Molecular Characterization of Peste des Petits Ruminants Viruses From Outbreaks Caused by Unrestricted Movements of Small Ruminants in Pakistan

Abstract

Peste des petits ruminants (PPR) is an endemic disease of small ruminants, and vaccination has been the method of control but outbreaks are continuously occurring in Pakistan. The following study presents a detailed investigation of an outbreak, suspected to be PPR, probably introduced by PPRV-infected sheep and goats from Sindh Province (north-west) to Punjab Province (central) of Pakistan during the flood relief campaign in 2011. A total of 70 serum samples from 28 different flocks were tested with competitive ELISA (H antibodies), which detected 24 (34.2%) samples positive for PPRV antibodies. Nasal swabs and faeces were tested with immunocapture ELISA (N antigen), which detected 18 (25.7%) samples positive for PPRV antigen. The RNA detected positive (n = 28, 40%) using real-time PCR was subjected to conventional PCR for the amplification of the fusion and nucleoprotein genes. Sequencing of both genes and subsequent phylogenetic analysis indicated the grouping of all the sequences to be in lineage IV along with other Asian isolates of PPRV. However, sequences of both genes were divided into two groups within lineage IV. One group of viruses clustered with previously characterized Pakistani isolates, whereas the other group was distinctly clustered with isolates from the Middle East or India. The sequence identity indicated the introduction of at least one population of PPRV from a different source and circulation in the local flocks of small ruminants, which emphasized the need to obtain health clearance certificate before movement of animals. The results of this study provide baseline data for the genetic characterization of different PPRV populations in Pakistan.

Estudio epidemiológico y modelación espacial de peste de pequeños rumiantes (PPR) en el área central de Irán

“…The reported prevalence of PPR in goats at present study was 1.37% and was in opposite with the results higher prevalence reported by Al-Dubaib (26) (13,(19)(20)(21)(22). Aunque puede no haber una variación significativa en las tasas de incidencia de la enfermedad, se ha establecido una mayor mortalidad en los caprinos infectados con PPRV que en ovinos (23).…”

“…Soundararajan et al (18) also showed a higher mortality rate among infected goats than sheep in a large organized farm. However, higher seroprevalence in sheep as compared to goats has been observed in some other studies (13,(19)(20)(21)(22) Although sheep and goats may not vary significantly in qualifications of disease incidence but a higher mortality rate in PPRV infected goats than in sheep has been established (23).…”

Peste des Petits Ruminants Viruses Re-emerging in China, 2013-2014

“…It is widely believed that the spread of PPRVs is closely related to the movement of herds (Balamurugan et al., ; Singh et al., ; Munir et al., ), as is equally plausible in China. In recent years, continued high price of mutton in China led to vigorously developed goats and sheep husbandry.…”

Phylogenetic analysis of peste des petits ruminants virus from outbreaks in Turkey during 2008–2012

“…There was no subdivision among viruses. Munir et al (2013) detected a clear division in 2 groups among sequences of PPR viruses isolated from an outbreak and indicated that the genetic divergence among PPR viruses was slightly higher in the N gene (6.2%) than the F gene (5.2%). The analyses of the N, M, F, and H gene sequences of virulent isolates and vaccine strains of PPR viruses of Indian origin showed considerable sequence homology among lineage IV viruses .…”