Shigellosis in an Urban Slum in Kenya: Risk Factors and Antimicrobial Resistance

Shigella spp are among the notable causes of global diarrheal disease and death, accounting for 13.2% of deaths in 2016. Antimicrobial resistance complicates shigellosis management. Understanding local disease epidemiology is crucial for developing effective preventive strategies, including vaccine use.

We investigated antimicrobial resistance, risk factors (socioeconomic, behavioral, and water, sanitation and hygiene (WaSH), and clinical characteristics of Shigella diarrhea in Mukuru informal settlement and surrounding villages in Nairobi, Kenya. Patients presenting with diarrhea, fever, or both in treatment centers had stool or rectal swab samples cultured, and bacteria was identified through biochemical and serologic tests.

The rate of Shigella isolation among the 4689 individuals presenting with diarrhea was 1.4% across all ages, with a similar isolation rate (1.5%) among children <5 years of age. The majority of the Shigella spp (40 [59.7%]) were Shigella flexneri, and the majority of S flexneri (34 of 40 [85%]) were resistant to trimethoprim-sulfamethoxazole; however, all were sensitive to amoxicillin-clavulanate, ceftazidime, ceftriaxone, and cefpodoxime. The rate of multidrug resistance was higher in Shigella sonnei (13 [48.1%]) than in S flexneri (3 [7.5%]). Shigella positivity was associated with bloody diarrhea, severe/moderate dehydration, coated tongue, and high fever. Consumption of street food was also associated with Shigella diarrhea.

Despite low prevalence, shigellosis still poses a significant burden of diarrheal disease, warranting future incidence studies. First-line antibiotics against Shigella remain effective, but intermediate resistance to azithromycin and ciprofloxacin is a concerning trend. Improving household food preparation and handling could potentially reduce Shigella infections.