Community-onset febrile illness in HIV-infected adults: Variable pathogens in terms of CD4 counts and transmission routes

Objectives The objective of the study is to investigate the causes of febrile illness among HIV-infected adults visiting the emergency department (ED) of a designated hospital for HIV care in Taiwan, an area of a low HIV prevalence.

Methods From January 2004 to December 2012, all febrile HIV-infected adults visiting the ED were retrospectively investigated. Recent CD4 lymphocyte counts near ED visits and HIV transmission route were designated as major predictors for the analyses. All variables and clinical information were derived from chart records.

Results Of the 196 eligible HIV-infected adults, major causes of febrile illness were lower respiratory tract infections (68, 34.7%), skin and soft tissue infections (31, 15.8%), intra-abdominal infections (22, 11.2%), and urinary tract infections (11, 5.6%). There were 150 pathogens identified. Staphylococcus aureus (51, 34.0%) and Pneumocystis jirovecii (26, 17.3%) were the major pathogens. In a multivariate analysis, injection drug use (odds ratio, 15.18; P <.001) and skin and soft tissue infections (odds ratio, 18.45; P =.001) were independently associated with S aureus infections, and the proportion of S aureus increased steadily with CD4 lymphocyte count (γ = 0.99; P =.01). Of pneumonic patients with recognized pathogens, P jirovecii pneumonia was frequently associated with patients having a CD4 lymphocyte count of less than 100 cells/mm³ (25/25, 100% vs 16/30, 53.3%; P <.001).

Conclusions The causes of febrile illness in HIV-infected adults visiting the ED varied according to CD4 count and transmission route. Two independent risk factors, intravenous drug use and skin and soft tissue infections, were associated with S aureus infections. For HIV-infected adults with lower respiratory tract infections, a CD4 lymphocyte count of less than 100 cells/mm³ was a risk factor for P jirovecii pneumonia.