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Antimicrobials used in chicken farming for therapeutic and/or prophylactic purposes may result in unacceptable levels of edible residues, if withdrawal periods are not respected. To evaluate the risk in Vietnam, we validated an analytical method to detect antimicrobial residues from chicken meat samples and carried out a pilot cross-sectional study to identify optimal sampling strategies. A total of 45 raw meat samples were collected from 4 markets, 1 slaughterhouse and 4 farms (5 per site) in Northern Vietnam, between March and April 2021. Farmers were asked about antimicrobials used during sampled production cycles (5 chickens sampled per batch). Samples were analysed using liquid chromatography-tandem mass spectrometry for the presence of 68 antimicrobials at a pre-defined validation concentration. 7 compounds were identified from 4 classes (tetracyclines, sulphonamides, macrolides, and fluoroquinolones). In markets, where the source of sampled chickens was unknown, a diverse pool of residual antimicrobials was detected in 20% (4/20) of the meat samples. No residues were detected in samples from the slaughterhouse. No residues were detected in chickens from the one farm that reported using antimicrobials, whereas sulfadimethoxine, doxycycline and tilmicosin residues were identified from the other 3 farms reporting no antimicrobial use. The probability of detecting antimicrobial residues present in a flock based on sampling a single chicken was estimated at 0.93 (highest density interval 0.735–0.997). The preliminary results suggest a disparity between farmers' reports on antimicrobial drug use and actual usage, and that the analysis of a single sample per farm has a high probability of detecting antimicrobial residues, if present. [ABSTRACT FROM AUTHOR]

Background. The extensive use of carbamate pesticides in agriculture has increased serious public concern regarding the environment and food safety. Carbamate pesticides have been reported to cause deleterious effects on the immune system and fertility issues in both humans and animals. A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of carbamate residues in vegetables has been developed and validated with quantification levels respecting the action levels established for the maximum residue limits (MRL) according to the European Union, World Health Organization (WHO), and Vietnam. Materials and methods. In the proposed method, the pretreatment protocol was shortened to reduce time, and chemical usage was also minimized to decrease cost. The validation was performed according to the Commission Implementing Regulation (EU) 2021/808, which includes linearity, limits of detection (LOD), limits of quantification (LOQ), recovery, and repeatability. Results. Based on the LC-MS/MS experiments, the matrix-matched calibration method showed good performance in the concentration from 5 to 200 µg/kg for vegetable samples, with a correlation coefficient of R2 value of > 0.996. The limits of quantification for all carbamate pesticides were 5 µg/kg. Recoveries of all carbamate pesticides were from 91 to 109% and repeatabilities (RSD) were < 10%. Conclusion. The validation data indicate the developed LC/MS/MS method is suitable for the determination of carbamate pesticides in vegetables. [ABSTRACT FROM AUTHOR]

Antibiotic residue stands as a significant ongoing environmental issue, with aquaculture being a major source of annual antibiotic discharge into the ocean. Nevertheless, there is still an incomplete evaluation of antibiotic residues in the Beibu Gulf, an area encompassed by two prominent aquaculture nations, China and Vietnam. The present systematic review and meta-analysis was conducted to examine the presence antibiotic residues in the Beibu Gulf based on published studies. Data were obtained through eight databases up to December 19th, 2023, and were updated on April 15th, 2024. The pooled concentration of antibiotic residues in seawater was 5.90 (ng/L), ranging from 5.73 to 6.06 (ng/L), and was 8.03 (ng/g), ranging from 7.77 to 8.28 (ng/g) in sediments. Fluoroquinolones, tetracyclines, and macrolides were identified as the main antibiotics found in both seawater and sediment samples. The Beibu Gulf showed higher antibiotic levels in its western and northeastern areas. Additionally, the nearshore mangrove areas displayed the highest prevalence of antibiotic residues. It is strongly advised to conduct regular long-term monitoring of antibiotic residues in the Beibu Gulf. Collaborative surveys covering the entire Beibu Gulf involving China and Vietnam are recommended. • Antibiotic residues data of the Beibu Gulf from 17 studies were analyzed using meta-analysis by Stata software. • Concentration of antibiotics in the Beibu Gulf was lower than most Asian bays both in seawater and sediments. • The highest concentration of the antibiotic residues was shown in nearshore mangrove samples. [ABSTRACT FROM AUTHOR]

Residue concentrations of fifteen antibiotics including sulfonamides, quinolones, macrolides, β-lactams, and trimethoprim in lakes from Hanoi metropolitan area, Vietnam, were analyzed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC/MS-MS) to elucidate their occurrence and behavior in urban environment. For surface water, the average concentrations of five antibiotic classes decreased in the order: sulfonamides (117.9 ng/L) > β-lactams (31.28 ng/L) > quinolones (20.19 ng/L) > macrolides (17.74 ng/L) > trimethoprim (8.93 ng/L). While the highest concentration of SMX was detected at 806.5 ng/L in surface water, those obtained in sediment were only at 1.35 ng/g because of their high solubility in water. Quinolones were found at a maximal concentration of 158.7 ng/L for OFL in water phase whereas those in sediment phase were 4,017 ng/g due to their great affinity in sediment. These findings revealed the different fate and release mechanisms of each antibiotic group in the environment. The ecological risk assessment implied some targeted compounds, and in particular, OFL and AZM could pose high risks to algae in the aquatic ecosystem. [ABSTRACT FROM AUTHOR]

Antibiotic residues and antimicrobial resistance in surface water are issues of global concern, especially in developing countries. In this study, the occurrence of seven antibiotics and one antiparasitic agent was determined in surface water samples collected from four rivers running through Hanoi urban area in the Red River Delta, northern Vietnam. The pharmaceuticals in water samples were analyzed by solid-phase extraction combined with liquid chromatography–tandem mass spectrometry method. The concentrations of pharmaceuticals in our samples ranged from 3050 to 16,700 (median 7800) ng/L, which were generally higher than levels found in river water from many other locations in the world. Amoxicillin, oxfendazole, and lincomycin were the most dominant and frequently detected compounds (detection rate 100%), which together accounted for 76 ± 14% of total concentrations. Sulfacetamide and sulfamethoxazole were detected at moderate concentrations in more than two-thirds of the analyzed samples. The remaining antibiotics (i.e., azithromycin, ciprofloxacin, and ofloxacin) were found at lower detection frequency and concentrations. Antibiotic concentrations in the water samples were not significantly different between the investigated rivers. Meanwhile, levels of pharmaceuticals in the samples collected in February 2020 were higher than those found in the remaining samples, largely due to the sharp decrease in sulfamethoxazole and azithromycin concentrations of the samples collected in March and April. Considerable ecological risks of antibiotics in surface water were estimated for some compounds such as amoxicillin, ciprofloxacin, and ofloxacin. [ABSTRACT FROM AUTHOR]

In this study, an analytical method for the simultaneous determination of 7 major pharmaceutical residues in Vietnam, namely, carbamazepine, ciprofloxacin, ofloxacin, ketoprofen, paracetamol, sulfamethoxazole, and trimethoprim, in surface water and hospital wastewater has been developed. The method includes enrichment and clean-up steps by solid phase extraction using mix-mode cation exchange, followed by identification and quantification using an ultrahigh-performance liquid chromatography and tandem mass spectrometry and employing electrospray ionization (UPLC-ESI-MS/MS). Seven target compounds were separated on the reversed phase column and detected in multiple reaction monitoring (MRM) mode within 6 minutes. The present study also optimized the operating parameters of the mass spectrometer to achieve the highest analytical signals for all target compounds. All characteristic parameters of the analytical method were investigated, including linearity range, limit of detection, limit of quantification, precision, and accuracy. The important parameter in UPLC-ESI-MS/MS, matrix effect, was assessed and implemented via preextraction and postextraction spiking experiments. The overall recoveries of all target compounds were in the ranges from 55% to 109% and 56 % to 115% for surface water and hospital wastewater, respectively. Detection limits for surface water and hospital wastewater were 0.005–0.015 µg L−1 and 0.014–0.123 µg L−1, respectively. The sensitivity of the developed method was allowed for determination of target compounds at trace level in environmental water samples. The in-house validation of the developed method was performed by spiking experiment in both the surface water and hospital wastewater matrix. The method was then applied to analyze several surface water and hospital wastewater samples taken from West Lake and some hospitals in Vietnam, where the level of these pharmaceutical product residues was still missed. Sulfamethoxazole was present at a high detection frequency in both surface water (33% of analyzed samples) and hospital wastewater (81% of analyzed samples) samples. [ABSTRACT FROM AUTHOR]

Antibiotic residues in chicken meat samples is a serious public health concern due to their harmful effects on consumers' health. We conducted this research in 2017 to determine antibiotic residues in chicken meat samples and to describe the knowledge, attitude, and practice (KAP) of farmers on the antibiotic uses in poultry farms at Tay Ninh province. Farmers who raised chickens at their farmhouses were surveyed using a KAP survey questionnaire, and 106 chicken meat samples were analyzed for 29 kinds of antibiotic residues. The results showed that 27.4% samples were positive with 11 kinds of 4 antibiotic groups: fluoroquinolones, sulfonamides, tetracycline, and macrolides. A total of 50.9% farmers needed to improve their knowledge on the appropriate use of antibiotics. Although 54.7% famers had positive attitude, just 17% had good practices. It was recommended that the levels of antibiotic residues in chickens should be communicated to food safety and veterinary authorities, chicken farmers, and the general public. Enhancing the training and coaching for each group of farmers to improve their knowledge and practices on the appropriate use of antibiotics in raising chickens is needed. Local government should enhance the level of control and punishment for drug sellers and end users regarding the use of banned antibiotics in chickens. [ABSTRACT FROM AUTHOR]

The development and validation of a throughput method for the determination of 25 antibacterial drugs (two β-lactams, eight quinolones, two macrolides, five sulfonamides, trimethoprim, four tetracyclines and three amphenicols) in pangasius fish muscle by LC-MS/MS were performed. A simple, efficient and fast extraction procedure was developed using acetonitrile and a 0.1 M EDTA solution as solvents for extraction. All compounds were determined in a single run, and chromatographic separation was achieved using a Zorbax SB C18 column with a mobile phase comprised of purified water +0.1% formic acid (A) and acetonitrile +0.1% formic acid (B) in a linear gradient program. The method was validated aαording to the requirements of European Decision 2002/657/EC. To quantify the analytes, matrix-matched analytical curves were constructed with spiked blank tissues and showed linearity (r2) higher than 0.99. For all analytes, the precision and accuracy were determined at the levels of 3 ng/g (low), 10 ng/g (low-middle), 50 ng/g (high-middle) and 100 ng/g (high). The precision (CV%) was lower than 18.6% and the accuracy (determined as recovery) was between 65% and 119%. The limit of quantitation was 3.0 ng/g, with the exception of chloramphenicol, which was 0.3 ng/g, and amoxicillin and doxycycline, which were 10 ng/g. The method was successfully applied to analyze pangasius muscle samples from Vietnam available at the Brazilian retail market, and 5 out of 40 samples showed the presence of low-residue levels of enrofloxacin and, consequently, must be considered out of conformity. It is recommended that competent authorities should avoid the commercialization of pangasius fillet contaminated with residues of this veterinary drug. Unlabelled Image • A simple multiresidue LC-MS/MS method for antibiotic in pangasius is reported. • A high-throughput sample preparation for analysis of 25 antibiotics was performed. • Validation figures of merit provided with very low limit of quantitation obtained. • First report of antibiotic residues in pangasius from the Brazilian retail market. • Five of forty pangasius fillet samples showed low levels of enrofloxacin residues. [ABSTRACT FROM AUTHOR]

Salinity intrusion into coastal regions is an increasing threat to agricultural production of salt sensitive crops like paddy rice. In the coastal Mekong Delta, farmers respond by shifting to more salinity tolerant agricultural production systems such as alternating rice-shrimp and permanent shrimp. While shrimps are sensitive to pesticide residues used on rice, the use of antibiotics in shrimp farming can cause contamination in rice crops. These patterns of cross-contamination are not well documented empirically in the rapidly changing agricultural landscape. Our objective was to understand changing pollution patterns induced by shifts in agricultural land use system. We addressed this by i) documenting pesticide and antibiotic use in three different agriculture land use systems (permanent rice, alternating rice-shrimp and permanent shrimp), and by ii) determining residues of pesticides and antibiotics in top soil layers of these three land use systems. Samples were taken in Sóc Trăng and Bến Tre province in the Mekong Delta, Vietnam. Chemical analyses comprised 12 of the most commonly used pesticides in rice paddies and six common antibiotics used in shrimp production. Results showed that residues of pesticides were present in all agricultural land use systems, including shrimp aquaculture. Active ingredients were mostly fungicides with a maximum concentration of 67 μg kg−1 found for isoprothiolane in permanent rice systems, followed by alternating rice-shrimp and permanent shrimp systems. Furthermore, antibiotics were present ubiquitously, with fluoroquinolones accumulating to larger amounts than sulfonamides and diaminopyrimidines. All concentrations were below critical lethal threshold values. Overall, farmers were most conscious of agrochemical use in alternating rice-shrimp systems to prevent harm to shrimps, which was reflected in overall lower concentrations of agrochemicals when compared to rice systems. Thus, alternating rice-shrimp systems present a low risk option in terms of food safety, which may bring additional benefits to this so far rather low-input system in brackish water transition zone. • Salt water intrusion shifts land use towards alternating/permanently saline systems. • Permanent shrimp and rice farms are sources of antibiotic and pesticide pollution, respectively. • Alternating rice-shrimp farming is a low-input system for antibiotics and pesticides. • Interconnected channel system facilitate cross-contamination between land use systems. [ABSTRACT FROM AUTHOR]

Foodborne illness is a difficult public health burden to measure, with accurate incidence data usually evading disease surveillance systems. Yet, the global scope of foodborne disease and its impacts on socioeconomic development make it an important health risk to address, particularly in low- and middle-income countries. In Vietnam, rapid development has seen large-scale commercial operations rise to coexist amongst traditional value chains in the food landscape, most of which operates outside of a domestic food safety network. Rapid socioeconomic development has also seen an increase in meat consumption, with pork being the most consumed meat product nationally. Expanding pork value chains, and the increasing diversity of actors within them, facilitates the growth and propagation of hazards which are passed onto Vietnamese consumers. In order to guide illness prevention and governance efforts, this review was conducted to examine health risks associated with pork consumption in Vietnam. Synthesis of the available literature provided evidence that Salmonella spp. bacteria are a major cause of foodborne illness from Vietnamese pork products. However, contaminants of global concern, including Salmonella spp. and Trichinella spiralis, occur alongside those considered neglected tropical diseases, such as Taenia solium. Infections and complications associated with ingestion of Streptococcus suis bacteria are also an issue, with Streptococcus suis infections usually limited to occupational infections amongst meat handlers in modernised value chains. A risk factor underscoring transmission of Trichinella spiralis, Taenia solium, and Streptococcus suis in Vietnam that emerges from the literature is the consumption of dishes containing raw or undercooked pork. Available data indicates that infections associated with raw pork consumption disproportionately affect men and people in regional mountainous areas of northwest Vietnam, where many of Vietnam's ethnic minority communities reside. In addition, epidemiological data from recorded disease outbreaks that result from raw pork consumption demonstrate that these outbreaks usually follow major sociocultural events such as weddings, funerals, and Lunar New Year celebrations. Potential health impacts resulting from residues of antibiotics and heavy metals are also cause for concern, though the direct links between chemical contaminants in food and the development of disease are difficult to conclusively deduce. [ABSTRACT FROM AUTHOR]

We examine effective measures to reduce the use of prohibited antibiotics among shrimp farmers in Southern Vietnam based on an econometrics approach. We implemented a randomized controlled trial with three interventions: a) providing a technical workshop, b) quantifying the unobserved residue level of antibiotics, and c) offering price premiums for higher quality shrimp, defined as the absence of major prohibited antibiotics in our study. Using three years of panel data, we estimate the intention-to-treat effects of each intervention and find that quantifying the residue level had strong positive effects in improving farmers' knowledge and practices and reducing the probability of detecting antibiotics ex post. This result is driven by those farmers who had positive detection ex ante. Our findings suggest that providing residue test results for farmers is an effective way to solve the antibiotic residue problems in aquacultural sector in developing countries. (145 words). • Quantifying residues of antibiotics improves farmers' knowledge and practices. • Quantifying residues also reduces the probability of antibiotics detection ex post. • Farmers who had positive detection ex ante changed farming practices ex post. [ABSTRACT FROM AUTHOR]

The usage of antimicrobials in livestock production is a driver for antimicrobial resistance worldwide. Reducing the use of antibiotics in the animal sector is a priority and requires a change in practices. Vietnam has diverse husbandry and antimicrobial use practices. The objective of this study was to determine the socio-economic and technical factors associated with antibiotic usage patterns on chicken farms in the north and south of Vietnam. Semi-structured interviews (n = 34) and on-farm questionnaires (n = 125) were conducted to collect socio-economic, technical, biosecurity, health management, and antibiotic usage data. Using Multivariate Corresponding Analysis, we identified three production systems (A, B, C) and three patterns of antibiotic usage (1, 2, 3). Group A raised indoor exotic chickens in an intensive setting and was associated with group 1, which used antibiotics according to company recommendations for both treatment and prevention. Group C raised free-range chickens for their own consumption and was associated with group 2, which used antibiotics according to drugstore advice for treatment. Finally, group B was a market-oriented, semi-confined system associated with group 3, which practiced experience-based antibiotic use and overuse. Farms in the south of Vietnam were associated with group 3 and those in the north with group 2. The prediction of antibiotic usage patterns based on farming practices could lead to the identification of a group of farms to be targeted in order to foster the more prudent use of antibiotics in Vietnam. • Patterns of antibiotic usage were associated with socio-economic and technical factors. • Own experience usage of antibiotics was associated with family commercial farms. • The decision to use antibiotics within integrated farms is mainly driven by the integrator. • Drugstores must be included in actions aiming to reduce the use of antibiotics. [ABSTRACT FROM AUTHOR]

A cross-sectional survey was designed to investigate the proportion of tetracycline residues in marketed pork in suburb and urban districts in Hanoi. A total of 290 raw muscle samples were randomly collected from open markets in these districts. The samples were qualitatively screened for tetracycline residues using the agar inhibition test, and Bacillus cereus (ATCC 11778) as the reference strain. The inconclusive samples were then analyzed using high-performance liquid chromatography (HPLC). The positive samples from either test were defined as positive results. Overall, 5.5% of all collected samples were positive for tetracycline residues. The proportion of positive samples from shops in suburb districts was significantly ( P < 0.05) different from those collected from shops in urban districts. So, the factor of region was identified as a risk factor of tetracycline residue proportion in raw pork with an odds ratio (OR) of 4.03 (95% CI = 1.12, 14.45). For the other factors, such as season, type of shop, type of abattoir, origin of meat, etc., the difference in proportion of positive samples within each factor was substantial but not statistically significant. These factors were identified as nonrisk factors. Such a high proportion may pose a potential hazard to public health, particularly since they might induce drug resistance of pathogenic micro-organisms. [ABSTRACT FROM AUTHOR]

Pharmaceutical manufacturers in Vietnam are producing a wide variety of antibiotics for human and veterinary use. Consequently, the water discharged from those facilities can contain residues of antibiotics, which could have adverse impact on the environment. However, studies on the occurrence of antibiotics in the wastewater from pharmaceutical manufacturers in Vietnam are almost non-existent. In this study, water samples were collected at around the outlets of four pharmaceutical manufacturing plants as well as from a hospital and an aquaculture farm around Hanoi in 2016 and 2017. Fifteen antibiotics from four major classes (β-lactam, quinolones, macrolides, sulfonamides) were monitored, using a validated LC-MS/MS method, based on their number of registrations at the Ministry of Health. Ten antibiotics, ampicillin, cefuroxime, cefotaxime, clarithromycin, azithromycin, sulfamethoxazole, trimethoprim, ofloxacin, norfloxacin, and ciprofloxacin were detected in the samples at different concentrations. Notably, sulfonamides and quinolones were occasionally detected at very high concentration, such as sulfamethoxazole (252 μg/L), trimethoprim (107 μg/L), ofloxacin (85 μg/L), and ciprofloxacin (41 μg/L). In this study, concentrations of antibiotic residues in effluent of pharmaceutical plants were higher than those from other sources. The antibiotic-resistance tests indicated the widespread resistance to common antibiotics like quinolone and sulfonamides in the collected samples. This finding suggests that wastewater from pharmaceutical manufacturers could be an important source of antibiotics and antibiotic-resistant bacteria in the aquatic environment of Vietnam., (Copyright © 2018. Published by Elsevier B.V.)