Capacity and needs assessment of veterinary services in Vietnam in biosecurity, biosafety and One Health.

The Asia-Pacific region is recognised as an epicentre of emerging infectious diseases (EIDs), of which 75% are zoonotic in nature. Vietnam is recognised as a potential hotspot for zoonotic EIDs. There is a growing recognition that progress towards global health security requires greater focus on collaboration between the human health and animal health sectors to control diseases at their animal source and prevent against human health impacts. Assessment of veterinary epidemiology capacity in Vietnam is paramount to strengthening the health security of Asia-Pacific. This study aims to evaluate the national capacity and needs of veterinary services in Vietnam in biosecurity, biosafety and One Health. A cross-sectional, convergent mixed-methods study was conducted between November 2020 and April 2021. An online questionnaire was administered to government-employed field veterinarians. Descriptive analyses and logistic regression models were performed using survey responses to understand capacity in the field. Semi-structured interviews were also conducted with stakeholders in veterinary services including government, academia, research institutes, non-profit and international organisations. Coding and thematic analysis using a deductive approach was used for data collected from interviews to contextualise findings from the survey and understand institutional capacity. In total, 178 field veterinarians completed the online survey and 25 stakeholders were interviewed. The majority of participants had reported receiving training in biosecurity and biosafety, including use of personal protective equipment. Most respondents reported practicing good biosecurity measures (92%) and good biosafety measures (88%). Physical and socioeconomic barriers to practicing biosecurity were reported to be prevalent for smallholder farmers, which may suggest a gap in the capacity of veterinary services to provide cost-effective and practical biosecurity strategies. Seventy five percent of participants had never or rarely participated in One Health approaches in the field in the last 12 months and 69% reported further training as a high priority. There was a knowledge gap reported amongst district and commune-level veterinary staff about the need for, and awareness of multisectoral collaboration. Respondents that completed postgraduate qualifications in epidemiology or Field Epidemiology Training Programs (adjusted OR: 3.06; 95% CI: 1.01, 9.23, p = 0.046) and had longer job tenure between 10-12 years (OR: 10.38; 95% CI: 3.06, 35.15, p = <0.001) were more likely to have higher levels of experience in One Health. This study identified gaps in knowledge, attitudes and adoption of practices related to biosecurity, biosafety and One Health specifically in lower-level or less experienced veterinary staff without further training opportunities in epidemiology. These findings enable prioritisation of training, policy, and planning activities to further enhance the national capacity of veterinary services in Vietnam.

Reducing antimicrobial use in chicken production in Vietnam: Exploring the systemic dimension of change.

Antibiotic use in livestock production is one of the drivers of antibiotic resistance and a shift towards better and reduced antibiotic usage is urgently required. In Vietnam, where there are frequent reports of the misuse and overuse of antibiotics, little attention has been paid to farmers who have successfully changed their practices. This qualitative study aims to understand the transition process of Vietnamese chicken farmers toward reduced antibiotic usage. We conducted semi-structured interviews with 18 chicken farmers, 13 drug sellers, and 5 traders using participatory tools and a socio-anthropological approach. We explored the farmers' histories, current and past antibiotic usage, methods used to reduce antibiotic use, and motivations and barriers to changing practices. Through the thematic analysis of the farmers' transcripts, we identified technical, economic, and social factors that influence change. Out of eighteen farmers, we identified ten farmers who had already reduced antibiotic usage. The main motivations included producing quality chickens (tasty and safe) while reducing farm expenditures. Barriers were related to poor biosecurity in the area, market failures, and the farmers' lack of knowledge. Innovation led to overcome these obstacles included the local development of handmade probiotics and the organization of farmer cooperatives to overcome economic difficulties and guarantee product outlets. Knowledge was increased by workshops organized at the communal level and the influence of competent veterinarians in the area. We showed that the transition process was influenced by several components of the system rather than by any individual alone. Our study demonstrated that local initiatives to reduce antibiotic use in Vietnamese chicken production do exist. As changes depend on the system in which stakeholders are embedded, systemic lock-ins must be removed to allow practices to change. The promotion of locally-developed solutions should be further encouraged.

Effect of light-touch intervention and associated factors to microbial contamination at small-scale pig slaughterhouses and traditional pork shops in Vietnam.

Traditional pork value chains dominate the production and distribution of pork in Vietnam; however, the high level of microbiological contamination in pork may increase the risk of food-borne disease for consumers. There is limited evidence about how to feasibly and scalably reduce microbial contamination in pork sold in traditional markets. This study aimed to assess the effectiveness of light-touch interventions for changing worker behaviour in small-scale slaughterhouses and vendors at traditional pork shops, as well as to identify risk factors for pork contamination. The intervention packages consisted of providing hygiene tools and delivering a food safety training which had been designed in a participatory way and covered 10 small-scale slaughterhouses and 29 pork shops. Pig carcasses, retailed pork, contact surfaces, and hands were sampled to measure the total bacterial count (TBC) and Salmonella contamination before, three and six weeks after the intervention, and trainee practices were observed at the same time. Linear and generalized linear mixed effects models were constructed to identify risk factors for TBC and Salmonella contamination at the slaughterhouses and pork shops. The interventions at slaughterhouses and pork shops both showed a slight reduction of TBC contamination in pig carcasses and Salmonella prevalence in retailed pork, while the TBC in retailed pork decreased only marginally. For slaughterhouses, the regression model indicated that smoking or eating during slaughtering (indicating poor hygienic practices) was associated with TBC increasing, while cleaning floors and wearing boots reduced TBC contamination. For pork shops, using rough materials (cardboard or wood) to display pork was the only factor increasing TBC contamination in pork, whereas cleaning knives was associated with lower TBC. Besides, the presence of supporters and wearing aprons reduced the probability of Salmonella contamination in pork. The findings highlight the effectiveness of light-touch interventions in reducing microbial contamination in pig carcasses at small-scale slaughterhouses and pork at traditional shops over the study period.

Molecular characterization of Cryptosporidium and Giardia in environmental samples and faecal samples from biogas users in Bac Giang, Vietnam.

Little is known about Cryptosporidium and Giardia in biogas waste and humans in Vietnam. There is a potential risk of infections during or after using the biogas system. The detected protozoan genotypes are zoonotic pathogens, and contamination of vegetables may relay through runoff to the surface waters and soil. The objective of this study was to understand the role of the environment in the epidemiology of human infections in Bac Giang province, Vietnam, with a focus on investigating the presence of Cryptosporidium spp. genotypes and Giardia assemblages among 239 environmental samples and 94 faecal samples of biogas users. PCR and sequencing analysis were used to identify the occurrence and genotypes of Cryptosporidium and Giardia in these samples. Results showed that 13/333 (3.9 %) and 9/333 (2.7 %) samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively. Characterization revealed the presence of Cryptosporidium scrofarum, C. suis, C. meleagridis, C. bailey and Giardia intestinalis assemblage A and E. C. scrofarum and Giardia assemblage E were identified for the first time in humans in Bac Giang. The current information from the above investigations will be valuable for protozoan source tracking and control interventions against Cryptosporidium and Giardia infection associated with biogas wastes in Vietnam.

An overview of human helminthioses in Vietnam: Their prevention, control and lessons learnt.

In Vietnam, helminthioses remain a major threat to public health and contribute to the maintenance of poverty in highly endemic regions. Through increased awareness of the damaging effects caused by helminthioses, the Vietnamese government has implemented many national programs over the past 30 years for the prevention and control of the most important helminthioses, such as, lymphatic filariasis, soil transmitted helminths, food borne zoonotic helminths, and others. Various control strategies have been applied to reduce or eliminate these worms, e.g. mass drug administration, economic development, control of vectors or intermediate hosts, public health interventions through education, proper composting procedures for excreta potentially containing helminth eggs, and the expansion of food supply chains and improved technologies for the production and inspection of food products. These control measures have resulted in a significant reduction in the distribution and transmission of helminth infections and have improved the overall living conditions and health outcomes of the Vietnamese citizens. However, the persistence of several helminth diseases continues in some endemic areas, especially where poverty is widespread and local traditions include the consumption of raw foods, especially fish and meats. This manuscript provides an overview of the helminth infection prevention and control programs conducted in Vietnam, their achieved results, learned lessons, and future works.

Seroprevalence and Associated Risk Factors of Trichinellosis and T. Solium Cysticercosis in Indigenous Pigs in Hoa Binh Province, Vietnam.

Trichinellosis and cysticercosis remain challenges to human health and animal productivity worldwide, especially in developing countries. While information on the occurrence of both diseases is infrequent, they are endemic in parts of Vietnam and mainly related to indigenous pigs kept by ethnic minorities. This study aimed to determine the seroprevalence and risk factors of both diseases in indigenous pigs and explore the perception and awareness of both human and pig trichinellosis and cysticercosis of pig farmers. A total of 352 pig sera samples from 131 holdings were collected and analyzed using ELISA antibody tests in six communes in the Da Bac districts of Hoa Binh province, Vietnam. A survey was conducted with representatives from these households to understand the knowledge and perspective on food-borne parasitic diseases. Overall, the seroprevalence of trichinellosis and T. solium cysticercosis was 13.6% (95% CI 10.2-17.7) and 1.7% (95% CI 0.6-3.7), respectively. The seroprevalence of trichinellosis was significantly higher in female and older pigs. Risk perception and knowledge of interviewed people on both human and pig trichinellosis and cysticercosis of pig farmers was poor. Risky practices, including free roaming of pigs and eating undercooked or fermented pork, were observed. Educational and awareness campaigns aligned with further research on feasible practice changes are critical to addressing these issues.

Decades of emerging infectious disease, food safety, and antimicrobial resistance response in Vietnam: The role of One Health.

Since facing outbreaks of severe acute respiratory syndrome and avian influenza A in 2003, Vietnam has increasingly applied a One Health approach to address emerging infectious diseases of animal origin. Here, we reflect on the challenges and opportunities of One Health in the context of zoonoses, food safety, and antimicrobial resistance, drawing on a stocktake of One Health training, policy, and research in Vietnam. We also report on the results of a virtual consultation workshop held on July 2021 with representatives from 32 institutions in Vietnam to explore future One Health directions. As Vietnam approaches nearly two decades of disease preparedness and response, we hope our experiences can provide practical insights to support countries in developing coordination mechanisms and moving the One Health agenda forward toward better public health outcomes.

Exploring gender differences in knowledge and practices related to antibiotic use in Southeast Asia: A scoping review.

Inappropriate use of antibiotics has been one of the main contributors to antimicrobial resistance, particularly in Southeast Asia. Different genders are prone to different antibiotic use practices. The objective of this scoping review is to understand the extent and type of evidence available on gender differences in antibiotic use across Southeast Asia. The search strategy for this scoping review involved PubMed, Semantic Scholar, BioMed Central and ProQuest. Two-level screening was applied to identify the final sample of relevant sources. Thematic content analysis was then conducted on the selected final sources to identify recurring themes related to gender differences in antibiotic use and a narrative account was developed based on the themes. Recommendations for next steps regarding reducing inappropriate antibiotic use and gender considerations that need to be made when developing future interventions were also identified. Research on gender and antibiotic use remains scarce. Studies that discuss gender within the context of antibiotic use often mention differences between males and females in knowledge, attitudes and/or behaviour, however, do not explore reasons for these differences. Gender differences in antibiotic use were generally examined in terms of: (i) knowledge of antibiotic use and antimicrobial resistance and (ii) practices related to antibiotic use. Evidence indicated that differences between males and females in knowledge and practices of antibiotic use varied greatly based on setting. This indicates that gender differences in antibiotic use are greatly contextual and intersect with other sociodemographic factors, particularly education and socioeconomic status. Educational interventions that are targeted to meet the specific needs of males and females and delivered through pharmacists and healthcare professionals were the most common recommendations for reducing inappropriate use of antibiotics in the community. Such targeted interventions require further qualitative research on factors influencing differences in knowledge and practices related to antibiotic use among males and females. In addition, there is also a need to strengthen monitoring and regulation practices to ensure accessibility to affordable, quality antibiotics through trusted sources.

Engaging Stakeholders in the Design of One Health Surveillance Systems: A Participatory Approach.

Many One Health surveillance systems have proven difficult to enforce and sustain, mainly because of the difficulty of implementing and upholding collaborative efforts for surveillance activities across stakeholders with different values, cultures and interests. We hypothesize that only the early engagement of stakeholders in the development of a One Health surveillance system can create an environment conducive to the emergence of collaborative solutions that are acceptable, accepted and therefore implemented in sustainable manner. To this end, we have designed a socio-technical framework to help stakeholders develop a common vision of their desired surveillance system and to forge the innovation pathway toward it. We implemented the framework in two case studies: the surveillance of antimicrobial resistance in Vietnam and that of Salmonella in France. The socio-technical framework is a participatory and iterative process that consists of four distinct steps implemented during a workshop series: (i) definition of the problem to be addressed, (ii) co-construction of a common representation of the current system, (iii) co-construction of the desired surveillance system, (iv) identification of changes and actions required to progress from the current situation to the desired situation. In both case studies, the process allowed surveillance stakeholders with different professional cultures and expectations regarding One Health surveillance to gain mutual understanding and to reconcile their different perspectives to design the pathway toward their common vision of a desired surveillance system. While the proposed framework is structured around four essential steps, its application can be tailored to the context. Workshop facilitation and representativeness of participants are key for the success of the process. While our approach lays the foundation for the further implementation of the desired One Health surveillance system, it provides no guarantee that the proposed actions will actually be implemented and bring about the required changes. The engagement of stakeholders in a participatory process must be sustained in order to ensure the implementation of co-constructed solutions and evaluate their effectiveness and impacts.

Microbial contamination and associated risk factors in retailed pork from key value chains in Northern Vietnam.

Pork and pork products are important staple food in the diet of Vietnamese consumers. The safety of pork, including biological contamination, is a concern to several public authorities and value chain actors. This cross-sectional study aimed to identify Salmonella and total bacterial count (TBC) contamination of cut pork sold in different outlets, and determine the potential factors leading to contamination. A total of 671 pork samples were collected from different retail channels in three provinces in Northern Vietnam. Hygiene conditions and practices at pork vending premises were also observed and recorded. Data analysis used descriptive statistics and regression analysis. Overall, Salmonella prevalence in retailed pork was 58.1%. Salmonella contamination in pork from traditional retail, modern retail and food services were 60.5%, 50.9% and 80.5%, respectively. Eighty percent and 68% of fresh pork in canteen and street food was contaminated with Salmonella. Only a small proportion of a subset of the pork samples (6.2%) tested met the Vietnamese standard requirement for TBC contamination. Average concentration of TBC in fresh pork in traditional retail, modern retail and food services were 6.51 (SD: 0.64), 6.38 (0.65), and 6.96 (0.85) LogCFU/g, respectively. Transport time, use of the same tools for pork and other types of meat, storage temperature, and environment hygiene are important factors that might affect microbial contamination. The findings underline the high level of microbial contamination, which requires practical interventions to improve food safety hygiene practices and behavior of pork retailers.

International, Transdisciplinary, and Ecohealth Action for Sustainable Agriculture in Asia.

Sustainably intensifying agriculture to secure food for people, while minimizing the human, animal, and environmental health impacts is an unprecedented global food security challenge. Action research is needed to understand and mitigate impacts, with Ecosystem approaches to health (Ecohealth) emerging as a promising framework to support such efforts. Yet, few have critically examined the application of Ecohealth principles in an agricultural context, particularly in Southeast Asia where agricultural intensification is rapidly expanding. In this paper, we evaluate the strengths, challenges, and opportunities of agriculture-related Ecohealth projects in low-resource settings of Vietnam, Thailand, Indonesia, and China, drawing on a case study of the Field Building Leadership Initiative (FBLI). To do this, we used a developmental evaluation framework involving several iterative cycles of document reviews, interviews, focus groups, and outcome harvesting with researchers, partners, and community members involved in FBLI. Results highlight the importance of transdisciplinarity, participation, and knowledge-to-action principles in co-generating knowledge and co-developing practical solutions. Implementing such principles presents challenges in terms of coordinating regional collaborations, managing high workloads, meaningfully engaging communities, and ensuring ongoing monitoring and evaluation. To address these challenges, there is a need to strengthen capacity in integrated approaches to health, improve institutionalization of Ecohealth, foster community engagement, and systematically monitor and evaluate efforts. Ecohealth holds significant promise in improving food security, but only when considerable time is spent developing and implementing projects with communities.

Understanding Antibiotic Residues and Pathogens Flow in Wastewater from Smallholder Pig Farms to Agriculture Field in Ha Nam Province, Vietnam.

BACKGROUND: Contact with livestock wastewater on farms and in communities can pose a risk to human and animal health. METHODS: This cross-sectional study was conducted in 180 households and 24 pig farms (96 wastewater samples) to explore information about pig production, livestock waste management, antibiotic use, and to analyze antibiotic residues and microbial contamination, respectively. RESULTS: Of the 120 households raising pigs, biogas systems were the most commonly used to treat animal waste (70%), followed by compositing (19%), and the remaining respondents discharged waste directly into drains or ponds (11%). The majority of respondents (78%) used antibiotics to treat and prevent disease in pigs, but 32% of them did not know of any disadvantages of antibiotic abuse. ELISA assays were performed on half of the wastewater samples (n = 48), demonstrating that residues of flouroquinolones and sulfonamides were present in 6.3% (3/48) and 22.9% (11/48) of tested samples, respectively. The average residual level of sulfamethazine was 27.8 ug/l. Further, E. coli concentrations exceeding regulatory levels in Vietnam were found in nearly all samples. Salmonella spp. was also found in 57.3% of samples, though prevalence rates varied across the different sites. Finally, G. lamblia was found in 8.4% of samples, and C. parvum was found in 5.2% of samples. CONCLUSIONS: This study suggests that livestock wastewater carried potential harmful pathogens and antibiotic residues that could come into contact with humans in the community. Thus, appropriate operation and application of livestock wastewater treatment (such as biogas or composting) and management should be a continued focused.

Knowledge, attitudes and practices of livestock and aquaculture producers regarding antimicrobial use and resistance in Vietnam.

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.

Risk factors associated with Salmonella spp. prevalence along smallholder pig value chains in Vietnam.

The objective of this study was to investigate the prevalence of, and risk factors for, Salmonella contamination along the smallholder pig value chain in northern Vietnam. Repeat cross-sectional (for farm and pork shops) and longitudinal (for slaughterhouses) studies were carried out in Hung Yen and Nghe An provinces in four sampling periods over a year (April 2014 to February 2015). In total, 72 pig farms and 217 pork shops were visited during the period, and 13 slaughterhouses were visited four times. Information on management and hygiene practices was collected using checklists and questionnaires, and risk factor analyses at the farm, slaughterhouse, and pork shop levels were performed using generalized mixed-effects models with the significant levels 10%. Salmonella prevalence was 36.1%, 38.9%, and 44.7% on pig pen floors, pig carcasses in slaughterhouses, and cut pork in pork shops, respectively. The risk factor for Salmonella prevalence on pig pen floors were having a pig pen next to a household (p = 0.06) and free access to the farm by visitors (p = 0.06). Our slaughterhouse model found a single risk factor for carcass contamination: slaughter area close to lairage without hygienic measures (p = 0.03). For pork shops, presence of flies or insects on pork at shop (p = 0.02) and use of a cloth at pork shop (p = 0.02) were risk factors. The Salmonella prevalence on pig carcass and cut pork was significantly lower in winter compared to that in other seasons. Our study results highlighted the need of improving farm hygiene at farm level, and pork hygiene practices to avoid cross-contamination at the slaughterhouse and market levels, to reduce the risk of salmonellosis through pork consumption in northern Vietnam.

Simulating Cross-Contamination of Cooked Pork with Salmonella enterica from Raw Pork through Home Kitchen Preparation in Vietnam.

Pork is the most commonly consumed meat in Vietnam, and Salmonella enterica is a common contaminant. This study aimed to assess potential S. enterica cross-contamination between raw and cooked pork in Vietnamese households. Different scenarios for cross-contamination were constructed based on a household survey of pork handling practices (416 households). Overall, 71% of people used the same knife and cutting board for both raw and cooked pork; however, all washed their hands and utensils between handling raw and cooked pork. The different scenarios were experimentally tested. First, S. enterica was inoculated on raw pork and surfaces (hands, knives and cutting boards); next, water used for washing and pork were sampled to identify the presence and concentration of S. enterica during different scenarios of food preparation. Bootstrapping techniques were applied to simulate transfer rates of S. enterica cross-contamination. No cross-contamination to cooked pork was observed in the scenario of using the same hands with new cutting boards and knives. The probability of re-contamination in the scenarios involving re-using the cutting board after washing was significantly higher compared to the scenarios which used a new cutting board. Stochastic simulation found a high risk of cross-contamination from raw to cooked pork when the same hands, knives and cutting boards were used for handling raw and cooked pork (78%); when the same cutting board but a different knife was used, cross-contamination was still high (67%). Cross-contamination between was not seen when different cutting boards and knives were used for cutting raw and cooked pork. This study provided an insight into cross-contamination of S. enterica, given common food handling practices in Vietnamese households and can be used for risk assessment of pork consumption.

Community Participatory Interventions to Improve Farmer Knowledge and Practices of Household Biogas Unit Operation in Ha Nam Province, Vietnam.

CONTEXT: The use of biogas systems to treat livestock waste is a common practice in Vietnam. However, farmers' knowledge and practices of the safe and appropriate use of household biogas units (HBUs) are still limited and could negatively impact human, animal, and environmental health. OBJECTIVE: To assess the effectiveness of an intervention to improve knowledge and practices of biogas operation among farmers in 2 communes of Ha Nam Province, Vietnam. DESIGN: A community-based intervention approach. SETTING: This study was conducted from 2015 to 2016 in 2 communes of Ha Nam Province, Vietnam. PARTICIPANTS: Only farmers with HBUs (N = 399) participated in this research. Farmers were assigned to either an intervention group or a control group at a ratio of 1:2. INTERVENTION: Two intervention steps were implemented over a 6-month period as follows: (i) the core farmer group trained in 6 steps of HBU safe handling practice; and (ii) the core farmer group conducted peer-to-peer communication with its neighbors in the commune using the provided material. MAIN OUTCOME MEASURE(S): Farmers' knowledge and practices in biogas operation were assessed by a structured questionnaire. The questionnaire was administered before (baseline) and after the intervention (follow-up) to both the control and intervention groups. RESULTS: There was a significant difference in the knowledge and practices of biogas operation between the 2 groups, in which farmers in the intervention group demonstrated better understanding of the related topic than the control group (P < .05, t test). A linear regression model indicated that baseline and follow-up scores in both knowledge and practices of the intervention group were higher than those of the control group. After the intervention, the mean difference score in knowledge and practices between the intervention and control groups was 5.0 and 2.0 points, respectively (P < .01). CONCLUSION: A community-based intervention approach could be applied to improve knowledge and practices among farmers in using biogas systems. However, further studies should be conducted to assess the sustainability and effectiveness of this model.

Turning poop into profit: Cost-effectiveness and soil transmitted helminth infection risk associated with human excreta reuse in Vietnam.

Human excreta is a low cost source of nutrients vital to plant growth, but also a source of pathogens transmissible to people and animals. We investigated the cost-savings and infection risk of soil transmitted helminths (STHs) in four scenarios where farmers used either inorganic fertilizer or fresh/composted human excreta supplemented by inorganic fertilizer to meet the nutrient requirements of rice paddies in the Red River Delta, Vietnam. Our study included two main components: 1) a risk estimate of STH infection for farmers who handle fresh excreta, determined by systematic review and meta-analysis; and 2) a cost estimate of fertilizing rice paddies, determined by nutrient assessment of excreta, a retailer survey of inorganic fertilizer costs, and a literature review to identify region-specific inputs. Our findings suggest that farmers who reuse fresh excreta are 1.24 (95% CI: 1.13-1.37, p-value<0.001) times more likely to be infected with any STH than those who do not handle excreta or who compost appropriately, and that risk varies by STH type (Ascaris lumbricoides RR = 1.17, 95% CI = 0.87-1.58, p-value = 0.29; Hookworm RR = 1.02, 95% CI = 0.50-2.06, p-value = 0.96; Trichuris trichiura RR = 1.38, 95% CI = 0.79-2.42, p-value = 0.26). Average cost-savings were highest for farmers using fresh excreta (847,000 VND) followed by those who composted for 6 months as recommended by the WHO (312,000 VND) and those who composted for a shorter time (5 months) with lime supplementation (37,000 VND/yr); however, this study did not assess healthcare costs of treating acute or chronic STH infections in the target group. Our study provides evidence that farmers in the Red River Delta are able to use a renewable and locally available resource to their economic advantage, while minimizing the risk of STH infection.

Household Exposure to Livestock and Health in the CHILILAB HDSS Cohort, Vietnam.

In Vietnam, pigs and poultry are predominantly produced by small-scale farmers, creating challenges for zoonotic disease management. The objective of this study was to characterize practices related to livestock and manure management and to measure association with 3 self-reported health symptoms (coughing, fever, and diarrhea/nausea/vomiting) in a region currently undergoing health transitions. We analyzed cross-sectional survey data collected from a subset (N = 5520) of the Chi Linh Health and Demographic Surveillance System cohort in Chi Linh district, Vietnam. Bivariate analyses indicated that female gender was a significant risk factor for all 3 health symptoms, whereas age (≥60 years), suburban living, low education level, and household wealth were risk factors for 2 symptoms. Overall, we found no indication that biogas production or exposure to livestock and manure adversely affected human health. Efforts to control zoonotic disease transmission should prioritize utilization of veterinarians, enhanced farm biosecurity, and improvements to commune drinking water/wastewater infrastructure.

Seasonal and geographical distribution of bacillary dysentery (shigellosis) and associated climate risk factors in Kon Tam Province in Vietnam from 1999 to 2013.

BACKGROUND: Bacillary dysentery (BD) is an acute bacterial infection of the intestine caused by Shigella spp., with clinical symptoms ranging from fever to bloody diarrhoea to abdominal cramps to tenesmus. In Vietnam, enteric bacterial pathogens are an important cause of diarrhoea and most cases in children under 5 years of age are due to Shigella strains. The serogroups S. flexneri and S. sonnei are considered to be the most common. The main objective of this study was to, for the first time, assess the seasonal patterns and geographic distribution of BD in Vietnam, and to determine the climate risk factors associated with the incidence of BD in Kon Tum Province, where the highest rate of bacillary dysentery was observed from 1999 to 2013. METHODS: The seasonal patterns and geographic distribution of BD was assessed in Vietnam using a seasonal-trend decomposition procedure based on loess. In addition, negative binomial regression models were used to determine the climate risk factors associated with the incidence of BD in Kon Tum Province, from 1999 to 2013. RESULTS: Overall, incidence rates of BD have slightly decreased over time (except for an extremely high incidence in 2012 in the north of Vietnam). The central regions (north/south central coast and central highlands) had relatively high incidence rates, whereas the northwest/east and Red River Delta regions had low incidence rates. Overall, seasonal plots showed a high peak in the mid-rainy reason and a second smaller peak in the early or late rainy season. The incidence rates significantly increased between May and October ("wet season") across the country. In Kon Tum Province, temperature, humidity, and precipitation were found to be positively associated with the incidence of BD. CONCLUSIONS: Our findings provide insights into the seasonal patterns and geographic distribution of BD in Vietnam and its associated climate risk factors in Kon Tum Province. This study may help clinicians and the general public to better understand the timings of outbreaks and therefore equip them with the knowledge to plan better interventions (such as improving water, sanitation, and hygiene conditions) during peak seasons. This can, in turn, prevent or reduce outbreaks and onwards transmission during an outbreak.

Assessing potential health impacts of waste recovery and reuse business models in Hanoi, Vietnam.

OBJECTIVES: In resource-constrained settings, the recovery of nutrients and the production of energy from liquid and solid waste are important. We determined the range and magnitude of potential community health impacts of six solid and liquid waste recovery and reuse business models in Hanoi, Vietnam. METHODS: We employed a health impact assessment (HIA) approach using secondary data obtained from various sources supplemented with primary data collection. For determining the direction (positive or negative) and magnitude of potential health impacts in the population, a semiquantitative impact assessment was pursued. RESULTS: From a public health perspective, wastewater reuse for inland fish farming, coupled with on-site water treatment has considerable potential for individual and community-level health benefits. One of the business models investigated (i.e. dry fuel manufacturing with agro-waste) resulted in net negative health impacts. CONCLUSIONS: In Hanoi, the reuse of liquid and solid waste-as a mean to recover water and nutrients and to produce energy-has considerable potential for health benefits if appropriately managed and tailored to local contexts. Our HIA methodology provides an evidence-based decision-support tool for identification and promotion of business models for implementation in Hanoi.