Ka]. Cases were identified by disease surveillance and confirmed by PCR or culture. Two controls, matched by residence (within 250m) and gender were recruited. Matched analysis and conditional logistic regression were used to analyze data.
Results: We interviewed 70 cases and 140 controls. Case-patients were 18-72 years of age (median 40), 87% male; 79% from KK region. 17% disposed of dead animal (OR=20.1; 95%CI 2.6-156); 24% contacted sick animal (OR=14; 95%CI 3.2-61.5), 43% slaughtered animal (OR=7.3; 95%CI 3-17.9), 77% raised animals (OR=6.3; 95%CI 2.6-15.4), 50% contacted animal products (OR=4.2; 95%CI 2-8.8), 31% ate meat from their own farm (OR=3.9; 95%CI 1.5-10.4). Buying meat from butcher shop was protective (OR=0.4; 95%CI 0.2-0.8). 33% of case-patients reported soil-contact, but that was not associated with disease. In 2011 and 2012, 21 and 25 animal anthrax cases were reported, respectively.
Conclusions: Anthrax is an ongoing problem in Georgia. It is unclear why the number of cases increased in 2012, however, several risk factor for disease were identified. The source of human anthrax was most likely contact with a sick animal, slaughtering or disposing of carcass. We recommended use of personal protective equipment when slaughtering animals, enforcement of regulations to prevent slaughtering and sale of meat from sick animals, and vaccination of animals against anthrax. Vaccination of animals against anthrax in KK and KA was conducted in autumn 2012.
Keywords: cutaneous anthrax, case-control study, outbreak, Georgia