A study, published Tuesday in the American Journal of Public Health, found that poor living and working environments for miners of diamonds and precious metals is significantly fueling the spread of tuberculosis in sub-Saharan Africa, Reuters reports.

Researchers estimate that up to 760,000 cases of TB could be the result of “crowded living and working conditions, dust in mines, and the spread of HIV,” the news service writes. For the study, “scientists took data on mining between 2001 and 2005 and compared them with TB incidence and death rates for 44 countries in sub-Saharan Africa. They found evidence that mining had a significant impact on the spread of TB, and that the risk appeared to be worst in countries with high levels of HIV.”

While HIV/AIDS is considered a major reason for the increase in TB cases, study leader David Stuckler of Oxford University and “colleagues said data shows that HIV is only one of several factors involved in TB’s spread in the region,” the news service writes. The annual incidence of TB in sub-Saharan Africa rose from 173 cases per 100,000 people in 1990 to 351 cases per 100,000 people in 2007, according to Reuters. 

The study notes that men who travel long distances to work in mines, such as from Botswana to South Africa, are at greatest risk of contracting TB. Their wives and children are also at high risk of catching the disease because the men often travel between work and home many times a year. “The study also found that when countries reduced their mining activity, TB rates fell more quickly, or rose less, than in neighboring nations where mining rates were stable or increased,” according to the news service (Kelland, 6/1).

The researchers noted that miners’ travel can disrupt treatment, which could lead to the development of drug-resistant strains, SAPA/East Coast Radio reports. The study “concludes that mining companies and governments must work together to achieve ‘similar levels of risk to those observed in Western mines,’ especially since mines in Africa were owned by the same companies,” the news service writes. The researchers recommended that health programs focus on helping miners continue care when they travel to work and conduct screenings to diagnose TB early (6/1).