The EZARET Study: Exploring Zoonotic Association and Risks for Extrapulmonary Tuberculosis in PNG

PNG has a high proportion of TB cases that are extrapulmonary i.e.occurring in the body somewhere other than the lungs (42% in 2016 compared to a global rate of 14% in 2017). Of the TB cases that are diagnosed, a low proportion are confirmed through bacteriological tests (26% in PNG, and around17% in East New Britain). Without such confirmation, the cause of PNG’s high rates of extrapulmonary TB is unclear.

There have been recent calls for action globally to explore zoonotic TB – TB that occurs in animals and is transmitted to humans. In 2018 the WHO Global TB report estimated that there were 142,000 cases globally of TB caused by M. bovis, a mycobacterium passed to humans by cattle and other mammals.

M.bovis has been associated with higher rates of extrapulmonary TB. It is not known if M.bovis still occurs in PNG as there has not been any testing in recent years.

Objective

EZARET is a mixed methods study that aims to:

• determine the proportion of TB that occurs in the lymph nodes (presumptive TB lymphadenitis) that is attributable to M. tuberculosis complex in three provinces in PNG: East New Britain Province (ENB), Eastern Highlands Province (EH), and National Capital District
• determine the proportion of presumptive TB lymphadenitis and of M. tuberculosis complex confirmed cases that are attributable to M. bovis in 3 provinces in PNG
• explore animal–human interactions that may pose a risk for zoonotic infections.

Timeline

2018–2023.