title: Observation of risk factors, clinical manifestations and genetic characterization of recent Newcastle Disease Virus outbreak in West Malaysia.
abstract: BACKGROUND
  Newcastle disease virus remains a constant threat in commercial poultry farms despite intensive vaccination programs. Outbreaks attributed to ND can escalate and spread across farms and states contributing to major economic loss in poultry farms.
  
  
  RESULTS
  Phylogenetic analysis in our study showed that eleven of the samples belonged to genotype VIId. All farms were concurrently positive with two immunosuppressive viruses; Infectious Bursal Disease Virus (IBDV) and Marek's Disease Virus (MDV). Amino acid sequence analysis confirmed that eleven of the samples had sequence motifs for velogenic/mesogenic strains; three were lentogenic.
  
  
  CONCLUSIONS
  In conclusion, no new NDV genotype was isolated from the 2011 NDV outbreak. This study suggests that the presence of other immunosuppressive agents such as IBD and MDV could have contributed to the dysfunction of the immune system of the chickens, causing severe NDV outbreaks in 2011. Risk factors related to biosecurity and farm practices appear to have a significant role in the severity of the disease observed in affected farms.
authors: Department of Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia. seetha.jaganathan@rhonema.com.|Asia-Pacific Special Nutrients Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, 46100, Petaling Jaya, Selangor, Malaysia. seetha.jaganathan@rhonema.com.|Vet Food Agro Diagnostic Sdn. Bhd., Lot 18B, Jalan 241, Section 51A, 46100, Petaling Jaya, Selangor, Malaysia. seetha.jaganathan@rhonema.com.
authors: Seetha
authors: S
authors: Jaganathan
authors: Department of Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia. ooi@upm.edu.my.
authors: Peck Toung
authors: PT
authors: Ooi
authors: Department of Biotechnology, Faculty of Biotechnology & Molecular Science, Universiti Putra Malaysia, 43400, UPM, Serdang, Selangor, Malaysia. phanglaiyee@upm.edu.my.
authors: Lai Yee
authors: LY
authors: Phang
authors: Department of Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia. zeenathul@upm.edu.my.
authors: Zeenathul Nazariah Binti
authors: ZN
authors: Allaudin
authors: Rhone Ma Malaysia (M) Sdn Bhd, Lot 18B, Jalan 241, Section 51A, 46100, Petaling Jaya, Selangor, Malaysia. karen.yip@rhonema.com.
authors: Lai Siong
authors: LS
authors: Yip
authors: Rhone Ma Malaysia (M) Sdn Bhd, Lot 18B, Jalan 241, Section 51A, 46100, Petaling Jaya, Selangor, Malaysia. raymond.choo@rhonema.com.
authors: Pow Yoon
authors: PY
authors: Choo
authors: Rhone Ma Malaysia (M) Sdn Bhd, Lot 18B, Jalan 241, Section 51A, 46100, Petaling Jaya, Selangor, Malaysia. bankeong.lim@rhonema.com.
authors: Ban Keong
authors: BK
authors: Lim
authors: Merial S.A.S., Bio R&D, 254, Rue Marcel Merieux, 69007, Lyon, France. stephane.lemiere@merial.com.
authors: Stephane
authors: S
authors: Lemiere
authors: Merial S.A.S., Bio R&D, 254, Rue Marcel Merieux, 69007, Lyon, France. jean-christophe.audonnet@merial.com.
authors: Jean-Christophe
authors: JC
authors: Audonnet
mesh_terms: D000818:Animals; D002645:Chickens; D004196:Disease Outbreaks / Q000662:veterinary*; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D008296:Malaysia / Q000453:epidemiology; D009521:Newcastle Disease / Q000453:epidemiology*; D009522:Newcastle disease virus / Q000235:genetics*; D010802:Phylogeny; D011201:Poultry Diseases / Q000453:epidemiology / Q000821:virology*; D012307:Risk Factors; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D014764:Viral Proteins