Abstract

LOPEZ-HEYDECK, Sandra Maricruz; ALONSO-MORALES, Rogelio Alejandro; MENDIETA-ZERON, Hugo  and  VAZQUEZ-CHAGOYAN, Juan Carlos. Porcine reproductive and respiratory syndrome (PRRS): Review. Rev. mex. de cienc. pecuarias [online]. 2015, vol.6, n.1, pp.69-89. ISSN 2448-6698.

The porcine reproductive and respiratory syndrome (PRRS), is a viral disease that is manifested in severe reproductive failure in pregnant sows, lower levels of semen quality in boars, and respiratory problems in pigs of all ages but mainly piglets. Economically it is one of the most important diseases worldwide and is present in the majority of porcine producing countries, where, in most of them, it is still endemic. The PRRS virus (PRRSV) has a high mutation rate, reason why there is great genetic diversity in the North American linage strains (NA PRRSV), and between the NA PRRSV and the European (EU PRRSV) lineages. This affects strain homogeneity and gives few or null cross antigenicity among strains, which is important for a successful vaccine. The modified virus vaccine, is the only commercially available vaccine that provides some level of immunity confidence, but it has shown the possibility to revert to pathogenicity by mutation or recombination with field strains. The commercially available vaccines are only used to diminish the level of impact of the disease. The virus shows the capacity of immune suppression and immune regulation, which allows the virus to extend the viremia period in infected animals. The virus spreads through saliva, trans placental and mammal secretions and with a high probability feces, been the main transmission by direct contact and secondary by infected objects; also shows a posterior selectivity toward a limited lymphoid tissue, this enables it to remain unnoticed until favorable conditions allow the disease to develop into an outbreak or pandemic.

Keywords : Porcine reproductive; respiratory syndrome.