Carriage of antimicrobial-resistant bacteria in a high-density informal settlement in Kenya is associated with environmental risk-factors

Abstract

BackgroundThe relationship between antibiotic use and antimicrobial resistance varies with cultural, socio-economic, and environmental factors. We examined these relationships in Kibera, an informal settlement in Nairobi - Kenya, characterized by high population density, high burden of respiratory disease and diarrhea. Methods. Two-hundred households were enrolled in a 5-month longitudinal study. One adult (≥18 years) and one child (≤5 years) participated per household. Biweekly interviews (n=1,516) were conducted and 2,341 stool, 2,843 hand swabs and 1,490 water samples collected. Presumptive E. coli (n=34,042) were isolated and tested for susceptibility to nine antibiotics.ResultsEighty percent of E. coli were resistant to ≥3 antibiotic classes. Stool isolates were resistant to trimethoprim (mean: 81%), sulfamethoxazole (80%), ampicillin (68%), streptomycin (60%) and tetracycline (55%). Ninety-seven households reported using an antibiotic in at least one visit over the study period for a total of 144 episodes and 190 antibiotic doses. Enrolled children had five times the number of episodes reported by enrolled adults (96 vs. 19). Multivariable linear mixed-effects models associated children eating soil from the household yard and informal hand-washing stations with increased numbers of antimicrobial-resistant bacteria (counts increasing by 0·27-0·80 log10 and 0·22 to 0·51 log10 respectively, depending on the antibiotic tested). Rainy conditions were associated with reduced carriage of antimicrobial-resistant bacteria (1·19 to 3·26 log10 reduction depending on the antibiotic tested).ConclusionAntibiotic use provided little explanatory power for the prevalence of antimicrobial resistance. Transmission of resistant bacteria in this setting through unsanitary living conditions likely overwhelms incremental changes in antibiotic use. Under such circumstances, sanitation, hygiene, and disease transmission are the limiting factors for controlling the presence of resistant bacteria.

Antimicrobial Susceptibility and Genetic Basis of Resistance of <i>Klebsiella spp</i> Isolated from Diarrheic and Non-Diarrheic Children at Health Facilities in Mukuru Informal Settlement, Nairobi, Kenya

“…Multi drug resistance in slums areas ensures faster spread due to high density of humans and livestock living in close proximity, frequent antibiotic misuse and insufficient drinking water, drainage and sanitation infrastructure. These settlements therefore serve as hotspots for AMR transmission [19] [20].…”

Prevalence of colonization with multidrug-resistant bacteria in communities and hospitals in Kenya

“…These were then grouped by cluster (in Kibera) or village (in Asembo). Within consenting households, a child < 5 years and an adult ≥ 18 years (assumed to have different exposures and widely varying risk factors for colonization with the target organisms 14 ) were selected at random from among age-eligible household members. Selected participants were further screened to exclude individuals who had not consistently resided in the household for at least four weeks prior to the study, and those with fever, diarrhea, or cough on the day of the visit.…”