Abstract:
Background: Narok County has recorded the highest global isolation of the foodborne Shiga
toxin‑producing Escherichia coli (STEC). Nevertheless, information regarding transmission risk in
the food systems is limited. Objective: This study aimed to investigate risk factors associated with
isolation of STEC from bulked farm milk in Narok County. Materials and Methods: STEC strains
were isolated and identified using standard bacteriological and molecular methods. Management
practices data were collected through face‑to‑face interviews. Logistic regression analyses determined
the relevant predictors and model performance. Results: E. coli was isolated from 15.1% (confidence
interval [CI]: 9.2–21.0, n = 139) of the raw milk samples; the majority (85.7%, CI: 70.8–100.0,
n = 21) of the isolates were confirmed to be STEC through multiplex polymerase chain reaction
and sequencing targeting gadA, stx 1, stx 2, eaeA, and hlyA genes. Informal education (odds
ratio [OR] = 30.7; 95% CI: 6.6–142.5; P < 0.001) and housing livestock (OR = 19.2; 95% CI:
5.2–71.5; P < 0.001) emerged as significant predictors of STEC isolation. Informal education and
indoor housing of dairy animals were associated with increased likelihood of isolation of STEC
from raw milk (adjusted OR [AOR] = 13.9, P < 0.001) and (AOR = 9.0, P < 0.001), respectively.
Conclusions: Our findings provide evidence of poor milk handling practices on farms. The
prevalence of STEC in milk may pose a risk to public health and food safety. Therefore, proper
hygienic practices in dairy farms are recommended.
