Anthrax is an acute disease of warm-blooded animals, including human beings, caused by spore-forming gram-positive, non-motile bacillus anthracis [1]. The name of the bacterium is derived from “anthrakis”, the Greek word for coal, because anthrax in humans causes black, coal-like lesions on the skin at the site of inoculation [2].
Anthrax is a zoonotic bacterial disease caused by Bacillus anthracis, which primarily affects herbivorous wildlife and livestock and is usually fatal among these animals. Zoonoses are diseases that are transmissible between animals (domestic and wildlife) and humans. It has been estimated that 60% of all human diseases and around 75% of emerging infectious diseases are zoonotic, among which anthrax is a serious disease that can affect most mammals and several species of birds [3].
Anthrax is an important but neglected zoonosis in many parts of the world. The disease is mainly endemic in developing countries [3, 4].
In Ethiopia, anthrax is endemic and occurs before and after the rainy season. Most commonly, anthrax cases are reported in areas with high levels of salt soil [5]. It is one of the top five important livestock diseases and the second top priority zoonotic disease, next to rabies, in Ethiopia, which remains a major problem for animals and public health in Ethiopia. Particularly, the Amhara Regional state is frequently affected by diseases due to a humid, sub-humid environment, weak animal health services, and a lack of awareness of the community about animal anthrax case management, which leads to widespread outbreaks [6,7,8].
In Ethiopia, from July 2016 to January 30/2019, according to Ethiopian Public Health Institute (EPHI) and Public Health Emergency Management (PHEM) surveillance data, a total of 1,188 suspected human anthrax cases and 15 deaths with a case fatality rate (CFR) of 1.3%, were reported from four regions (Tigray, Amhara, Oromia, and South Nation nationalities of people (SNNPR). The highest number of cases were reported from Amhara (816), followed by Tigray (250), SNNPR (89), and Oromia (32). The highest number of deaths [9] was reported in Amhara (67% of the total deaths), with Oromia and Tigray having 2 deaths each (13.3%), and SNNPR one death (6.7%) [10].
Although suspected cases of anthrax in livestock are reported from Farta woreda, few are officially confirmed via polymer chain reaction (PCR) [10]. Previous studies in Ethiopia indicate that the disease is well recognized by rural communities but little is known about its prevalence, epidemiology, and public health significance (11.
The most efficient ways of preventing and controlling anthrax infection in domestic herds are sustainable surveillance, annual vaccination of livestock, and proper carcass disposal management [6,7,8,9,10].
Justification of the study
On March 23, 2019, suspected human anthrax cases and the deaths of animals were captured from social media (Facebook) scanning. To verify this rumor, the Amhara Public Health Institute communicated with the South Gondar zone health department officers and confirmed that two suspect cases of human anthrax were admitted to Debre Tabor General Hospital and an additional two animal deaths were reported from the Farta district. Simultaneously, we communicated with the Ethiopian Public Health Institute for further confirmation of cases through the testing of clinical specimens (Fig. 1). They collected blood and tissue scraps from suspected human anthrax cases.
Outbreak investigations of anthrax are important for strengthening the surveillance system, clarifying gaps, identifying anthrax cases early, and strongly promoting a one-health approach. Therefore, this study addresses the root causes of the anthrax outbreak and identifies anthrax cases for the implementation of prevention and control activities in the South Gondar zone, prioritizing anthrax as a public health threat for the time being. The objectives of this study were to verify the existence of outbreaks and identify risk factors for anthrax in Farta woreda, South Gondar zone, Amhara region, in March 2019.