Increased incidence of meningococcal disease in HIV-infected individuals associated with higher case-fatality ratios in South Africa

Abstract

We aimed to compare the incidence of meningococcal disease amongst HIV-infected and uninfected individuals and to evaluate whether HIV is a risk factor for mortality and bacteremia amongst patients with meningococcal disease. Cohort surveillance study. We conducted laboratory-based surveillance for meningococcal disease in Gauteng Province, South Africa. HIV status and outcome data were obtained at sentinel sites. Incidence in HIV-infected and uninfected persons was calculated assuming a similar age-specific HIV prevalence in tested and untested individuals. Risk factors for death and bacteremia (as compared with meningitis) were evaluated using multivariable logistic regression. From 2003 to 2007, 1336 meningococcal cases were reported. Of 504 patients at sentinel sites with known outcome, 308 (61%) had HIV serostatus data. HIV prevalence amongst cases of meningococcal disease was higher than the population HIV prevalence in all age groups. The incidence of meningococcal disease in HIV-infected individuals was elevated in all age groups with an age-adjusted relative risk of 11.3 [95% confidence interval (CI) 8.9-14.3, P < 0.001]. The case-fatality ratio (CFR) was 20% (27/138) amongst HIV-infected and 11% (18/170) amongst HIV-uninfected individuals [odds ratio (OR) 2.1, 95% CI 1.1-3.9]. On multivariable analysis, CFR was greater amongst patients with bacteremia (35%, 29/82) compared with meningitis (7%, 16/226) (OR 7.8, 95% CI 3.4-17.7). HIV infection was associated with increased odds of bacteremia (OR 2.7, 95% CI 1.5-5.0). HIV-infected individuals may be at increased risk of meningococcal disease. The increased CFR in HIV-infected patients may be explained by their increased odds of bacteremia compared to meningitis.