Pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH) in the German CAPNETZ-Cohort

The objective of this study was to identify the pathogen spectrum of community acquired pneumonia in people living with HIV (PLWH), and to compare it with a matched HIV negative group in order to reassess therapeutic strategies for PLWH.

Seventy-three (n = 73) PLWH (median CD4 3-6 months before CAP: 515/µl; SD 309) with community acquired pneumonia (CAP) were matched with 218 HIV-negative CAP controls in a prospective study design. Pathogen identifications used blood culture, samples from the upper and lower respiratory tract (culture and multiplex PCR) and urinary pneumococcal and legionella antigen test.

Although the vaccination rate among PLWH with CAP was significantly higher (pneumococcal vaccination: 27.4 vs. 8.3%, p < 0.001; influenza vaccination: 34.2 vs. 17.4%, p = 0.009), pneumococci were found most frequently as pathogen among both PLWH (n = 19/21.3%) and controls (n = 34/17.2%; p = 0.410), followed by Haemophilus influenzae (PLWH, n = 12/13.5%, vs. controls, n = 25 / 12.6%; p = 0.850). Staphylococcus aureus was found equally in 20.2 and 19.2% in PLWH and controls, but infection or colonization could not be distinguished. Mortality during 6-month follow-up was significantly higher for PLWH (5/73, or 6.8%) versus controls (3/218, or 1.4%), however with lower case numbers than previously reported. Typical HIV-associated pathogens such as Pneumocystis jirovecii were found only exceptionally.

Our study underscores the persistent clinical burden of CAP for PLWH. From pathogen perspective, empirical antibiotic treatment for CAP in PLWH on antiretroviral therapy should cover pneumococci and Haemophilus influenzae and may be adopted from valid common recommendations.