Seasonal variation in the etiology of bloodstream infections in a febrile inpatient population in a developing country.

OBJECTIVES

Published data suggest that Streptococcus pneumoniae, non-typhi Salmonella species, and Mycobacterium tuberculosis are the predominant causes of bloodstream infection (BSI) in hospitalized populations in sub-Saharan Africa. This study was conducted during the wet season to ascertain the etiology and prevalence of BSI among febrile inpatients in a hospital where the dry season BSI profile in a similar study population had already been documented.

METHODS

In the period from March to May 1998, consecutive febrile (> or = 37.5 degrees C) adult (> or = 14 y) patients presenting to a Malawi hospital were enrolled after providing informed consent. Following clinical evaluation, blood was drawn for culture (bacteria, mycobacteria, and fungi), human immunodeficiency virus (HIV) testing, and malaria smears.

RESULTS

Of 238 enrolled patients, 173 (73%) were HIV-positive and 67 (28%) had BSI. The predominant wet season BSI pathogens were non-typhi Salmonella species (41%), M. tuberculosis (19%), and Cryptococcus neoformans (9%) (cf. the predominant dry season pathogen was S. pneumoniae). Mycobacteremia was more likely in HIV-positive than in HIV-negative patients (13/173 vs. 0/65; P < 0.05). A logistic regression model yielded clinical predictors of BSI that included chronic fever, oral candidiasis, or acute diarrhea.

CONCLUSION

Pathogens causing BSI in febrile inpatients in a Malawi teaching hospital vary by season. Season- and country-specific studies, such as this one, provide data that may facilitate empirical therapy of febrile illnesses whose etiologies vary by season.