What researchers described
as a "radical" bid to cut down on tuberculosis among South African
gold miners has failed to prevent infections or deaths, according to a study.
A high proportion – as
many as 3% – of miners begin treatment for the contagious lung
disease each year.
Tuberculosis spreads easily
among miners due to the close quarters in which they work, and the epidemic has
worsened along with the rise in HIV infections, according to the article in the
New England Journal of Medicine.
Read: Treating TB
Preventative drug therapy
The clinical trial led by
scientists at the London School of Hygiene and Tropical Medicine offered
thousands of South African miners a preventative drug therapy called isoniazid
over the course of nine months.
Previous research had shown
the drug was effective at preventing latent tuberculosis infection from
progressing to full-blown disease.
However, this trial showed
that while the therapy did appear to prevent TB while the participants were
taking it, the effects quickly wore off once they stopped.
One year after the end of
the intervention, researchers did not find any difference in the number of TB
cases among workers in the mines where TB preventive therapy was offered,
compared to mines that continued their standard practices.
No reduction in deaths
The trial therefore did not
reduce the number of cases or deaths from the disease.
"HIV, exposure to
silica dust in the mines and close working and living conditions predispose
South African gold miners to TB," said lead investigator Alison Grant, a
professor of international health.
Read: Diagnosing TB
control methods were not working, we investigated a radical approach to TB
control. Our study shows that isoniazid preventive therapy works while people
take it, but, in this setting, the effect was not enough to improve overall TB
A better approach
The findings suggest that a
better approach might include a combination of factors, from better TB testing
to prompter treatment for TB as well as HIV, along with preventative therapy
According to the World
Health Organization, TB is closely behind HIV/Aids as the top infectious killer
More than eight million
people were sickened by TB in 2012 and 1.3 million died from it.
How TB spreads
10 quick TB facts
(Picture: Black man blowing nose from Shutterstock)