Epidemiology

Epidemiology of pneumococcal disease in HIV shows post-HAART shift

Last Updated: 2005-07-15 15:02:15 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Highly active antiretroviral therapy (HAART), along with the use of pneumococcal vaccines, appears to have reduced the incidence of bacteremic pneumococcal disease among HIV-infected individuals, Spanish and German researchers report.

And in the post-HAART era, the researchers found, HIV patients' risk factors for pneumococcal disease are becoming more similar to those seen in people without HIV.

There is evidence that the incidence of invasive pneumococcal infection among people with HIV is in decline, which could be due both to the introduction of HAART and the use of pneumococcal vaccines, Dr. Roman Pallares of IDIBELL-Hospital de Bellvitge in Barcelona and colleagues write in the July 11 issue of the Archives of Internal Medicine.

The researchers prospectively studied 142 episodes of pneumococcal bacteremia in 122 adults with HIV. Eighty-five of the infections occurred in 1986-1996, defined as the pre-HAART era, while 57 occurred after the introduction of HAART in 1997-2001.

Pre-HAART, pneumococcal bacteremia incidence was 24.1 episodes per 1,000 patient years, while post-HAART it fell to 8.2. Patients who developed the infection after HAART had a higher mortality rate and more associated comorbidity.

Patients with associated comorbidity, usually cirrhosis of the liver, were more than three times more likely than those with no such comorbidity to develop pneumococcal bacteremia in the post-HAART era, while those who abused alcohol or smoked cigarettes had a more than five-fold greater risk. Prior hospitalization tripled the risk, while having a CD4 cell count below 100 cells per microliter more than doubled it.

HAART use cut pneumococcal bacteremia risk by 63%, while pneumococcal vaccine reduced risk by 61%.

As patients with HIV are living longer, the researchers note, comorbidities such as hepatitis C infection and HAART-linked cardiovascular disease and diabetes mellitus may become more important as risk factors for pneumococcal disease.

"In the HAART era, the increasing prevalence of comorbidities that are well-known risk factors for pneumococcal infection (e.g. chronic liver disease, diabetes, and cardiovascular diseases) may foretell a continuing global burden of infectious disease in the HIV-infected population," they conclude.

Arch Intern Med 2005;165:1533-1540.