National Institute of Veterinary Research

Hanoi, Vietnam

National Institute of Veterinary Research

Hanoi, Vietnam
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Imai K.,Obihiro University of Agriculture and Veterinary Medicine | Ogawa H.,Obihiro University of Agriculture and Veterinary Medicine | Bui V.N.,Obihiro University of Agriculture and Veterinary Medicine | Bui V.N.,National Institute of Veterinary Research | And 5 more authors.
Antiviral Research | Year: 2012

The effect of cotton textiles containing Cu 2+ held by zeolites (CuZeo-textile) on the inactivation of H5 subtype viruses was examined. Allantoic fluid (AF) containing a virus (AF virus) (0.1ml) was applied to the textile (3×3-cm), and incubated for a specific period at ambient temperature. After each incubation, 0.9ml of culture medium was added followed by squeezing to recover the virus into the medium. The recovered virus was titrated using Madin-Darby canine kidney (MDCK) cells or 10-day-old embryonated chicken eggs.The highly pathogenic H5N1 and the low pathogenic H5N3 viruses were inactivated on the CuZeo-textile, even after short incubation. The titer of A/chicken/Yamaguchi/7/04 (H5N1) in MDCK cells and in eggs declined by >5.0 log 10 and 5.0log 10, respectively, in 30s. The titer of A/whooper swan/Hokkaido/1/08 (H5N1) in MDCK cells declined by 2.3 and 3.5 in 1 and 5min, respectively. When A/whistling swan/Shimane/499/83 (H5N3) was treated on the CuZeo-textile for 10min, the titer declined by >5.0log 10 in MDCK cells and by >3.5log 10 in eggs. In contrast, no decrease in the titers was observed on cotton textiles containing zeolites alone (Zeo-textile). Neither cytopathic effects nor NP antigens were detected in MDCK cells inoculated with the H5N1 virus treated on the CuZeo-textile. The viral genes (H5, N1, M, and NP) were amplified from the virus treated on the CuZeo-textile by RT-PCR. The hemagglutinating activity of the CuZeo-textile treated virus was unaffected, indicating that virus-receptor interactions were maintained. Electron microscopic analysis revealed a small number of particles with morphological abnormalities in the H5N3 virus samples recovered immediately from the CuZeo-textile, while no particles were detectable in the 10-min treated sample, suggesting the rapid destruction of virions by the Cu 2+ in the CuZeo-textile. The loss of infectivity of H5 viruses could, therefore, be due to the destruction of virions by Cu 2+. Interestingly, CuCl 2 treatment (500 and 5000μM) did not have an antiviral effect on the AF viruses (H5N1 and H5N3) even after 48h of incubation, although the titer of the purified H5N3 virus treated with CuCl 2 declined greatly. The antiviral effect was inhibited by adding the AF to the purified H5N3 virus prior to the CuCl 2 treatment. The known antibacterial/antifungal activities of copper suggest that the CuZeo-textile can be applied at a high level of hygiene in both animals and humans. © 2011 Elsevier B.V..

Schou T.W.,Copenhagen University | Permin A.,Copenhagen University | Christensen J.P.,Copenhagen University | Cu H.P.,National Institute of Veterinary Research | Juul-Madsen H.R.,University of Aarhus
Comparative Immunology, Microbiology and Infectious Diseases | Year: 2010

The present study is the first demonstration of an association of the genetic serum Mannan-binding lectin (MBL) concentration with bacterial infections in chickens. The genetic serum MBL concentration was determined in two chicken breeds, and the association with the specific Pasteurella multocida humoral immune response during an experimental infection was examined. Furthermore, we examined the association of the genetic serum MBL concentration with systemic infection. The chickens with systemic infection had a statistically significant lower mean serum MBL concentration than the rest of the chickens, suggesting that MBL plays an important role against P. multocida. A statistically significant negative correlation was found between the specific antibody response and the genetic serum MBL concentration for both breeds. This indicates that MBL in chickens is capable of acting as the first line of defence against P. multocida by diminishing the infection before the adaptive immune response takes over. © 2008 Elsevier Ltd.

Leta S.,Adami Tullu Research Center | Dao T.H.T.,National Institute of Veterinary Research | Mesele F.,Adami Tullu Research Center | Alemayehu G.,Semera University
PLoS Neglected Tropical Diseases | Year: 2014

Visceral leishmaniasis (also known as kala-azar) is classified as one of the most neglected tropical diseases. It is becoming a growing health problem in Ethiopia, with endemic areas that are continually spreading. The annual burden of visceral leishmaniasis (VL) in Ethiopia is estimated to be between 4,500 and 5,000 cases, and the population at risk is more than 3.2 million. There has been a change in the epidemiology of VL in Ethiopia. Over the last decades, almost all cases and outbreaks of VL were reported from arid and semi-arid parts of the country; however, recent reports indicated the introduction of this disease into the highlands. Migration of labourers to and from endemic areas, climatic and environmental changes, and impaired immunity due to HIV/AIDS and malnutrition resulted in the change of VL epidemiology. HIV spurs the spread of VL by increasing the risk of progression from asymptomatic infection towards full VL. Conversely, VL accelerates the onset of AIDS. In Ethiopia, VL epidemiology remains complex because of the diversity of risk factors involved, and its control is becoming an increasing challenge. This paper reviews the changes in epidemiology of VL in Ethiopia and discusses some of the possible explanations for these changes. The prospects for novel approaches to VL control are discussed, as are the current and future challenges facing Ethiopia's public health development program. © 2014 Leta et al.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: KBBE-2007-1-3-05 | Award Amount: 3.98M | Year: 2008

African swine fever (ASF) in EU member states is currently confined to Italy (Sardinia), it was recently introduced to Caucasian regions and it is highly prevalent in sub-Saharan African countries. In both the EC and Africa changes in the epidemiology of the disease have recently been observed, related to newly emerging strains of ASFV, emphasising the serious threat this disease represents to the growing pig farming sector in Africa and Europe. This project will provide new tools and strategies for the control of ASF in Africa and reduce the risk of importation and/or spread of the disease in EU member states The project will evaluate the current ASF epidemiology in Africa, develop and validate a generic risk assessment for the introduction of ASF into EU countries and subsequent control strategies. The project will also develop and validate new antibody and nucleic acid-based diagnostic tools for ASF, including front line and pen-side tests, which will be supplied to diagnostic facilities in Africa and the Animal Health Laboratories in the EU for the early detection of potential ASFV incursions, in particular by the newly emerging strains. Additionally the project will study the interaction of ASFV and host genes following experimental infection with a view to obtaining attenuated recombinant virus strains that may be potential future candidates for a vaccine and the characterization of pig immune mechanisms relevant for survival following infection with ASFV. The new strategies and the tools developed within this project will be transferred to African partners, and other interested countries, and established in these countries through local training/workshops and technology transfer.

Clausen J.H.,Copenhagen University | Madsen H.,Copenhagen University | Murrell K.D.,Copenhagen University | Van P.T.,Research Institute For Aquaculture No1 | And 5 more authors.
Emerging Infectious Diseases | Year: 2012

Worldwide, >18 million persons were infected with fish-borne zoonotic trematodes in 2002. To evaluate the effectiveness of interventions for reducing prevalence and intensity of fish-borne zoonotic trematode infections in juvenile fish, we compared transmission rates at nurseries in the Red River Delta, northern Vietnam. Rates were significantly lower for nurseries that reduced snail populations and trematode egg contamination in ponds than for nurseries that did not. These interventions can be used in the development of programs for sustained control of zoonotic trematodes in farmed fish.

Guarino A.,University of Naples Federico II | Dupont C.,University of Paris Descartes | Gorelov A.V.,University College Dublin | Gottrand F.,Center Hospitalier University | And 5 more authors.
Expert Opinion on Pharmacotherapy | Year: 2012

Introduction: Acute diarrhea remains a major problem in children and is associated with substantial morbidity, mortality and costs. While vaccination against rotavirus could reduce the burden of the disease, the persistent impact of intestinal infections requires effective treatment in adjunct to oral rehydration solutions, to reduce the severity and duration of diarrhea. Several therapeutic options have been proposed for acute diarrhea, but proof of efficacy is available for few of them, including zinc, diosmectite, selected probiotics and racecadotril. However, at present there is no universal drug, and therapeutic efficacy has only been shown for selected drugs in selected settings, such as: outpatients/inpatients, developed/developing countries and viral/bacterial etiology. Areas covered: This narrative review reports the opinions of experts from different countries of the world who have discussed strategies to improve the management of diarrhea. Expert opinion: More data are needed to optimize the management of diarrhea and highlight the research priorities at a global level; such priorities include improved recommendations on oral rehydration solution composition, and the reevaluation of therapeutic options in the light of new trials. Therapeutic strategies need to be assessed in different settings, and pharmacoeconomic analyses based on country-specific data are needed. Transfer to clinical practice should result from the implementation of guidelines tailored at a local level, with an eye on costs.

Dang S.T.T.,Copenhagen University | Petersen A.,Statens Serum Institute | Van Truong D.,National Institute of Veterinary Research | Chu H.T.T.,Hanoi University | Dalsgaard A.,Copenhagen University
Applied and Environmental Microbiology | Year: 2011

Integrated livestock-fish aquaculture utilizes animal excreta, urine, and feed leftovers as pond fertilizers to enhance the growth of plankton and other microorganisms eaten by the fish. However, antimicrobial-resistant bacteria may be transferred and develop in the pond due to selective pressure from antimicrobials present in animal feed, urine, and feces. In an experimental pig-fish farm located in periurban Hanoi, Vietnam, nine piglets were provided feed containing 5 μg of tetracycline (TET)/kg pig weight/day and 0.45 μg of enrofloxacin (ENR)/kg pig weight/day during the second and fourth (last) months of the experiment. The aim of this study was to determine the association between the provision of pig feed with antimicrobials and the development of antimicrobial resistance, as measured in a total of 520 Escherichia coli and 634 Enterococcus strains isolated from pig manure and water-sediment pond samples. MIC values for nalidixic acid (NAL) and ENR showed that E. coli and Enterococcus spp. overall exhibited significant higher frequencies of resistance toward NAL and ENR during the 2 months when pigs were administered feed with antimicrobials, with frequencies reaching 60 to 80% in both water-sediment and manure samples. TET resistance for both indicators was high (>80%) throughout the study period, which indicates that TET-resistant E. coli and Enterococcus spp. were present in the piglets before the initiation of the experiment. PCR-based identification showed similar relative occurrences of Enterococcus faecium, Enterococcus faecalis, and other Enterococcus spp. in the water-sediment and manure samples, suggesting that Enterococcus spp. isolated in the ponds originated mainly from the pig manure. The development of antimicrobial resistance in integrated animal husbandry-fish farms and possible transfers and the impact of such resistance on food safety and human health should be further assessed. © 2011, American Society for Microbiology.

Sindberg D.,Copenhagen University | Nissen S.,Copenhagen University | Anh N.T.L.,National Institute of Veterinary Research | Johansen M.V.,Copenhagen University
Veterinary Parasitology | Year: 2013

The study was conducted to evaluate copro-diagnostic techniques for detection of small trematode eggs in dogs. FLOTAC, a novel flotation technique, and DBL, a sieving and sedimentation technique developed at the former Danish Bilharziasis Laboratory (DBL), were compared using 53 subsamples from four copro-positive dogs. Moreover, a modified version of the DBL technique and the Kato-Katz (KK) thick smear were later compared using faecal samples from 21 dogs. The four techniques were pair-wise compared regarding sensitivity, infection intensity and practical applicability. For the former two techniques, egg recovery subsequent to storage and reproducibility were also compared. The DBL technique detected all 53 subsamples positive for small trematode eggs. Based on 17 subsamples, mean infection intensity of 47. ±. 49 eggs per gram of faeces (EPG) was detected by the technique. Due to large amount of sediment, examination of a single subsample required an average of 3. hours. The FLOTAC technique was found less sensitive (82%) than the DBL technique and recovered significantly less eggs (4. ±. 6 EPG). Both sensitivity and intensity were further reduced following storage. As the FLOTAC technique requires specialised equipment, safety disposal and personal protective equipment, it was found less suited than the DBL technique for a basic laboratory. Additionally, poor reproducibilities were found for both the DBL and FLOTAC techniques (30. ±. 15% and 38. ±. 33%, respectively). Based on the 21 faecal samples, the modified version of the DBL technique was found more sensitive (85%) than the KK technique (68%), whereas egg counts were significantly higher for the latter (23. ±. 26 EPG vs. 482. ±. 909 EPG). By modifying the DBL technique, it was possible to diminish the retained sediment and examination time to a maximum of an hour, which was also the time required by the KK technique, although the latter was faster and more easily processed. Based on the results obtained in this study, none of the techniques evaluated were found applicable in their current form for detection of small trematode eggs in faeces from dogs in Vietnam. © 2013 Elsevier B.V.

Huong L.Q.,Copenhagen University | Madsen H.,Copenhagen University | Anh L.X.,Hue Universities of Agriculture and Forestry | Ngoc P.T.,National Institute of Veterinary Research | Dalsgaard A.,Copenhagen University
Science of the Total Environment | Year: 2014

Biogas digesters are widely promoted and increasingly used to treat and generate gas from pig slurry worldwide. The objective of this study was to describe manure management practices with focus on biogas digestion among small scale pig farmers in Hue (50 farmers) and Hanoi (96 farmers) and to assess fecal contamination levels in biogas effluent. Results showed that 84% of the farmers in Hanoi and 42% in Hue used both pig slurry and human excreta for biogas production. Biogas digestion only reduced E. coli concentrations by 1 to 2 log units to 3.70±0.84 Escherichia coli (log10) cfu/ml on average in effluent as compared with raw slurry. Biogas effluent was commonly used to fertilize vegetables or discharged directly into the garden or aquatic recipients. Reduced problems with bad smells and flies were reported as main reasons for establishing a biogas digester. Further studies are needed to assess human and animal health hazards associated with the discharge and use of biogas effluent from small-scale biogas systems. © 2013 Elsevier B.V.

Oanh T.K.N.,Bioscience Technology | Oanh T.K.N.,National Center for Veterinary Diagnosis | Nguyen V.K.,National Institute of Veterinary Research | De Greve H.,Vrije Universiteit Brussel | Goddeeris B.M.,Bioscience Technology
Infection and Immunity | Year: 2012

Edema disease (ED) in piglets is caused by Shiga toxin Stx2e-producing Escherichia coli. We show that a genetically disarmed Stx2e toxoid is a safe antigen that generates antiserum protecting piglets against the Stx2e toxin. Immunization of suckling piglets with the Stx2e toxoid was safe, had no adverse effects on growth of the piglets, and resulted in effective prevention of edema disease clinical symptoms after challenge with the Stx2e toxin. Our data showed that maternal immunity against the Stx2e toxoid can be transmitted from the vaccinated sows to the piglets via the colostrum. Very high levels of Stx2e-specific serum antibodies persisted in these piglets until 1 month postweaning, bridging the critical period in which the weaned piglets are most susceptible to edema infection. Challenge with Stx2e toxin resulted in clinical signs of edema disease and death of all control piglets from nonimmunized sows, whereas none of the piglets from immunized sows developed clinical signs of ED. © 2012, American Society for Microbiology.

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