Anthrax in humans and animals in north west Bangladesh

Anthrax causes significant economic loss and human suffering in Bangladesh, where the disease in animals is locally known as "Torka". The prevalence of disease is reported to be high in animals in the north-west regions of the country, and people become infected by handling diseased animals or infected animal products.

Vaccinating livestock is a key aspect of an anthrax control program, but this is impeded in Bangladesh due to the limited number of vaccines that are produced in the country. In some countries, human vaccines are available for people who are at occupational risk of acquiring anthrax, but no human vaccines are currently manufactured in Bangladesh.

Therefore, a cohesive disease prevention and control strategy is required, but there are insufficient data available to inform the development of such a strategy. For example, little is known about the socio-demographic distribution of human cases and the specific risk factors associated with outbreaks of infection; and the actual annual incidence of anthrax in livestock has not been reliably estimated.

This project is based in the northwestern regions of Bangladesh and it has two integrated branches:

  • A case-control study to investigate risk factors for people contracting cutaneous anthrax.
  • An enhanced pilot surveillance program of reported cases of anthrax in the major livestock species.

Objectives

Human case-control study

  • To obtain information about the socio-demographic characteristics of human cases of cutaneous anthrax.
  • To undertake a case-control study to assess risk factors associated with the occurrence of human anthrax.
  • To determine the sensitivity and specificity of the WHO symptom-based case definitions of human anthrax as applied in Bangladesh.

Enhanced livestock surveillance

  • To measure the number of anthrax cases in livestock that are reported to the upazilla veterinary office through the enhanced surveillance program.
  • To evaluate case reporting through the enhanced program as compared to the existing program.
  • To independently assess the effectiveness of village volunteers to conduct anthrax surveillance.

Intended outcomes

A functioning, one health, surveillance network for reporting animal anthrax cases will be formed that includes farmers, village volunteers and village heads, veterinary field assistants, members of the cooperative society, upazilla livestock officers, upazilla veterinary surgeons, community health workers and upazilla medical doctors. This should result in more accurate livestock surveillance data, which in turn will inform policy makers as to where to target the limited resources available for anthrax control.

The data from the concurrent case-control study will be used to produce recommendations for measures that prevent transmission from animal cases to people.

Taken together, the data from the surveillance programme and the case-control study of human anthrax will be used to provide policy recommendations for the development of an effective prevention and control program for anthrax in people and their livestock in Bangladesh.

The collaborative experiences gained through these two studies will guide future efforts to apply a one health approach to investigating other important zoonotic diseases.