Prevalence Estimation and Genetic Characterization of Porcine Parainfluenza Virus 1 (PPIV-1) in Hungary and the First Report of the Virus in Slovakia

In the last few decades, many new paramyxoviruses have been discovered, causing diverse, mostly respiratory diseases in animals and humans. The porcine parainfluenza virus 1 (PPIV-1, species Porcine respirovirus 1), which has been reported in many countries worldwide, was found in both healthy and clinically ill pigs showing respiratory signs. Here, we report the expected prevalence and genetic diversity of PPIV-1 in Hungarian pig herds and the detection in one Slovakian pig farm, which is the first report of evidence for the presence of the virus in the country. To estimate the prevalence in Hungary 211 oral fluid samples were collected from 23 large-scale swine herds in a systematic way and tested by real-time quantitative RT-PCR. The presence of the virus was detected in 10 of the 23 Hungarian farms (43%) included in our study. One hundred eighty-one nasal swab samples were collected cross-sectionally from three Hungarian and one Slovakian PPIV-1-positive herd and PPIV-1 was most prevalent in 6-week-old pigs on farms located in Hungary and in the 2-week-old pigs on the Slovakian farm. Phylogenetic analysis of three Hungarian and two Slovakian PPIV-1 F-gene sequences showed high-nucleotide identity (>93%) and all belonged to Clade I, together with the other European strains.