Virus inmunosupresores en Uruguay: detección de enfermedad de Marek, anemia aviar, enfermedad infecciosa de la bursa y de leucosis aviar en granja de ponedoras

Resumen

Due to the lack of information about the status of chicken immunosuppressive virus in Uruguay, we decided to evaluate the serological status of some virus of interest in the poultry industry. We also used molecular detection to assess the virus’s presence. Two broiler farms and fifteen-layer farms located in Canelones and Montevideo were sampled. Samples of blood (n=46), and tissues (n=46) were collected from birds of different ages. By using indirect ELISA, the infectious bursal disease virus (IBDV) was detected in 80 % and Chicken Infectious Anemia Virus (CIAV) was detected in 71 % of the samples. For Avian Leukosis virus (ALV), it was found that 83 % of birds have the Retrovirus, since it was performed by direct ELISA looking for the ALV P27 protein. For the molecular detection of the viruses, DNA (n= 83) and ARN (n=46) extraction kit (QIAGEN) was used in feather and spleen samples. For qPCR, GPS kits were used for each agent. 19.2 % (16/83) samples were positive for Gallid herpesvirus 2 (MDV), with an average cT of 34.52 (minimum of 27.09 and maximum of 37.27). The feather samples being the most positive. The qPCR for ALV was performed with two kits, one for subtype A (ALV-A dtec-RT-qPCR), and another for subtype B (ALV-B dtec-RT-qPCR). For ALV-B, all samples analyzed were negative (n=46), while for ALV-A, 44/46 samples were positive, with a minimum cT of 14.94 and maximum of 25.77. qPCR for IBDV was performed using the IBDV dtec-RT-qPCR kit. A total of 26/46 samples were positive for IBDV, with a minimum cT of 25.24 and a maximum of 35.02. The results obtained so far indicate the presence and circulation of immunosuppressive viruses in the regions analyzed. Molecular characterization of the MDV, CIAV and ALV are still in progress. Birds are vulnerable to the clinical presence of any other virus or bacterium prevalent in the environment due to the presence and circulation of immunosuppressive viruses. It is important to continue with the diagnostics of these viruses to achieve a better understanding in the dynamic of the infection in Uruguay´s production systems. Financial support: Instituto Nacional de Investigaciones Agropecuarias de Uruguay (INIA), Proyecto FPTA -377.