Prevalence and seroepidemiology of Haemophilus parasuis in Sichuan province, China

Haemophilus parasuis , the causative agent of Glässer’s disease, has been reported widely, but seldom is known about its epidemiology in Sichuan province, China. The objective was to reveal the prevalence and distribution of H.parasuis in the area. Widely sampling and isolation was performed initially and following serotyping multiplex PCR (serotyping-mPCR) combined with agar gel diffusion (GD) was subjected to these strains. From January 2014 to May 2016, 254 H.parasuis field strains were isolated from 576 pigs with clinical symptoms, for the frequence of 44.10%. Statistically significant differences of infection incidence were found in three age groups and seasons. Serovars 5(25.98%) and 4(23.62%) were the most prevalent and non-typeable isolates accounted for 7.87%. In geographical distribution, serovars 5 and 4 were prepotent in both major two parts of Sichuan province. The results confirmed the compound approach was dependable and revealed the diversity and distribution of serovars in Sichuan province, which was promising to know relevant vaccinal candidates and further prevention.