Combating TB/HIV co-infection

Meena is just one of the 1.1 million people globally who needed simultaneous treatment for TB and HIV in 2011, and out of which 430,000 died. TB-HIV is indeed a critical public health issue because more than 11 million of the 34 million people living with HIV (PLHIV) not only have latent tuberculosis infection, they  also are 21–34 times more likely to develop active TB than people without HIV. TB is still the leading cause of death among people with HIV with about one in four AIDS-related deaths attributable to TB.

According to WHO estimates, India has the highest burden of TB in the world with 2.3 million cases (out of a global incidence of 8.7 million) and about 320,000 deaths occurring annually. 5% or 0.11 million of the TB patients in India are HIV positive too. India thus accounts for about 10% of the global burden of HIV-associated TB with 100,000 patients co-infected with the two diseases annually. Without timely diagnosis and treatment, a large number of these doubly sick people are likely to die.

A suppressed immune system makes PLHIV more vulnerable to both drug-susceptible and multi drug-resistant TB (MDR-TB). They may also have decreased absorption of TB medicines, especially rifampicin, which may lead to the acquisition of drug-resistant strains of TB. MDR-TB has been shown to be almost twice as common in PLHIV as in those who are not infected with HIV.  The high pill burden and overlapping toxicities of the dual medication for MDR-TB along with ART make adherence a big challenge. Limited resources and lack of proper diagnostic facilities further compound the problem. According to Dr Anthony Harries, Director (Research) at International Union Against Tuberculosis and Lung Disease (the Union), “MDR-TB and HIV are a deadly combination and if one does not intervene timely to start ART death rates become extremely high. It is important to test early for drug-resistant TB and in high HIV burden areas to test for HIV, and to intervene with ART early enough.”

This is in consonance with the World Health Organization MDR-TB guidelines: Antiretroviral therapy is recommended for all patients with HIV and drug-resistant TB, requiring second-line anti-tuberculosis drugs, irrespective of CD4 cell-count, as early as possible (within the first 8 weeks) following initiation of anti-tuberculosis treatment.

There is an overwhelming consensus to integrate TB and HIV programmes. Studies indicate that an integrated approach to TB and HIV services with an emphasis on early diagnosis linked to TB and HIV treatment can be extremely effective in managing the TB epidemic and reducing mortality among HIV-infected TB patients. Yet in India, joint delivery of integrated TB-HIV services still remains a dream. According to the Revised National TB Control Programme Annual Status Report 2013, only about 56% (8, 21,807) of the TB patients in India were examined and 5% (44,063) were found to be HIV positive during the year 2012. However, it is heartening to note that provision is now being made for whole blood (finger prick) HIV screening test in all Designated Microscopy Centres and Provider Initiated HIV Testing and Counselling among presumptive TB cases in all high HIV prevalent settings in India. Isoniazid prophylaxis therapy (IPT) has also been accepted for prevention of TB among PLHIV.

Among HIV-infected TB patients diagnosed in 2012, 32,313 (92%) were started on co-trimoxazole prophylaxis and 26,051 (74%) were started on ART.

Dr Stephen Lawn of London School of Hygiene and Tropical Medicine blames poor diagnostics as another impediment to conquer HIV associated TB. According to him, “We need diagnostics which can work at very low CD4 counts and we need rapid detection of drug resistant TB. It would indeed be a golden day when we have same day diagnostic and same day treatment start—enter ART clinic and on day one itself get to know whether there is TB or not. Testing and treating all TB-HIV co infected people irrespective of CD4 count should be the aim. ART and IPT given together to PLHIV reduce TB risk by 80%.”

In an interview given to CNS, Dr Paula Fujiwara, Scientific Director at the Union, stressed upon the need of ‘commitment and ownership by the national TB and HIV programmes to integrate and link their services, so that if a person with TB is counselled and accepts an HIV test, it should be done right there, rather than send him/her to another place, where there is a greater likelihood that s/he may face another long queue, and/or change his/her mind.  If a person is taking both TB and HIV medicines, they should be given at the same time if possible, especially in the TB clinics, where DOTS is the standard of care.’

Dr Fujiwara further said that, “All PLHIV need to be assessed for TB, and even if they have latent TB infection, the health care providers must be convinced of the importance of giving them IPT so that they do not develop active TB. The patients too must be convinced to see the potential benefits of taking medicines to prevent the TB disease, rather than treating it after getting infected. Another key issue that needs to receive more attention is that people who are infected with TB, whether HIV positive or not, who also smoke tobacco, need to be educated that they are at greater risk of developing active TB disease. Also, infection control is important.  Clinics, hospitals and homes should be well ventilated.  People should always cover their mouths when they cough. Persons with HIV should not be cared for in the same location as persons with active TB.”

The way forward would be to prevent TB infection and treat HIV. According to Dr Valérie Schwoebel from the Union, “The real challenge is early diagnosis of TB in PLHIV in order to improve the patients’ chances to get cured. This can be done through the Three I’s Strategy-- Infection control, intensified case finding for TB, and IPT. Infection control consists in taking precautions to reduce transmission of the TB bacilli disseminated in the air by (i) implementing airborne infection control measures and (ii) diagnosing and treating TB early in the family/contacts of PLHIV.  Intensified case-finding means that searching for TB should always be an integral part of the medical follow-up of PLHIV and TB diagnostics and treatment services should be easily available to them. IPT can prevent the development of active TB disease in PLHIVs already infected by the TB bacilli but not yet sick.  The treatment lasts at least 6 months and must be delivered in settings where careful evaluation and follow-up of patients is organized.”

Thus while IPT is a backbone for PLHIV to help prevent them from developing active TB disease, ART suppresses the growth of HIV and restores the immune defence mechanisms, reducing the occurrence of opportunistic infections and improving quality of life. Early diagnosis, timely initiation of treatment for both diseases and careful monitoring are essential to treat TB in PLHIV and identify HIV infection in people with TB. Referring PLHIV patients to another clinic for TB testing and vice versa is bound to result in defections. Taking treatment from two different places can become very challenging and result in high treatment dropout rates for TB-HIV co-infected patients. ART treatment for PLHIV needs to be decentralised, just like TB treatment, so that even doctors in Primary Health Centres are able to prescribe at least the first line standardised ART regimens, along with TB treatment. Perhaps it would be good to have a ‘one-stop outlet’ where both TB and HIV services are available. Then patients will not have to move away from the facility where they are on ART if they develop TB, nor go to a new facility as TB patients when they are already receiving ART elsewhere. It is essential that services for these co-infected patients be scaled up and coordinated within the general health system. This is bound to strengthen the provisions of adequate care even in settings facing tremendous economic and political challenges.

Source: Citizen News Service