TB therapy and HIV tied to risk of MDR pneumococcal disease
HIV infection, tuberculosis (TB) treatment, age, and other factors raised the odds of multidrug-resistant (MDR) invasive pneumococcal disease (IPD) over a 5-year study period in South Africa before the pneumococcal vaccine era.
MDR Streptococcus pneumonia complicates disease management and poses a particular threat to people with HIV. Researchers in South Africa’s National Health Laboratory Service and collaborators at other institutions conducted this study to determine risk factors for MDR IPD and the potential value of vaccination with the 13-valent pneumococcal conjugate vaccine (PCV13) to reduce disease burden.
The investigators collected IPD data by lab-based surveillance from 2003 through 2008. They defined multidrug resistance as lack of bacterial susceptibility to three or more antibiotic classes.
The research team identified 20,100 cases of IPD, or which 3708 (18%) had MDR isolates. Prevalence of MDR isolates rose from 16% (461 of 2891) to 20% (648 of 3326) over the study period (P < 0.001). Serotypes included in the PCV13 vaccine accounted for 94% of MDR strains.
Multivariable logistic regression analysis identified the following independent predictors of MDR IPD, at the following odds ratios (OR) (and 95% confidence intervals):
• PCV13 serotypes (1486 of 6407): OR 6.3 (5.0 to 7.9)
• Pediatric serotypes (3382 of 9980): OR 12.8 (10.6 to 15.4)
• Age under 5 versus 15 to 64 (802 of 3110): OR 2.0 (1.8 to 2.3)
• Age 65 or older versus 15 to 64 (39 of 239): OR 1.5 (1.0 to 2.2)
• HIV infection (975 of 4636): OR 1.5 (1.2 to 1.8)
• Previous antibiotic use (242 of 803): OR 1.7 (1.4 to 2.1)
• Previous hospital admission (579 of 2450): OR 1.2 (1.03 to 1.4)
• Urban location (883 of 4375): OR 2.0 (1.1 to 3.5)
• TB treatment (246 of 1021): OR 1.2 (1.03 to 1.5)
“The effect of many of the MDR risk factors could be reduced by more judicious use of antibiotics,” the researchers propose.
“Because PCV13 serotypes account for most MDR infections,” they observe, “pneumococcal vaccination may reduce the prevalence of multidrug resistance.”
Source: Penny Crowther-Gibson, Cheryl Cohen, Keith P. Klugman, Linda de Gouveia, Anne von Gottberg, for the Group for Enteric, Respiratory, and Meningeal Disease Surveillance in South Africa (GERMS-SA). Risk factors for multidrug-resistant invasive pneumococcal disease in South Africa, a setting with high HIV prevalence, in the prevaccine era from 2003 to 2008. Antimicrobial Agents and Chemotherapy. 2012; 56: 5088-5095.
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