Injecting drug users comprise almost 10% of people living with HIV but face many obstacles in treatment, noted Dr Paul Nunn of the WHO at the release of treatment guidelines for injecting drug users at the 2008 International AIDS Conference in Mexico City.
The World Health Organisation released ‘Policy guidelines for collaborative TB and HIV services for injecting and other drug users – an integrated approach’ at the ongoing International AIDS Conference in Mexico.
Dr Paul Nunn, coordinator of TB-HIV and anti-TB drug resistance at the Stop-TB department of the WHO, pointed out that about three million injecting drug users are living with HIV, translating into almost 10 per cent of people living with HIV. HIV among injecting drug users (IDUs) is emerging as a concern in Africa and Asia. Also, as injecting drug use is illegal, IDUs face obstacles in getting treatment.
Unsafe injecting drug use is now a major route of transmission for HIV. Nearly one in three of all new HIV infections outside Africa (two in three in some countries) are attributable to unsafe injecting drug use. TB-HIV prevalence is as high as 50 per cent in China and Estonia where access to medical services is also low. There are no policies addressing patients with TB-HIV in prisons.
TB is a major cause of death for people living with HIV, but drug users who are HIV-positive face stigma, discrimination and barriers to accessing life-saving treatments.
The guidelines aim to improve access to antiretroviral drugs for drug users living with HIV, as well as Isoniazid preventive therapy (IPT) that significantly reduces the risk of TB disease in people living with HIV.
IPT is not widely used but even where IPT is available, health care and outreach workers face major challenges in delivering full care to drug users who are often marginalised by homelessness, poverty, imprisonment, and by public and political hostility. These factors contribute to the transmission of both HIV and TB, and at the same time are barriers to TB, HIV and drug dependence treatment.
Preventive treatment for TB possible in resource-poor settings
Isoniazid preventive therapy (IPT) reduces the risk of active disease in people who have a recent or latent TB infection and is one of the three ‘I’s, essential services that HIV programmes should provide in order to reduce the burden of TB in people with HIV – the other two are intensified case finding and infection control.
However, wide scale implementation has been lagging in many resource-limited settings because of concerns about the ability to monitor for drug toxicity and adequately screen for active disease – if there is active disease IPT alone could lead to drug resistance to Isoniazid. Many countries have been waiting for more programmatic experience from other resource-constrained settings.
The evidence has come from Western Kenya where a collaborative programme between the Moi University in Kenya and the Indiana University in the US, put close to 10,000 people with HIV on IPT, achieving high rates of treatment completion with lower rates of TB in people who completed treatment.
“IPT within a large HIV treatment programme in sub-Saharan Africa appears both feasible and effective in preventing active tuberculosis,” said Dr Lameck Diero of Moi University, who reported the findings.
HIV viral subtype A has higher risk of transmission
HIV viral subtype and concurrent genital ulcer disease (GUD) plays a clear role in the risk of HIV transmission, according to a study from Uganda presented at the XVII International AIDS Conference in Mexico City.
Investigators looking at a long-term study assessed rates of, and risk factors for, HIV transmission among serodiscordant (one partner is negative, one HIV positive) heterosexual couples in Rakai, Uganda. They looked at whether particular HIV-1 subtypes were associated with a higher rate of transmission. They found that HIV subtype A was transmitted nearly twice as often as subtype D – though subtype D is more common in the population.
Other significant risk factors for HIV transmission were lower reported condom use and higher viral load. Also, transmission was four times more likely if the positive partner was under 30 compared with over 40 years old. The presence of genital ulcers, especially in the HIV-negative partner, also had a strong effect.
Data on subtype differences in transmission “are crucial for HIV vaccine development programmes, for understanding the dynamics of HIV-1 epidemics in different geographical regions, and for future prediction of the pandemic,” the investigators stated.
InfoChange News & Features, August 2008