The incidence of invasive pneumococcal disease (IPD) is >7-times higher in people living with HIV (PLWHIV) compared with the general population in the Netherlands, according to a study published in Clinical Infectious Diseases. Further, the results of this study also demonstrated that the incidence of community-acquired pneumonia (CAP) >8-times higher among PLWHIV compared with the general population.

In this nested case-control cohort study, researchers identified 24 cases of IPD in 21 individuals with HIV and 318 cases of CAP in 215 individuals with HIV who received care at the Amsterdam University Medical Centers (UMC) from June 2008 through December 2017. Researchers used a multivariable conditional regression analysis to identify risk factors for pneumococcal and unspecified CAP in PLWHIV who were receiving combination antiretroviral therapy (cART); for each case, 1 control matched for year of HIV diagnosis was selected. Researchers calculated the incidence rates of IPD, pneumococcal CAP, pneumococcal disease (pneumococcal CAP + IPD), and all CAP grossly and per subgroup (CD4 count, cART treatment status, and the occurrence of the disease before or after 2015). Patients with a newly diagnosed HIV infection, defined as date of HIV diagnosis within 60 days of the IPD or CAP episode, were excluded from analysis.

The overall incidence rates were 111 for IPD cases, 1529 for CAP, and 159 for pneumococcal CAP per 100,000 patient-years of follow-up.  Stratified results demonstrated that IPD rates were the highest among patients without cART or with a CD4 count <500 cell/μL (490 and 246 per 100,000 patient-years follow-up, respectively) compared with patients receiving cART or patients with a CD4 count >500 cell/μL.

Incidence rates for CAP and pneumococcal disease demonstrated a similar trend. Patients with CD4 counts >500 cells/μL and those receiving cART (946 and 69 per 100,000 patient-years follow-up for CAP and pneumococcal disease, respectively) demonstrated the lowest incidence rates.

Limitations of this study included that calculations of IPD incidence ratios were based on a relatively small number of cases. The rates of pneumococcal CAP and pneumococcal disease reported in this study likely an underestimation of the real disease burden as a result of limited sensitivity of sputum culture and also because urinary antigen tests were not performed. Databases used for collection of vaccine uptake figures covered vaccinations administered at a general practitioner’s office; however, because Dutch guidelines do not recommend pneumococcal vaccination in PLWHIV, researchers these databases likely do not reflect real-world figures.

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“Although data on the clinical benefit of pneumococcal vaccination in [PLWHIV] are limited, our study demonstrates that the burden of pneumococcal disease remains high,” the researchers concluded. “With S pneumoniae as the most commonly identified pathogen of CAP, and all serotyped pneumococcal isolates being covered by available pneumococcal vaccines, we provide additional argumentation against the poor current adherence to international recommendations for pneumococcal vaccination.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Garcia Garrido HM, Mak AMR, Wit FWNM, et al. Incidence and risk factors for invasive pneumococcal disease and community-acquired pneumonia in human immunodeficiency virus–infected individuals in a high-income setting [published online October 21, 2019]. Clin Infect Dis. doi: 10.1093/cid/ciz728