The emergence of the infection of subgroup J avian leukosis virus escalated the tumor incidence in commercial Yellow chickens in Southern China in recent years

Authors: LI, HAIJUAN - Guangxi University; WANG, PEIKUN - Guangxi University; LIN, LULU - Guangxi University; SHI, MENGYA - Guangxi University; GU, ZHANMING - Guangxi University; HUANG, TENG - Guangxi University; MO, MEI-LAN - Guangxi University; WEI, TIANCHAO - Guangxi University; Zhang, Huanmin; WEI, PING - Guangxi University

Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/14/2018
Publication Date: 10/19/2018
Publication URL: https://handle.nal.usda.gov/10113/6471022
Citation: Li, H., Wang, P., Lin, L., Shi, M., Gu, Z., Huang, T., Mo, M., Wei, T., Zhang, H., Wei, P. 2018. The emergence of the infection of subgroup J avian leukosis virus escalated the tumor incidence in commercial Yellow chickens in Southern China in recent years. Transboundary and Emerging Diseases. 66(1):312-316. https://doi.org/10.1111/tbed.13023.
DOI: https://doi.org/10.1111/tbed.13023

Interpretive Summary: A total of 81 clinic cases of tumors was collected from commercially local breeds of yellow chickens managed on farms in southern China during year 2010-2017. The suspicious tumor tissue samples were closely examined for common oncogenic avian viruses in cell culture followed by PCR and immunofluorescence analyses. During 2010-2012, Marek's disease virus (MDV) mono-infection was found to be the dominant cases (52.4%, 11/21) followed by co-infection of MDV+ALVs (19.1%, 4/21). Started from year 2013, ALV-J mono-infection became dominant in inducing the tumor cases (83.3%, 5/6, in year 2013). During the last four years (2014-2017), co-infections between ALV-J and MDV as well as between subgroups of ALV caught up (23.4% and 18.5%, respectively), each was right behind the ALV-J incidence (33.3%), and together, surpassed the ALV-J mono-infection incidence. In contrast to the dominant MDV mono-infection cases before year 2013, the emerging ALV-J mono-infection and ALV-J involved co-infections were largely responsible for occurrence of avian virus-induced tumor incidences in the commercially operated local Yellow breeds of chickens in south China. This result indicated that eradication measures against ALV-J on chicken farms, especially on farms with the Yellow chickens, ought to be enhanced to reverse the trend. This is of critical importance not only to control ALV-J infection in the local breeds, but also in imported breeds as well.

Technical Abstract: A total of 81 clinical cases of suspected tumors was submitted to our laboratory from Yellow chicken farms in southern China during the years 2010 through 2017. The tumor-like tissue samples were closely examined for common oncogenic avian viruses in cell culture and further analyzed using polymerase chain reaction (PCR). During 2010-2012, Marek's disease virus (MDV) mono-infection was found to be the dominant cause of the tumor incidences (52.4%, 11/21) followed by co-infection of MDV+ALVs (19.1%, 4/21). Starting from the year 2013 the mono-infection of avian leukosis virus subgroup J (ALV-J) became the dominant agent of the tumor cases (83.3%, 5/6). During the most recent four years (2014-2017), co-infections involving ALV-J and MDV or between ALV subgroups have increased (23.4% and 18.5%, respectively), but each of the co-infections was still slightly lower than the ALV-J mono-infection incidence (33.3%). In contrast to the dominant MDV mono-infection cases before 2013, more recently, the emerging ALV-J mono-infection and ALV-J co-infections were largely responsible for the occurrence of avian virus-induced tumor incidences in the commercial local Yellow breeds of chickens in southern China. These results indicated that eradication measures against ALV on all chicken farms, especially on farms with the Yellow chickens, ought to be enhanced to reverse this trend.