Abstract
The study was designed to conduct a sero-epidemiology of Peste Des Petitis Ruminants (PPR) in
sheep in some selected areas of Bangladesh for molecular characterization of its causal agent and
to find out the degree of relationship of F and H genes of the PPRV of sheep with that of other
sheep and goat isolates. For conducting sero-epidemiolgical study blood samples were taken from
a total of 13 selected sheep populated locations. A total of 1033 sheep of two breeds blood samples
were collected. Farms were surveyed and owner and attendant were interviewed with PPR
outbreak report form developed by SAARC regional leading diagnostic laboratory for PPR with
considering the parameters i.e., geographical locations, ecological zones, species, breed, age, sex,
rearing system, vaccination status and antibody status of vaccinated animal and animal recovered
from PPR during the period of October 2014 to March 2017. Serological test was done by
competitive ELISA with PPR ELISA kits. Findings of the sero-epidemiological investigations of
PPR in present study revealed that the overall sero-prevalence of PPR in native sheep was 61.2%.
The sero-prevalence was highest in Chapai Nawabganj, Nawabganj sadar (96.8%) and lowest in
Rajshahi, Godagari (25%). According to ecological zone, highest (88.1%) sero-prevalence was
recorded in old Brahmmaputra river basin. Age wise sero-prevalence was highest in above 1-2
year age and lowest in below 1 year age group. Male sheep showed comparatively higher seroprevalence (68.9%) than that of female (60.1%). Regarding rearing system, highest sero-prevalence
was in farming system of 84.8%. About 88.2% sero-positivity was observed in PPR suspected
recovered sheep compared to vaccinated sheeр (84.1%). Among the nine variables five variables
were found statistically significant for PPR prevalence. For molecular detection of PPRV and
genome sequence of F and H gene of field virus of the study area, a total of 126 nasal swabs were
collected from PPR suspected sick sheep from Dhaka, Mymensingh, Noakhali, Gaibanda, Khulna.
The presence of virus in the field samples were detected by RT-PCR of F gene (448 bp) and H gene
(328 bp). Out of 126 nasal swab samples, 45 (35.7%) samples were found positive for PPRV with
both (F and H) set of primer. PCR product was purified, sequenced and phylogenetic analysis
revealed that Bangladeshi isolate PPR/BD/Savar/Sheep/2017 was grouped in lineage IV. F and H
genes of this isolates were found very close to the isolates of BD/PPR/Netrokona-1/2011 of
Bangladesh; PPRV/RAJ-DHOL-31/2005 of India; PPRV-UP-SHAHJ-18/2004 of India for F gene
and PPRV/Tibet/2010 of China, PPRV/Izatnagar/9 of India, PPRV/China/33/07 of China and
PPRV/Bhopal/03 of India for H gene. These isolates were Chinese and Indian origin. For F gene,
the sequence divergences was ranged from 0.000 to 0.021% within linage IV and similarity varied
from 98.4 to 100%. In case of H gene similar results were also observed in divergence ranged from
0.000 to 0.0087% among linage IV and others and similarity varied from 93.3 to 100% respectively.
The cleavage site motif of the present isolate was compared with different isolates of sheep and
goat. Among the isolates, PPRV-RAJ-DHOL-39/2007 isolates of sheep showed differences in
cleavage motif site of F gene. From the findings of molecular study it can be assumed that the
recent Bangladeshi isolate along with the recent and previous isolates from neighboring countries
are genetically quite similar and are apparently developing into a new sub-lineage within lineage
IV.