Prevalence, Associated Risk Factors and Antibiotic Susceptibility Patterns of Common Diarrheagenic Bacteria Isolated from Food Handler Populations in Nairobi, Kenya

Background: Diarrheal disease is estimated to cause 29% of illness among adults and is also the major cause of illness and hospitalization for children under 5 years of age.  Despite the high cases of food borne illness, there is still low reporting, diagnosis and recording of infection rates. Food handlers play a significant role in food borne pathogens transmission due to their direct contact with food and drinks. This study aimed at determining the prevalence, associated risk factors and antibiotic susceptibility profiles of common diarrheagenic bacterial pathogens among food handler populations in Nairobi. Materials and Methods: A cross-sectional study was conducted by systematically enrolling consenting food handlers working in the hospitality industry in Nairobi into the study. Self-reported data focusing on Water, Sanitation and Hygiene (WASH)-related behaviors of the participants was collected through a structured, closed-ended questionnaire. Stool samples were obtained and bacteriological analysis performed using conventional stool culture methods. The recovered bacterial isolates thereafter underwent Antibiotic Susceptibility Testing (AST) using the disk diffusion method to determine their resistance profiles. To assess the factors associated with antimicrobial resistance, Poisson regression modeling (univariate and multivariate) was used on the count outcome (number of antimicrobials to which a sample was resistant). Results: A total of 231 isolates were confirmed as the pathogens of interest after biochemical testing: Escherichia coli (178/885), Klebsiella pneumoniae (47/885), Salmonella spp (5/885) and Shigella (1/885). Almost all the recovered isolates showed resistance to erythromycin (97%) while about 81% exhibited resistance to amoxicillin-clavulanic acid. There was intermediate resistance seen against cefotaxime (40%), cefepime (33%), cefuroxime (53.75%) and gentamicin (27%). Low level of resistance was found against meropenem (1%), ciprofloxacin (10%) and chloramphenicol (9%). Of the E. coli isolates obtained, 41 (23%) were multi drug resistant and 2 (1.12%) were both Multi Drug Resistant and Pan Drug Resistant (PDR). Only 1 Klebsiella spp isolate was MDR. None of the Salmonella spp and Shigella spp was found to be Multi-Drug Resistant. Regular handwashing was found to be the most significant risk factor for infection with a pathogenic bacteria (p<0.05: 95% CI: [-0.339-0.127]). Food handlers who practiced regular handwashing had significantly lower antimicrobial resistance counts based on their incident rate ratios (IRRs) (IRR = 0.85, p = 0.029). Conversely, wearing hairnets (IRR = 2.55, p < 0.001) and working in informal eateries (IRR = 1.51, p = 0.005) or middle-level restaurants (IRR = 1.43, p = 0.008) were associated with higher resistance counts. Conclusion: A fairly high prevalence of diarrheagenic bacterial pathogens (26%) was found among the food handler population. There was also notably high levels of antibiotic resistance to commonly used drugs for diarrhea management, with medium and high levels of drug resistance to common first line drugs like erythromycin and amoxicillin-clavulanic acid being observed. Efforts should be made to improve access to clean water for both personal and hotel use for the sake of proper food hygiene practices such as handwashing. Sensitization for increased awareness on the importance of proper handwashing practices should also be done more regularly at the workplaces. All workers should also be medically examined appropriately and regularly before certification and advised to seek proper treatment in case of gastrointestinal illness to ensure proper administration of antibiotics for treatment to reduce potential cases of drug resistance.