Risk factors for household colonization by extended-spectrum cephalosporin-resistant enterobacterales (ESCrE) in Botswana

The epidemiology of community colonization with extended-spectrum cephalosporin-resistant Enterobacterales (ESCrE) in low- and middle-income countries (LMICs) is largely uncharacterized. In the community, the household is of particular importance. Identifying risk factors for household ESCrE colonization is critical to inform antibiotic resistance reduction strategies.

Participants were enrolled at 6 clinics in Botswana. All participants had rectal swabs collected for selective plating and confirmation of ESCrE. Data were collected on demographics, comorbidities, antibiotic use, healthcare exposures, travel, and farm/animal contact. Households were considered exposed if any member had the exposure of interest. Households with ESCrE colonization (cases) were compared to non-colonized households (controls) to identify risk factors for household ESCrE colonization.

From 1/1/20 − 9/4/20, 327 households were enrolled. The median (IQR) number of people enrolled per household was 3 (2–4) ranging from 2 to 10. The median (IQR) age of subjects was 18 years (5–34) and 304 (93%) households included at least one child. Of 327 households, 176 (54%) had at least one household member colonized with ESCrE. Independent risk factors [adj OR (95%CI)] for household colonization were: (1) horse/donkey exposure [2.32 (1.05, 5.10)]; (2) yogurt consumption [1.73 (1.04, 2.88)]; (3) region [2.83 (1.48,5.43)]; and (4) enrollment during pre-COVID lockdown [2.90 (1.66, 5.05)].

ESCrE household colonization was common with evidence of geographic variability as well as a possible role of animal exposure. The role of yogurt exposure requires further study with consideration of source (commercial, homemade). Further prospective studies of household ESCrE colonization with longitudinal assessments of exposures are required to identify effective prevention strategies.