Peste des Petits Ruminants Virus (PPRV) is a morbillivirus that affects goats and sheep, causing widespread epizootics with significant animal productivity loss. The virus is non-segmented, negative-sense RNA-based, and part of the Paramyxoviridae family. Researchers focus on this virus due to its high transmissibility, its host specificity, and its role in transboundary livestock diseases across several continents.
Virus Structure and Genome Organization
The PPRV genome contains ~15,948 nucleotides, encoding six essential structural proteins. These include:
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Nucleoprotein (N) – responsible for encapsidation of the RNA genome.
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Phosphoprotein (P) – assists in polymerase function.
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Matrix protein (M) – maintains virion structure.
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Fusion protein (F) – enables membrane fusion during cell entry.
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Hemagglutinin (H) – critical for host receptor binding.
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Large protein (L) – the catalytic core of the viral RNA-dependent RNA polymerase.
Genome mapping and sequencing resources are available via NCBI GenBank and NCBI Virus Database. These datasets enable the identification of point mutations, deletions, and recombination events critical for lineage classification.
Lineages and Molecular Phylogeny
PPRV is categorized into four major genetic lineages:
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Lineage I – Found in West Africa.
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Lineage II – Historically seen in Nigeria, now observed in broader West Africa.
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Lineage III – Present in East Africa, Sudan, and parts of the Middle East.
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Lineage IV – Predominantly detected in Asia, including China and India.
Phylogenetic data from USDA FADDL support evolutionary studies and origin tracing using F and N gene fragments.
Transmission and Susceptibility
The host range of PPRV is narrow, mostly affecting Caprinae species. Transmission is via:
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Direct contact through respiratory secretions.
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Contaminated feed and water sources.
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Human-assisted movement of animals between herds and markets.
Detailed investigations from the University of California, Davis School of Veterinary Medicine confirm that infected animals release large quantities of virus during the acute phase, increasing environmental contamination risk.
Clinical Signs and Pathology
Infected small ruminants exhibit:
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High internal temperature
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Mucopurulent nasal discharge
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Oral lesions
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Dehydration
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Bronchopneumonia
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Gastrointestinal involvement with watery output
Histopathological analysis available from Cornell University’s Animal Health Diagnostic Center shows lymphoid tissue necrosis, alveolar hemorrhage, and erosive stomatitis.
Global Spread and Regional Dynamics
The spread of PPRV has been tracked across:
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North and Sub-Saharan Africa
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Arabian Peninsula
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South and Southeast Asia
Maps provided by FAO EMPRES-i and outbreak databases from the World Organisation for Animal Health (WOAH) trace disease incursions and viral introductions. Lineage IV has replaced Lineages I and II in several regions, suggesting competitive dominance or increased viral fitness.
Diagnostic Technologies
Detection and identification involve:
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RT-qPCR (targeting N or F gene)
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c-ELISA for antibody detection
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LAMP assays for field-level confirmation
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Lateral flow assays (LFAs) for rapid screening
Protocols are published through USDA National Veterinary Services Laboratories (NVSL) and validated in peer-reviewed databases like PubMed.
Experimental Infections and In Vitro Models
Research laboratories such as Colorado State University Veterinary Diagnostic Laboratory conduct PPRV infection experiments in Vero-SLAM cells. These cells express signaling lymphocyte activation molecule (SLAM), a primary receptor for morbilliviruses.
Animal challenge studies have highlighted differences in virulence between field isolates. Genomic adaptations, such as glycoprotein changes in the F and H genes, influence host-pathogen interaction strength.
Vaccine Development and Field Use
Live attenuated vaccines, especially those based on Nigeria 75/1 and Sungri 96, are effective for long-term protection. The International Livestock Research Institute (ILRI) supports production and delivery of thermostable vaccine formulations for use in regions with limited cold-chain capacity.
Vaccine coverage models developed by University of Florida’s One Health Center indicate that herd immunity above 70% significantly reduces outbreak probability.
Eradication Campaign and Research Coordination
The PPR Global Eradication Programme (PPR-GEP) by FAO and WOAH targets eradication by 2030 through:
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Coordinated mass vaccination
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Movement control
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Epidemiological surveillance
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Cross-border cooperation
Universities like Texas A&M College of Veterinary Medicine contribute training and molecular diagnostic capacity-building under this global framework.
Environmental Stability and Disinfection
PPRV is inactivated by:
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Sunlight
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Drying
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pH extremes
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Detergents (SDS, NP-40)
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Sodium hypochlorite and ethanol
Research from Iowa State University College of Veterinary Medicine confirms that effective biosecurity measures can eliminate virus from fomites and contaminated surfaces within 24–48 hours.
Socio-Economic Dimensions
Small ruminants are critical to pastoral and mixed crop-livestock systems, especially in drylands. PPRV outbreaks reduce meat, milk, fiber yield, and market value of affected animals. Studies from the University of Nairobi Department of Veterinary Services describe significant trade losses due to movement bans.
Field campaigns rely on local veterinary networks trained through collaborations like University of Georgia’s PPR Regional Support Programs.
Genetic Engineering and Future Tools
Advanced approaches for disease control include:
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Recombinant virus vectors for multivalent vaccines.
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CRISPR-based diagnostics under evaluation in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID).
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Portable real-time sequencing using Oxford Nanopore platforms.
The Bioinformatics Resource Center at the J. Craig Venter Institute is actively modeling virus evolution under selective pressure from vaccine-induced immunity.
Conclusion
Peste des Petits Ruminants Virus remains a priority transboundary livestock pathogen due to its potential to devastate entire goat and sheep populations. Researchers, diagnosticians, veterinarians, and field workers must continue collaborative work across national and institutional boundaries. Genomic surveillance, cold-chain resilient vaccines, and molecular diagnostics are essential to achieving the global elimination of PPRV by 2030.
For more technical data, see: