Project documents

• Tran Thi Tuyet-Hanh,
• Dang Xuan Sinh,
• Pham Duc Phuc,
• Tran Thi Ngan,
• Chu Van Tuat,
• Delia Grace,
• Fred Unger &
• Hung Nguyen-Viet

International Journal of Public Health volume 62, pages75–82 (2017)

Objectives

This study assesses the risk of exposure to hazardous chemical residues in pork meat, liver, and kidney collected at wet markets in Nghe An and Hung Yen provinces and discusses health impact implication.

Methods

514 pig feed, kidney, liver, and pork samples were pooled and qualitatively and quantitatively analyzed for tetracyclines, fluoroquinolones, sulphonamide, chloramphenicol, β-agonists, and heavy metals. We compare the results with current regulations on chemical residues and discuss health implications.

Results

Legal antibiotics were found in feed. Tetracycline and fluoroquinolones were not present in pork, but 11% samples were positive with sulfamethazine above maximum residue limits (MRL); 11% of packaged feed and 4% of pork pooled samples were positive for chloramphenicol, a banned substance; two feed, two liver, and one pork samples were positive for β-agonists but did not exceed current MRL; 28% of pooled samples had lead, but all were below MRL; and all samples were negative for cadmium and arsenic. Thus, the health risks due to chemical hazards in pork in Hung Yen and Nghe An seemed not as serious as what were recently communicated to the public on the mass media.

Conclusions

There is potential exposure to sulphonamide, chloramphenicol, and β-agonists from pork. Risk communication needs to focus on banned chemicals, while informing the public about the minimal risks associated with heavy metals.

ackground

Entamoeba histolytica is an important protozoan intestinal infection in resource-poor settings, including Vietnam. The study objective was to assess risk factors of E. histolytica infection in a community in Vietnam, where wastewater and human excreta are used in agriculture. A case-control study was conducted among residents of Hanam province, Northern Vietnam. Cases (n = 46) infected with E. histolytica and non-infected controls (n = 138) were identified in a cross-sectional survey among 794 randomly selected individuals and matched for age, sex and place of residence. Potential risk factors including exposure to human and animal excreta and household wastewater were assessed with a questionnaire.

Results

People from households with an average socio-economic status had a much higher risk of E. histolytica infection (odds ratio [OR]=4.3, 95% confidence interval [CI]: 1.3-14.0) compared with those from households with a good socioeconomic status. Those individuals who never or rarely used soap for hand washing had a 3.4 times higher risk for infection (OR=3.4, 95% CI: 1.1-10.0), compared to those who used always soap. In contrast, none of the factors related to use of human or animal excreta was statistically significant associated with E. histolytica infection. People having close contact with domestic animals presented a greater risk of E. histolytica infection (OR = 5.9, 95% CI: 1.8-19.0) than those without animal contact. E. histolytica infection was not associated with direct contact with Nhue river water, pond water and household's sanitary conditions, type of latrine or water source used.

Conclusions

Our study suggests that in settings where human and animal excreta and Nhue River water are intensively used in agriculture, socio-economic and personal hygiene factors determine infection with E. histolytica, rather than exposure to human and animal excreta in agricultural activities.

Aquaculture systems are highly complex, dynamic and interconnected systems influenced by environmental, biological, cultural, socio-economic and human behavioural factors. Intensification of aquaculture production is likely to drive indiscriminate use of antibiotics to treat or prevent disease and increase productivity, often to compensate for management and husbandry deficiencies. Surveillance or monitoring of antibiotic usage (ABU) and antibiotic resistance (ABR) is often lacking or absent. Consequently, there are knowledge gaps for the risk of ABR emergence and human exposure to ABR in these systems and the wider environment. The aim of this study was to use a systems-thinking approach to map two aquaculture systems in Vietnam – striped catfish and white-leg shrimp – to identify hotspots for emergence and selection of resistance, and human exposure to antibiotics and antibiotic-resistant bacteria. System mapping was conducted by stakeholders at an interdisciplinary workshop in Hanoi, Vietnam during January 2018, and the maps generated were refined until consensus. Thereafter, literature was reviewed to complement and cross-reference information and to validate the final maps. The maps and component interactions with the environment revealed the grow-out phase, where juveniles are cultured to harvest size, to be a key hotspot for emergence of ABR in both systems due to direct and indirect ABU, exposure to water contaminated with antibiotics and antibiotic-resistant bacteria, and duration of this stage. The pathways for human exposure to antibiotics and ABR were characterised as: occupational (on-farm and at different handling points along the value chain), through consumption (bacterial contamination and residues) and by environmental routes. By using systems thinking and mapping by stakeholders to identify hotspots we demonstrate the applicability of an integrated, interdisciplinary approach to characterising ABU in aquaculture. This work provides a foundation to quantify risks at different points, understand interactions between components, and identify stakeholders who can lead and implement change.

The use of human excreta as fertiliser in agriculture is a common practice in parts of South East Asia benefiting production but at the same time a risk factor for increased helminth infections. This paper describes the hygienic handling of human excreta for use in agriculture in Central Vietnam from a practical farming perspective presenting the farmers perceived health risks and benefits of its use. Further, in the study findings are discussed relating to the new Vietnamese guidelines for the use of human excreta in agriculture to their implications on an on-farm context. A total of 471 households in five communes responded to a structured questionnaire. This survey was supplemented by focus group discussions, key informant interviews and participant observations. More than 90% of the surveyed households used their own excreta as fertiliser and a total of 94% composted the excreta before use, either inside or outside the latrine. However, due to the prevailing design of the latrine and the three annual cropping seasons, it was found that for a minimum of one cultivation season per year 74% of the households will have only 3–4 months for composting before the input is needed in production, which is short of the 6 months stipulated in the national guidelines. The community associated great benefits from using human excreta in agriculture, especially if composted, and did not associate risks with the use of composted excreta if it was dry and lacked odour. It is recommended that the guidelines be revised and attempts made to identify ways of reducing the time needed to ensure the die-off of helminth eggs, including the use of pH regulators, such as an increased use of lime in the latrines.

Background: We assessed the risk of helminth infections in association with the use of wastewater and excreta in agriculture in Hanam province, northern Vietnam. In two cross-sectional surveys, we obtained samples from 1,425 individuals from 453 randomly selected households. Kato-Katz thick smear and formalin-ether concentration techniques were used for helminth diagnosis in two stool samples per person. Socio-demographic and water, sanitation and hygiene related characteristics, including exposure to human and animal excreta and household wastewater management, were assessed with a questionnaire.

Results: Overall 47% of study participants were infected with any helminth (Ascaris lumbricoides 24%, Trichuris trichiura 40% and hookworm 2%). Infections with intestinal protozoa were rare (i.e. Entamoeba histolytica 6%, Entamoeba coli 2%, Giardia lamblia 2%, Cryptosporidium parvum 5% and Cyclospora cayetanensis 1%). People having close contact with polluted Nhue River water had a higher risk of helminth infections (odds ratio [OR]=1.5, 95% confidence interval [CI] 1.1-2.2) and A. lumbricoides (OR=2.1, 95% CI 1.4-3.2), compared with those without contact. The use of human excreta for application in the field had an increased risk for a T. trichiura infection (OR=1.5, 95% CI 1.0-2.3). In contrast, tap water use in households was a protective factor against any helminth infection (i.e. T. trichiura OR=0.6, 95% CI 0.4-0.9). Prevalences increased with age and males had generally lower prevalences (OR=0.8, 95% CI 0.6-1.0), participants performing agricultural (OR=1.5, 95% CI 1.1-2.1) and having a low educational level (OR=1.7, 95% CI 1.2-2.4) were significantly associated with helminth infections. None of the factors related to household's sanitary condition, type of latrine, household's SES, use of animal excreta, and personal hygiene practices were statistically significant associated with helminth infection.

Conclusions: Our study suggests that in agricultural settings, direct contact with water from Nhue River and the use of human excreta as fertiliser in the fields are important risk factors for helminth infection. Daily use of clean water is likely to reduce the risk of worm infection. Deworming policies and national programs should give more attention to these agricultural at risk populations.

Background

In Vietnam, dengue fever (DF) is still a leading cause of hospitalization. The main objective of this study was to evaluate the seasonality and association with climate factors (temperature and precipitation) on the incidences of DF in four provinces where the highest incidence rates were observed from 1994 to 2013 in Vietnam.

Methods

Incidence rates (per 100,000) were calculated on a monthly basis from during the study period. The seasonal-decomposition procedure based on loess (STL) was used in order to assess the trend and seasonality of DF. In addition, a seasonal cycle subseries (SCS) plot and univariate negative binomial regression (NBR) model were used to evaluate the monthly variability with statistical analysis. Lastly, a generalized estimating equation (GEE) was used to assess the relationship between monthly incidence rates and weather factors (temperature and precipitation).

Results

We found that increased incidence rates were observed in the second half of each year (from May through December) which is the rainy season in each province. In Hanoi, the final model showed that 1 °C rise of temperature corresponded to an increase of 13% in the monthly incidence rate of DF. In Khanh Hoa, the final model displayed that 1 °C increase in temperature corresponded to an increase of 17% while 100 mm increase in precipitation corresponded to an increase of 11% of DF incidence rate. For Ho Chi Minh City, none of variables were significant in the model. In An Giang, the final model showed that 100 mm increase of precipitation in the preceding and same months corresponded to an increase of 30% and 22% of DF incidence rate.

Conclusion

Our findings provide insight into understanding the seasonal pattern and associated climate risk factors.

Material flow analysis (MFA) is a useful methodology to describe and quantify complex systems based on the law of mass conservation. It was further adapted to suit the specific conditions in developing countries where the available data is scarce and uncertain. The ‘adapted MFA’ methodology optimises the number of parameters, describes these parameters as probability distributions and assesses the accuracy and uncertainty of the model values by Monte Carlo simulation.

This study illustrates the first successful application of the ‘adapted MFA’ methodology in a small and low-income area including two neighbouring communes in rural northern Vietnam, where environmental sanitation and traditional agricultural practices are strongly interlinked and have an impact on the surrounding environment. Moreover, data on this area is typically scarce and uncertain. The obtained results reveal that the agricultural system was a significant source of nutrients (nitrogen (N) and phosphorous (P)), which affect the surrounding environment mainly due to the overuse of chemical fertilizers. Every year, there were 103 ± 39 tonnes of N released into the atmosphere, 25 ± 3 tonnes of N leached to the surface water and 14 ± 2 tonnes of P accumulated in the soil, all originating from the applied chemical fertilizers. In addition, the sanitation system was also a critical source of nutrients that enter the surface water. 69 ± 6 tonnes of N and 23 ± 4 tonnes of P came from households through effluents of on-site sanitation systems (such as latrines and septic tanks) and were directly discharged to surface water every year. Moreover, the whole system annually generated a large nutrient source (214 ± 56 tonnes of N; 58 ± 16 tonnes of P) in the form of wastewater, faecal sludge, animal manure and organic solid wastes.

The validated MFA was used to model different scenarios for the study site. The first scenario demonstrated that if nutrient management is not improved, wastewater as well as faecal sludge and organic solid waste are expected to double in the year 2020 as compared to that in 2008. The second and third scenario revealed possible strategies to significantly reduce environmental pollution and reuse nutrient sources predicted to be available in the year 2020.

Background

Despite the potential health risks of wastewater and excreta use as fertiliser in agriculture, it is still widespread in Vietnam. However, the importance of diarrheal risk in adults’ associated with the combined exposures to both excreta and wastewater use in agriculture is largely unknown. This study was carried out to determine diarrhoeal incidence and associated risk factors among the adult population exposed to wastewater and excreta used in agriculture in Hanam province, Vietnam.

Methods

An open cohort of 867 adults, aged 16–65 years, was followed weekly for 12 months to determine the incidence of diarrhoea. A nested case–control study was used to assess the risk factors of diarrhoeal episodes. Two hundred and thirty-two pairs of cases and controls were identified and exposure information related to wastewater, human and animal excreta, personal hygiene practices, and food and water consumption was collected.

Results

The incidence rate of reported diarrhoea was 0.28 episodes per person-years at risk. The risk factors for diarrhoeal diseases included direct contact with the Nhue River water (odds ratio [OR] = 2.4, attributable fraction [AF] 27%), local pond water (OR = 2.3, AF 14%), composting of human excreta for a duration less than 3 months (OR = 2.4, AF 51%), handling human excreta in field work (OR = 5.4, AF 7%), handling animal excreta in field work (OR = 3.3, AF 36%), lack of protective measures while working (OR = 6.9, AF 78%), never or rarely washing hands with soap (OR = 3.3, AF 51%), use of rainwater for drinking (OR = 5.4, AF 77%) and eating raw vegetables the day before (OR = 2.4, AF 12%).

Conclusions

Our study shows that professional exposure to wastewater and excreta during agricultural activities are significantly contributing to the risk of diarrhoea in adults. The highest attributable fractions were obtained for direct contact with Nhue River and local ponds, handling practices of human and animal excreta as fertilisers, lack of protective measures while working and poor personal hygiene practices, and unsafe food and water consumption were associated with the risk of diarrhoeal episodes in adults. Improve personal hygiene practices and use of relevant treated wastewater and excreta as the public health measures to reduce these exposures will be most effective and are urgently warranted.

The use of wastewater in agriculture and aquaculture has a long tradition throughout Asia. For example, in Hanoi, it creates important livelihood opportunities for > 500,000 farmers in peri-urban communities. Discharge of domestic effluents pollute the water streams with potential pathogenic organisms posing a public health threat to farmers and consumers of wastewater-fed foodstuff. We determined the effectiveness of Hanoi's wastewater conveyance system, placing particular emphasis on the quality of wastewater used in agriculture and aquaculture. Between April and June 2014, a total of 216 water samples were obtained from 24 sampling points and the concentrations of total coliforms (TC), Escherichia coli, Salmonella spp. and helminth eggs determined. Despite applied wastewater treatment, agricultural field irrigation water was heavily contaminated with TC (1.3 × 107 colony forming unit (CFU)/100 mL), E. coli (1.1 × 106 CFU/100 mL) and Salmonella spp. (108 most probable number (MPN)/100 mL). These values are 110-fold above Vietnamese discharge limits for restricted agriculture and 260-fold above the World Health Organization (WHO)'s tolerable safety limits for unrestricted agriculture. Mean helminth egg concentrations were below WHO tolerable levels in all study systems (< 1 egg/L). Hence, elevated levels of bacterial contamination, but not helminth infections, pose a major health risk for farmers and consumers of wastewater fed-products. We propose a set of control measures that might protect the health of exposed population groups without compromising current urban farming activities. This study presents an important example for sanitation safety planning in a rapidly expanding Asian city and can guide public and private entities working towards Sustainable Development Goal target 6.3, that is to improve water quality by reducing pollution, halving the proportion of untreated wastewater and increasing recycling and safe reuse globally.

This case study examines the design, implementation, and evaluation of Risk Communication and Community Engagement (RCCE) strategies for antimicrobial resistance (AMR) prevention in the Mekong River Delta. Through training, strategy development, and grassroots communication campaigns, the initiative enhances awareness, knowledge, and community action to combat AMR.

This case study details the design, trial, and implementation of the Multi-Sectoral Coordination Mechanism Assessment Toolkit (M-CMAT) for zoonosis prevention and control at sub-national levels in Vietnam. The toolkit provides a structured approach to evaluating coordination mechanisms, identifying strengths and gaps, and informing policy and strategy development to enhance disease prevention.

Authors: Edi Basuno, Khieu Borin, Erin Michelle Crocetti, Sonia Fèvre, Pierre Horwitz,
Nguyen Thanh Huong, Jing Fang, Pongsri Maskhao, Suzanne McCullagh, Karen Morrison,
Hung Nguyen-Viet, Craig Stephen, Céline Surette, Tran Thi Tuyet Hanh, Dinh Xuan Tung,
Bob Williams, Iwan Willyanto

This training manual, and the Field Building Leadership Initiative (FBLI) of which it is one component, is part of a global initiative to build capacity in ecosystem approaches to health. Although several books and journals provide
materials for learners about Ecohealth, the FBLI Ecohealth Trainer Manual is intended primarily for lecturers, teachers, and trainers. The focus here is on how to teach Ecohealth, providing teachers and trainers with a starting point from which to explore, improvise, adapt, and develop diverse educational Ecohealth learning experiences for and with their participants.
Ecohealth workers globally share a common set of principles and are grounded in a common pre-analytic vision (see Preface). However, the actual applications and techniques, growing out of local experiences, often differ from region to region, rooted as they are in different cultural and ecological contexts. Thus, complementary training materials are being created in Canada, Latin America, and West Africa, led by Communities of Practice in Ecohealth in each of those regions. As editors, we have attempted to explicitly link the initiatives in Asia with others globally, while enabling the regionally-based authors to remain true to their own experiences.
In keeping with the participatory, transdisciplinary, and systemic nature of Ecohealth, these training manuals are works in progress, open to new insights and evidence, as we work together to better understand – and more effectively promote – the health of people and the planet we share with all other life.

David Waltner-Toews and Pierre Horwitz, Executive editors

Overview

One Health (OH) is a trans-disciplinary collaborative effort which aims to improve the health of animals, humans, and the environment. This knowledge can be applied for the optimal health of all communities, animals, and the environment on a local, national, and global scale. The OH approach calls for a shift in developing, implementing and sustaining health policies to engage with medicine, public health, veterinary science, environmental sciences and other fields that relate to health, land use and human interactions.

The South East Asia One Health Network (SEAOHUN) aims to foster sustainable trans-disciplinary capacity building in response to infectious and zoonotic diseases. This network includes South East Asian universities from Vietnam, Thailand, Malaysia, and Indonesia. The network in Vietnam, known as Vietnam One Health University Network (VOHUN), focuses on applying OH policies and teachings in Vietnam. Created in 2011, VOHUN promotes the OH approach through university trainings and research to inspire a new generation of lecturers and researchers. This will equip them with the knowledge and skills needed to integrate the OH approach throughout the country. VOHUN has brought together 18 medical, veterinary, nursing and public health universities to promote and develop OH principles and practices. Moving forward, from 2015 to 2019, the One Health Workforce aims to continue developing the OH capacity through training programs, activities, and research. This will provide the necessary information to detect, prevent and respond to zoonotic and other infectious disease outbreaks.

This manual will serve as a template for lecturers teaching the OH approach to undergraduate and graduate students. This manual aims to teach aspiring OH professionals all the necessary knowledge and skills they need to address health related problems and develop solutions.

This manual was developed in collaboration between VOHUN, the Hanoi Medical University (HMU)’s Centre for Public Health and Ecosystem Research (CENPHER), and Veterinarians without Borders (VWB) Canada.

Overview

One Health (OH) is a trans-disciplinary collaborative effort which aims to improve the health of animals, humans, and the environment. This knowledge can be applied for the optimal health of all communities, animals, and the environment on a local, national, and global scale. The OH approach calls for a shift in developing, implementing and sustaining health policies to engage with medicine, public health, veterinary science, environmental sciences and other fields that relate to health, land use and human interactions.

The South East Asia One Health Network (SEAOHUN) aims to foster sustainable trans-disciplinary capacity building in response to infectious and zoonotic diseases. This network includes South East Asian universities from Vietnam, Thailand, Malaysia, and Indonesia. Additional information can be found on the website link: http://seaohun.org

The network in Vietnam, known as Vietnam One Health University Network (VOHUN), focuses on applying OH policies and teachings in Vietnam. VOUHN was officially created in 2011 and is based out of the Hanoi University of Public Health in Hanoi, Vietnam. The vision of VOHUN aims to foster sustainable trans- disciplinary capacity-building in response to emerging and re-emerging infectious and zoonotic diseases throughout Vietnam. The VOHUN mission is to leverage the training, education, and research capacities of the university network to build the skills, knowledge and attitude base for OH leaders.

This manual will serve as a learning resource and reference source for students as they learn about the One Health approach, in courses, training sessions, and other programs. This can also be used to assist students as they enter into the workforce. This manual aims to guide aspiring OH professionals all the necessary knowledge and skills they need to address health related problems on a local and nation scale, while promoting solutions, mitigating potential disease outbreaks, and developing the One Health workforce in Vietnam and throughout South East Asia!

This manual was developed in collaboration between VOHUN, the Hanoi Medical University (HMU)’s Centre for Public Health and Ecosystem Research (CENPHER), and Veterinarians without Borders (VWB) Canada.

Knowledge aim:

Understand the basic knowledge about One Health concept and One Health approach;

Risk analysis and solutions, controlling the zoonosis

In Vietnam, pork is the most consumed meat, and contamination of pork with Salmonella spp. is a serious public health problem. This study aimed to trace the value chain forward from pig slaughterhouses to markets in order to elucidate the dynamics of Salmonella contamination on the pork value chain in Hung Yen, Vietnam. This survey was conducted between January and February 2014 in two randomly selected slaughterhouses in Hung Yen. Swab samples were collected from 88 carcasses and of them, 21 carcasses were traced to the markets and pork samples were collected from these samples. Microbial tests were performed to detect the presence of Salmonella from carcass samples at slaughterhouses. MPN was determined in addition to the presence of Salmonella for pork at markets.

The Salmonella prevalence on carcasses was 25.0% (22/88, 95%CI : 16.7%-35.6%), and on pork at markets was 28.6% (6/21, 95%CI : 12.2%-52.3%). There was no significant difference in prevalence between carcasses (25.0%) and pork (28.6%, x2＝0.0034, df＝1, p＝0.95). There was no significant difference in the prevalence of Salmonella on pig carcass samples between the two slaughterhouses (22.2% (10/45) and 27.9% (12/43), x2＝0.18, df＝1, p＝0.71). The transition of Salmonella contamination status on pork was observed, and the kappa value 0.53, and attributable risk percent 53.3% calculated suggested that more than half of the Salmonella prevalence in marketed pork can be attributable to contamination in slaughterhouse. MPN of positive pork samples ranged from < 0.3 to 1.5MPN/g. The prevalence remained high at the same level between the slaughterhouse and market, and the contamination largely occurs before the end of slaughtering due to inadequate hygiene, but cross-contamination during transportation and marketing also poses a risk to humans.

The use of antibiotics in livestock production is considered a major driver of antibiotic resistance on a global scale. In Vietnam, small- and medium-scale livestock producers dominate the domestic market and regulatory pushes have done little to decrease antibiotic use. In order to inform future policy directions, this study aims to explore knowledge, attitudes, and practices amongst livestock producers to identify their perspectives on antibiotic use and resistance. A total of 392 small- and medium-scale producers specialized in pig, poultry and aquaculture production participated in the study. The results showed that the primary reason for antibiotic use reported by producers was for the treatment of infections (69%). However, prophylactic use was also evident, with farmers reporting other reasons for antibiotic use such as “animals display abnormal symptoms or behaviour” (55%), the “weather is about to change” (25%), or “animals on neighboring farms fall ill” (27%). Only one-fifth of producers demonstrated favorable attitudes towards antibiotic use and preventing antibiotic resistance. Moreover, administering antibiotics remained the preferred countermeasure directly applied by farmers at the first indication of disease (17%), compared to enacting hygiene (10%) or quarantine (5%) measures. The results showed divergent trends amongst producers, with pig producers demonstrating higher levels of knowledge, more favorable attitudes, and higher self-reported utilization of good practice. Better knowledge, attitudes, and practices were also associated with producers who engaged in efforts to explore information on antibiotic use and resistance, which improved incrementally with the number of sources consulted and hours invested. However, there were some areas where increased knowledge or more favorable attitude scores did not translate into better practices. For instance, producers with higher levels of formal education performed significantly better than those with lower education in terms of knowledge and attitude, though both groups reported similar practices. The findings of this study may support future interventions to prevent both antibiotic misuse and the development of antimicrobial resistance.

Pork safety is an important public health concern in Vietnam and is a shared responsibility among many actors along the pork value chain. We examined the knowledge, perceptions, and practices regarding food safety, disease, and health risk among selected pork value chain actors (slaughterhouse owners and workers, people living around slaughterhouses, pork sellers, consumers, and veterinary and public health staff) in three districts in Hung Yen Province, Vietnam. We randomly selected 52 pork value chain actors to be surveyed through questionnaires, observation checklists, key informant interviews, and focus group discussions. Most slaughterhouse workers acquired knowledge and experience of food safety through “learning by doing” rather than from training by a veterinary or public health professional. Both slaughterhouse worker and pork seller groups had some accurate perceptions about pig diseases and foodborne diseases; however, misperceptions of risk and, especially, of zoonoses were present. Furthermore, while workers and sellers often use cloths to dry the meat and clean equipment, they did not think this was a risk for meat contamination. Moreover, when sellers wear protective equipment, such as gloves, masks, or hats, consumers perceive that the sellers may have health issues they are trying to conceal and so consumers avoid buying from them. The perceived freshness of pork, along with trust in the seller and in the pork production process, were strong indicators of consumer preference. And yet, pork value chain actors tend to trust their own individual food safety practices more, rather than the practices of other actors along the chain. Veterinary and public health staff emphasized the gap between regulations and food safety practices. Education and training on food safety risks and proper handling are priorities, along with integrated and intensive efforts to improve food safety among pork value chain actors.

Food safety, Perception, Pig slaughterhouse, Pork, Practice, Vietnam

• Sinh Dang-Xuan,
• Hung Nguyen-Viet,
• Fred Unger,
• Phuc Pham-Duc,
• Delia Grace,
• Ngan Tran-Thi,
• Max Barot,
• Ngoc Pham-Thi &
• Kohei Makita

International Journal of Public Health volume 62, pages93–102 (2017)

Objectives

To quantify salmonellosis risk in humans through consumption of boiled pork in urban Hung Yen Province, Vietnam, using a quantitative microbial risk assessment.

Methods

We collected 302 samples along the pork value chain in Hung Yen between April 2014 and February 2015. We developed a model in @Risk, based on microbiological, market, and household surveys on cooking, cross-contamination and consumption, and conducted sensitivity analysis.

Results

Salmonella prevalence of pen floor swabs, slaughterhouse carcasses and cut pork were 33.3, 41.7 and 44.4%, respectively. The annual incidence rate of salmonellosis in humans was estimated to be 17.7% (90% CI 0.89–45.96). Parameters with the greatest influence risk were household pork handling practice followed by prevalence in pork sold in the central market. Wide confidence interval in the incidence estimate was mainly due to the variability in the degree of reduction in bacteria concentration by cooking, and pork consumption pattern.

Conclusions

The risk of salmonellosis in humans due to boiled pork consumption appears to be high. Control measures may include improving the safety of retailed pork and improving household hygiene.