Testing for tuberculosis, HIV co-infection

Published in The Hindu on May 22, 2008

Mycobacterium - Photo -  CDC
Routine referral programme will greatly improve the detection rate of both the diseases. — Photo: CDC

A programme to routinely test patients infected with HIV for TB and vice versa has taken off in Tamil Nadu from January this year. Testing for co-infection goes a long way in reducing the mortality rate.

There are 760 Voluntary Counselling and Testing Centres (VCTC) that test for HIV, and 30 centres, one each in the district headquarter hospital, that test for TB in the State.

Though patients were cross referred even earlier, the response was not very encouraging as some patients never actually got themselves tested for the other disease. This was particularly so in the case of TB patients.

The misconception

“They don’t think they [TB patients] are at high risk for HIV,” said Dr. Soumya Swaminathan, Senior Deputy Director of the Chennai based Tuberculosis Research Centre.

Another major problem was that HIV positive patients were referred to get tested for TB only if they showed clinical symptoms. So the chances of missing out many patients who were co-infected with TB but not showing clinical symptoms were high.

But the current programme — routine referral — has taken steps to address these issues. The outreach workers will make sure that those willing to be tested for the other disease are not missed. The outreach workers will accompany the patients.

Under the cross referral programme, about 5,700 patients were referred from VCTC to TB testing centres in 2005, 19,000 in 2006, and 37,000 last year. “90 per cent of the people referred completed all the three sputum investigations,” said Ms. Supriya Sahu, Project Director, Tamil Nadu State AIDS Control Society (TANSACS). “And we found nearly 4,400 TB cases among them. And almost 90 per cent of them are put on DOTS [Directly Observed Treatment, Short-course].”

But in the case of TB, about 80,000 people become diseased every year. Of the 80,000, only about 6,100 were tested for HIV in 2005, 19,000 in 2006, and 25,000 last year in the State.

The next big challenge will be to get both the HIV and TB testing done under one roof. This will greatly improve the detection rate of both the diseases.

“It will be prudent to test for HIV if found positive for TB and vice versa under one roof. We are working towards such integration,” said Ms. Sahu.


According to her, some 15-20 centres already undertake both the tests at the same place. Training the laboratory technicians in testing for HIV and TB is already under way.

But the challenges to motivate TB patients to get tested for HIV even under the routine referral programme persist.

“Only about 5 per cent of TB patients [the WHO has now downscaled the prevalence to 2 per cent] would be positive for HIV,” Dr. Swaminathan said. Finding ways of motivating the TB patients is thus very important.

It has been found that many of the TB patients who are found to be co-infected with HIV are in an advanced stage of HIV infection.

The initiative to get the routine referral going came from the Central TB Division. According to the WHO, routine referral is required wherever the generalised HIV epidemic is more than 1 per cent.

The most important outcome of routine referral programme has been that the HIV testing centres (VCTC) have become ideal locations for detecting TB patients. “20-25 per cent of HIV positive patients are found to be positive for TB as well,” Dr. Swaminathan said.

The prevalence is the same even among those who are not infected with HIV. “It was expected, but this rate is surprising,” Dr. Swaminathan stressed.

For instance, last year, nearly 37,000 were referred from the VCTC to TB testing centres. Of the approximate 37,000, only 13,200 were HIV positive.

The number of patients co-infected with TB was nearly 1,600.

The remaining 23,700 referred to TB testing centres were HIV negative but found to be TB patients.