Prevalence of bacterial infections and utility of leucocytosis in predicting infections amongst adult sickle cell patients admitted to Mulago National Referral Hospital

Abstract

Background: Bacteraemia occurs less in SCA patients above 10 years of age yet they are usually admitted in crisis with a higher leucocyte count compared to normal population. We set out to determine the prevalence of blood-culture positive bacterial infections, the common bacterial isolates and to assess the role of the WBC counts in the diagnosis of culture-positive bacterial infections in this patient population. Methodology: A cross-sectional study was carried out in the emergency ward Mulago National Referral Hospital and included 105 admitted patients with SCD. Demographic characteristics were noted, blood samples were taken for culture/sensitivity testing and CBC. A ROC curve was constructed to establish the WBC cut-off point that signified a positive blood culture. Results: Results from 101 patients were analysed for this study. Of these 57(56.4%) were females. The median age (IQR) was 20 (95% CI.16-25). 98% of the patients either had moderate or severe anemia. The mean WBC counts (IQR) was 17.9 (IQR: 12.7-24.6). Majority of the participants, (82.2%), had a leucocytosis. Eight patients (7.9%, CI. 4.0-15.2) had positive cultures that yielded staphylococcus aureus (4). Escherichia coli (1), Serratia marcensis (1), Acinetobacteria (1) and Salmonella non typhi group D (1). With the exception of Salmonella non typhi group D, several isolates showed resistance to commonly prescribed drugs on the Ugandan market. The ROC curve did not indicate any WBC cut-offs suggestive of bacteraemia. Conclusion: Given that the raised WBC counts may be of non-infectious aetiology, with low prevalence of bacteraemia in the study population and the documented resistance to antimicrobials, treatments should be guided by laboratory culture and sensitivity results.