HIV a major risk factor for MDR TB in Ukraine

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Between 10% and 20% of new TB cases in Russia and the Ukraine may be multidrug resistant, with HIV infection a major risk factor for acquiring MDR TB in the Ukraine, according to surveys presented at the 38th World Lung Health conference in Cape Town, South Africa today.

XDR-TB (tuberculosis that is resistant to rifampicin, isoniazid, a fluoroquinolone and an injectable TB drug) was also detected in two districts studied.

MDR -B is defined as tuberculosis which is resistant to two of the first-line drugs, rifampicin and isoniazid. It requires treatment for 18-24 months with a regimen of up to six drugs, some of them injectable, and a period of isolation from the community that may last for six to eight months.

Glossary

multidrug-resistant tuberculosis (MDR-TB)

A specific form of drug-resistant TB, due to bacilli resistant to at least isoniazid and rifampicin, the two most powerful anti-TB drugs. MDR-TB usually occurs when treatment is interrupted, thus allowing organisms in which mutations for drug resistance have occurred to proliferate.

drug resistance

A drug-resistant HIV strain is one which is less susceptible to the effects of one or more anti-HIV drugs because of an accumulation of HIV mutations in its genotype. Resistance can be the result of a poor adherence to treatment or of transmission of an already resistant virus.

active TB

Active disease caused by Mycobacterium tuberculosis, as evidenced by a confirmatory culture, or, in the absence of culture, suggestive clinical symptoms.

extensively drug-resistant TB (XDR-TB)

A form of drug-resistant tuberculosis in which bacteria are resistant to isoniazid and rifampicin, the two most powerful anti-TB drugs, plus any fluoroquinolone and at least one injectable second-line drug. 

pilot study

Small-scale, preliminary study, conducted to evaluate feasibility, time, cost, adverse events, and improve upon the design of a future full-scale research project.

 

MDR -B has long been a concern in the countries of the former Soviet Union due to the disintegration of the health system since 1990, coupled with antiquated TB control efforts. While the rest of the world has been embracing directly observed therapy in the community, the former Soviet countries remain largely committed to a Soviet-era style of TB control, with mass X-ray programmes for adults, annual tuberculin skin testing in children and compulsory hospitalisation of all TB patients. As the health system has fragmented and moved towards a private model, physicians have become increasingly indifferent to TB.

These factors have led to a huge upsurge in TB cases; between 1992 and 2002 TB rates doubled in Ukraine, reaching an estimated level of 40,000 cases per year by 2004 (82 notifications per 100,000 inhabitants)..

DOTS is only now being introduced in the Russian Federation, through a WHO-sponsored pilot programme in six regions, and longer-term funding of the pilots is uncertain.

Surveys of drug resistance have produced conflicting results over the past decade, but evidence from the Baltic states of Lithuania, Latvia and Estonia, as well as from Central Asia, has pointed to rising rates of MDR-TB.

However, figures on drug resistance have not always been accurate due to a lack of standardisation of drug susceptibility testing between laboratories.

But a survey carried out in 2005 in six oblasts (administrative districts) of the Russian Federation, in which laboratories used standardised methods of testing for TB drug resistance, found that 9.5% of new TB cases were multi-drug resistant in 2005, compared with 7.8% in 2002.

Among people previously treated for TB, MDR-TB was detected in 18.7% of patients, compared with 14.5% in 2002.

When researchers looked for extensively drug-resistant TB in two oblasts they found that 9.7% of 468 MDR cases had resistance to all second-line drugs.

In Ukraine, a study of TB patients in the city of Donetsk found that among 1293 consecutive TB patients diagnosed smear-positive between July 2005 and June 2006, 15.5% of those diagnosed with TB for the first-time had MDR-TB. Among those previously treated for TB, 41.5% had multidrug resistant TB.

The Ukrainian researchers found that 21% of their TB patients were HIV-positive, and that the rate of MDR TB was significantly higher in HIV-positive patients, who had a 50% higher risk of being diagnosed with MDR-TB as their first TB infection.

Amongst prisoners the rate of MDR-TB was even higher: 21% in newly diagnosed TB patients and 52% in those previously treated for TB. Among HIV-positive patients in prison, who comprised 17% of the 203 incarcerated TB cases), 58% had MDR-TB (a risk ratio of 1.6 compared to HIV-negative TB patients).

The researchers say that clinical management of MDR TB is seriously compromised by interactions between second-line TB drugs and antiretrovirals, which were provided to all patients who qualified according to Ukrainian treatment guidelines. The high rates of MDR-TB are a concern for HIV management in the former Soviet Union. Reporting by the Russian Ministry of Health shows that in the Russian Federation, 52% of `late stage` HIV patients had active TB in 2006, and 2.6% of all HIV-positive people had active TB. However, despite the high testing rate among at-risk groups, particularly injecting drug users and people attending sexually transmitted infection clinics, only 46% of HIV-positive people have been tested for TB. HIV prevalence among TB patients was 1.2% nationally, but reached 8% in one region.

Investigators from the Russian Ministry of Health concluded that integration of HIV/TB services is an urgent priority in the Russian Federation.

However, in Ukraine, which has a better-developed system of HIV care than the Russian Federation, Dr Kateryna Gamazina, PATH Country Program Director told aidsmap that TB and HIV services remained entirely separate. A pilot integration project, sponsored by PATH, has just got underway, but based on the political difficulties of introducing DOTS to Ukraine, the challenges should not be underestimated, she said.

References

Korobitsyn A et al. HIV testing coverage and HIV prevalence among new patients with tuberculosis in the Russian Federation. 38th World Conference on Lung Health, Cape Town, abstract PS-71645-10, 2007.

Somova TR et al. Extreme drug-resistant (XDR) tuberculosis in Vladimir and Orel oblasts, Russia. 38th World Conference on Lung Health, Cape Town, abstract PS-71791-11, 2007.