Factors associated with occurrence of salmonellosis among children living in Mukuru slum, an urban informal settlement in Kenya

Abstract

Background: In Kenya, typhoid fever and invasive non-typhoidal salmonellosis present a huge burden of disease, especially in poor-resource settings where clean water supply and sanitation conditions are inadequate. The epidemiology of both diseases is poorly understood in terms of severity and risk factors. The aim of the study was to determine the disease burden and spatial distribution of salmonellosis, as well as socioeconomic and environmental risk factors for these infections, in a large informal settlement near the city of Nairobi, from 2013 to 2017. Methods: Initially, a house-to-house baseline census of 150,000 population in Mukuru informal settlement was carried out and relevant socioeconomic, demographic, and healthcare utilization information was collected using structured questionnaires. Salmonella bacteria were cultured from the blood and faeces of children < 16 years of age who reported at three outpatient facilities with fever alone or fever and diarrhea. Tests of association between specific Salmonella serotypes and risk factors were conducted using Pearson Chi-Square (χ 2) test. Results: A total of 16,236 children were recruited into the study. The prevalence of bloodstream infections by Non-Typhoidal Salmonella (NTS), consisting of Salmonella Typhimurium/ Enteriditis, was 1.3%; Salmonella Typhi was 1.4%, and this was highest among children < 16 years of age. Occurrence of Salmonella Typhimurium/ Enteriditis was not significantly associated with rearing any domestic animals. Rearing chicken was significantly associated with high prevalence of S. Typhi (2.1%; p = 0.011). The proportion of children infected with Salmonella Typhimurium/ Enteriditis was significantly higher in households that used water pots as water storage containers compared to using water directly from the tap (0.6%). Use of pit latrines and open defecation were significant risk factors for S. Typhi infection (1.6%; p = 0.048). The proportion of Salmonella Typhimurium/ Enteriditis among children eating street food 4 or more times per week was higher compared to 1 to 2 times/week on average (1.1%; p = 0.032).

Out-of-pocket payment for healthcare among urban citizens in Dhaka, Bangladesh

“…Most of them (64%) suffered from acute illnesses such as fever, flu, diarrhoea and so on. It is noteworthy that the urban environment (particularly Dhaka, where the population density is so high and resources are scarce) may provide a favourable setting for the spread of various infectious diseases, especially in slums [ 35 , 36 , 42 ]. Further, migration and rapid urbanisation can result in new diseases from remote rural areas appearing in cities [ 1 ].…”

“…The major explanatory variables utilised in this study are based on the socioeconomic factors of patients with acute and chronic diseases, following earlier studies in various urban settings [31,[34][35][36][37][38][39][40]. The age of the population is categorised into four groups (younger than 5, 5-14, 15-60 and older than 60).…”

Case-control investigation of invasive Salmonella disease in Malawi reveals no evidence of environmental or animal transmission of invasive strains, and supports human to human transmission

“…Our results and interpretation are consistent with and extend those of several previous reports. Firstly, in Kenya, iNTS infections caused by Salmonella Typhimurium or Enteritidis in an informal urban settlement were not found to be associated with the rearing of any domestic animals [48]. Secondly, in Burkina Faso the only isolates that matched the index cases were obtained from the stool of household members, despite extensive animal and water sampling in the households of iNTS patients [49].…”

Entamoeba species infection in patients seeking treatment for diarrhea and abdominal discomfort in Mukuru informal settlement in Nairobi, Kenya

“…This age group in Kenya comprises of young adults who are likely buy food from the streets with low standards of hygiene and therefore exposing them to foodborne diseases. A recent study reported that buying food from the street as a common behaviour for residents of Mukuru slums and found significant association of this habit with salmonella disease ( Mbae et al, 2020 ). This study found an inverse relationship between E. histolytica infections and diarrhea.…”