The study, published in PLOS One (6 October), notes this has a “significant impact on disease transmission as well as healthcare delivery”.
“With TB, once infected, one is infected for life. That is why we call that as latent TB. It can flare up as active TB any time.”
T. Jacob John, Christian Medical College, Vellore, India
Since there are no nationally representative data on infections among TB health workers, the study looked at 18 different individual studies from seven countries — Bangladesh, Brazil, China, India, South Africa, Uganda and Zimbabwe.
The study found 43 per cent of India’s TB healthcare workers with latent tuberculosis infection (LTBI), which refers to inactive and no transmissible infection that carries lifetime risk of progressing. The prevalence of LTBI, however, was higher in South Africa, 64 per cent, and China, 54 per cent, and was the lowest in Brazil, 37 per cent.
The studies from the seven countries yielded tuberculosis skin test reports from 9,545 healthcare workers 3,951 of whom tested positive.
The prevalence of tuberculosis was found to be lower among medical students, about 6.9 per cent, but went up to 97 per cent among all types of healthcare workers.
Sharifa Nasreen, lead author of the study, tells SciDev.Net that while the findings are not surprising since these come from high-burden countries, “It was surprising that data from only 7 out of 22 high-burden countries are available even though it is known which countries contribute most to the burden of tuberculosis worldwide.”
T. Jacob John, a virologist and retired professor from the Christian Medical College, Vellore, India, adds that while India took proper steps for preventing hospital transmission to both patients and staff in HIV cases, it took no steps for TB.
“Therefore, anecdotally, there’s a lot of TB among doctors and nurses, even drug resistance and some mortality,” John says.“Hospital staff are vulnerable two ways — because they are in India, a hyper endemic country with half of adults already infected [with latent TB], plus hospitals collect TB patients so staffs are at risk of infection.” While the study says that the risk of latent TB flaring into active state is about 10-15 per cent, John adds, “With TB, once infected, one is infected for life. That is why we call that as latent TB. It can flare up as active TB any time.”
John, who has been part of India’s public health programmes, says, “I guess government is aware but hospital infection control is not part of their mandate.”
This piece was produced by SciDev.Net’s South-East Asia & Pacific desk.