Abstract:
Peste des petits ruminants (PPR) is a viral disease which primarily affects small ruminants, causing significant economic losses for the livestock industry,wild ruminantsandcamels.In this study, blood serum (n=1649) from non-vaccinated sheep (n=723), goats (n=658) and camels (n=268) of all ages and sexes werecollectedinacross-sectionalstudyinHail,Bagaa,ShenanandGhazalah.SaudiArabia.The seroprevalece of PPRVwasdeterminedbyNP-epitopesbasedcompetitive ELISA.Theoverallprevalencewas57.1%. Goatshadasignificantlyhigherseroprevalenceof 75.3%comparedto59.4%obtainedfromsheep,whereas 4.5% were positive from camel samples.TheprevalenceofPPRwasincreasingfrom27.9%in2011to77.3%in2016.Seropositivitywashigherinwet seasons(60.9to61.4%) compared to56.7%indryhotseason.Species,yearandlocation appearedtobe havingsignificanteffect(p<0.01)onthefrequencyofcirculatingantibodiesinthestudy.
Clinical investigation was carried out during the suspected outbreaks of PPR/FMD in sheep and goats in Hail from February to May 2016. Saudi Arabia. During the outbreaks 271 (20.6%) died out of 648 (49.3%) of affected animals, the overall morbidity in goats (33.3%) was higher as compared to sheep (12.3%), with a case fatality rate in goats that reached 74.69% in the 2ndoutbreak on April 2016. Affected animals exhibited fever, stomatitis, mucopurulent to bloody nasal/ocular discharges, watery to bloody diarrhea and lameness. The major gross lesions were erosive stomatitis, hemorrhages inlung, liver, abomasum, small and large intestine. PPRV NP was detected in sheep (n=20) and goats (n=18).Anti-PPRV NP was also detected among sheep and goats (n=162) by ELISA, 3ABC-FMDenzyme immunoassay were positive (n=6) when ovine sera were tested.
PPRV-RNA was extracted from suspected animal samples (n=18) and were screened by real time-PCR. Moreover, to assess the phylogenomics, the N gene was amplified and sequenced from sheep and goats (n=12). Nucleotide identity among Hail strains was identified to be 96.2-100%, while identity with previously sequenced Saudi Arabian strains and with reference PPRV retrieved from Gene Bank was found to be 94.1-98% and 81.2-100%, respectively. Phylogenetic analysis revealed that Hail PPRV strains clustered in four separate groups within lineage IV indicating genetic divergence based on N gene. These findings further support the importance of continuous characterization of PPRV strains in small ruminants to support the global eradication plan.
