Quantifying Levels of Peste Des Petits Ruminants (PPR) Virus in Excretions from Experimentally Infected Goats and Its Importance for Nascent PPR Eradication Programme.

Satya Parida,A Banyard,Mana Mahapatra,M Selvaraj,R Pope,S Gubbins

doi:10.3390/v11030249

Satya Parida, A Banyard + Show 4 more

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https://doi.org/10.3390/v11030249

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Journal: Viruses	Publication Date: Mar 12, 2019
Citations: 24	License type: CC BY 4.0

Affiliation: The Pirbright Institute, Animal and Plant Health Agency

Abstract

Following the successful eradication of rinderpest, the World Organization of Animal Health (OIE) and the Food and Agriculture Organisation (FAO) have set a goal to globally eradicate Peste des petits ruminants (PPR) by 2030. To support the eradication programme we have quantified the levels of PPR virus (PPRV) nucleic acid excreted in body fluids (blood, feces, saliva, nasal and eye swabs) of PPRV-infected goats to ascertain which days post-infection animals are potentially infectious, and hence direct quarantine activities. The data will also indicate optimal sample strategies to assess presence of PPR infection in the naturally infected herd. Peak PPRV nucleic acid detection in different bodily fluids was between 5 and 10 days post-infection. As such, this period must be considered the most infectious period for contact transmission, although high viral load was observed through RNA detection in nasal excretions from two days post-infection until at least two weeks post-infection. Percentage sample positivity was low both in eye swabs and saliva samples during the early stage of infection although RNA was detected as late as two weeks post-infection. From the individual animal data, PPRV was detected later post-infection in fecal material than in other body fluids and the detection was intermittent. The results from this study indicate that nasal swabs are the most appropriate to sample when considering molecular diagnosis of PPRV.

Highlights

Peste des petits ruminants (PPR), places a huge disease burden on agriculture across the developing world, in particular affecting small ruminant production and in turn increasing poverty in many developing countries [1,2]
Evidence for a number of other novel morbilliviruses has been reported in bats and rodents, live virus has not been isolated to date [7]
Animals developed a pronounced leucopenia, post-challenge, with leucocyte counts reaching as low as ~4000 leucocytes/mm3 of blood by 7 dpc for Lineage IV (Morocco strain) and 9 dpc for Lineage II PPR virus (PPRV) (Ghana strain), with a gradual recovery in leucocyte numbers observed after this point for those not terminated according to the clinical score sheet (Figure 1c)

Summary

Introduction

Peste des petits ruminants (PPR), places a huge disease burden on agriculture across the developing world, in particular affecting small ruminant production and in turn increasing poverty in many developing countries [1,2]. PPRV has a non-segmented single-stranded negative sense RNA genome that contains six contiguous, non-overlapping transcription units that encode six structural proteins: the nucleocapsid protein (N); the phosphoprotein (P); the matrix protein (M); the fusion protein (F); the haemagglutinin protein (H) and the large (L) polymerase protein and Viruses 2019, 11, 249; doi:10.3390/v11030249 www.mdpi.com/journal/viruses. Viruses 2019, 11, 249 two non-structural proteins (V and C protein) that are encoded from the P-gene transcription unit using overlapping open reading frames (ORFs) and co-transcriptional editing to access the third ORF to generate C [8]. PPR was long considered to be confined to West Africa but later it was described throughout Africa (except some southern African countries) from south of the Sahara to north of the Equator, as well as in the Middle

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