The effect of cassava foliage (Manihot esculenta) on gastrointestinal parasites of small ruminants in Cambodia

The overall aim of this project was to evaluate whether cassava foliage mitigates gastrointestinal (GI) nematode infections in young goats in Cambodia. The nematocidal activity of fresh cassava foliage was investigated in four trials with experimentally infected pen-fed goats. In the first experiment, the activity on incoming larvae and established adult worms were tested following short-term feeding of fresh foliage for three weeks. Goats (4-6 months) were first treated with ivermectin. After six weeks, they were re-infected with ~2000 mixed infective third-stage GI nematode larvae (L3). There was only a slightly reduction in the faecal egg counts (FEC) during the cassava feeding periods. In the second experiment, the effects of prolonged feeding of fresh (CaF) or ensiled (CaS) cassava foliage for ten weeks using the same type of set up as in experiment one. The inoculations were in accordance with the first trial, except that 3000 L3 were administrated. It was found that CaF only reduced worm fecundity, while feeding CaS also reduced the worm burdens, but only of Haemonchus contortus. Although this was promising, it was realized that the possible effects of a high protein content in cassava silage was a confounder. Accordingly, a third trial was conducted. The aim was to compare the antiparasitic effects in goats fed CaS, and a supplement of urea molasses and soybean meal (UM). The results indicated that the UM supplementation supported only resilience (weight gain, anaemic state) against GI parasite infection, whereas parasite fecundity and worm burden were more or less unaffected. In the final experiment special attention was paid on the antiparasitic effects of CaS. Both cassava foliage and paragrass (Brachiaria mutica) were ensiled with two fermentative additives (sugar palm syrup or rice bran) and were then fed in a similar fashion to the previous experiments. CaS still provided consistent results irrespective of the fermentative additive used. It is concluded that cassava foliage can be used to reduce the adverse effects of GI nematode infections in goats, in particular when offered as silage

Diarrhea illness in livestock keeping households in Cambodia: An analysis using a One Health framework

Background: Most of human diarrheal pathogens are zoonotic, and transmission of the pathogens can occur by contaminated food, water, environment and direct contact with animals especially for livestock keepers. Yet little is known of the relative importance of different risk factors especially in under-studied countries. The objectives of this study were to identify risk factors for diarrhea in livestock keepers in Cambodia and detect diarrhea-causing pathogenic bacteria in both humans and livestock within a One Health approach. Of special interest were the links between diarrhea and food consumption and livestock-keeping. Materials and methods: We used an existing dataset from a questionnaire survey conducted in 400 livestock farms in Prey Veng and Kampot Prefectures between February and March 2013 as well as laboratory results on bacterial isolation from fecal and swab samples from livestock and poultry, and human stool samples. Laboratory results were available for up to three animals of each species kept by a household, and for up to three human samples from households reporting at least one case of human diarrhea in the previous 2 weeks. Presence of Escherichia coli, Shigella spp. and Salmonella spp. was investigated in both animal and human samples, in addition to Aeromonas spp., Vibrio spp. and Plesiomonas spp. in animal samples and Campylobacter spp. in human samples. Univariable and multivariable risk factor analyses were performed by generalized linear mixed model. Results: Household-level diarrhea incidence rate was 9.0% (36/400). The most statistically significant factor associated with diarrhea in multivariable analysis was water treatment for drinking and cooking (OR = 0.33, 95%CI: 0.16–0.69, p = 0.003), followed by number of days consuming egg within 2 weeks (OR = 1.16, 95%CI: 1.04–1.29, p = 0.008), number of children under 5 years old (OR = 1.99, 95%CI: 1.14–3.49, p = 0.016) and keeping poultry (OR = 0.36, 95%CI: 0.14–0.92, p = 0.033). Animal samples for bacterial culture test were collected at 279 cattle, 165 pig and 327 poultry farms, and bacteria were detected from 6 farms with the isolation of Escherichia coli O157 (non H7) from 1 cattle and 1 pig sample, Aeromonas caviae from 1 pig sample and Salmonella spp. from 3 chicken samples. In human samples, 17 out of 67 individual samples were positive for the culture test, detecting Escherichia coli O157 (non H7) from 7 samples and Shigella spp. from 10 samples. None of the households where target bacteria were detected from animal samples had human samples collected due to lack of diarrhea episodes in the household. Conclusions: It has often been hypothesized that keeping livestock may increase the incidence of diarrhea through multiple pathways. Contrary to this, we found livestock-keeping was not associated with increased risk, but food-related behavior and children under 5 years of age were strongly associated with increased risk. We discuss mediating and confounding factors and make recommendations for reducing the burden of diarrheal disease in Cambodia and more widely in low- and middle-income countries

Diarrhea illness in livestock keeping households in Cambodia: An analysis using a One Health framework

BackgroundMost of human diarrheal pathogens are zoonotic, and transmission of the pathogens can occur by contaminated food, water, environment and direct contact with animals especially for livestock keepers. Yet little is known of the relative importance of different risk factors especially in under-studied countries. The objectives of this study were to identify risk factors for diarrhea in livestock keepers in Cambodia and detect diarrhea-causing pathogenic bacteria in both humans and livestock within a One Health approach. Of special interest were the links between diarrhea and food consumption and livestock-keeping.Materials and methodsWe used an existing dataset from a questionnaire survey conducted in 400 livestock farms in Prey Veng and Kampot Prefectures between February and March 2013 as well as laboratory results on bacterial isolation from fecal and swab samples from livestock and poultry, and human stool samples. Laboratory results were available for up to three animals of each species kept by a household, and for up to three human samples from households reporting at least one case of human diarrhea in the previous 2 weeks. Presence of Escherichia coli, Shigella spp. and Salmonella spp. was investigated in both animal and human samples, in addition to Aeromonas spp., Vibrio spp. and Plesiomonas spp. in animal samples and Campylobacter spp. in human samples. Univariable and multivariable risk factor analyses were performed by generalized linear mixed model.ResultsHousehold-level diarrhea incidence rate was 9.0% (36/400). The most statistically significant factor associated with diarrhea in multivariable analysis was water treatment for drinking and cooking (OR = 0.33, 95%CI: 0.16–0.69, p = 0.003), followed by number of days consuming egg within 2 weeks (OR = 1.16, 95%CI: 1.04–1.29, p = 0.008), number of children under 5 years old (OR = 1.99, 95%CI: 1.14–3.49, p = 0.016) and keeping poultry (OR = 0.36, 95%CI: 0.14–0.92, p = 0.033). Animal samples for bacterial culture test were collected at 279 cattle, 165 pig and 327 poultry farms, and bacteria were detected from 6 farms with the isolation of Escherichia coli O157 (non H7) from 1 cattle and 1 pig sample, Aeromonas caviae from 1 pig sample and Salmonella spp. from 3 chicken samples. In human samples, 17 out of 67 individual samples were positive for the culture test, detecting Escherichia coli O157 (non H7) from 7 samples and Shigella spp. from 10 samples. None of the households where target bacteria were detected from animal samples had human samples collected due to lack of diarrhea episodes in the household.ConclusionsIt has often been hypothesized that keeping livestock may increase the incidence of diarrhea through multiple pathways. Contrary to this, we found livestock-keeping was not associated with increased risk, but food-related behavior and children under 5 years of age were strongly associated with increased risk. We discuss mediating and confounding factors and make recommendations for reducing the burden of diarrheal disease in Cambodia and more widely in low- and middle-income countries

Manure management and public health : Sanitary and socio-economic aspects among urban livestock-keepers in Cambodia

Livestock manure is a valuable source of nutrients for crop production, but can also pose a public health hazard and have negative environmental impacts. This study investigated manure management practices among urban and peri-urban livestock keepers in Cambodia, to identify risk behaviours and socio-economic aspects associated with the handling of manure. A survey including 204 households was conducted, using a structured questionnaire with questions on demographics, socio-economic characteristics and household practices related to manure management. Faecal samples were obtained from pig pens and pig manure storage units for analysis of the potential zoonotic pathogens Salmonella enterica (Polymerase Chain Reaction (PCR)), Ascaris suum and Trichuris suis (McMaster flotation technique). The survey revealed a difference in management between cattle and pig manure. Cattle manure was most commonly used as fertiliser for crop production (66%) (p < 0.001), whereas pig manure was most commonly dumped in the environment (46%) (p < 0.001). Logistic regression models showed that households with a lower socio-economic position were more likely to dump pig manure (p < 0.001), with scarcity of agricultural land (p < 0.001) and lack of carts for transportation of manure (p < 0.01) being identified as contributing factors. Salmonella enterica was detected in 9.7% of manure samples, while Ascaris suum and Trichuris suis were detected in 1.6% and 2.4% of the samples, respectively. The results presented in this study indicate that manure management by urban and peri-urban households may pose a public health threat and an environmental hazard. There is evidently a need for further knowledge support to the livestock keepers to promote good management practices

Inflow of pigs (frequency groups) in the participating households during the past 12 months (n = 204), (Cambodia 2014–2015).

<p>Inflow of pigs (frequency groups) in the participating households during the past 12 months (n = 204), (Cambodia 2014–2015).</p

Household characteristics among pig-keepers in urban and peri-urban Phnom Penh (n = 204), (Cambodia 2014–2015).

<p>Household characteristics among pig-keepers in urban and peri-urban Phnom Penh (n = 204), (Cambodia 2014–2015).</p

Perceived constraints to pig-keeping amongst the households studied (n = 102)^* (Cambodia 2014–2015).

<p>Perceived constraints to pig-keeping amongst the households studied (n = 102)^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0182247#t004fn001" target="_blank">*</a>} (Cambodia 2014–2015).</p

Carriage of carbapenemase- and extended-spectrum cephalosporinase-producing Escherichia coli and Klebsiella pneumoniae in humans and livestock in rural Cambodia; gender and age differences and detection of bla(OXA-48 )in humans

Objectives This study investigates the frequency and characteristics of carbapenemase-producing Escherichia coli/Klebsiella pneumoniae (CPE/K) and extended-spectrum cephalosporinase-producing E. coli/K. pneumoniae (ESCE/K) in healthy humans and livestock in rural Cambodia. Additionally, household practices as risk factors for faecal carriage of ESCE/K are identified. Methods Faecal samples were obtained from 307 humans and 285 livestock including large ruminants, pigs and poultry living in 100 households in rural Cambodia in 2011. Each household was interviewed, and multilevel logistic model determined associations between household practices/meat consumption and faecal carriage of ESCE/K. CPE and ESCE/K were detected and further screened for colistin resistance genes. Results CPE/K isolates harbouring bla(OXA-48 )were identified in two humans. The community carriage of ESCE/K was 20% in humans and 23% in livestock. The same ESBL genes: bla(CTX-M-15), bla(CTX-M-14), bla(CTX-M-27), bla(CTX-M-55), bla(SHV-2), bla(SHV-12), bla(SHV-28); AmpC genes: bla(CMY-2), bla(CMY-42,) bla(DHA-1); and colistin resistance genes: mcr-1-like and mcr-3-like were detected in humans and livestock. ESCE/K was frequently detected in women, young children, pigs and poultry, which are groups in close contact. The practice of burning or burying meat waste and not collecting animal manure indoors and outdoors daily were identified as risk factors for faecal carriage of ESCE/K. Conclusions Faecal carriage of E. coli and K. pneumoniae harbouring extended-spectrum cephalosporinase genes are common in the Cambodian community, especially in women and young children. Exposure to animal manure and slaughter products are risk factors for intestinal colonization of ESCE/K in humans.Funding Agencies|Swedish Civil Contingencies Agency; Swedish International Development Cooperation Agency [2010-7876]; Swedish Research Council VR [2016-02606]</p