Pathological Characteristics of Domestic Pigs Orally Infected with the Virus Strain Causing the First Reported African Swine Fever Outbreaks in Vietnam.

African swine fever (ASF) is currently Vietnam's most economically significant swine disease. The first ASF outbreak in Vietnam was reported in February 2019. In this study, VNUA/HY/ASF1 strain isolated from the first ASF outbreak was used to infect 10 eight-week-old pigs orally with 103 HAD50 per animal. The pigs were observed daily for clinical signs, and whole blood samples were collected from each animal for viremia detection. Dead pigs were subjected to full post-mortem analyses. All 10 pigs displayed acute or subacute clinical signs and succumbed to the infection between 10 to 27 (19.8 ± 4.66) days post-inoculation (dpi). The onset of clinical signs started around 4-14 dpi. Viremia was observed in pigs from 6-16 dpi (11.2 ± 3.55). Enlarged, hyperemic, and hemorrhagic lymph nodes, enlarged spleen, pneumonia, and hydropericardium were observed at post-mortem examinations.

Detection and genetic characterization of canine distemper virus isolated in civets in Vietnam.

Canine distemper (CD), caused by the canine distemper virus (CDV), is a lethal systemic disease to a wide range of wild and domestic carnivorous hosts, including civets. In this study, a possible CD outbreak in a backyard farm with 32 diseased civets (Viverricula indica) in Hanoi, Vietnam, was investigated. The sick civets showed CD-like clinical signs such as anorexia, sedentary behavior, diarrhea, dermatitis, nasal, and footpad hyperkeratosis. Various tissue samples collected from the dead civets were utilized for molecular screening of CDV and histopathological examination. The genetic detection and characterization confirmed that samples collected from dead civets tested positive for CDV. The phylogenetic analysis based on the full-length H gene sequences indicated that all CDV strains isolated from civets belonged to the Asia-1 lineage and were closely related to the CDV strains previously reported from dogs in Thailand, China, and Vietnam. Histopathological examination showed severe interstitial pneumonia, hemorrhagic alveolar septa, necrotic alveolar epithelial cells, necrotic, degenerated, or lost Purkinje cells, eosinophilic intracytoplasmic inclusion bodies, edema, and perivascular cuff. This study confirmed the detection of CDV in civets for the first time in Vietnam.

Essential Oils from the Leaves, Stem, and Roots of Blumea lanceolaria (Roxb.) Druce in Vietnam: Determination of Chemical Composition, and In Vitro, In Vivo, and In Silico Studies on Anti-Inflammatory Activity.

Blumea lanceolaria (Roxb.) Druce, a flowering plant, is used for treating cancer and inflammatory diseases. In this study, we determined the chemical composition of the EOs extracted from the leaves (LBEO), stem (SBEO), and roots (RBEO) of B. lanceolaria and analyzed their anti-inflammation potential. Overall, 30 compounds representing 99.12%, 98.44%, and 96.89% of total EO constituents of the leaves, stem, and roots, respectively, were identified using GC-MS. ELISA, Western blotting, and qRT-PCR studies showed that LBEO, SBEO, and RBEO inhibited multiple steps in the inflammatory responses in the RAW 264.7 cell model, including NO production; TNF-α, IL-6, iNOS, and COX-2 transcription and translation; and phosphorylation of IκBα and p65 of the NF-κB pathway. In the carrageenan-induced paw edema model, all three EOs inhibited paw edema at both early and delayed phases. Molecular docking studies indicated that the main components of B. lanceolaria EOs (BEOs) targeted and inhibited major components of inflammation-related pathways, including the arachidonic acid metabolic pathway, NF-κB pathway, and MAPK pathway. We present the first study to characterize the chemical composition of BEOs and confirm their potent anti-inflammatory effects in in vitro, in vivo, and in silico analysis. These results can facilitate the development of effective anti-inflammatory drugs with limited side effects in the future.

Estimation of basic reproduction number (R0) of African swine fever (ASF) in mid-size commercial pig farms in Vietnam.

African swine fever (ASF) is a devastating disease affecting the global swine industry. Recently, it has spread to many countries in Africa, Europe, Asia, and the Caribbean, leaving severe damage to local, regional, national, and global economies. Due to its highly complex molecular characteristics and pathogenesis, the development of a successful vaccine has been an unmet challenge. Therefore, ASF control relies solely on biosecurity, rapid detection, and elimination. Epidemiological information obtained from natural ASF outbreaks is critical for designing and implementing ASF control measures. Basic reproduction number (R0), an epidemiological metric used to describe the contagiousness or transmissibility of infectious agents, is an important epidemiological tool. In this study, we have calculated R0 for the in-farm spread of ASF among fattening pigs and sows in two midsize commercial pig farms, HY1 and HY2, that practice the spot removal approach in controlling ASF outbreaks in Vietnam. The R0 values for the sows and fattening pigs were 1.78 (1.35-2.35) and 4.76 (4.18-5.38) for HY1 and 1.55 (1.08-2.18) and 3.8 (3.33-4.28) for HY2. This is the first study to evaluate the transmission potential of ASF in midsize commercial pig farms in Vietnam. Based on the R0 values, we predict that the spot removal approach could be used to successfully control ASF outbreaks in midsize commercial sow barns but not in fattening pens.

Blood parameters and pathological lesions in pigs experimentally infected with Vietnam's first isolated African swine fever virus.

African swine fever virus (ASFV) is a notable virus and one of the most serious global threats to the pig industry. Improving awareness about host-virus interactions could facilitate the understanding of the disease pathogenesis. Therefore, we investigated changes in blood parameters, viral loads, and pathological changes in ASFV-inoculated pigs according to the time of death after the onset of viremia. For the analyses, the ASFV-infected pigs (n = 10) were divided into two groups (five pigs/group) according to their time of death after the onset of viremia. The blood cell count dynamics and serum biochemistry profiles were similar between the groups; however, viral load distribution was different. A comparison of the histopathological changes and immunohistochemistry results between the two groups indicated that the lymphoid system, particularly the spleen, was more damaged in the early stage of the disease than in the last stage. Additionally, the virus-induced lesions in other organs (liver and kidney) were more severe in the late stage than in the early stage. Our findings provide invaluable information on the characteristics of blood parameters and pathological lesions in pigs infected with the Asia-epidemic ASFV strain and the course of ASF, targeting internal organs in pigs. Overall, this study characterizes the host-pathogen interaction in ASFV infection, offering insight for the establishment of ASF control strategies.

Gender-focused analysis and opportunities for upgrading within Vietnam's smallholder pig value chains.

Gender influences participation in food value chains (VCs) with implications for VC upgrading. This study investigated roles as well as differences in production activities, awareness, training, and attitudes between men and women in Vietnam's smallholder pig VCs. Data were gathered from a survey of 1,014 actors in different nodes along the chain, and the results showed that both men and women participated in all nodes of the VCs. Women were mainly in charge of routine husbandry activities (e.g., preparing feed, feeding animals, and cleaning pig pens) and participated in input supply (34.7%), pig production (60.2%), pork processing (63.6%), retailing (93.1%), and home preparation and cooking (100%). Men were more often responsible for tasks requiring strength, knowledge, and skills (e.g., disease management) and had greater involvement in larger-scale farming (60-80%) and slaughtering activities (98.0%). Selling of pigs was handled by both genders, but mainly men (73-80%), especially in larger farms. Likely challenges for upgrading pig VCs include limited training for producers, low concern for occupational health risks in all nodes, and misperceptions about food safety. In general, this study found no clear evidence of perceived gender inequality in the smallholder pig VCs in lowland Vietnam. Gendered upgrading in pig VCs should focus on improving women's ability to access veterinary services and animal disease management and on educating relevant VC actors about occupational health risks.

Molecular and histopathological characterization of lumpy skin disease in cattle in northern Vietnam during the 2020-2021 outbreaks.

Lumpy skin disease (LSD) is a serious emerging infectious disease in cattle caused by a virus of the family Poxviridae. According to the Department of Animal Health, LSD first occurred in Vietnam at the end of October 2020 in Cao Bang and Lang Son provinces. So far, the disease has infected over 63,000 animals, resulting in 9170 deaths occurring in 32 different provinces in northern and central Vietnam. In this study, skin samples from lumpy skin disease virus (LSDV)-infected cattle from the northern provinces of Vietnam displaying clinical symptoms including fever (> 40 °C), runny nose, drooling, and skin lesions were used for genetic characterization and histopathology. Genetic analysis of the partial P32 (LSDV074), partial F (LSDV117), complete RPO30 (LSDV035), and complete G-protein-coupled-chemokine-like receptor (GPCR) (LSDV011) genes showed that all Vietnamese LSDV strains belonged to the genus Capripoxvirus and were closely related to LSDV strains isolated in China. Microscopic examination of the skin lesions showed thickening of the epidermal layer of the skin and hair follicles, hyperplasia of sebaceous glands, intracytoplasmic inclusion bodies, and hemorrhages in the mesoderm.

Multiple variants of African swine fever virus circulating in Vietnam.

African swine fever (ASF) is a contagious and deadly viral disease affecting swine of all ages. ASF was first reported in Vietnam in February 2019, and it is now considered endemic in Vietnam. In this study, 122 ASF-positive samples collected from domestic pigs in 28 different provinces of northern, central, and southern Vietnam during outbreaks in 2019-2021 were genetically characterized. The findings confirmed that all ASF virus (ASFV) strains circulating in Vietnam belonged to p72 genotype II, p54 genotype II, CD2v serogroup 8, and CVR gene variant type I. However, further analysis based on the tandem repeat sequences located between I73R and I329L genes revealed that there were three different variants of ASFV, IGR I, II, and III, circulating in the domestic pig population in Vietnam. The IGR II variants were the most prevalent (117/122 strains) and were detected in pigs in all of the provinces tested, followed by IGR III (4/122 strains) and IGR I (1/122 strains). This study confirms for the first time the presence of IGR III variants in Vietnam.

Molecular profile of African swine fever virus (ASFV) circulating in Vietnam during 2019-2020 outbreaks.

African swine fever (ASF) is a highly infectious disease of pigs caused by African swine fever virus (ASFV). In order to identify potential genetic variations among ASFV strains circulating in Vietnam, 26 ASFV isolates from organs and blood samples collected from domestic pigs from 23 different provinces of northern, central and southern Vietnam during 2019-2020 ASF outbreaks were genetically characterized. Nucleotide sequences were determined for a portion of the B646L (p72) gene, the complete E183L (p54) gene, the variable region of EP402R (CD2v), the central variable region (CVR) of pB602L, and a tandem repeat sequence (TRS) between the I73R and I329L genes. Analysis of the partial B646L (p72) and EP402R (CD2v) gene sequences and the full-length E183L (p54) gene sequence showed that all 26 ASFV isolates belonged to genotype II and serotype VIII and that they were identical to the strain Georgia/2007/1 and all ASFV strains sequenced in China. The TRS between the I73R and I329L genes contained a 10-nucleotide insertion that was observed in the Chinese ASFV strain CN201801 isolated from domestic pigs in 2018, but not in the Georgia/2007/1 and China/Jilin/2018/boar strains isolated from wild boar in China. This is the first intra-epidemic genome analysis reported for the ASFV strains circulating in Vietnam.

Mapping the pork value chain in Vietnam: a systematic review.

In Vietnam, pork is the most commonly consumed type of meat, and the demand is expected to rise even further. Nevertheless, food safety is a major concern, as the country bears a high burden of food-borne diseases, including these caused by pork products. Knowledge of the flows of pigs and pork from producers up to the consumers is important; however, up to now, a comprehensive overview is lacking. We addressed this by conducting a systematic review on the pork value chain (PVC) mapping for the country. Four international and three Vietnamese databases were searched for data on the pork value chain in Vietnam, and the results were reported according to the PRISMA guidelines. Data obtained from the retained records showed that 10 main PVC types are present in Vietnam, comprising of five main actors including: producers, middlemen, slaughter men, retailers and consumers. Among the identified chains, the one involving producers, slaughter men, retailers and consumers is the most common one, with up to 75% of pork following this route. In cities or export routes to other countries, middlemen and/or traders are important additional actors in the PVCs. The small scale of PVC linkages is prominent. The presence of middlemen, pig traders and pork traders is contributing to further distribution of pork products in geographical terms. Transactions between actors in the traditional PVCs in Vietnam are characterized by the absence of official contracts; therefore, the linkages in the chains are loose and the origin of pork is not traceable. More industrial forms of PVCs are slowly developing; however, the traditional PVCs are still prevailing in Vietnam. The weak linkages between actors and poor hygienic practices in these chains form a risk to pork safety.

Molecular typing of conjunctivitis-causing adenoviruses in Hanoi, Vietnam from 2017 to 2019 and complete genome analysis of the most prevalent type (HAdV-8).

Adenoviral conjunctivitis is a common epidemic worldwide. In Vietnam, up to 80,000 patients are infected with adenoviral conjunctivitis annually. However, there are few investigations on the pathogenic adenoviruses that cause conjunctivitis. In total, 120 eye-swab samples were collected from patients with viral conjunctivitis symptoms in Hanoi, Vietnam from 2017 to 2019. Human adenoviruse (HAdV) was detected in 67 samples (55.83%) using polymerase chain reaction amplification of at least one of three HAdV-specific marker genes (hexon, penton, and fiber). Of the 67 HAdV samples, 46 samples could be analyzed by all three marker genes. DNA sequence analysis and phylogenetic tree building based on the three marker genes from the 46 HAdV samples revealed five different HAdV types associated with conjunctivitis in Hanoi, including HAdV-3 (4.3%), HAdV-4 (2.2%), HAdV-8 (89.1%), HAdV-37 (2.2%), and a potential recombinant type between types HAdV-8 and HAdV-3 (2.2%). This showed that HAdV-8 was the most common type identified in Hanoi. Complete genome analysis of HAdV-8 isolated from a Vietnamese patient (VN2017) using Sanger sequencing revealed 34 unique nucleotide changes, indicating that the adenovirus continuously accumulates new mutations. Hence, continuous surveillance of HAdV-8 changes in Vietnam is necessary in the future.

Exposure to Messages on Risk Factors for Noncommunicable Diseases in a Rural Province of Vietnam.

BACKGROUND: Providing messages on risk factors for noncommunicable diseases (NCDs) plays an important role in preventing disease. OBJECTIVES: This study investigated how often adults living in a rural area in northern Vietnam heard about risks factor for NCD and where they obtained that information. METHODS: A cross-sectional survey was conducted using a multistage stratified cluster sampling to recruit 2970 participants. Data analyses were adjusted for all variables in a two-level multilevel Poisson regression model. RESULTS: Overall, 77% of respondents had heard about NCDs, while 38.3 to 50% had been exposed to messages on risk factors of NCDs in the last month. Television, radio, and friends/neighbors were the most common sources of information. Most people exposed information no more than one or two sources. Factors associated with exposure to messages about risk were occupation, age group, education, and economic status. CONCLUSION: Intervention programs should focus on providing information primarily through television, considering influencing factors as well ensuring that messages reach target audiences.

Procarcinogens - Determination and Evaluation by Yeast-Based Biosensor Transformed with Plasmids Incorporating RAD54 Reporter Construct and Cytochrome P450 Genes.

In Vietnam, a great number of toxic substances, including carcinogens and procarcinogens, from industrial and agricultural activities, food production, and healthcare services are daily released into the environment. In the present study, we report the development of novel yeast-based biosensor systems to determine both genotoxic carcinogens and procarcinogens by cotransformation with two plasmids. One plasmid is carrying human CPR and CYP (CYP3A4, CYP2B6, or CYP2D6) genes, while the other contains the RAD54-GFP reporter construct. The three resulting coexpression systems bearing both CPR-CYP and RAD54-GFP expression cassettes were designated as CYP3A4/CYP2B6/CYP2D6 + RAD54 systems, respectively and used to detect and evaluate the genotoxic potential of carcinogens and procarcinogens by selective activation and induction of both CPR-CYP and RAD54-GFP expression cassettes in response to DNA damage. Procarcinogens were shown to be predominantly, moderately or not bioactivated by one of the CYP enzymes and thus selectively detected by the specific coexpression system. Aflatoxin B1 and benzo(a)pyrene were predominantly detected by the CYP3A4 + RAD54 system, while N-nitrosodimethylamine only moderately activated the CYP2B6 + RAD54 reporter system and none of them was identified by the CYP2D6 + RAD54 system. In contrast, the genotoxic carcinogen, methyl methanesulfonate, was detected by all systems. Our yeast-reporter system can be performed in 384-well microplates to provide efficient genotoxicity testing to identify various carcinogenic compounds and reduce chemical consumption to about 53% as compared with existing 96-well genotoxicity bioassays. In association with a liquid handling robot, this platform enables rapid, cost-effective, and high-throughput screening of numerous analytes in a fully automated and continuous manner without the need for user interaction.

Estimating the incidence of malignant mesothelioma in Vietnam: a pilot descriptive cancer registration study.

INTRODUCTION: Global asbestos consumption has shifted toward lower income countries, particularly in the Asian region including Vietnam where asbestos and asbestos-containing products have been imported since the late 1960s. METHODS: This pilot descriptive epidemiological study aimed to provide contemporary estimates of malignant mesothelioma incidence (histological subtype M9050/3; ICD-O-3) by gender and age group as recorded across nine cancer registries in Vietnam. RESULTS: We identified 148 incident cases of malignant mesothelioma during 1987-2013. The majority of cases were recorded in the Hanoi region (n = 93) and were aged 55 years or older (n = 96). DISCUSSION: By carefully reviewing existing cancer registry records in Vietnam, we identified a larger number of malignant mesothelioma cases than previously estimated. We recommend the use of cancer registry data in tracking future asbestos-related disease in Vietnam.

Genotoxicity of chemical compounds identification and assessment by yeast cells transformed with GFP reporter constructs regulated by the PLM2 or DIN7 promoter.

Yeast cells transformed with high-copy number plasmids comprising a green fluorescent protein (GFP)-encoding gene optimized for yeast under the control of the new DIN7 or PLM2 and the established RNR2 and RAD54 promoters were used to assess the genotoxic potential of chemical compounds. The activity of potential DNA-damaging agents was investigated by genotoxicity assays and by OxoPlate assay in the presence of various test compounds. The fluorescence signal generated by GFP in response to DNA damage was related to the different concentrations of analytes and the analyte-dependent GFP synthesis. The use of distinct DNA damage-inducible promoters presents alternative genotoxicity testing strategies by selective induction of promoters in response to DNA damage. The new DIN7 and PLM2 systems show higher sensitivity than the RNR2 and RAD54 systems in detecting 4-nitroquinoline-N-oxide and actinomycin D. Both DIN7 and PLM2 systems are able to detect camptothecin while RNR2 and RAD54 systems are not. Automated laboratory systems with assay performance on 384-well microplates provide for cost-effective high-throughput screening of DNA-damaging agents, reducing compound consumption to about 53% as compared with existing eukaryotic genotoxicity bioassays.

Genome-wide responses to carbonyl electrophiles in Bacillus subtilis: control of the thiol-dependent formaldehyde dehydrogenase AdhA and cysteine proteinase YraA by the MerR-family regulator YraB (AdhR).

Quinones and alpha,beta-unsaturated carbonyls are naturally occurring electrophiles that target cysteine residues via thiol-(S)-alkylation. We analysed the global expression profile of Bacillus subtilis to the toxic carbonyls methylglyoxal (MG) and formaldehyde (FA). Both carbonyl compounds cause a stress response characteristic for thiol-reactive electrophiles as revealed by the induction of the Spx, CtsR, CymR, PerR, ArsR, CzrA, CsoR and SigmaD regulons. MG and FA triggered also a SOS response which indicates DNA damage. Protection against FA is mediated by both the hxlAB operon, encoding the ribulose monophosphate pathway for FA fixation, and a thiol-dependent formaldehyde dehydrogenase (AdhA) and DJ-1/PfpI-family cysteine proteinase (YraA). The adhA-yraA operon and the yraC gene, encoding a gamma-carboxymuconolactone decarboxylase, are positively regulated by the MerR-family regulator, YraB(AdhR). AdhR binds specifically to its target promoters which contain a 7-4-7 inverted repeat (CTTAAAG-N4-CTTTAAG) between the -35 and -10 elements. Activation of adhA-yraA transcription by AdhR requires the conserved Cys52 residue in vivo. We speculate that AdhR is redox-regulated via thiol-(S)-alkylation by aldehydes and that AdhA and YraA are specifically involved in reduction of aldehydes and degradation or repair of damaged thiol-containing proteins respectively.