Hospital-acquired infection in patients with systemic lupus erythematosus: a case-control study in a southern Chinese population

The objective of this study is to investigate the current situation of hospital-acquired infection (HAI) in lupus patients from a southern Chinese population. A case-control study was performed. Data from Jan. 2007 to Jan. 2017 were collected. Each lupus patient with HAI was compared with two control individuals without infection selected from the same period of time. Three hundred and sixty episodes of HAI were analyzed. The average Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score at admission was 13.2 ± 7.2. The respiratory tract (58.8%) was most commonly involved, followed by the bloodstream (10.9%). Most episodes were bacteria-associated (50.0%), followed by viral infection (34.8%) and fungal infection (15.2%). Pathogenic bacteria were isolated in 87 episodes, among which 60 episodes were gram-negative bacteria (GNB)-related. Multidrug-resistant strains were detected in 46.4% of bacterial isolates. Fungi were isolated in 49 episodes. Candida albicans (46.9%) was the leading pathogen. Fifty-four episodes of virus infection were confirmed. In multivariate analysis, SLEDAI score (OR 1.1, 95% CI 1.1–1.2, P < 0.001), lupus nephritis (OR 3.7, 95% CI 2.7–5.1, P < 0.001), high dose of GC (OR 2.7, 95% CI 1.8–3.9, P < 0.001), and treatment with CYC (OR 2.9, 95% CI 2.1–4.0, P < 0.001) were risk factors for HAI. HAI in Chinese lupus patients had a unique epidemiology feature, which was characterized by common respiratory tract and bloodstream involvement and predominance of GNB with a high drug resistance rate. A variety of new pathogens including fungi and viruses emerged in the HAI patients. A history of nephritis or a higher SLEDAI score in SLE patients predicted HAI. Moreover, treatment with high dose of GC and CYC was also the main risk factor for HAI.