Prevalence of trichinellosis and cysticercosis in indigenous pigs from ethnic minorities for selected communes in the Central Highlands (Dak Lak)

Traditionally applied free grazing/roaming of pigs is a known risks factor for selected zoonoses such trichinellosis and cysticercosis which have the potential to cause long lasting health problems in affected humans with sporadic complications such as fatal encephalitis. The ban of free grazing in pigs due to recent policy changes may have contributed to a decrease of both zoonoses and consequently making pork from local or wild pigs safer for the consumer. Despite of the ban some farmers might still use free roaming management at least partly for certain age classes of their pigs. Information on the presence of these zoonoses in pigs produced by ethnic groups is lacking or not updated. Therefore, a serological survey was carried out to provide base line information on the presence of cysticercosis and/or trichinellosis in native pigs in selected communes of the Central Highlands as being part of the Cross CRP project “Scoping study to evaluate the potential of integrated indigenous pig systems to improve livelihoods and safe pork consumption for poor ethnic minority smallholders in the Central Highlands of Vietnam”. While the serological sampling was implemented by WASI all laboratory analysis were carried out by NIVR, a research institute with known experience on the diagnosis for both zoonoses in Vietnam. In addition NIVR provided a training on sample collection and storage

Genetic characterization of an H5N1 avian influenza virus from a vaccinated duck flock in Vietnam

This study reports the genetic characterization of a highly pathogenic avian influenza virus subtype H5N1 isolated from a moribund domestic duck in central Vietnam during 2012. In the moribund duck’s flock, within 6 days after vaccination with a commercial H5N1 vaccine (Re-5) to 59-day-old birds, 120 out of 2,000 ducks died. Genetic analysis revealed a substantial number of mutations in the HA gene of the isolate in comparison with the vaccine strains, Re-1 and Re-5. Similar mutations were also found in selected Vietnamese H5N1 strains isolated since 2009. Mutations in the HA gene involved positions at antigenic sites associated with antibody binding and also neutralizing epitopes, with some of the mutations resulting in the modification of N-linked glycosylation of the HA. Those mutations may be related to the escape of virus from antibody binding and the infection of poultry, interpretations which may be confirmed through a reverse genetics approach. The virus also carried an amino acid substitution in the M2, which conferred a reduced susceptibility to amantadine, but no neuraminidase inhibitor resistance markers were found in the viral NA gene. Additional information including vaccination history in the farm and the surrounding area is needed to fully understand the background of this outbreak. Such understanding and expanded monitoring of the H5N1 influenza viruses circulating in Vietnam is an urgent need to provide updated information to improve effective vaccine strain selection and vaccination protocols, aiding disease control, and biosecurity to prevent H5N1 infection in both poultry and humans.Japan Society for the Promotion of Science. Grant-in-Aid for the Bilateral Joint ProjectsHeiwa Nakajima FoundationNational Institute of Allergy and Infectious Diseases (U.S.) (Contract HHSN2662007000010C