An Epidemiologic Review of Enteropathogens in Gaborone,Botswana: Shifting Patterns of Resistance in an HIV Endemic Region

Background

The epidemiology of diarrheal disease in Botswana, an HIV endemic region, islargely unknown. Our primary objective was to characterize the prevalentbacterial and parasitic enteropathogens in Gaborone, Botswana. Secondaryobjectives included determining corresponding antimicrobial resistancepatterns and the value of stool white and red blood cells for predictingbacterial and parasitic enteropathogens.

Methodology/Principal Findings

A retrospective cross-sectional study examined laboratory records of stoolspecimens analyzed by the Botswana National Health Laboratory in Gaborone,Botswana from February 2003 through July 2008. In 4485 specimens the mediansubject age was 23 [interquartile range 1.6–34]years. Overall, 14.4% (644 of 4485) of samples yielded apathogen. Bacteria alone were isolated in 8.2% (367 of 4485),parasites alone in 5.6% (253 of 4485) and both in 0.5%(24 of 4485) of samples. The most common bacterial pathogens wereShigella spp. and Salmonella spp.,isolated from 4.0% (180 of 4485) and 3.9% (175 of4485) of specimens, respectively. Escherichia coli (22 of4485) and Campylobacter spp. (22 of 4485) each accountedfor 0.5% of pathogens. Comparing antimicrobial resistance amongShigella spp. and Salmonella spp.between two periods, February 2003 to February 2004 and July 2006 to July2008, revealed an increase in ampicillin resistance amongShigella spp. from 43% to 83%(p<0.001). Among Salmonella spp., resistance tochloramphenicol decreased from 56% to 6%(p<0.001). The absence of stool white and red blood cells correlatedwith a high specificity and negative predictive value.

Conclusions/Significance

Most gastroenteritis stools were culture and microscopy negative suggestingthat viral pathogens were the majority etiologic agents in this Botswanacohort. Shigella spp. and Salmonella spp.were the most common bacteria; Isospora spp. andCryptosporidium spp. were the most common parasites.Resistance to commonly used antimicrobials is high and should be closelymonitored.