SuMMARyThe excretion and transmission of PRRSV was studied through RT-nPCR in nasal secretion and serum samples, together with detection of antibodies by ELISA. Thirty pigs, of 3 weeks age, were used and they were randomly assigned into 6 groups. One group of pigs (G1) was inoculated intranasally with 2 ml and intramuscularly with 1 ml with the 2402 isolate in a concentration of 10 5.7 TCID50 per ml, and they were kept for 35 days in an isolation unit. Four groups (G2, G3, G4, G5) were used as susceptible and they were in contact with the inoculated pigs (G1). Group 1 showed that the Chilean PRRSV isolated induces a condition of viremia beginning at 3 days post infection (dpi), increasing at 7 dpi , and then declines until 35 dpi (P < 0.1). The virus was detected in the nasal swabs, from 3 dpi, increasing at 7 dpi, and remaining like that until 19 dpi. On the other hand, G2 had a 60% of viremic animals at 5 days post contact (dpc) and then 100% at 12 dpc; G3 showed a 80% of positive pigs at 5 dpc and 100% at 12 dpc; G4 had 100% of viremic pigs at 5 and 12 dpc; and finally, G5 showed only a 60% of positive animals at 12 dpc. The results suggest that the national isolate induces an early viremia and is excreted through nasal secretions; moreover, it induces sero-reaction in presence of viremia. It can be concluded that the national isolate of PRRSV was transmitted from G1 to the contact groups between 3 and 28 dpi, being this transmission more effective between 3 and 21 dpi.Palabras clave: PRRS, PRRSV, transmisión, excreción.

In 2009, a novel swine influenza A virus (IAV) emerged causing a global pandemic that highlighted the role of swine as a reservoir. To date, there is limited information about swine IAV circulating in Latin America. We identified two swine H1N2 and one divergent swine H3N2 viruses that co-circulated in Chilean swine together with the 2009 H1N1 pandemic strain (A(H1N1)pdm09). Phylogenetic analysis revealed several human-to-swine IAV introductions occurring as early as the mid-1980s, and since 2009, several introductions of the A(H1N1)pdm09 strain. Antigenic cartography confirmed that these viruses were antigenically unique and identified drifted variants within the clusters. Human sera from the Chilean general population showed an age-dependent mid to low-level antibody-mediated protection against swine H1N2 and A(H1N1)pdm09-like viruses and poor protection against the swine H3N2 virus, highlighting the zoonotic potential of this strain. Our results underscore the epidemiological importance of studying swine IAV in Latin America for epidemic and pandemic preparedness.