Invasive pneumococcal disease in HIV-infected adults: clinical changes after the introduction of the pneumococcal conjugate vaccine in children.

Background: Few data exist on the implications of widespread use of 7-valent pneumococcal conjugate vaccine in children in the invasive pneumococcal disease (IPD) in HIV-infected adults. We conducted a multicenter study to analyze differences in clinical presentation of IPD between HIV-infected and non-HIV-infected adults in the prevaccine and postvaccine era.

Methods: Study of all cases of IPD in HIV-infected adults diagnosed since 1996 to 2010. Episodes were classified into prevaccine (1996-2001), early postvaccine (2002-2004), and late postvaccine period (2005-2010). For each case, we identified an HIV-negative control patient with IPD matched by hospital, age, and vaccine period.

Results: Two hundred twenty-one episodes of IPD in HIV-infected patients were diagnosed. The incidence of IPD decreased from 7.81 to 3.69 episodes per 1000 patient-years (-53%; 95% confidence interval: -65% to -36%, P < 0.001) between prevaccine and late postvaccine period. There was an 81% (95% confidence interval: -88% to -69%, P < 0.001) decrease of IPD caused by vaccine serotypes. In late postvaccine period IPD in HIV-infected patients was associated to higher rates of respiratory failure (28.4% vs. 48.4%, P = 0.011), greater intensive care unit admission (8.2% vs. 21.7%, P = 0.02) and a higher need for mechanical ventilation (5.9% vs. 16.3%, P = 0.033). In the prevaccine period, non-HIV-infected patients had a more severe illness than in those with HIV infection; however, these differences disappeared in the late postvaccine period.

Conclusions: In the late postvaccine era, the incidence of IPD in HIV-infected patients has decreased, however, clinical presentation seems to have changed to a more severe illness. The widespread use of highly active antiretroviral therapy, polyssacharide vaccine, and 7-valent pneumococcal conjugate vaccine has contributed to these changes.