Pneumococcal bacteremia with pneumonia. Mortality in acquired immunodeficiency syndrome

Abstract

Objective: To compare mortality due to bacteremic pneumococcal pneumonia in patients with acquired immunodeficiency syndrome (AIDS) vs (control) patients without human immunodeficiency virus (HIV) infection. Non-AIDS patients with HIV infection were incidentally tabulated as a separate group.

Design: A two-year retrospective study.

Setting: Inpatients of St. Clare's Hospital, a community hospital in New York City.

Patients: Forty-nine patients had 50 separate episodes with at least one positive blood culture for Streptococcus pneumoniae (all were penicillin-sensitive) and pneumonia on chest roentgenogram. Twenty-four patients had no HIV infection, 14 patients had AIDS, and 11 patients with 12 bacteremic episodes were HIV-positive without AIDS.

Interventions: Treatment for pneumonia was determined by the patient's individual physician.

Measurements and main results: AIDS patients with pneumonia had a mortality of 57.1 percent (8/14), which was significantly higher than the 25 percent (6/24) seen in patients without HIV infection (p less than 0.025, two-sample test for independent proportions). Septic shock, usually occurring within the first five days of hospitalization, was the primary cause of death, occurring in six of eight AIDS patients and six of six patients without HIV infection. If the mortality in the first five days of hospitalization was excluded, the mortality would drop to 33.3 percent in the AIDS population and 5.3 percent in patients without HIV infection. Eleven HIV-infected patients without AIDS survived 12 episodes of bacteremic pneumococcal pneumonia.

Conclusions: Bacteremic pneumococcal pneumonia in the setting of AIDS has a survival rate of less than 50 percent with septic shock as the usual mode of death. This is the highest pneumococcal pneumonia mortality rate ever reported in a large subgroup of patients in the antibiotic era. On the other hand, HIV-infected patients without progression to AIDS have an excellent chance for survival. This may be related in part to young age, absence of many underlying diseases, and a better humoral immune system.