| 1. |
- Atterby, Clara, et al.
(author)
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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 blaOXA-48 in humans.
- 2019
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In: Zoonoses and Public Health. - : Wiley-VCH Verlagsgesellschaft. - 1863-1959 .- 1863-2378. ; 66:6, s. 603-617
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Journal article (peer-reviewed)abstract
- 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 blaOXA-48 were identified in two humans. The community carriage of ESCE/K was 20% in humans and 23% in livestock. The same ESBL genes: blaCTX-M-15 , blaCTX-M-14 , blaCTX-M-27 , blaCTX-M-55 , blaSHV-2 , blaSHV-12 , blaSHV-28 ; AmpC genes: blaCMY-2 , blaCMY-42, blaDHA-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.
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| 2. |
- Magnusson, Ulf, et al.
(author)
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Antimicrobial resistance at the livestock-human interface: implications for Veterinary Services
- 2021
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In: Revue Scientifique et Technique- Office International des Epizooties. - : O.I.E (World Organisation for Animal Health). - 0253-1933 .- 1608-0637. ; 40, s. 511-521
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Journal article (peer-reviewed)abstract
- The emergence of antimicrobial resistance (AMR) is a major global public health issue, but it also jeopardises the effectiveness of antimicrobials as a means of curing infections in animals that threaten their health, welfare and productivity. Several reports show that infections in humans caused by antimicrobial-resistant pathogens may be linked to antimicrobial use (AMU) and AMR in food-producing animals; however, to what extent this happens is unknown. Use of antimicrobials drives the emergence of AMR, therefore, their extensive over-use and misuse in livestock is of concern.Robust AMU and AMR data are important to monitor the progress of interventions aiming to reduce AMR in the livestock sector. However, not all countries have complete data on antibiotic sales or use, so our current knowledge of global AMU is primarily based on modelling estimates. Antimicrobial resistance prevalence data are limited, particularly in low- and middle-income countries, but in some high-income regions fairly robust data are available. It should also be noted that monitoring guidelines and protocols are available to provide globally harmonised AMR data.Using antimicrobials rationally and not using them for disease prevention purposes is key to reducing AMU. To ensure that these drugs are used appropriately we must ensure that: a) veterinary services are accessible and affordable for farmers; b) antibiotics are only sold on prescription; c) veterinarians earn no revenue linked to the sale or prescription of antibiotics; d) veterinarians have substantial skills in preventive medicine (good animal husbandry, efficient biosecurity and vaccinology); and e) the benefits of preventive measures must appeal to farmers so that they are willing to pay for them.
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| 3. |
- Osbjer, Kristina
(author)
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Detection of African swine fever virus in free-ranging wild boar in Southeast Asia
- 2021
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In: Transboundary and Emerging Diseases. - : Hindawi Limited. - 1865-1674 .- 1865-1682. ; 68, s. 2669-2675
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Journal article (peer-reviewed)abstract
- African Swine Fever (ASF) is a highly contagious and fatal viral disease affecting both domestic and wild suids. The virus was introduced to Southeast Asia in early 2019 and has since spread rapidly throughout the region. Although significant efforts have been made to track and diagnose the disease in domestic pigs, very little is known about ASF in free-ranging wild boar and their potential role in maintaining the disease within Southeast Asia. Through a collaboration between government and non-government actors in Laos, Viet Nam, and Cambodia, investigations were conducted to (a) characterize the interface between domestic pigs and wild boar, (b) document risk factors for likely ASF spillover into wild boar populations by way of this interface, and (c) determine whether ASF in wild boar could be detected in each country. An extensive overlap between wild boar habitat and domestic pig ranging areas was found around villages bordering forests in all three countries, creating a high-risk interface for viral spillover between domestic pig and wild boar populations. Fifteen and three wild boar carcasses were detected through passive reporting in Laos and Viet Nam, respectively, in 2019 and early 2020. Four of five carcasses screened in Laos and two of three in Viet Nam were confirmed positive for African swine fever virus using real-time PCR. There were no confirmed reports of wild boar carcasses in Cambodia. This is the first confirmation of ASF in wild boar in Southeast Asia, the result of a probable viral spillover from domestic pigs, which highlights the importance of early reporting and monitoring of ASF in wild boar to enable the implementation of appropriate biosecurity measures.
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| 4. |
- Osbjer, Kristina, et al.
(author)
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Detection of Campylobacter in human and animal field samples in Cambodia
- 2016
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In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS). - : Wiley. - 0903-4641 .- 1600-0463. ; 124:6, s. 508-515
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Journal article (peer-reviewed)abstract
- Campylobacter are zoonotic bacteria and a leading cause of human gastroenteritis worldwide with Campylobacter jejuni and C. coli being the most commonly detected species. The aim of this study was to detect Campylobacter in humans and livestock (chickens, ducks, pigs, cattle, water buffalo, quail, pigeons and geese) in rural households by routine culturing and multiplex PCR in faecal samples frozen before analysis. Of 681 human samples, 82 (12%) tested positive by PCR (C. jejuni in 66 samples and C. coli in 16), but none by routine culture. Children were more commonly Campylobacter positive (19%) than adult males (8%) and females (7%). Of 853 livestock samples, 106 (12%) tested positive by routine culture and 352 (41%) by PCR. Campylobacter jejuni was more frequent in chickens and ducks and C. coli in pigs. In conclusion, Campylobacter proved to be highly prevalent by PCR in children (19%), ducks (24%), chickens (56%) and pigs (72%). Routine culturing was insufficiently sensitive in detecting Campylobacter in field samples frozen before analysis. These findings suggest that PCR should be the preferred diagnostic method for detection of Campylobacter in humans and livestock where timely culture is not feasible.
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| 5. |
- Osbjer, Kristina, et al.
(author)
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Household practices related to disease transmission between animals and humans in rural Cambodia
- 2015
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In: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 15
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Journal article (peer-reviewed)abstract
- Background: Zoonotic diseases are disproportionately affecting poor societies in low-income countries and pose a growing threat to public health and global food security. Rural Cambodian households may face an increased likelihood of exposure to zoonotic diseases as people there live in close association with livestock. The objectives of the study was to identify practices known to influence zoonosis transmission in rural Cambodian households and relate the practices to agro-ecological region, socio-economic position, demographics, livestock management and zoonosis awareness.Methods: The study was conducted in three different agro-ecological regions of Cambodia; 10 villages each in the central lowlands, north-west wetlands and on the south coast, where information was obtained in questionnaires administered to 300 households, and 30 village heads and animal health workers.Results: Descriptive analysis revealed a gender difference in responsibility for livestock and that the main purpose of raising livestock was for sale. Few respondents (6%) perceived a likelihood of disease transmission in their village between livestock, humans and wildlife, despite household practices related to zoonosis transmission being common. More than one-forth of households practised behaviours such as culling sick animals for consumption, eating animals found dead and allowing animals to enter sleeping and food preparation areas. Associations between household practices and possible explanatory factors were analysed with multivariable models using generalised estimation equations to account for clustering of practices within villages. Factors found to influence household practices were agro-ecological region, socio-economic position, number of people in the household, livestock species reared and awareness of zoonoses.Conclusions: Cambodia has experienced numerous fatal human cases of zoonotic influenza and extensive influenza information campaigns have been run, yet only a few of the households surveyed here reported the threat of zoonosis to be a concern in their village. Zoonosis awareness was positively related to hand washing behaviour, but other practices associated with an increased or decreased likelihood of exposure to zoonotic pathogens were unaffected by awareness. The findings indicate a knowledge-to-action gap among rural farmers and highlight the necessity for reconstructed interventions in zoonotic disease control.
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| 6. |
- Osbjer, Kristina, et al.
(author)
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Influenza A Virus in Backyard Pigs and Poultry in Rural Cambodia
- 2017
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In: Transboundary and Emerging Diseases. - : WILEY. - 1865-1674 .- 1865-1682. ; 64:5, s. 1557-1568
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Journal article (peer-reviewed)abstract
- Surveillance of influenza virus in humans and livestock is critical, given the worldwide public health threats and livestock production losses. Livestock farming involving close proximity between humans, pigs and poultry is often practised by smallholders in low-income countries and is considered an important driver of influenza virus evolution. This study determined the prevalence and genetic characteristics of influenza A virus (IAV) in backyard pigs and poultry in Cambodia. A total of 751 animals were tested by matrix gene-based rRT-PCR, and influenza virus was detected in 1.5% of sampled pigs, 1.4% of chickens and 1.0% of ducks, but not in pigeons. Full-length genome sequencing confirmed triple reassortant H3N2 in all IAV-positive pigs and various low pathogenic avian influenza subtypes in poultry. Phylogenetic analysis of the swine influenza viruses revealed that these had haemagglutinin and neuraminidase genes originating from human H3N2 viruses previously isolated in South-East Asia. Phylogenetic analysis also revealed that several of the avian influenza subtypes detected were closely related to internal viral genes from highly pathogenic H5N1 and H9N2 formerly sequenced in the region. High sequence homology was likewise found with influenza A viruses circulating in pigs, poultry and wild birds in China and Vietnam, suggesting transboundary introduction and cocirculation of the various influenza subtypes. In conclusion, highly pathogenic subtypes of influenza virus seem rare in backyard poultry, but virus reassortment, involving potentially zoonotic and pandemic subtypes, appears to occur frequently in smallholder pigs and poultry. Increased targeted surveillance and monitoring of influenza circulation on smallholdings would further improve understanding of the transmission dynamics and evolution of influenza viruses in humans, pigs and poultry in the Mekong subregion and could contribute to limit the influenza burden.
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| 7. |
- Osbjer, Kristina, et al.
(author)
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Risk factors associated with Campylobacter detected by PCR in humans and animals in rural Cambodia
- 2016
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In: Epidemiology and Infection. - 0950-2688 .- 1469-4409. ; 144:14, s. 2979-2988
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Journal article (peer-reviewed)abstract
- Campylobacter are worldwide-occurring zoonotic bacteria, with the species Campylobacter jejuni and C. coli commonly associated with diarrhoea in children in low-income countries. In this cross-sectional study, the prevalence of C. jejuni and C. coli in human and livestock faecal samples was detected by PCR and zoonotic risk factors associated with human Campylobacter positivity were identified. In total 681 humans and 753 livestock (chickens, ducks, pigs, cattle) from 269 households were sampled. Children aged < 16 years were more frequently Campylobacter positive (19%) than adults (8%) and multilevel logistic models revealed that human C. jejuni positivity was associated with the following household practices: home-slaughtering [odds ratio (OR) 2.4, P = 0.01], allowing animals access to sleeping and food preparation areas (OR 2.8, P = 0.02), and eating undercooked meat (OR 6.6, P = 0.05), while frequent consumption of beef was protective (OR 0.9, P = 0.05). Associations were stronger for home-slaughtering (OR 4.9, P = 0.004) with C. jejuni infection in children only. Campylobacter was highly prevalent in pigs (72%) and chickens (56%) and risk factors associated with human Campylobacter positivity were identified throughout the meat production chain. The findings underline the importance of studying source attributions throughout the production chain and the need for upgraded understanding of Campylobacter epidemiology in low-income countries.
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| 8. |
- Osbjer, Kristina
(author)
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Zoonoses in rural Cambodia : a one health perspective on influenza and campylobacter
- 2016
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Doctoral thesis (other academic/artistic)abstract
- Zoonotic diseases, transmissible between animals and humans, make up the majority of emerging infectious diseases, posing a threat to public health and global food security. The emergence of infections is partly driven by close contact between humans and livestock, which is common in smallholder livestock farming in rural tropical areas. The aim of this thesis was to provide information on the animal-human interplay in rural tropical areas in general and in Cambodia in particular, focusing on influenza A virus and Campylobacter as examples of zoonotic pathogens. Interviews were carried out in 300 rural households and samples were collected in the same households from humans and livestock, primarily chickens, ducks, pigs and cattle. In the households studied, a clear gender division in livestock responsibility was observed. Practices associated with zoonosis exposure were common, but the threat of zoonoses was not reported to be a concern. Furthermore, knowledge and awareness of zoonoses did not markedly reduce practices associated with increased zoonosis exposure, thereby revealing a knowledge-to-behaviour gap. Sampled pigs and poultry had 1.3% overall prevalence of influenza A virus. Highly pathogenic subtypes were not found, but virus reassortment, involving potentially zoonotic and pandemic subtypes, seemed to occur frequently. Routine culture was insufficiently sensitive in detecting Campylobacter in field samples frozen before analysis. In contrast, PCR proved more sensitive and C. jejuni, C. coli or both were detected in 8% of adults, 19% of children, 56% of chickens, 24% of ducks, 72% of pigs and 5% of cattle. Moreover, a number of household practices along the meat production chain, from livestock rearing and slaughter to meat consumption, were associated with human C. jejuni and C. coli positivity. In conclusion, presence of pathogens with zoonotic potential and insufficient zoonosis management was shown on Cambodian smallholdings. The novel data presented on zoonosis epidemiology and household risk factors can help guide future interventions in zoonosis prevention, detection and control for improved health and livelihoods in rural tropical areas.
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| 9. |
- Rortana, Chea, et al.
(author)
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Prevalence of Salmonella spp. and Staphylococcus aureus in Chicken Meat and Pork from Cambodian Markets
- 2021
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In: Pathogens. - : MDPI. - 2076-0817. ; 10:5
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Journal article (peer-reviewed)abstract
- Salmonella spp. and Staphylococcus aureus are two of the most common foodborne bacteria in animal-source foods (ASF) that cause illness worldwide. This study aimed to determine the prevalence of Salmonella spp. and S. aureus in chicken meat and pork in markets in Cambodia. Sampling was done in 52 traditional markets and 6 supermarkets in 25 provinces of Cambodia between October 2018 and August 2019. In total, 532 samples were obtained: chicken meat and pork (n = 408, 204 of each), chicken and pork cutting board swabs (n = 124, 62 of each). All samples were analyzed for the presence of Salmonella spp. and S. aureus; colony-forming units per gram (CFU/g) of coagulase-positive Staphylococci (CPS) were counted, and a subset of samples was also analyzed for the most probable number (MPN, n = 136) of Salmonella. The overall prevalence of Salmonella spp. and S. aureus were 42.1% (224/532) and 29.1% (155/532), respectively, with 14.7% (78/532) of samples containing both bacteria. The prevalence of Salmonella spp. in chicken meat was 42.6%, on chicken cutting board it was 41.9%, on pork it was 45.1%, and the pork cutting board 30.6%. Chicken meat had a significantly (p-value < 0.05) higher prevalence of S. aureus, 38.2%, compared to the chicken cutting board, 17.7%, pork 28.9%, and pork cutting board 11.3%. Mean MPN-Salmonella was 10.6 MPN/g in chicken and 11.1 MPN/g in pork samples. Average Log CFU/g of CPS in chicken and pork samples were 2.6 and 2.5, respectively. The results indicate that chicken meat and pork in Cambodia were highly contaminated with Salmonella spp. and S. aureus, posing risks to consumers’ health. Urgent interventions are necessary to improve hygiene for safer meat in Cambodian markets.
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| 10. |
- Rortana, Chea, et al.
(author)
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Quantitative risk assessment of salmonellosis in Cambodian consumers through chicken and pork salad consumption
- 2022
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In: Frontiers in Sustainable Food Systems. - : Frontiers Media S.A.. - 2571-581X. ; 6
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Journal article (peer-reviewed)abstract
- Salmonella is a globally important foodborne bacterial pathogen that poses a high risk to human health. This study aimed to estimate the risk to Cambodian consumers from acquiring salmonellosis after consuming chicken and pork salad, using a quantitative microbial risk assessment (QMRA). Chicken and pork salads are typical Cambodian dishes containing raw vegetables and boiled chicken meat or pork. As previously described, chicken meat and pork samples (n = 204 of each) were collected from traditional markets in 25 Cambodian provinces to generate data on Salmonella contamination. Salad preparation and consumption practices were surveyed in 93 Cambodian households and this information was used to design an experiment to assess Salmonella cross-contamination from raw meat to ready-to-eat salad. In the part of the study reported here, data on consumption, Salmonella in salad, dose-response, and predicted salmonellosis were modeled using Monte Carlo simulations at 10,000 iterations. The prevalence of Salmonella in chicken meat and pork were set to 42.6 and 45.1%, respectively, with average most probable number (MPN) per gram of Salmonella in chicken meat was 10.6 and in pork 11.1 MPN/g, based on an earlier study. Half of the interviewed households cooked meat for the salad directly after purchase. The QMRA model showed that the modeled annual risk of salmonellosis from consuming chicken salad, pork salad and both chicken and pork salad were 11.1% probability of illness per person per year (90% CI 0.0-35.1), 4.0% (90% CI 0.0-21.3), and 14.5% (90% CI 0.0-33.5), respectively. The factors most influencing the estimate were cross-contamination while preparing the salad, followed by the prevalence of Salmonella in chicken meat and pork at the market. The wide confidence interval for the incidence was mainly due to the variability in reducing bacteria concentration by cooking and salad consumption. The predicted risk of salmonellosis due to chicken and pork salad consumption is high, and the study provides evidence supporting control measures of improving the safety of retailed chicken and pork obtained from markets to households and improving food preparation methods in the household.
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| 11. |
- Ström Hallenberg, Gunilla, et al.
(author)
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Antibiotic use in pig farms at different levels of intensification-Farmers' practices in northeastern Thailand
- 2020
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In: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 15:12
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Journal article (peer-reviewed)abstract
- Understanding the patterns and drivers of antibiotic use in livestock is crucial for tailoring efficient incentives for responsible use of antibiotics. Here we compared routines for antibiotic use between pig farms of two different levels of intensification in Khon Kaen province in Thailand. Among the 113 family-owned small-scale farms (up to 50 sows) interviewed did 76% get advice from the pharmacy about how to use the antibiotics and 84% used it primarily for treating disease. Among the 51 medium-scale-farms (100-500 sows) belonging to two companies did 100% get advice about antibiotic use from the company's veterinarian (P<0.0001) and 94% used antibiotics mostly as disease preventive measure (P<0.0001). In 2 small scale farms 3(rd) generation cephalosporins, tylosin or colistin were used; antibiotics belonging to the group of highest priority critically important antimicrobials for human medicine. Enrofloxacin, belonging to the same group of antimicrobials, was used in 33% of the small-scale and 41% of the medium-scale farms. In the latter farms, the companies supplied 3-4 antibiotics belonging to different classes and those were the only antibiotics used in the farms. The median and mean estimated expenditure on antibiotics per sow was 4.8 USD (IQR = 5.8) for small-scale farms and 7 USD and 3.4 USD for the medium-scale farms belonging to the two respective companies. Our observations suggest to target the following areas when pig farming transitions from small-scale to medium-scale: (i) strengthening access to professional animal health services for all farmers, (ii) review of the competence and role of veterinary pharmacies in selling antibiotics and (iii) adjustment of farming company animal health protocols towards more medically rational use of antibiotics.
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| 12. |
- Ström Hallenberg, Gunilla, et al.
(author)
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Manure management and public health : Sanitary and socio-economic aspects among urban livestock-keepers in Cambodia
- 2018
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In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 621, s. 193-200
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Journal article (peer-reviewed)abstract
- 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.
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