Tuberculosis

Tuberculosis Late Diagnosis and Mortality Decrease among HIV Positive People in U.S.

The rate of death due to tuberculosis (TB) in the U.S. has decreased by half since the early 1990s, mostly attributable to a reduction among HIV positive people, according to a study described in the November 26, 2010 Morbidity and Mortality Weekly Report. What's more, among people with HIV, the proportion who were not diagnosed with TB until after they died also declined, reflecting better access to medical care.

Centers for Disease Control and Prevention (CDC) investigators looked at the effect of HIV infection on the risk of death during treatment for tuberculosis in the U.S.

Worldwide, TB incidence increased from 125 cases per 100,000 people in 1990 to 142 cases per 100,000 in 2004, primarily due to the HIV epidemic, the study authors noted as background. People with HIV are at increased risk for TB infection and development of TB disease, and also have a higher risk of TB-related death.

"This is documented most clearly in resource-limited settings, where limited access to antiretroviral therapy (ART) and other health care services contribute to the elevated mortality," they wrote.

The impact of HIV on TB outcomes is less clear in high-income countries such as the U.S., however. In this study, investigators analyzed data from all culture-positive patients with TB documented between 1993 and 2008, as reported to the CDC's National TB Surveillance System.

Results

• The proportion of TB patients with documented HIV test results increased substantially, from 36% in 1993 to 79% in 2008.
• The proportion of all TB patients who died during TB treatment decreased from 18% (2445 out of 13,629) in 1993 to 9% (682 out of 7578) in 2006.
• Among patients coinfected with TB and HIV, 41% (950 out of 2337) died during treatment in 1993, falling to 20% (131 of 663) in 2006.
• Among HIV negative TB patients, 8% died during treatment in 1993 compared with 5% in 2006.
• The proportion of HIV/TB coinfected patients who were first diagnosed with TB after death fell from 7% (191 out of 2927) in 1993 to 4% (32 out of 768) in 2006.
• In addition, among TB patients with unknown HIV status, 6% (624 out of 10,468) were diagnosed with TB after death in 1993, but this proportion did not decline over time.

These findings show that the decrease in deaths among people with TB between 1993 and 2008 was mostly entirely attributable to a reduction in mortality among people with HIV.

"In 2008, however, 21% of patients with TB still had unknown HIV status, and this proportion was even higher in certain demographic groups," wrote the authors of an accompanying editorial note. "This is unacceptable given that knowledge of HIV status is essential for appropriate treatment and that current guidelines recommend HIV testing for all patients with TB in the United States."

Based on these results, the investigators recommended, "Further reductions in mortality can be achieved by enhanced TB/HIV program collaboration and service integration."

Investigator affiliations: Dept of Medicine, Albert Einstein College of Medicine, Bronx, NY; Div of TB Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention; EIS Officer, CDC.

12/14/10

Reference

S Shah, K Cain, S Marks, and others. Mortality Among Patients with Tuberculosis and Associations with HIV Status -- United States, 1993 -- 2008. Morbidity and Mortality Weekly Report 59(46): 1509-1513 (Abstract). November 26, 2010.