(From the 2011 TB Progress Report)
# 6828
Despite great advances made against tuberculosis since the introduction of antibiotics in the 1940s, in recent years we’ve seen the rise of new drug resistant strains of this killer disease; MDR-TB (Multi-drug Resistant Tuberculosis) and XDR-TB (Extensively Drug Resistant Tuberculosis).
Although the numbers have decreased in recent years, in 2010 1.4 million deaths were attributed TB, and it remains one of the three greatest causes of death of women (ages 14-44) in the world.
In 2009, the NIH had this to say about the global spread of the disease, including the fact that about 1 in 5 active cases of TB are also co-infected with HIV.
Today, one-third of the world’s population is thought to be infected with Mycobacterium tuberculosis (Mtb), the microbe that causes TB.
An estimated 13.7 million people have the active form of the disease. In 2007, approximately 9.27 million people developed TB, of whom 1.37 million were HIV positive, and 1.75 million died, including 456,000 individuals co-infected with HIV.
And in 2010, the World Health Organization announced:
Drug-resistant tuberculosis now at record levels
18 MARCH 2010 | GENEVA | WASHINGTON DC -- In some areas of the world, one in four people with tuberculosis (TB) becomes ill with a form of the disease that can no longer be treated with standard drugs regimens, a World Health Organization (WHO) report says.
Also from the World Health Organization:
Tuberculosis and HIV
The risk of developing tuberculosis (TB) is estimated to be between 20-37 times greater in people living with HIV than among those without HIV infection. In 2010, there were 8.8 million new cases of TB, of which 1.1 million were among people living with HIV.
In response to demands from countries, WHO recommends 12 TB/HIV collaborative activities, including the Three I's for HIV/TB. The WHO HIV/AIDS and TB Departments and their partners, including community groups, work collaboratively on joint HIV/TB advocacy, policy development and implementation in countries.
The Three I’s
- Intensified TB case finding
- Isoniazid preventive therapy
- Infection control for TB.
While the incidence of co-infection with XDR-TB and HIV is rising, little is known about the effectiveness of treatment of these patients.
We’ve some new research, appearing in the CDC’s EID Journal, indicating that among a small cohort of patients followed in South Africa over 2 years – disappointingly - only 22% were cured or successfully completed treatment.
A few excerpts ( reparagraphed for readability), but follow the link to read the entire study:
Treatment Outcomes for Extensively Drug-Resistant Tuberculosis and HIV Co-infection
Max R. O’Donnell , Nesri Padayatchi, Charlotte Kvasnovsky, Lise Werner, Iqbal Master, and C. Robert Horsburgh
Abstract
High mortality rates have been reported for patients co-infected with extensively drug-resistant tuberculosis (XDR-TB) and HIV, but treatment outcomes have not been reported. We report treatment outcomes for adult XDR TB patients in KwaZulu-Natal Province, South Africa. Initial data were obtained retrospectively, and outcomes were obtained prospectively during 24 months of treatment.
A total of 114 XDR TB patients were treated (median 6 drugs, range 3–9 drugs); 82 (73%) were HIV positive and 50 (61%) were receiving antiretroviral therapy. After receiving treatment for 24 months, 48 (42%) of 114 patients died, 25 (22%) were cured or successfully completed treatment, 19 (17%) withdrew from the study, and 22 (19%) showed treatment failure.
A higher number of deaths occurred among HIV-positive patients not receiving antiretroviral therapy and among patients who did not show sputum culture conversion. Culture conversion was a major predictor of survival but was poorly predictive (51%) of successful treatment outcome.
Discussion
The main findings of our study were a high mortality rate (42%) and a low rate of successful treatment outcomes (22%) for XDR TB patients after completion of 24 months of treatment in a setting with a high incidence of HIV.
All deaths in this cohort occurred in the first 12 months after start of treatment. Predictors of deaths in this cohort included TB-specific (TB culture conversion) and HIV-specific (ART use) factors. Consistent with findings in other studies of treatment of drug-resistant TB/HIV, HIV was not independently associated with death (12,13,20).
Although HIV was not independently associated with death, use of ART among HIV-infected patients was associated with improved survival.
Sex appeared to modify the association between death and HIV because female sex was associated with higher survival rates among HIV-negative XDR TB patients but with higher death rates in women co-infected with HIV than in men co-infected with HIV.
However, this finding was not significant in all strata. TB culture conversion was a useful predictor of survival and treatment outcome. However, it was not sufficiently sensitive in this cohort to be a surrogate for successful TB treatment outcome, given the number of patients who ultimately showed treatment failure (n = 7), defaulted (n = 7), or died (n = 4) after TB culture conversion.
The authors conclude by saying:
Although not addressed by our study, improvements in treatment outcomes for patients co-infected with MDR TB and HIV will require changes in HIV- and TB-related factors. For HIV, these include more rapid HIV testing for early initiation of ART, appropriate monitoring of CD4 T-cell counts, HIV virus load testing, appropriate opportunistic infection prophylaxis, and improvement in ART adherence.
Although not addressed by our study, we recommend that for TB these improvements include widespread implementation of rapid diagnostics, particularly for smear-negative disease; early drug susceptibility testing for first-line and second line agents; improvement in adherence for second-line TB drugs; development of more effective anti-TB drugs and regimens; and guidance of drug selection by timely and ongoing drug susceptibility testing.
While often overshadowed by other issues, the HIV AIDS epidemic (exacerbated by TB) in South Africa (and much of Sub-Saharan Africa) continues to devastate the populace.
The UNAIDS website lists the following grim statistics for South Africa, a country that has seen more than a 10 year-drop in life expectancy since HIV began to spread in the 1980s:
HIV AND AIDS ESTIMATES (2011)
- Number of people living with HIV
- 5,600,000 [5,300,000 - 5,900,000]
- Adults aged 15 to 49 prevalence rate
- 17.30% [16.60% - 18.10%]
- Adults aged 15 and up living with HIV
- 5,100,000 [4,900,000 - 5,400,000]
- Women aged 15 and up living with HIV
- 2,900,000 [2,700,000 - 3,000,000]
- Children aged 0 to 14 living with HIV
- 460,000 [410,000 - 520,000]
- Deaths due to AIDS
- 270,000 [240,000 - 300,000]
- Orphans due to AIDS aged 0 to 17
- 2,100,000 [2,000,000 - 2,300,000]
