RESUMEN
Escherichia coli commonly inhabits the gut of humans and animals as part of their microbiota. Though mostly innocuous, some strains have virulence markers that make them pathogenic. This paper presents results of a cross-sectional epidemiological study examining prevalence of diarrheagenic E. coli (DEC) pathotypes in stool samples of asymptomatic healthy children (n = 540) in Dagoretti South subcounty, Nairobi, Kenya. E. coli was cultured and pathotyped using PCR to target specific virulence markers associated with Shiga-toxin, enteropathogenic, enterotoxigenic, enteroaggregative, entero-invasive and diffusely adherent E. coli. Overall prevalence of DEC pathotypes was 20.9% (113/540) with enteropathogenic E. coli being the most prevalent (34.1%), followed by enteroaggregative E. coli (23.5%) and Shiga-toxin producing E. coli (22.0%) among positive samples. We found evidence of co-infection with multiple pathotypes in 15% of the positive samples. Our models indicated that at the household level, carriage of DEC pathotypes in children was associated with age group [12-18 months] (OR 1.78; 95%CI 1.03-3.07; p = 0.04), eating matoke (mashed bananas) (OR 2.32; 95%CI 1.44-3.73; p = 0.001) and pulses/legumes (OR 1.74; 95%CI 1.01-2.99; p = 0.046) while livestock ownership or contact showed no significant association with DEC carriage (p>0.05). Our findings revealed significant prevalence of pathogenic DEC circulating among presumptive healthy children in the community. Since there has been no previous evidence of an association between any food type and DEC carriage, unhygienic handling, and preparation of matoke and pulses/legumes could be the reason for significant association with DEC carriage. Children 12-18 months old are more prone to DEC infections due to exploration and hand-to-mouth behavior. A detailed understanding is required on what proportion of positive cases developed severe symptomatology as well as fatal outcomes. The co-infection of pathotypes in the rapidly urbanizing environment needs to be investigated for hybrid or hetero-pathotype circulation that have been implicated in previous infection outbreaks.
RESUMEN
Introduction: Campylobacter bacteria is a major cause of foodborne-related bacterial gastroenteritis in humans worldwide. It is known to cause diarrhea in young children which has been shown to directly affect their weight and height as a result of malnutrition. Severe cases of diarrhea can also lead to death. Most of the burden is experienced in resource-limited countries in Africa and Southeast Asia where the disease is linked to poor hygiene and sanitation. The objective of this study was to determine the prevalence of Campylobacter in children aged between 6 and 24 months in Nairobi, Kenya and identify potential risk factors associated with their occurrence. Methods: A cross-sectional study was carried out between May to December 2021. A total of 585 randomly selected households were visited in two wards (Uthiru/Ruthimitu and Riruta) in Dagoretti South sub-county, Nairobi. A questionnaire regarding how children's food is handled, the major foods consumed, sanitation and hygiene, and animal ownership was conducted among caregivers to identify associated risk factors. Stool samples were collected from 540/585 children and screened for the presence of Campylobacter using culture-based methods and confirmed through PCR. Results: Of the 540 children's stool samples processed, Campylobacter isolates were detected in 4.8% (26/540). Campylobacter jejuni (C. jejuni) was the most common species in 80.8% of positive samples compared to Campylobacter coli (C. coli) in 26.9% of samples. In six samples, both C. jejuni and C. coli were isolated, while in four samples, it was not possible to speciate the Campylobacter. Drinking cow's milk (OR 4.2, 95% CI 1.4 - 12.6) and the presence of animal feces in the compound (OR 3.4, 95% CI 1.1 - 10.3) were found to be statistically associated with Campylobacter carriage in children. Discussion: The carriage of Campylobacter in children in this community indicates a need for further investigation on source attribution to understand transmission dynamics and inform where to target interventions. Awareness creation among caregivers on good personal and food hygiene is needed, including boiling milk before consumption. Implementation of biosecurity measures at the household level is highly recommended to reduce contact between animals and humans.
