Mortality Among Patients with Tuberculosis and Associations with HIV Status --- United States, 1993--2008

Mortality Among Patients with Tuberculosis and Associations with HIV Status --- United States, 1993--2008
Weekly
November 26, 2010 / 59(46);1509-1513

Worldwide, tuberculosis (TB) incidence increased from 125 cases per 100,000 population in 1990 to 142 cases per 100,000 population in 2004, primarily because of the human immunodeficiency virus (HIV) epidemic (1). Persons with HIV are at increased risk for TB disease, and those with TB have a high risk for 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 (1). The impact of HIV on patients with TB is less clear in resource-rich nations such as the United States. To understand the impact of HIV on the risk for death during TB treatment in the United States, data were analyzed for all culture-positive patients with TB from 1993 to 2008, and the proportion that died was determined and stratified by HIV test result. Mortality data were restricted to patients reported before 2007. The proportion of all patients with TB who died during TB treatment decreased from 2,445 of 13,629 (18%) in 1993 to 682 of 7,578 (9%) in 2006. Among patients with TB and HIV, 950 of 2,337 (41%) died during treatment in 1993; this proportion declined to 131 of 663 (20%) in 2006. The proportion of patients with TB and HIV who received their TB diagnosis postmortem dropped from 191 of 2,927 (7%) in 1993 to 32 of 768 (4%) in 2006; 624 of 10,468 (6%) persons with TB and unknown HIV status received their TB diagnosis postmortem in 1993, and this proportion did not decline. Further reductions in mortality can be achieved by enhanced TB/HIV program collaboration and service integration.

Since 1993, all cases of TB diagnosed in the United States have been reported to CDC and entered into the National TB Surveillance System (NTSS), a comprehensive database that contains demographic, clinical, and outcome data. All culture-confirmed cases of TB were reviewed by CDC to determine 1) the proportion of cases diagnosed postmortem and 2) the proportion of cases in persons who were alive at diagnosis and who died during TB treatment; results then were stratified by HIV status (i.e., HIV infected, HIV uninfected, or HIV status unknown). The HIV-unknown category included patients with indeterminate or unknown results as well as patients who were not offered or refused testing. Rates of HIV test reporting during 2007--2008 were stratified by selected demographic characteristics. Mortality analyses were restricted to patients reported before 2007 (to allow 2 years for treatment outcomes to be reported) and to those whose outcomes were known (excluding patients who moved, were lost to follow-up, were uncooperative with treatment, or whose outcome was missing or listed as other). Because California reports HIV test results only for patients who receive diagnoses of acquired immunodeficiency syndrome (AIDS), and does not report the HIV status of those who test negative, all data from California were excluded.

The proportion of patients with TB who had documented HIV test results increased substantially, from 6,015 of 16,507 (36%) in 1993 to 6,234 of 7,872 (79%) in 2008 (Figure 1). The proportion of patients with TB who had a known outcome and were alive at diagnosis but died during TB treatment decreased from 2,445 of 13,629 (18%) in 1993 to 682 of 7,578 (9%) in 2006 (Figure 2). Among patients with TB and HIV, 950 of 2,337 (41%) died during treatment in 1993; this proportion declined to 299 of 1,393 (21%) in 1997 and later to 131 of 663 (20%) in 2006 (Figure 2). By contrast, the proportion of TB patients without HIV who died during treatment decreased from 213 of 2,705 (8%) in 1993 to 281 of 5,315 (5%) in 2006. For patients with unknown HIV status, 1,282 of 8,587 (15%) died in 1993, with no decrease in proportion observed over the study period (Figure 2). Among patients with HIV who received diagnoses of TB, 191 of 2,927 (7%) received their TB diagnosis postmortem in 1993, which decreased to 32 of 768 (4%) in 2006. Among culture-confirmed cases of TB that occurred in persons who were HIV uninfected, 53 of 3,080 (2%) received their TB diagnosis postmortem in 1993, a proportion that decreased to 31 of 5,762 (1%) in 2006. Of those with unknown HIV status, 624 of 10,468 (6%) received their TB diagnosis postmortem; that proportion did not decline.

Among those with known HIV status, 2,932 of 6,015 (49%) patients with TB had HIV infection in 1993 and accounted for 950 of 1,163 (82%) deaths during treatment and 191 of 244 (78%) patients who received a TB diagnosis postmortem. In 2006, 769 of 6,533 (12%) patients with reported status had HIV, but accounted for 131 of 412 (32%) and 32 of 63 (51%) of those who died during treatment and those who received a TB diagnosis postmortem, respectively.

HIV testing during 2007--2008 was lower in certain demographic groups than the overall sample, notably, 102 of 201 (51%) patients aged ≤4 years, 95 of 144 (66%) patients aged 5--14 years, 1,824 of 3,253 (56%) patients aged ≥65 years, and 2,154 of 3,056 (70%) non-Hispanic white patients had HIV test results reported (Table).

Reported by

S Shah, MD, Dept of Medicine, Albert Einstein College of Medicine, Bronx, New York. K Cain, MD, S Marks, MPH, MA, Div of TB Elimination, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention; J Cavanaugh, MD, EIS Officer, CDC.

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Mortality Among Patients with Tuberculosis and Associations with HIV Status --- United States, 1993--2008