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• Identification of Causative Agent of Lotus Blight Disease in Thua Thien Hue in 2022

  Ha Viet Cuong, Tran Thi Thu Ha, Le Quy Thao, Huynh Thi Tam Thuy, Le Van Vinh

  Date Received: 02-02-2023 / Date Accepted: 18-04-2023

   Abstract PDF (VIETNAMESE)

  Blight is a destructive disease of Lotus (Nelumbo nucifera) that has emerged in Thua Thien Hue province in recent years. The objective of this study was to identify the etiological agent responsible for the disease. The pathogenicity of microorganisms isolated from diseased Lotus plants was evaluated by inoculating healthy Lotus plants with these isolates. The pathogenic fungus was evaluated for its morphological characteristics on potato dextrose agar (PDA) medium and on pieces of pine needles. Molecular identification of the pathogenic fungus was performed based on the sequencing of three barcode genes, including Internal Transcribed Spacer (ITS), Translation Elongation Factor 1 gene (ef1), and beta-tubulin (tub2). Symptom evaluation of diseased Lotus plants in nature suggested that the pathogen primarily attacked the upper part of the plant. Eight morphologically distinct bacterial and seven fungal isolates were obtained from the typical diseased petioles. Artificial inoculation of all bacterial and fungal isolates on leaf veins and petioles of Lotus plants revealed that only one fungal isolate, designated as N1, was pathogenic to Lotus, producing symptoms resembling those of the diseased plants in the field. Morphological evaluation, including the characteristics of fungal mycelia on PDA medium and the characteristics of conidia, identified the N1 isolate as a member of the genus Lasiodiplodiaof the family Botryosphaeriaceae. Molecular identification identified the N1 isolate as Lasiodiplodia theobromae. To the best of our knowledge, this is the first report in the world and in Vietnam that identifies L. theobromaeas the causative agent of blight disease in Lotus plants.

• Status of Reproductive Diseases and Clinical Treatment of Metritis of Buffalo Cows Raised in The Northern Provinces of Vietnam

  Nguyen Van Thanh, Nguyen Thi Thanh Ha

  Date Received: 18-04-2017 / Date Accepted: 26-07-2017 / Date Published: 12-06-2025

   Abstract PDF (VIETNAMESE)

  ABSTRACT

  DOI: https://doi.org/10.31817/tckhnnvn.2017.15.7.

• Pathology and Histopathology of Vaccinated Chickens Challenged with AnA/H5N1 Avian Influenza Virus

  Nguyen Van Lam, To Long Thanh, Nguyẽn Thị Thúy Mạn, Nguyẽn Dang Thọ, Vũ Dang Dòng

  Date Received: 25-07-2017 / Date Accepted: 15-01-2018

   Abstract PDF (VIETNAMESE)

  To evaluate the pathological changes of chickens vaccinated against avian influenza (AI), then challenged with a virulent AI virus, experiments were conducted using a virulent A/H5N1 virus belonging to clade 2.3.2.1C (A/Ck/Vietnam(KienGiang)/NCVD15A7/2015(H5N1)). After virulent challenge, the dead chickens or chickens surviving until the end of the experiment were examined for macroscopic and microscopic lesions of the visceral organs. The examined specimens were visceral organs and macroscopic and microscopic lesions were examined by thorough necrosy and microscopical examination of HE stained specimens. The chickens were divided into 4 groups: Three experimental groups were vaccinated against AI and unvaccinated chickens as control. Chickens in all 4 groups were intranasally challenged with a virulent virus of 106TCID50/100 ul/animal and monitored for 10 days after challenge. The results showed that all control chickens died before the experiment ended, while 21/30 chickens of 3 experimental groups survived. Macroscopic lesions in chickens of chicken group vaccinated with Navet-vifluvac vaccine were pulmonary edema, congestion and hemorrhage. For chickens of chicken group vaccinated with Re-5 vaccine, in addition to pulmonary edema with swelling, congestion and hemorrhage, there were also hemorrhage in the thigh muscle, neck, intestines and liver. For chickens of chicken group vaccinated with Re-6 vaccine, pulmonary odema and spot haemorrhage were observed. Chickens of control group showed lesions typical for chickens infected with AI viruses. Microscopic lesions in the control chicken were severe and typical of AI. This indicated that unvaccinated chickens, after challenged with a virulent A/H5N1 virus exhibited more severe and typical lesions than vaccinated chickens, then challenged with the virulent virus.

• Status And Impact of Epidemiological Factors on Cassava Mosaic Disease (Begomovirus stanleyi) in Vietnam

  Tran Van Chien, Le Thi Lan Huong, Nguyen Hoang Trung Anh, Nguyen Minh Trang, Trinh Xuan Hoat, Ha Viet Cuong

  Date Received: 23-04-2025 / Date Accepted: 14-08-2025 / Date Published: 28-08-2025

   Abstract PDF (VIETNAMESE)

  Cassava mosaic disease is the most serious disease affecting cassava worldwide and its is caused by at least 11 viruses belonging to the genus Begomovirus. In Vietnam, cassava mosaic disease was first reported in Tay Ninh province in 2017 and rapidly spread throughout the country. The objectives of this study were to assess the status of cassava mosaic disease in major cassava-growing regions, identify epidemiological factors influencing the disease, and confirm its causal agent. Field surveys conducted in 2022 showed that cassava mosaic disease was present in 10 out of 12 surveyed provinces, with an average disease prevalence of 70.4%. The average disease incidence (DI), disease severity index (DSI), and adult whitefly (Bemisia tabaci) density were 75.4%, 2.80, and 2.51 individuals per plant, respectively. Statistical analyses revealed that: (i) cassava variety determined DI, DSI, and whitefly density; (ii) plant age influenced DSI; (iii) plants propagated from infected cuttings had higher DSI than those infected via whiteflies; (iv) adult whitefly density had a slight effect on DI but no effect on DSI. PCR testing of 507 cassava leaf samples and sequencing of 15 virus isolates confirmed that Sri Lankan cassava mosaic virus (Begomovirus stanleyi) was the sole causal agent of cassava mosaic disease in Vietnam at the time of investigation.

  DOI: https://doi.org/10.31817/tckhnnvn.2025.23.8.02

• Pathological characterization and PCR application for diagnosis Edwardsiella ictaluriinfecting Channel catfish (Ictalurus punctatus)

  Truong Dinh Hoai, Kim Van Van, Dao Le Anh, Nguyen Thi Huyen, Nguyen Van Tuyen, Vu Duc Manh, Nguyen Thi Huong Giang, Truong Quang Lam, Nguyen Thi Lan

  Date Received: 28-10-2019 / Date Accepted: 24-02-2020

   Abstract PDF (VIETNAMESE)

  This study was conducted to determine the pathological characteristics and to apply PCR method to diagnose the disease caused by Edwardsiella ictalurifor Channel catfish (Ictalurus punctatus) in Northern provinces of Vietnam. The infected Channel catfish was collected and determined the clinical symptoms,gross features and microscopic lesionsusing through clinical observation and histopathologicalmethods. Subsequently, PCR method was applied to confirmed the pathogen. The results revealedthat the diseased fish exhibited the symptoms of lethargy swimming, mucusin the gills, haemorrhage of gill operculum, fins, anus. The liver and kidneys contained white spots, intestinal walls and epithelial cells were severe haemorrhage. Theevaluation byPCR showed that all affected fish was infected with E.ictaluri. Histopathological examination revealedthat the gill tissue, liver, kidney, and intestines were the most severely damaged organs. Gills exhibited the hyperplasia and hemorrhage, while liver and kidneys are necrosis and loose structure, decreasing cells and severed haemorrhage.

• Study Method Base on Biological Networks for Disease Candidate Gene Prediction

  Vu Thi Luu, Tran Thi Thu Huyen, Nguyen Van Hoang, Nguyen Thi Huyen, Le Duc Hau

  Date Received: 21-12-2016 / Date Accepted: 23-02-2017

   Abstract PDF (VIETNAMESE)

  Predicting genes which may associate with disease is one of the important goals of biomedical research. There have been many computational methods developed to rank genes involved in a particular disease. However, due to the complex relationship between genes and the diseases, many genes that cause genetic diseases have not yet been discovered. The problem of ranking genes to identify the disease-associated gene has drawn attention of many researchers. To find a good method to predict target genes that cause diseases with high performance, we have conducted a survey of prediction methods based on biological network. We then proposed a new method using a Boolean network model. In biological network, defects by mutations on genes/proteins may cause a disease to occurin a person. Also, these mutations may affect other genes/proteins through structures of the biological networks. In this study, we proposed to use Boolean network model to assess the relevance of candidate genes to a disease of interest by measuring the degree of mutational effect from known disease-associated genes to candidate genes. Particularly, we mutated known disease-associated genes and measured the effect of this mutation on candidate genes based on Boolean dynamics of biological networks. Based on this measured value, candidate genes can be prioritized and finally top-ranked candidate genes can be selected as novel promising disease genes. Simulation results on a set of diseases showed that the proposed method is superior to a state-of-the-art one, which is based on a random walk with a restart algorithm. Using the proposed method, we have identified 27 genes associated with breast cancer with evidences from literature.

• A MEGALOCYTIVIRUS INVOLVED IN DARK BODY DISEASE OF CLIMBING PERCH (Anabas testudineus) CULTURED IN VIETNAM

  Dang Thi Lua, Le Thi May, Ikuo Hirono

  Date Received: 28-01-2016 / Date Accepted: 29-03-2016

   Abstract PDF (VIETNAMESE)

  Bệnh đen thân đã và đang được xem là một trong những mối nguy đối với nghề nuôi cá rô đồng thâm canh ở Việt Nam. Bệnh thường xuất hiện ở cá trong giai đoạn từ 20 đến 65 ngày tuổi và tỷ lệ cá chết do bệnh gây ra từ 40 đến 100%. Dấu hiệu bệnh lý điển hình của cá bị bệnh là toàn thân cá chuyển màu đen, gan xuất huyết hoặc chuyển màu nhợt nhạt, ruột không có hoặc có rất ít thức ăn. Bệnh được xác định là có liên quan tới tác nhân vi rút. Kết quả phân tích dưới kính hiển vi điện tử đã phát hiện thấy sự có mặt của các tiểu phần vi rút trong gan và thận của cá bệnh nhưng không phát hiện thấy trong tổ chức não. Vi rút có dạng hình khối đa diện đường kính khoảng 150-160 nm và có vỏ capsid bao quanh. Vi rút cũng có thể nhận biết bằng kỹ thuật PCR khi sử dụng cặp mồi đặc hiệu cho protein MCP của Iriovirus RSIV gây bệnh trên cá tráp đỏ. Kết quả phân tích cây phả hệ dựa trên sự tương đồng của đoạn gen MCP đặc trưng cho nhóm Iridovirus đã xác định được vi rút ở cá rô đồng bị bệnh đen thân thuộc giống Megalocytivirus, họ Iridoviridae và gần gũi với vi rút gây hoại tử thận và lách truyền nhiễm ISKNV. Kết quả nghiên cứu này đã khẳng định sự liên quan của Megalocytivirus đối với bệnh đen thân trên cá rô đồng nuôi thâm canh ở Việt Nam.

• Behaviors of Farmers Towards Pig Diseases in Hung Yen Province

  Nguyen Thi Thu Huyen, Pham Van Hung

  Date Received: 07-12-2015 / Date Accepted: 18-03-2016 / Date Published: 06-08-2025

   Abstract PDF (VIETNAMESE)

  This paper investigates disease situation and responses of farmers to pig diseases in Hung Yen province. Descriptive statistics, classification, comparison, T test and analysis of economic efficiency are utilized. It has been found that some common diseases occur more often at piglet weaning stage in comparison to other growth stages. When common diseases occur, farmers usually treat by themselves. Therefore, training on skills for diagnosis and treatment of common diseases should be offered for farmers. In addition, training to improve skills for local veterinarians should be also implemented because they do not oly sell veterinary drugs to farmers but also give farmers technical advices. Propaganda and regulations to mitigate and prevent the sale of pigs died of diseases should be taken to limit the spread of disease in the local pig herds. In addition, a mass campaign to improve farmers’s disease preventive practices such as pig barn sanitation, vaccination and action to disease occurrence in the household and the commune should also be carried out.

  DOI: https://doi.org/10.31817/tckhnnvn.2016.14.2.

• Studies on Damping-off Diseases Caused by Rhizoctonia solani Kühnof Some Crops in Hanoi, 2011-2012

  Do Tan Dung

  Date Received: 29-05-2013 / Date Accepted: 15-08-2013 / Date Published: 13-06-2025

   Abstract PDF (VIETNAMESE)

  Rhizoctonia solani Kühnis a soil-borne fungus that causes root rot disease on a wide range solanaceous, cucurbitaceous and fabaceous plants such as tomato, soybean, cucumber, yard long bean and groundnut. Field surveys conducted during 2011-2012 in Hanoi showed that the damping-off disease occurred on all host plants in the Hanoi region. However, the disease incidences varied from crop to crop, ranging from 2.8% on tomato, 4.55% on groundnut, 7.6% on cucumber to 7.46% on yard long bean. The morphological, biological studies and particularly pathogenicity tests of five R. solani isolates from five above-mentioned diseased plants showed that all isolates were identical in morphological, biological and pathogenic features. Bio-tests of the R.solani isolates on artificial medium showed that the antagonistic fungus (Trichoderma viride) is effective in controllingl R. solani. In the dual culture test (Petri disks test), the inhibition efficacies of T. viride to two isolates of R. solani isolated from tomato and cucumber were 79.1% and 79.8%, respectively. Potting test, in which plants were grown in sterilized soil in the greenhouse showed that the control efficacies of T. viride to these two R. solani isolates were 73.2% on tomato and 76.2% on cucumber..

  DOI: https://doi.org/10.31817/tckhnnvn.2013.11.4.

• Fusarium Wilt (Fusarium oxysporum f.sp. cubense) on Cavendish Banana in Vietnam

  Tran Ngoc Hung, Do Thi Vinh Hang, Nguyen Duc Huy

  Date Received: 03-02-2020 / Date Accepted: 21-05-2020 / Date Published: 12-06-2025

   Abstract PDF (VIETNAMESE)

  Vietnam, located in the center of origin for banana (Musaspp.), has abundant banana genetic diversity. Panama disease or Fusarium wilt, caused by Fusarium oxysporumf.sp cubense(Foc), is listed as a major disease constraint for stable production of ‘Pisang Awak’ banana nationwide. Until 2013, there were no reports on Foccausing Fusarium wilt disease in ‘Cavendish’ (group AAA) in Vietnam. However, leaf-yellowing symptoms, typical of banana fusarium wilt, were observed on ‘Cavendish’ in the northern part of Vietnam in 2014.The objectiveof this study was to identifyracesof Foccollected from ‘Cavendish’ and ‘Pisang Awak’ in the major banana production areas including Red River Delta, upper mountainous provinces in Northern of Vietnam. Races of Focwere indentified based on morphology, molecular characterization and their pathogenicity. The results of this study showed that Foc tropical race 4 (FocTR4) was found to be on ‘Cavendish’ cultivar, while Foc race 1 (Foc 1)was determined to be on ‘Pisang Awak’ cultivar. This study provides additional scientific information to controlFusariumwiltof banamamore effectively.

  DOI: https://doi.org/10.31817/tckhnnvn.2020.18.5.

• Evaluation of Susceptibility toWitches’ Broom ofLongan Varieties Grownin Mekong Delta

  Tran Thi My Hanh, Nguyen Thanh Hieu, Dao Thi Be Bay, Nguyen Van Hoa, Trinh Xuan Hoat

  Date Received: 16-05-2015 / Date Accepted: 28-07-2016

   Abstract PDF (VIETNAMESE)

  Longan gall mite, Eriophyes dimocarpi,is a vector of longan witches’ broom disease (LWBD). The causal agent of thedisease is very intricate and difficult to control. Management of this disease includes avarietal selection andvector control. The study onmanagement of longan gall mite and LWBD wásconducted at SOFRI and longangrowing areas in the Mekong Deltafrom April 2013 to November 2014. The results showed that Tieu da bo variety of longan was highlysusceptiblewhileEdor, Vung Tau and Thach kiet varieties were susceptibleandXuong com trang, Cui, Long Hung Yen varietiesand NL1-19 hybrid were moderately susceptible. Giong, Sai Gon and NL1-23 hybrid were moderately resistant. Meanwhile, Xuong com vang, Long and Supervarieties were highly resistant to thedisease after 11 months treatment. NL1-23 hybrid was moderately susceptible to this disease after 12months planting.

• Study on the Co-Infections of Several Pathogensin Chickens Having Respiratory Symptoms

  Nguyen Van Giap, Nguyen Thanh Trung, To Nhu Tuong, Truong Ha Thai, Chu Thi Thanh Huong, Dang Huu Anh, Mai Thi Ngan, Tran Thi Huong Giang, Le Van Truong, Vu Thi Ngoc, Cao Thi Bich Phuong, Huynh Thi My Le

  Date Received: 17-04-2023 / Date Accepted: 29-08-2023

   Abstract PDF (VIETNAMESE)

  Respiratory disease complex has emerged as a major challenge for the poultry industry. Pathogens and co-infections in respiratory disease complex such asviruses (AIV, IBV, ILTV, NDV, aMPV) and bacteria/mycoplasma (APG, ORT, APEC, MG) were anattractive research topics worldwide. In Vietnam, the etiology of respiratory diseases has only been noticed in the last few years. Due to its novelty, by molecular biology technique, this study was conducted to detect several pathogens in chickens suffering from respiratory diseases in northern Vietnam. There were 127/157 (80.9%) of the samples positive for at least 1 out of 9 viruses, bacteria/mycoplasma (AIV, IBV, ILTV, NDV, aMPV, APG, ORT, APEC, MG). Of those 127 positive samples, the highest frequency (100/127) was the co-infections between viruses and bacteria. Among 51 co-infection patterns, 41/51 patterns were the co-infection between 2-6 agents.

• Epidemiology Characteristics of Canine Distemper Diseases in Dogs in Hanoi

  Nguyen Thi Huyen, Pham Ngoc Thach, Nguyen Vu Son, Nguyen Huu Nam

  Date Received: 14-03-2019 / Date Accepted: 10-06-2019

   Abstract PDF (VIETNAMESE)

  This study aimedto determine the prevalence of Canine distemper disease in Hanoi as an important information for disease prevention. An epidemiological study on 18244 dogs was conducted in some veterinary clinics in Hanoi from 2013 to 2018. The clinical diagnosiswas based on the specific clinical signs. Treatment and clinical outcome were followed after confirming by CDV Ag test kit.The study found that575 (3,15%) dogswereinfected with Canine distemper virus (CDV) in 14 popular dog breeds with the typiclcal gastrointestinal, respiratory and neurological symptoms. Mong Coc breed hadthe highest positive proportion (6.32%), followed by Becgiebreed (5.56%), Corgi breed (4.28%), Alaska (4.27%). The lowest positive percentage (1.62%) was observed in Rottweiler breed. The infection and successful treatment percentage significantly differred from one year to another (P <0.05). Among age groups, dogsaged 2-6 months old hadthe highest CDV positive rate (60.35%), followed by group of 6-12 months old (15.13%), under 2 months old (12,35%) and lowest in over 12 months old dogs(12.17%). The prevalence of CDV among seasonsof winter, spring and autumn were 39.13%, 35.82% and 11.83%, respectively. The infected CDV dogs also had statistically significant difference in age and season of the year (P <0.05).

• Pathogenesis of Hp-Prrsv in Crossbred Wild Pigs through Experimental Innoculation

  Do Tien Duy, Nguyen Pham Huynh

  Date Received: 23-11-2018 / Date Accepted: 05-03-2019

   Abstract PDF (VIETNAMESE)

  The objective of this study was to examine the pathogenesis of highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) in crossbred-wild pigs through experimentally infected model. Twenty eight healthy crossbred-wild pigs, 42-49 day-old, originated from CSFV-PRRSV-negative farms were allocated in two experimental groups.The findings in clinical signs and pathology showed that the acute phase of infection took place from 5 to 14 days post infection. The major manifestations were fever, anorexia, respiratory failure, eye discharge and swelling, shivering and death. Severe interstitial pneumonia happened in all infected animals and interstitial pneumonia accompanied with hemorrhage recorded in died pigs. The laboratory indicators (viremia in the blood/tissues, IHC score, IgG antibodies, IL-1) were in homology with clinical pathology in acute phase of the disease. There were variations ofthe antigen distribution in various tissues over time-points post infection. This virus was first detected intheepithelial cells of bronchioles, stomach, kidney, bile duct and hepatic cells. The study results demonstrated that HP-PRRSV might cause severe pathology, wide antigenic distribution in visceral organs and could be fatal in crossbred-wild pigs through experimental infection.

• Effectof Salinity onOutbreak of Swollen Siphon Disease in Otter Clam(Lutraria philippinarumReeve, 1854)

  Dang Thi Lua, Pham Thi Yen

  Date Received: 15-03-2018 / Date Accepted: 29-01-2019

   Abstract PDF (VIETNAMESE)

  Swollen siphon disease has been considered to be a serious threat to otter clam farmingin Vietnam; however, the cause of the disease has not been clearly understood. In this study, salinity factor (salinity concentrations of 20‰, 25‰, 30‰, 35‰ and 40‰) was selected for evaluating its impact on the survival and outbreak of the swollen siphon disease in in vivoexperiments. The results showed that the otter clams died at salinity level less than or equal to 25‰and higher or equal to 35‰. However, the dead otter clamsdid not show any clinical signs of the swollen siphon disease. The results of the experiment of otter clam injected with diseased siphon’s filtrates and maintained at different salinity conditions ranking from 20‰to 40‰showedthat the salinity was significantly associated withmortality and outbreak of the swollen siphon diseaseshowing clinical signs. This study indicated that the salinity is not the cause of the swollen siphon disease in otter clam but it may be a risk factor that was significantly associated with the outbreak of the disease, particularly high salinitylevel(higher or equal to 35‰).

• Isolation of Bacteria Caused Hemorrhagic Disease for Catfish (Ictalurus punctatus) in The Northern Parts of Vietnam

  Trinh Thi Trang, Nguyen Thi Dung, Truong Dinh Hoai

  Date Received: 28-02-2017 / Date Accepted: 24-04-2017

   Abstract PDF (VIETNAMESE)

  Cat fish, Ictalurus punctatusis increasingly cultured in the Northern part of Vietnam.However, the diseaseson the fish have not yet studied extensively with limited literature. The study was implemented to isolate pathogenic bacteria causing hemorrhagic disease in catfish and to find out highly effective antibiotics for disease treatment. The result showed that the external signs of the diseases are black skin with lossing mucus and haemorrhagic spots in the head part, fins, and abdomen. The internal signs showed damaged kidney and liquid accumulated abdomen. Thirteen rod shape, gram negative bacterial strains that grew in selected R-S medium were isolated from diseased fish. These strains were identified as Aeromonas hydrophila. Histopathological analysis of hemorrhagic diseased catfish revealed structural changes with slight necroses in muscle and gill filaments. There were many necrotic areas and granulomatous lesions on the liver, kidney and spleen, hydrophytic kidney and spleen tissues. After 2 day period of infection,bacterial strainsCL18, CL20, CL24 and CL26 at 108CFU/fish caused hemorrhagic septicemia in healthy catfish similarly to those in natural infection. Among 7 types of antibiotics, Doxycylin most sensitive with 13 tested isolates. Therefore, the use of Doxycylin on catfish haemorrhagic disease treatment is highly effective.

• Morphological Characteristics and Causes of Blight Disease on Two Lotus Varieties Bach Diep and Hong (Nelumbo nucifera Gaertn.) Grown in My Duc and Chuong My, Hanoi

  Ngo Thi Hong Tuoi, Pham Thi Ngoc, Hoang Dang Dung, Ha Viet Cuong, Doan Thu Thuy

  Date Received: 11-06-2025 / Date Accepted: 17-09-2025 / Date Published: 30-09-2025

   Abstract PDF (VIETNAMESE)

  The study was conducted to evaluate the morphological characteristics and determine the cause of the blight disease of two varieties of lotus, Hong and Bach Diep, in My Duc commune and Chuong My ward - Hanoi. The research method included evaluating morphological characteristics according to UPOV standards (2023), isolating the fungus from diseased lotus samples according to the method of Burgess & cs. (2008), testing artificial infection in pots and mason jars. The results showed that both varieties have pink flowers, showy flowers fragrant, suitable for planting as ornamental plants and cultivation in eco-tourism areas. The Hong lotus variety has single-petal flowers, while the Bach Diep lotus variety has double-petal flowers. The fungus Lasiodiplodia theobromae was identified as the cause of the blight disease on two lotus varieties in My Duc commune and Chuong My ward. Both lotus varieties in the experiment were infected at a very severe level (level 9), with clear diseased leaves, petiole and the plants blighted after 10-14 days. The research results provide a scientific basis for proposing effective disease prevention and control measures. This is an important premise to protect production, preserve the environment and develop lotus growing areas in an ecological and sustainable direction.

  DOI: https://doi.org/10.31817/tckhnnvn.2025.23.9.01

• Production and Application of Fungal Antagonists Trichoderma to Control Some Soil-borne Fungal Diseases of Potato, Ground-nut and Soybean

  Nguyen Van Vien, Nguyen Thi Tu, Bui Van Cong

  Date Received: 04-11-2011 / Date Accepted: 19-02-2012 / Date Published: 13-06-2025

   Abstract PDF (VIETNAMESE)

  The present experiment was conducted to determine the effectiveness of fungal antagonist formulations derived from Trichoderma viride (CP2, CP3 and CP4) in controlling some soil-borne fungal diseases of potato, ground-nut and soybean. The T. viride  was isolated from the soybean soils at Phu Thi – Gia Lam and some other locations.  For potatoes, tuber treatment  with 50 g CP2,  200g CP4 and mixed with 100 kg manures per 10 kg tubers  gave the highest control efficiency against southern blight disease (58.3%),  For soybean, spraying CP3 at a concentration of 15g in 3 litters  per 30 m2 at seedling stage gave good control efficacy after 21 days (75.5% for the damping-off  and 67.7% for the southern blight ). Peanut seed treatment with 5g CP3 or CP2 per kg seeds gave good control of damping-off disease (80,8% and 79.4%, respectively.  In field demonstration plots potato, soybean and peanut yield increased by 9.7% , 12.2 %. and 15.6 %, respectively in comparison with the control.

  DOI: https://doi.org/10.31817/tckhnnvn.2012.10.1.

• ANALYSIS OF SWINE MOVEMENTS IN A PROVINCE IN NORTHERN VIETNAM AND APPLICATION IN THE DESIGN OF SURVEILLANCE STRATEGIES FOR INFECTIOUS DISEASES2

  E. Baudon, G. Fournie, D.T. Hiep, T. T. H. Pham, R. Duboz, M. Ge Ly, M. Peiris, B. J. Cowling, V. D. Ton, M. Peyre

  Date Published: 02-07-2025

   Abstract PDF (VIETNAMESE)

  While swine production is rapidly growing in South-East Asia, the structure of the swine industry and the dynamic of pig movements have not been well-studied. However, this knowledge is a prerequisite for understanding the dynamic of disease transmission in swine populations and designing cost-effective surveillance strategies for infectious diseases. In this study, we assessed the farming and trading practices in the Vietnamese swine familial farming sector, which accounts for most pigs in Vietnam, and for which disease surveillance is a major challenge. Farmers from two communes of a Red River Delta Province (northern Vietnam) were interviewed, along with traders involved in pig transactions. Major differences in the trade structure were observed between the two communes. One commune had mainly transversal trades that is between farms of equivalent sizes, whereas the other had pyramidal trades that is from larger to smaller farms. Companies and large familial farrow-to-finish farms were likely to act as major sources of disease spread through pig sales, demonstrating their importance for disease control. Familial fattening farms with high pig purchases were at greater risk of disease introduction and should be targeted for disease detection as part of a risk-based surveillance. In contrast, many other familial farms were isolated or weakly connected to the swine trade network limiting their relevance for surveillance activities. However, some of these farms used boar hiring for breeding, increasing the risk of disease spread. Most familial farms were slaughtering pigs at the farm or in small local slaughterhouses, making the surveillance at the slaughterhouse inefficient. In terms of spatial distribution of the trades, the results suggested that northern provinces were highly connected and showed some connection with central and southern provinces. These results are useful to develop risk-based surveillance protocols for disease detection in the swine familial sector and to make recommendations for disease control.

  DOI: https://doi.org/10.31817/tckhnnvn.2016.14.10.

• Application of RT-PCRfor Detection of InfectiousbronchitisDisease in Laying Hens in Some Northern Provinces of Vietnam

  Le Van Phan, Nguyen ThiLoan, Le Dinh Quyen, Duong Hong Quan, Le Huynh Thanh Phuong, Nguyen Ba Hien

  Date Received: 23-03-2016 / Date Accepted: 20-09-2016 / Date Published: 13-06-2025

   Abstract PDF (VIETNAMESE)

  Infectious bronchitis (IB) is one of the severe infectious disease causing tremendous economic losses in the poultry industry. In order to have an effective strategy for disease prevention and control, a method for rapid and accurate dectection of infectious bronchitis virus (IBV) is urgently needed. In this study, the tissue samples oflung, trachea and kidney collected from IB-suspected laying hens in three hen farms in Hanoi (Ba Vi District), Thai Nguyen and Bac Ninh have been diagnosed by the RT-PCR method. The diagnostic results showed that 34/71 (47,88%) samples were positive with the IBV.The common clinical signs ofIBV-infected hens included fever, depression, loss ofappetite,dyspnea, coughing, sneezing, tracheal rales, nasal discharge, diarrhea, fluid retention in the abdomen, facial swelling and conjunctivitis. The pathological signs in IBV-infected hensincluded kidney swelling (90%), tracheal hemorrhagea (77.5%), pulmonary hemorrhage and congestion(63,7%), inflammation of airsacculitis (60%) and upper respiratory tract (57,5%). Egg production and quality in IBV-infected laying hensdecreased by 20,7to 43%.

  DOI: https://doi.org/10.31817/tckhnnvn.2016.14.9.

• Biochemical and Haematological Parameters of Female Dogs Infected with Pyometra

  Su Thanh Long, Nguyen Thi Hoa, Vu NhuQuan, Trinh Dinh Thau

  Date Received: 03-07-2017 / Date Accepted: 27-09-2017 / Date Published: 12-06-2025

   Abstract PDF (VIETNAMESE)

  Pyometra is a common reproductive disease in female dogs, which negatively affects the reproductive performance and results in high mortality in the case of delayed diagnosis and treatment. In this study, biochemical and the haematological parameters were assessed in healthy and diseased female dogs. The dogs consisted of two groups, group 1 (control) with 10 healthy dogs and group 2 with 10 pyometra-infected dogs. The results revealed that infected dogs showed a decrease in red blood cell count and haemoglobin and mean corpuscular volume while white blood cell count (neutrophil, lymphocyte and monocyte) increased. In addition, the liver enzyme value like GOT, GPT remained constant in both healthy and diseased dogs but the parameters related to kidney function such as urine and creatine production moderately increased..

  DOI: https://doi.org/10.31817/tckhnnvn.2017.15.7.

• Isolation and Characterization of Lasiodiplodia theobromaeStrain Causing Dieback Disease on Grape in Ha Noi and Hung Yen

  Nguyen Thanh Huyen, Dang Thi Thanh Tam, Do Thuy Hien

  Date Received: 30-08-2023 / Date Accepted: 25-12-2023 / Date Published: 12-06-2025

   Abstract PDF (VIETNAMESE)

  Dieback is one of the most common diseases on grape that is caused by fungi belonging to the Botryosphaeriaceae family. Among these fungi, Lasiodiplodia theobromaehas been identified as the most virulent species. Unfortunately, the current treatments for this disease are still challenging and not truly effective. This study was conducted to determine the causative agent and biological characteristics of the grape dieback-causing fungus in Hanoi and Hung Yen as a basis for guiding effective measures in the prevention and treatment of dieback. From grape samples showing dieback disease collected in Hanoi and Hung Yen, three fungal strains were isolated through culture on the PDA medium and these strains were subsequently re-infected onto leaves and stems of grapes. Among them, CK1 and DN1 strains showed similar mycelial characteristics and pathogenicity. Therefore, the CK1 strain was selected for further experiments. Through the molecular identification method with the ITS1/ITS4 primer pair, the CK1 strain was confirmed asLasiodiplodia theobromae and was named L. theobromae CK1. L. theobromae CK1 exhibited good growth on the PDA medium, and the optimal conditions for the strain were 35C and a pH in the range of 6-8. In addition, during its growth, this fungal strain was also capable of producing cellulase, xylanase, and pectinase.

  DOI: https://doi.org/10.31817/tckhnnvn.2024.22.1.

• Main Pathological Characteristics and Distribution of Classical Swine Fever Virus

  Bui Thi To Nga, Kenji Kawashima, Bui Tran Anh Dao, Makoto Osaki, Nguyen Vu Son, Le Viet Hai, Tong Duc Thanh, Nguyen Thi Lua

  Date Received: 19-04-2023 / Date Accepted: 29-08-2023

   Abstract PDF (VIETNAMESE)

  The aimsof this study wereto investigate the pathological features and tisue tropism of classical swine fever virus (CSFV) in the internal organs of the naturally infected pigs in some provinces inNorth Vietnam. Necropsy was performed on 8 CSFV infected pigs at differentagesto observe the gross lesions, collect specimens for histopathological study and detect viral antigen by immunohistochemistry. The gross findings included haemorrhages, inflamation in lymph system, spleen margin infarction, petechialor diffusehaemorrhages in various organs. The microscopic lesions weremainly hyperemia,haemorrhages, lymphoid deleption, necrotic and vascular cuffing in most internal organs. Immunohistochemical examination revealed thepresent of CSFV antigen in all 12 organs with high virus load in lymph nodes, spleen, lung and kidney. This is the first report about tissue tropisms of CSFV in the infected pigs by using IHC method inNorthVietnam.These results suggested the circulating virus was high virulent and induced acute disease form in the infected herds.

• Automatic Quality Assessment of Potato Tuber Seeds using Computer Vision

  Dang Thi Thuy Huyen, Nguyen Thi Duyen, Ngo Tri Duong, Nguyen Van Dieu

  Date Received: 06-01-2023 / Date Accepted: 27-01-2023

   Abstract PDF (VIETNAMESE)

  This study aimedto design an automaticmodelfor quality assessment of potatotuber seeds by applying computer vision. In the study, a number of sproutsandtuber scab diseases (Actinomyces scabiesand Helminthosporium solani) were selected to evaluate the quality of potatotuber seeds. Apicture of the object was taken by Pi 2/3 camera and sentit to Raspberry Pi 4B embedded computer to process the received image with the YOLO-v4 algorithm. Initially,the model drew conclusions about the quality of the seed potatoes through counting the number of sprouts and identifying scabdiseases on tubers with an average processing time of 0.147 seconds. The rate of accurate identification of the diseaseson infected tubers was 93.33% with Actinomyces scabiesand94.74% with Helminthosporium solani.95.56% of sprouted tubers were counted correctly. This evaluation model can be used in an automatic sorting potato seed tubers before planting.

• Study on some Epidemiological Characteristics of African Swine Fever in Quynh Phu District, Thai Binh Province

  Tran Thi Ha, Truong Ha Thai, Lai Thi Lan Huong, Nguyen Van Giap, Chu Thi Thanh Huong

  Date Received: 20-05-2021 / Date Accepted: 02-07-2021

   Abstract PDF (VIETNAMESE)

  With the aim of studying some epidemiological characteristics of ASF in Vietnam, the study was conducted for the first time in pigs raised in Quynh Phu district, Thai Binh province.In Quynh Phu district, the epidemic started on 26thFeb, 2019 and then spread to the whole district. The average sickness rate of pigs in the district was 32%. In the farms under study, the disease occurred at high rate in small farms (71.43% on average) with the highest rate of 91.95%, while in 33.33% of mediumand large sized farms, the pigs were infected with the lower rate (41.23%). The rate of ASF-infected pigs was in the following order: boar (57.14%), porker (41.95%), sow (40.63%) and piglet (39 , 01%). The symptoms and lesions of ASFinfection were relatively similar among pigs. PCR analysis showed that the virus pre-existed in the farms. Virus sequencing showed that the gene fragment was similar to that of the pathogenic strains in other regions in Vietnam and around the world. In summary, ASF is a dangerous, fast-moving, and acute epidemic with complex epidemiological characteristics in Vietnam. It is essential to conduct research on the disease situation in other localities as well as other provinces in the country to compare the results between different localities to get the best overview of disease.