Control Of Peste Des Petits Ruminants Research Articles

First Report of the Emergence of Peste des Petits Ruminants Lineage IV Virus in Senegal.

Peste des petits ruminants (PPR) is a highly contagious viral disease and one of the deadliest affecting wild goats, sheep, and small ruminants; however, goats are generally more sensitive. The causative agent is the Peste des Petits Ruminants virus (PPRV), which is a single-stranded RNA virus of negative polarity belonging to the Paramyxoviridae family. In February 2020, an active outbreak of PPR was reported in a herd of a transhumant farmer in the village of Gainth Pathé (department of Kounguel, Kaffrine region, Senegal). Of the ten swabs collected from the goats, eight returned a positive result through a quantitative real-time PCR. The sample that yielded the strongest signal from the quantitative real-time PCR was further analyzed with a conventional PCR amplification and direct amplicon sequencing. A phylogenetic analysis showed that the sequence of the PPR virus obtained belonged to lineage IV. These results confirm those found in the countries bordering Senegal and reinforce the hypothesis of the importance of animal mobility between these neighboring countries in the control of PPRV. In perspective, following the discovery of this lineage IV in Senegal, a study on its dispersion is underway throughout the national territory. The results that will emerge from this study, associated with detailed data on animal movements and epidemiological data, will provide appropriate and effective information to improve PPR surveillance and control strategies with a view to its eradication.

Progress in vaccines against peste des petits ruminants virus

Peste des petits ruminants (PPR) is a highly contagious and economically important viral disease of both domestic (goats and sheep) and wild small ruminants. Due to the devastating effect of this disease on livestock and livelihoods, the Food and Agriculture Organization of the United Nations (FAO) and the World Organization for Animal Health (WOAH) endorsed the Global Strategy for the Control and Eradication of PPR (PPR GCES) and launched the PPR Global Eradication Programme (PPR GEP) to eradicate PPRV by 2030. In order to achieve this goal, a potent, safe and efficacious live-attenuated PPR vaccine with long-lasting immunity is available for immunoprophylaxis. However, the live-attenuated PPR vaccines are thermolabile and require maintenance of an effective cold chain to deliver to the field. In addition, infected animals cannot be differentiated from vaccinated ones (DIVA). To overcome these limitations, some new generation PPR vaccines have been developed: poxvirus vaccine, positive and negative marker vaccine through reverse genetic approach, chimeric vaccine, anti-idiotypic vaccine, subunit vaccine, virus-like particles vaccine, edible vaccine and combined vaccines. Novel recombinant PPR DIVA vaccines were evaluated in goats for safety and efficacy, and all vaccinated animals were clinically protected against an intranasal PPRV challenge. Furthermore, newly developed ELISAs were capable of differentiating between infected and vaccinated animals. Therefore, these DIVA vaccines and the associated tests can facilitate the serological monitoring process and speed up global PPR eradication through vaccination.

Modeling for Smart Vaccination against Peste des Petits Ruminants (PPR) in the Emirate of Abu Dhabi, United Arab Emirates.

Peste des petits ruminants (PPR) is a contagious and economically important transboundary viral disease of small ruminants. The United Arab Emirates (UAE) national animal health plan aimed to control and eradicate PPR from the country by following the global PPR control and eradication strategy which adopts small ruminants' mass vaccination to eradicate the disease from the globe by 2030. A smart vaccination approach, which is less expensive and has longer-term sustainable benefits, is needed to accelerate the eradication of PPR. In this study, a mathematical algorithm was developed based on animals' identification and registration data, belonging to the Abu Dhabi Agriculture and Food Safety Authority (ADAFSA), and other different parameters related to PPR risk occurrence. The latter included animal holding vaccination history, the number of animals per holding, forecasting of the number of animals and newborns per holding, the proximity of an animal holding to a PPR outbreak and the historical animal holding owner vaccination rejection attitude. The developed algorithm successfully prioritized animal holdings at risk of PPR infection within Abu Dhabi Emirate to be targeted by vaccination. This in turn facilitated the mobilization of field vaccination teams to target specific sheep and goat holdings to ensure the generation of immunity against the disease on a risk-based approach. The vaccination coverage of the targeted livestock population was increased to 86% and the vaccination rejection attitude was reduced by 35%. The duration of the vaccination campaign was reduced to 30 compared to 70 working days and hence can alleviate the depletion of human and logistic resources commonly used in classical mass vaccination campaigns. The results obtained from implementing the algorithm-based PPR vaccination campaign will reduce the negative impact of PPR on the UAE livestock sector and accelerate the achievement of the national PPR eradication plan requirements.

Seroprevalence and risk factors of Peste des petits ruminants in different production systems in Uganda

Peste des petits ruminants (PPR) is a highly contagious and fatal disease of mostly domestic goats and sheep. First reported in Uganda in 2007, the extent of peste des petits ruminants virus (PPRV) exposure, geographical distribution and risk factors of its transmission and spread are not clearly understood. In this study, we used cluster random sampling methodology to select study villages from three districts representing three different production systems along Uganda’s “cattle corridor”. Between October and December 2022, 2520 goat and sheep serum samples were collected from 252 households with no history of PPR vaccination in the past one year. The household heads were interviewed to assess possible risk factors of PPRV transmission using a structured questionnaire. The serum samples were screened with a commercial competitive enzyme-linked immunosorbent assay (cELISA) for PPRV antibodies. The determined overall true seroprevalence of PPRV was 27.3% [95% CI: 25.4–29.1]. The seroprevalence of PPRV antibodies in different production systems was 44.1% [95% CI: 40.6–47.7], 31.7% [95% CI: 28.4–35.0] and 6.1% [95% CI: 4.4–7.9] for pastoral, agropastoral and mixed crop-livestock production systems respectively. A mixed-effects multivariable logistic regression model revealed strong statistical evidence of association between female animals and PPRV antibody seropositivity compared to males [OR= 2.45, 95% CI: 1.7–3.5, p < 0.001]. The likelihood of being PPRV antibody seropositive significantly increased with increasing small ruminant age. Animals older than 3 years were more than three times as likely to be PPRV seropositive compared to animals aged under 1 year [OR= 3.41, 95% CI: 2.39–4.85, p < 0.001]. There was no statistical evidence of association between small ruminant species and PPRV antibody seropositivity (p = 0.423). Village flocks that interacted with neighboring flocks daily during grazing (IRR = 1.59, 95% CI: 1.19–2.13) and watering around swamps (IRR = 1.59, 95% CI: 1.19–2.13) were highly correlated with increased number of PPRV seropositive animals as compared to flocks that were more restricted in grazing and watered around other water sources other than swamps. Flocks from pastoral and agropastoral production systems were more than 10 times more likely to have seropositive animals than mixed crop-livestock flocks. Targeting PPR control interventions (vaccination and livestock movement control) to pastoral and agro-pastoral small ruminant production systems that are very prone to PPR incursions is recommended to prevent PPRV spread to low-risk smallholder mixed crop-livestock production systems.

Ex-ante impact of pest des petits ruminant control on micro and macro socioeconomic indicators in Senegal: A system dynamics modelling approach.

Vaccination is considered as the main tool for the Global Control and Eradication Strategy for peste des petits ruminants (PPR), and the efficacity of the PPR-vaccine in conferring long-life immunity has been established. Despite this, previous studies asserted that vaccination can be expensive and consequently, the effectiveness of disease control may not necessarily translate to overall profit for farmers. Also, the consequences of PPR control on socioeconomic indicators like food and nutrition security at a macro-national level have not been explored thoroughly. Therefore, this study seeks to assess ex-ante the impact of PPR control strategies on farm-level profitability and the socioeconomic consequences concerning food and nutrition security at a national level in Senegal. A bi-level system dynamics model, compartmentalised into five modules consisting of integrated production-epidemiological, economics, disease control, marketing, and policy modules, was developed with the STELLA Architect software, validated, and simulated for 30 years at a weekly timestep. The model was parameterised with data from household surveys from pastoral areas in Northern Senegal and relevant existing data. Nine vaccination scenarios were examined considering different vaccination parameters (vaccination coverage, vaccine wastage, and the provision of government subsidies). The findings indicate that compared to a no-vaccination scenario, all the vaccination scenarios for both 26.5% (actual vaccination coverage) and 70% (expected vaccination coverage) resulted in statistically significant differences in the gross margin earnings and the potential per capita consumption for the supply of mutton and goat meat. At the prevailing vaccination coverage (with or without the provision of government subsidies), farm households will earn an average gross margin of $69.43 (annually) more than without vaccination, and the average per capita consumption for mutton and goat meat will increase by 1.13kg/person/year. When the vaccination coverage is increased to the prescribed threshold for PPR eradication (i.e., 70%), with or without the provision of government subsidies, the average gross margin earnings would be $72.23 annually and the per capita consumption will increase by 1.23kg/person/year compared to the baseline (without vaccination). This study's findings offer an empirical justification for a sustainable approach to PPR eradication. The information on the socioeconomic benefits of vaccination can be promoted via sensitization campaigns to stimulate farmers' uptake of the practice. This study can inform investment in PPR control.

Peste Des Petits Ruminants Screening and Diagnostic Tests in African Wildlife in the Context of Rinderpest Eradication (1994–2007)

Peste des petits ruminants (PPR) virus causes a major disease in domestic and wild small ruminants. Understanding the role of wildlife in PPR virus ecology is important for PPR control and its eradication targeted worldwide in 2030. Developing diagnostic tools that provide reliable data for PPR detection in wildlife will help monitor wild populations for PPR and support the eradication program. We analyze a continental-scale dataset from African free-ranging wild ungulates (n = 2570) collected between 1994 and 2007. A Bayesian model estimated the performance of ELISA tests against PPR and rinderpest and their prevalence in African buffalo. The H- and N-ELISA tests used, not initially developed for wildlife, showed poor sensitivities for the detection of PPR antibodies in African buffalo. The estimations of PPR antibody prevalence derived from the results of these tests for animals presumably not exposed or potentially exposed to PPR were uncertain. Thus, poor performances of these PPR serological tests in wildlife would not allow robust estimations of PPR antibody prevalence in African buffalo and would be extremely speculative in non-buffalo wild ungulate species. We recommend that current and new tests be validated for wildlife hosts to provide sufficient sensitivity and specificity of detection and a diagnostic protocol be developed for PPR wildlife research.

Evaluation of monoclonal antibodies in immunofluorescence assay for rapid quality control of Peste des petits ruminants (PPR) vaccine

Peste des petits ruminants (PPR) is an acute viral disease of small ruminants with morbidity and mortality rates as high as 90 % and 100 % respectively. Vaccination using a homologous live-attenuated vaccine is the main control strategy available in endemic countries, and ensuring the quality of these vaccines is of utmost importance for PPR control. Currently, the quality control test to determine vaccine potency is the time-consuming and subjective tissue culture infectious dose (TCID50) assay involving titration on Vero cell line and reading the cytopathic effect (CPE) using light microscopy. In this study, an indirect immunofluorescent antibody test (IFAT) was evaluated for PPR vaccines potency testing. Accuracy and repeatability of the IFAT were also determined. Six PPR vaccine batches were produced and tested simultaneously by CPE reading and the IFAT. Vero cells were seeded in 96-well plates, and infected with 10-fold serial dilutions of the vaccines. CPEs were read continuously from day 3–14 after infection, and titers expressed in TCID50/ml. From 3–7 days post-infection, cells were fixed, incubated with anti-N and anti-H monoclonal antibodies (mAbs), and stained with a secondary antibody labeled with a fluorescent tag. Fluorescent foci of infection were detected using a fluorescence microscope, and titers were calculated as TCID50/ml. The results indicated that from day 4, the IFAT gave similar results to CPE readings of day 14 (intraclass correlation coefficient, ICC = 0.957, P < 0.0001). This is a three-fold reduction in time and can be used for rapid PPR vaccine potency evaluation. However, there was no difference observed between the results of the two mAbs (ICC = 0.910, P < 0.0001) indicating that both are equally sensitive and rapid. This result indicates that the IFAT may be more suited for potency testing of PPR vaccines as it saves time and minimizes analyst-related variability associated with CPE reading.

Peste des Petits Ruminants (PPR) Vaccination Cost Estimates in Burkina Faso.

Simple SummaryPeste des petits ruminants (PPR) causes high mortality in sheep and goats leading to negative social, cultural, and economic impacts on farmers who keep small ruminants. Since 2019, Burkina Faso has been implementing a national strategy to eliminate PPR. After two years of mass vaccination of small ruminants with significant resources invested, very little is known about the cost of vaccination and how it is distributed along with the different nodes of the vaccine distribution chain. This study aimed to fill this gap to inform decision-making in the allocation of the limited resources that are available. The results show that the cost of vaccination of a small ruminant is XOF 169 (USD 0.3) and XOF 103 (USD 0.18) if the vaccination is carried out by public and private vaccinators, respectively. Field activities and personnel bear the highest cost share. These results will inform a better resource allocation to improve the effectiveness and efficiency of small ruminants vaccination against PPR.Every year the government organizes country-wide vaccination campaigns targeting peste des petits ruminants (PPR) for small ruminants (sheep and goats). Despite the heavy investment in vaccination, no study has either rigorously estimated or described the cost of vaccine delivery. This study aimed to fill this gap by assessing and describing the cost of delivery of vaccines against PPR using the 2020 vaccination campaign data. The microcosting approach based on the World Health Organization (WHO) guidelines to construct comprehensive multiyear plans (cMYP) for human immunization programs was used. The cost data is presented for the public and private vaccine delivery channels separately and analyzed using three approaches considering activity lines, inputs, and nature of cost (fixed versus variable). Results show that the unit cost of vaccinating a sheep or goat is estimated at XOF 169 (USD 0.3) and XOF 103 (USD 0.18) through the public and private channels, respectively. Using the activity line framework, we found that the field activities including charges for vaccinator, cost of vaccination materials, and field transportation account for more than 50% of the vaccination cost. In terms of inputs, the personnel cost is the most significant contributor with 65%. Fixed costs are higher in the public sector with up to 46% compared to the private sector which is estimated to take 26% of the cost. This study informs veterinary services’ investment decision options for a better allocation of resources in implementing PPR and other small ruminant disease control efforts in Burkina Faso and the Sahel.

Peste des Petits Ruminants in Central and Eastern Asia/West Eurasia: Epidemiological Situation and Status of Control and Eradication Activities after the First Phase of the PPR Global Eradication Programme (2017-2021).

Simple SummaryPeste des petits ruminants (PPR) is a highly contagious viral disease of domestic and wild small ruminants. The disease is endemic to large parts of Africa, the Middle East and Asia and causes severe socioeconomic losses, especially in developing countries reliant on small ruminant value chains. Currently, PPR is the only animal disease targeted by the Global Eradication Programme (PPR GEP), which aims to eradicate the disease by 2030. Following the end of the first five-year phase of the PPR GEP, the goal of this review is to provide an update on the status of the eradication progress in one of the nine regions targeted for coordinated action in the PPR Global Control and Eradication Strategy, denominated Central Asia/West Eurasia. In addition to the original nine countries, regional meetings and activities have involved four additional countries based on shared epidemiological features, which are also reviewed here. The considered area spans from Eastern Europe to East Asia and features remarkable variability in terms of both PPR presence and enacted control efforts. The achievements and constraints encountered at regional and national levels are discussed, thus providing useful data for tailoring the next steps of the eradication programme to the peculiarities of the region.Peste des petits ruminants (PPR) is a highly contagious infectious disease of small ruminants caused by peste des petits ruminants virus (PPRV). PPR poses a significant threat to sheep and goat systems in over 65 endemic countries across Africa, the Middle East and Asia. It is also responsible for devastating outbreaks in susceptible wildlife, threatening biodiversity. For these reasons, PPR is the target of the Global Eradication Programme (PPR GEP), launched in 2016, which is aimed at eradicating the disease by 2030. The end of the first five-year phase of the PPR GEP (2017–2021) provides an ideal opportunity to assess the status of the stepwise control and eradication process. This review analyses 13 countries belonging to Eastern Europe, Transcaucasia, and Central and East Asia. Substantial heterogeneity is apparent in terms of PPR presence and control strategies implemented by different countries. Within this region, one country is officially recognised as PPR-free, seven countries have never reported PPR, and two have had no outbreaks in the last five years. Therefore, there is real potential for countries in this region to move forward in a coordinated manner to secure official PPR freedom status and thus reap the trade and socioeconomic benefits of PPR eradication.

Diagnosis and Control of Peste des Petits Ruminants Disease in Small Ruminants: A Review

Peste des Petits Ruminants (PPR) is an acute highly contagious febrile disease of sheep and goats characterized by erosive and necrotizing stomatitis and associated with severe pneumo-enteritis and bronchopneumonia ended by recovery or death. The aim of the present study was to throw light on the diagnosis and control of PPR. Diagnosis of PPR depends on clinical signs, pathological lesions, and specific detection of the viral antigen, viral genome, or specific antibodies by serological tests and nucleic acid-based assays. The most commonly used diagnostic techniques are cell culture isolation, agar gel immunodiffusion, hemagglutination tests, immunocapture ELISA, and competitive ELISA. In addition to the abovementioned techniques, virus neutralization tests and reverse transcriptase PCR are used. Peste des Petits Ruminants is characterized by high fever associated with watery nasal and ocular discharges, mucopurulent stomatitis, and broncho-pneumonia. Moreover, severe bloody diarrhea and the disease associated with high levels of mortality reached up to 90%. The diagnosis of viral diseases is important in determining the control strategies. Therefore, it can be concluded that recent diagnostic tools are urgently needed not only for the diagnosis but also for following-up combating programs and control of viral diseases. Early and rapid complete identification of infectious viral agents in small ruminants as well as in the surrounding environment is recommended for effective control of PPR. The control program depends mainly on vaccination, hygiene and sanitation measures, and effective quarantine measures.

Circulation of Peste des Petits Ruminants Virus Lineage-IV Haplotypes in Pakistan: implication for Control and Eradication

Peste des petits ruminants (PPR), a viral disease of small ruminants, was identified for the first time in Pakistan in 1991. Due to the availability of effective vaccine, FAO and OIE to set target of PPR control and eradication by 2030. The molecular signature of variation in the virus can assist in the control and eradication of a transboundary disease of PPR. In this study, the causative PPR virus was isolated in cell culture from suspected goats and sheep from Punjab, Pakistan. Out of swab samples, 74.2% produced cytopathic effect in cell culture and proceeded for amplification of nucleoprotein gene for genome based sequence comparison. Molecular typing showed that all of them belonged to the PPRV lineage IV. However, within lineage IV, haplotype variation was evident from the sequence analysis giving a clue of virus evolution over time in accordance with the route of disease spread. The isolated PPRVs being closely related to those from the neighboring countries of Dubai, Tajikistan and Iran. This subdivision indicates possible cross-border PPRV influx or efflux of PPRV strains through nomadism or trade from Northern areas (Tajikistan), across the south-western border of Taftan (Iran) and Dubai and other gulf countries. The study proposes joint effort by national and international animal health agencies to control and eradicate the transboundary disease of PPR in the region.

Spatio-temporal cluster analysis and transmission drivers for Peste des Petits Ruminants in Uganda.

Peste des Petits Ruminants (PPR) is a transboundary, highly contagious, and fatal disease of small ruminants. PPR causes global annual economic losses of between USD 1.5 and 2.0 billion across more than 70 affected countries. Despite the commercial availability of effective PPR vaccines, lack of financial and technical commitment to PPR control coupled with a dearth of refined PPR risk profiling data in different endemic countries has perpetuated PPR virus transmission. In Uganda, over the past 5 years, PPR has extended from northeastern Uganda (Karamoja) with sporadic incursions in other districts /regions. To identify disease cluster hotspot trends that would facilitate the design and implementation of PPR risk-based control methods (including vaccination), we employed the space-time cube approach to identify trends in the clustering of outbreaks in neighbouring space-time cells using confirmed PPR outbreak report data (2007-2020). We also used negative binomial and logistic regression models and identified high small ruminant density, extended road length, low annual precipitation and high soil water index as the most important drivers of PPR in Uganda. The study identified (with 90-99% confidence) five PPR disease hotspot trend categories across subregions of Uganda. Diminishing hotspots were identified in the Karamoja region whereas consecutive, sporadic, new and emerging hotspots were identified in central and southwestern districts of Uganda. Inter-district and cross-border small ruminant movement facilitated by longer road stretches and animal comingling precipitate PPR outbreaks as well as PPR virus spread from its initial Karamoja focus to the central and southwestern Uganda. There is therefore urgent need to prioritize considerable vaccination coverage to obtain the required herd immunity among small ruminants in the new hotspot areas to block transmission to further emerging hotspots. Findings of this study provide a basis for more robust timing and prioritization of control measures including vaccination.

Peste des petits ruminants – crucial challenges for the successful disease eradication

Peste des petits ruminants (PPR) is a highly infectious and economically important, viral disease of small ruminants caused by the peste des petits ruminants virus (PPRV), which belongs to the genus Morbilivirus in the family Paramyxoviridae. PPR control is mostly achieved through vaccination and/or slaughter of susceptible animals coupled with clinical or laboratory-based diagnosis. The control and eventual eradication of PPR is now one of the top priorities for the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE). In April 2015, the international community agreed on a global strategy for PPR eradication, setting 2030 as a target date for the elimination of the disease. There is a strong and lasting international consensus to eradicate PPR in order to protect the livelihoods of the world’s poorest populations. There are several crucial challenges to the eradication campaign programme: understanding small ruminant production, facilitating research to support the eradication campaign, improvement of laboratory diagnostics, optimizing vaccine delivery and novel vaccines, improving epidemiological understanding of the virus, defining infection of wildlife and other species, developing better control and animal movement, heightening serological monitoring, understanding socio-economic impact, and garnering funding and political actions.

Peste Des Petits Ruminants in Atypical Hosts and Wildlife: Systematic Review and Meta-Analysis of the Prevalence between 2001 and 2021.

Peste des petits ruminants (PPR) or goat plague is considered a leading, highly contagious, and most lethal infectious viral disease of small ruminants affecting the worldwide livestock economy and international animal trade. Although sheep and goats are the primarily affected, the PPR Virus (PPRV) host range has expanded to other livestock (large ruminants) and wildlife animals over the last few decades, resulting in serious concern to the ongoing PPR global eradication program, which is primarily optimized, designed, and targeted towards accessible sheep and goat population. A systematic review and meta-analysis study was conducted to estimate the prevalence and spill-over infection of PPRV in large ruminants (bovine and camel) and wildlife. Published articles from 2001 to October 2021 on the "PPR" were searched in four electronic databases of PubMed, Scopus, Science direct, and Google Scholars. The articles were then selected using inclusion criteria (detection/prevalence of PPRV in bovine, camel, and wildlife population), exclusion criteria (only sheep or goats, lack of prevalence data, experimental trial, test evaluation, and reviews written in other languages or published before 2001), and the prevalence was estimated by random effect meta-analysis model. In the current study, all published articles belonged to Africa and Asia. The overall pooled prevalence of PPR estimates was 24% (95% CI: 15-33), with 30% in Asia (95% CI: 14-49) and 20% in Africa (95% CI: 11-30). The overall estimated pooled prevalence at an Africa-Asia level in bovine and camel was 13% (95% CI: 8-19), and in wildlife, it was 52% (95% CI: 30-74) with significant heterogeneity (I2 = 97%) in most pooled estimates with a high prevalence in atypical hosts and wildlife across Asia and Africa. Over the last two decades, the host range has increased drastically in the wildlife population, even for prevalent PPR in the unnatural hosts only for a short time, contributing to virus persistence in multi-host systems with an impact on PPR control and eradication program. This observation on the epidemiology of the PPRV in unnatural hosts demands appropriate intervention strategies, particularly at the livestock-wildlife interface.

Peste des Petits Ruminants Virus Infection at the Wildlife-Livestock Interface in the Greater Serengeti Ecosystem, 2015-2019.

Peste des petits ruminants (PPR) is a viral disease of goats and sheep that occurs in Africa, the Middle East and Asia with a severe impact on livelihoods and livestock trade. Many wild artiodactyls are susceptible to PPR virus (PPRV) infection, and some outbreaks have threatened endangered wild populations. The role of wild species in PPRV epidemiology is unclear, which is a knowledge gap for the Global Strategy for the Control and Eradication of PPR. These studies aimed to investigate PPRV infection in wild artiodactyls in the Greater Serengeti and Amboseli ecosystems of Kenya and Tanzania. Out of 132 animals purposively sampled in 2015–2016, 19.7% were PPRV seropositive by ID Screen PPR competition enzyme-linked immunosorbent assay (cELISA; IDvet, France) from the following species: African buffalo, wildebeest, topi, kongoni, Grant’s gazelle, impala, Thomson’s gazelle, warthog and gerenuk, while waterbuck and lesser kudu were seronegative. In 2018–2019, a cross-sectional survey of randomly selected African buffalo and Grant’s gazelle herds was conducted. The weighted estimate of PPRV seroprevalence was 12.0% out of 191 African buffalo and 1.1% out of 139 Grant’s gazelles. All ocular and nasal swabs and faeces were negative by PPRV real-time reverse transcription-polymerase chain reaction (RT-qPCR). Investigations of a PPR-like disease in sheep and goats confirmed PPRV circulation in the area by rapid detection test and/or RT-qPCR. These results demonstrated serological evidence of PPRV infection in wild artiodactyl species at the wildlife–livestock interface in this ecosystem where PPRV is endemic in domestic small ruminants. Exposure to PPRV could be via spillover from infected small ruminants or from transmission between wild animals, while the relatively low seroprevalence suggests that sustained transmission is unlikely. Further studies of other major wild artiodactyls in this ecosystem are required, such as impala, Thomson’s gazelle and wildebeest.

Flock Level Economic Loss Due to Peste Des Petits Ruminants Outbreak in Transhumance Sheep and Goat Population in Himachal Pradesh (India)

Background: Quantification of economic losses due animal diseases like peste-des-petits ruminants (PPR) helps in visualizing the impact of the disease in relational context as well as assist in prioritizing the disease control/eradication options. This study aimed to estimate the farm-level economic losses due to the disease in the state of Himachal Pradesh and carry out a cost-benefit analysis of control programme through vaccination.Methods: An investigation was carried out on an outbreak of PPR in transhumance small ruminant population in Himachal Pradesh (HP). The incidence rates of PPR as obtained in the study were projected to the small ruminant population in the state.Result: The overall morbidity and mortality rates were 36.85% and 27.69% and 25.32% and 1.44%, in goats and sheep, respectively. The estimated annual economic loss due to PPR in HP was INR 2495 million (under high incidence scenario). Under moderate and low incidence rate assumptions, the total losses were estimated at INR 1871 million and INR 1265 million, respectively. Benefit-cost analysis of vaccination against the disease in the state was carried out and the Benefit-Cost Ratios (BCR), ranging between 43:1 to 198:1 revealed the economic feasibility of investment made in PPR control.

Recent advances in the laboratory diagnosis of peste des petits ruminants

Peste des petits ruminants (PPR) is a highly contagious and economically important, viral disease of small ruminants caused by the peste des petits ruminants virus (PPRV), which belongs to the genus Morbilivirus in the family Paramyxoviridae. PPR control is achieved mostly through vaccination and/or slaughter of susceptible animals coupled with clinical or laboratory-based diagnosis. Since clinical signs of PPR are not disease-specific and clinical diagnostics is not reliable, it should be confirmed by laboratory testing. Laboratory confirmation of clinical suspicions is made by detection of PPRV in blood, swabs or post-mortem tissues through classical virus isolation (VI), agar gel immunodiffusion (AGID)/agar gel precipitation test (AGPT), counter-immunoelectrophoresis (CIE), immunoperoxidase test (IPT) or enzyme-linked immunosorbent (ELISA) assays. However, these conventional methods have been superseded by more rapid, sensitive and accurate molecular diagnostic techniques based on the amplification of parts of either nucleocapsid (N) or fusion (F) protein gene, such as RT-PCR, real-time RT-PCR, reverse transcription loop-mediated isothermal amplification (RT-LAMP), reverse transcription recombinase polymerase amplification (RT-RPA) and Oxford nanopore MinION technology. Although these molecular diagnostic assays are accurate, rapid and sensitive, they have to be performed in laboratory settings, and samples must be transported under appropriate conditions from the field to the laboratory, which can delay the confirmation of PPRV infection. The recently developed immunochromatographic lateral flow device (IC-LFD) assay can be used in the field (“pen-side”) without the need for expensive equipment, so a well-established laboratory is not required. The control and eventual eradication of PPR is now one of the top priorities for the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE). In 2015, the international community agreed on a global strategy for PPR eradication, setting 2030 as a target date for elimination of the disease

A Review of the Current Status of Peste des Petits Ruminants Epidemiology in Small Ruminants in Tanzania.

Peste des petits ruminants (PPR) is a highly contagious viral disease of sheep and goats with high mortality. The disease is of considerable economic importance in countries such as Tanzania, where small ruminant products are important for sustainable livelihoods. This review assesses current knowledge regarding the epidemiology of PPRV in Tanzania, highlighting the challenges with respect to control and suggesting possible interventions. Thirty-three articles were identified after literature searches using Google Scholar and PubMed. Studies revealed that PPRV is endemic in sheep and goats in Tanzania, although seropositivity has also been reported in cattle, camels, buffalo, Grant's gazelle, wildebeest and impala, but with no clinical manifestation. Three lineages (lineage II to IV) of PPRV have been identified in Tanzania, implying at least two separate introductions of the virus. Diagnosis of PPR in Tanzania is mostly by observation of clinical signs and lesions at post mortem. Risk factors in Tanzania include age, sex, species, and close contact of animals from different farms/localities. Although there is an efficacious vaccine available for PPR, poor disease surveillance, low vaccine coverage, and uncontrolled animal movements have been the bane of control efforts for PPR in Tanzania. There is need for collaborative efforts to develop interventions to control and eradicate the disease. The establishment of a national reference laboratory for PPR, conduct of surveillance, the development of high-quality DIVA vaccines, as well as execution of a carefully planned national vaccination campaign may be key to the control and subsequent eradication of PPR in Tanzania and achieving the global goal of eradicating PPR by 2030.

Virus-Like Particles Derived From a Virulent Strain of Pest des Petits Ruminants Virus Elicit a More Vigorous Immune Response in Mice and Small Ruminants Than Those From a Vaccine Strain

Peste des petits ruminants (PPRs) is highly contagious, acute or subacute disease of small ruminants caused by peste des petits ruminants virus (PPRV). To date, several studies have designed and evaluated PPRV-like particles (VLPs) as a vaccine candidate for the prevention and control of PPR, with the majority of these VLPs constructed using sequences derived from a PPRV vaccine strain due to its high immunogenicity. However, because of the lack of available genetic material and certain structural proteins and/or the alteration of posttranslational glycosylation modifications, the immunogenicity of VLPs derived from a vaccine strain is not always optimal. In this study, two PPRV VLP candidates, derived from either the lineage IV Tibet/30 virulent strain or the lineage II Nigeria 75/1 vaccine strain, were generated using a baculovirus system through the coexpression of the PPRV matrix (M), hemagglutinin (H), and fusion (F) proteins in the high expression level cell line High Five. These VLPs were then used to immunize mice, goats, and sheep followed by two boosts after primary immunization. Both VLPs were found to induce a potent humoral immune response as demonstrated by the high ratio of immunoglobulin G1 (IgG1) to IgG2a. In all animals, both VLPs induced high titers of virus-neutralizing antibodies (VNAs), as well as H- and F-specific antibodies, with the Tibet/30 VLPs yielding higher antibody titers by comparison to the Nigeria 75/1 VLPs. Studies in mice also demonstrated that the Tibet/30 VLPs induced a more robust interleukin 4 and interferon γ response than the Nigeria 75/1 VLPs. Goats and sheep immunized with both VLPs exhibited a robust humoral and cell-mediated immune response. Furthermore, our results demonstrated that the VLPs derived from the virulent lineage IV Tibet/30 strain were more immunogenic, inducing a more potent and robust humoral and cell-mediated immune response in vaccinated animals by comparison to the lineage II Nigeria 75/1 vaccine strain VLPs. In addition, VNA titers were significantly higher among animals vaccinated with the Tibet/30 VLPs by comparison to the Nigeria 75/1 VLPs. Taken together, these findings suggest that VLPs derived from the virulent lineage IV Tibet/30 strain are more immunogenic by comparison to those derived from the lineage II Nigeria 75/1 vaccine strain and thus represent a promising vaccine candidate for the control and eradication of PPR.

Eradication of peste des petits ruminants: Application of new research to guide and facilitate the global elimination of the disease

Peste des petits ruminants (PPR) is a highly contagious viral disease of domestic and wild small ruminants caused by the peste des petits ruminants virus (PPRV), which belongs to the genus Morbilivirus in the family Paramyxoviridae. The PPRV causes disease in goats and sheep, as well as in wild ruminants, such as gazelle, deer, antelope, Nubian ibex, gemsbok and others. PPR was first recorded in early 1942 in Ivory Coast, West Africa, and spread to around 70 countries in Africa, the Middle East and Asia – regions that are home to over 80% of the world’s sheep and goats. Until 2018, PPR had never been detected in Europe. On 24th June 2018, however, the Bulgarian authorities reported cases of PPR in sheep in the village of Voden, Bolyarovo municipality of Yambol region, on the border with the Thrace region of Turkey. It was the first occurrence of PPR in Bulgaria and in the European Union (EU). The control and eventual eradication of PPR is now one of the top priorities for the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE). In 2015, the international community agreed on a global strategy for PPR eradication, setting 2030 as a target date for elimination of the disease. The aim of this paper was to highlight future research that could be performed to guide and facilitate the PPR eradication programme. Such research includes studies on PPR transmission and epidemiology, as well as the development and application of new-generation PPR vaccines capable of differentiating infected from vaccinated animals (DIVA). Moreover, there is a need for research to improve and adapt existing diagnostic techniques as well as to develop novel PPRV recognition methods, such as a lateral flow device for in-field use, that accelerate decisions about the implementation of control measures.