Haemophilus species bacteremia in adults. The importance of the human immunodeficiency virus epidemic.
Until the late 1970s, invasive infections caused by Haemophilus species were thought to occur mainly in children and only infrequently in adults. To report the largest series to date of Haemophilus species bacteremia (HB) from a single center. Retrospective. Large, tertiary care, general teaching hospital. We reviewed the charts of adult patients with HB detected from January 1, 1986, to December 31, 1994. Haemophilus strains were serotyped, and the antimicrobial resistance pattern was analyzed. One hundred sixteen patients had HB (0.26 cases per 1000 admissions). Thirty-eight children and 16 adults were excluded. Human immunodeficiency virus (HIV) infection was the most common underlying condition (n = 18 [29%]), followed by malignant neoplasms (n = 12 [19%]) and chronic obstructive pulmonary disease (n = 12 [19%]). Prevalence in HIV-positive patients was 5 cases per 1000 admissions vs 0.2 cases per 1000 admissions in HIV-negative patients. Infection was nosocomial in 16 patients (26%). Focal diseases were pneumonia in 41 patients (66%), cholangitis in 5 patients (8%), endocarditis in 3 patients (5%), meningitis and septic arthritis each in 1 patient (2%), and primary bacteremia in 9 patients (14%). The HIV-positive patients were significantly younger and presented more frequently with pneumonia (P < .05). Overall, 14 patients died (22%). Bacteremia was polymicrobial in 11 patients (18%). Haemophilus influenzae was isolated in 53 patients (85%). Rates of antimicrobial resistance were 11% to chloramphenicol sodium succinate, 48% to ampicillin sodium, 78% to erythromycin stearate, 76% to combined sulfamethoxazole and trimethoprim, 15% to rifampin, and 57% to clarithromycin. Infection with HIV has become the most common underlying disease in adults with HB in our hospital. Therapeutic approaches must take into account the high rate of antimicrobial resistance.