Surface waters in northern Tanzania harbor fecal coliform and antibiotic resistant Salmonella spp. capable of horizontal gene transfer

High diversity of Salmonella spp. from children with diarrhea, food, and environmental sources in Kilimanjaro - Tanzania: one health approach

Salmonella is one of the most frequent causes of diarrhea globally. This study used a One Health approach to identify Salmonella species in children admitted with diarrhea and tested samples from the cases' household environment to investigate their genetic similarity using whole genome sequencing. Surveillance of hospitalized diarrhea cases among children under 5 years was conducted in rural and urban Moshi Districts in the Kilimanjaro Region of Tanzania from July 2020 through November 2022. Household visits were conducted for every child case whose parent/caregiver provided consent. Stool samples, water, domestic animal feces, meat, and milk were collected and tested for Salmonella. Isolates were sequenced on the Illumina NextSeq platform. Multilocus Sequence Typing and phylogenetic analyses were performed to map the genetic relatedness of the isolates. Salmonella was isolated from 72 (6.0%) of 1,191 samples. The prevalence of Salmonella in children with diarrhea, domestic animal feces, food, and water was 2.6% (n = 8/306), 4.6% (n = 8/174), 4.2% (n = 16/382), and 17.3% (n = 39/225), respectively. Four (1.3%) of the 306 enrolled children had a Salmonella positive sample taken from their household. The common sequence types (STs) were ST1208, ST309, ST166, and ST473. Salmonella Newport was shared by a case and a raw milk sample taken from the same household. The study revealed a high diversity of Salmonella spp., however, we detected a Salmonella clone of ST1208 isolated at least from all types of samples. These findings contribute to understanding the epidemiology of Salmonella in the region and provide insight into potential control of foodborne diseases through a One Health approach.

Infection, colonization and shedding of Campylobacter and Salmonella in animals and their contribution to human disease: A review

Livestock meat and offal contribute significantly to human nutrition as sources of high-quality protein and micronutrients. Livestock products are increasingly in demand, particularly in low- and middle-income settings where economies are growing and meat is increasingly seen as an affordable and desirable food item. Demand is also driving intensification of livestock keeping and processing. An unintended consequence of intensification is increased exposure to zoonotic agents, and a contemporary emerging problem is infection with Campylobacter and Salmonella spp. from livestock (avian and mammalian), which can lead to disease, malabsorption and undernutrition through acute and chronic diarrhoea. This can occur at the farm, in households or through the food chain. Direct infection occurs when handling livestock and through bacteria shed into the environment, on food preparation surfaces or around the house and surroundings. This manuscript critically reviews Campylobacter and Salmonella infections in animals, examines the factors affecting colonization and faecal shedding of bacteria of these two genera as well as risk factors for human acquisition of the infection from infected animals or environment and analyses priority areas for preventive actions with a focus on resource-poor settings.

Water-Handling Patterns and Associated Microbial Profiles in relation to Hygiene in Babati Town, Tanzania

Introduction

In rapidly urbanizing centres in Tanzania, water supply infrastructure lags behind the speed of urbanization, affecting water availability and accessibility. We believe that inhabitants' access water using various ways which are characterizable and understanding them could inform about the risks to hygiene-related diseases. This study aimed at characterizing water-handling chains and their microbial profiles in Babati town to inform hygiene education policy and water supply planning.

Methodology

A cross-sectional study design employing a proportional sampling for each of the 8 wards was conducted between November 2016 and March 2017. A total of 564 samples of water were collected using the USA EPA procedures from 37 randomly selected households. Water samples were collected from the common sources of water as well as from the downstream points to multiple storage containers. Using EPA membrane filtration techniques, two microorganisms were tested: fecal coliforms and Salmonella typhi. Results. Three water-handling chains/patterns in Babati town were determined, and they were as follows: (i) untreated-source-to-treated-reservoir-to-households (untrS2trR2HH) chain, (ii) untreated-source-to-untreated-reservoir-to-households (untrS2untrR2HH) chain; (iii) untreated-source-straight-to-households (untrS2HH) chain. In terms of the microbial profile, the most contaminated water-handling chain was the untreated-source-straight-to-households (untrS2HH). The number of users in these three chains was not statistically significantly different (p=0.5226), meaning that all people utilized the various chains almost equally, depending on the water situation. Most households (83%) did not treat their drinking water making those using the untreated-source-to-household chain (untrS2HH) most vulnerable to waterborne diseases.

Conclusion

Determination of water-handling chains among the household is a novel approach which allows an understanding of the points at which highest fecal loading occurs. This approach therefore may inform the development of policies in the areas of household hygiene education, drinking water treatment, and water supply planning in urbanized towns in Tanzania and other developing countries.

Water, Sanitation, and Hygiene Practices Associated with Nutritional Status of Under-Five Children in Semi-Pastoral Communities Tanzania

Undernutrition among under-five children is a public health concern in developing countries and has been linked with poor water, sanitation, and hygiene (WASH) practices. This study aimed at assessing WASH practices and its association with nutritional status of under-five children in semi-pastoral communities of Arusha. The study was cross-sectional in design. Mother-child pairs from 310 households in four villages of Monduli and Longido were involved. Weight and height of children were measured using weighing scale and length/height board, respectively. Children's age was recorded using clinic cards. Hemoglobin level of each child was tested using Hemo Cue® Hb 201 + photometer (HemoCue AB, Ängelholm, Sweden) machine. Structured questionnaire was used to gather information on WASH, child morbidity, demographic, and sociocultural characteristics. Prevalence of stunted, underweight, wasted, anemia, and diarrhea were 31.6%, 15.5%, 4.5% 61.2%, and 15.5%, respectively. Children with diarrhea 2 weeks preceding the survey (P = 0.004), children using surface water for domestic purposes (P < 0.001), and those with uneducated mothers (P = 0.001) had increased risk of being stunted and underweight. Children introduced to complementary foods before 6 months of age (P = 0.02) or belonging to polygamous families (P = 0.03) had increased risk of being stunted. Consumption of cow's milk that is not boiled (P = 0.05) or being a boy (P = 0.03) was associated with underweight. Prevalence of undernutrition among under-five children in the population under study was alarming and it could be associated with poor WASH practices and other sociocultural factors. This study underlines the importance of incorporating WASH strategies in formulation of interventions targeting on promotion of nutrition and disease prevention in pastoral communities.

Influence of Water, Sanitation, and Hygiene Practices on Common Infections among Under-Five Children in Longido and Monduli Districts of Arusha, Tanzania

The study aimed at assessing water, sanitation, and hygiene practices and their influence on infectious diseases among under-five children in semipastoral communities of Arusha. The study was cross-sectional in design. Prevalence of infectious diseases among under-five children was derived from patients' attendance register. Mothers randomly sampled from households were interviewed using questionnaire. Information regarding child morbidity and sociodemographic and WASH characteristics was gathered. Hospital data revealed that 2/3 of under-five patients visited the hospitals annually were suffering from infectious diseases. Mean percentage of diarrhea prevalence for years 2013–2015 in Longido was higher than the mean of the respective years prevalence in Monduli (p = 0.02). Households' survey showed that 15.5% of under-five children were suffering from diarrhea. Children who consumed foods kept in kibuyu (p < 0.001) or used unboiled cows' milk (p = 0.01) or were drinking surface water (p = 0.04) or born to uneducated mothers (p = 0.01) had increased risk of developing diarrhea compared to their counterparts. Storing complementary foods in kibuyu was strongly associated with diarrhea among under-five children. To address the problem, communities under study need to be motivated through health education on food hygiene, proper handling of food storage containers, and domestic water treatment at the household level.

Load and Prevalence of Antimicrobial-Resistant Escherichia coli from Fresh Goat Meat in Arusha, Tanzania

Given the potential public health risks associated with a burgeoning goat meat industry in Tanzania, we estimated the load of Escherichia coli and the prevalence of antibiotic-resistant strains for goat meat by using a cross-sectional study design (June to July 2015). Five large (n = 60 samples) and five small (n = 64 samples) slaughterhouses were sampled over a period of four to six visits each. Meat rinsate was prepared and plated onto MacConkey agar, and presumptive E. coli colonies were enumerated and reported as CFU per milliliter of rinsate. In total, 2,736 presumptive E. coli isolates were tested for antibiotic drug sensitivity by using breakpoint assays against 11 medically important antibiotics. E. coli was recovered from almost all the samples (96.8%), with counts ranging from 2 to 4 log CFU ml^-1, and there was no significant difference (P = 0.43) in recovery according to facility size (average, 3.37 versus 3.13 log CFU ml^-1, large and small, respectively). Samples from large facilities had relatively higher prevalence (P = 0.026) of antibiotic-resistant E. coli compared with small facilities. This was mostly explained by more ampicillin (30.1 versus 12.8%) and amoxicillin (17.6 versus 4.5%) resistance for large versus small facilities, respectively, and more tetracycline resistance for small facilities (5.6 versus 10.6%, respectively). Large slaughter operations may serve as foci for dissemination of antibiotic-resistant bacteria via food products. More effective hygiene practices during slaughter and meat handling would limit the probability of transmitting antibiotic-resistant E. coli in goat meat.