Campylobacter Bacteremia

Abstract

Campylobacter is a very rare cause of bloodstream infection, although it has been found relatively frequently in patients infected with human immunodeficiency virus (HIV). The impact of highly active antiretroviral therapy (HAART) and new forms of immunosuppression on the incidence of Campylobacter bacteremia has not been sufficiently assessed. In this study we analyzed the incidence and microbiologic and clinical characteristics of Campylobacter bacteremia over 23 years.We reviewed the clinical records of all patients who had Campylobacter bacteremia from 1985 to 2007. Available strains were reidentified using universal polymerase chain reaction (PCR).During the study period, there were 71 episodes of Campylobacter bacteremia in 63 patients (0.24% of all bloodstream infections), and the incidence remained stable (mean, 0.06/1000 admissions per year and 0.47/100,000 inhabitants per year). Median age was 52 years (interquartile range, 31.25-72.5 yr), and 82% of patients were male. The underlying conditions included liver disease (21/64, 32.8%), HIV infection (15/64, 23.4%), malignancy (7/64, 10.9%), solid organ transplantation (2/64, 3%), hypogammaglobulinemia (10/64, 15.6%), and other (18/64, 31.2%). Twelve patients shared more than 1 underlying condition. Campylobacter bacteremia was community acquired in 81% of the episodes. The origin of the bloodstream infection was abdominal (43.5%), primary (26%), or extraintestinal (31%: respiratory 15%, cellulitis 4.8%, urinary 8%, other 3%). C jejuni was recovered in 66% of cases, C fetus in 19%, and C coli in 12%.Universal PCR was performed on 14 available strains. Molecular and conventional identification matched in 8 isolates. In contrast, molecular methods classified as C fetus (n = 2) and C jejuni (n = 1) 3 strains formerly identified only to genus level as Campylobacter species. In another 3 isolates, molecular identification was not consistent with the phenotypic identification (C fetus identified as C jejuni).Complications appeared in 23.9% of patients. Quinolone resistance was observed in 50% of the isolates. Only 37.8% of patients received appropriate empirical therapy. Mortality was 16.4%, although it was higher in HIV-infected patients than uninfected patients (33% vs. 10%; p = 0.04), in cases of hospital-acquired Campylobacter bacteremia compared with community-acquired cases (38.5% vs. 9.4%; p = 0.02), and in the presence of complications compared with patients without complications (100% vs. 0%; p < 0.001). The incidence of recurrence was 5% (3 patients with humoral immunodeficiency). There was a higher proportion of HIV-infected patients among patients with Campylobacter bacteremia in the pre-HAART era (1985-1996) than in the HAART era (1997-2007)-27.5% (11/40) vs. 14.3% (4/28)-although the difference was not statistically significant. Debilitating diseases such as chronic obstructive pulmonary disease emerged as predisposing conditions in the HAART era (0% before HAART era vs. 14.3% in HAART era; p = 0.032).Campylobacter bacteremia is no longer a significant disease of HIV-positive patients on HAART, but often affects other immunocompromised patients as well. Campylobacter bacteremia has an extraintestinal origin in as many as 31% of cases, and humoral immunodeficiency must be sought in patients with recurrent episodes. Quinolones should not be considered for empirical therapy.