Serological Investigation of Peste Des Petits Ruminants in East Shewa and Arsi Zones, Oromia Region, Ethiopia

Recapitulation of Peste des Petits Ruminants (PPR) Prevalence in Small Ruminant Populations of Pakistan from 2004 to 2023: A Systematic Review and Meta-Analysis

Peste des petits ruminants (PPR) is an extremely transmissible viral disease caused by the PPR virus that impacts domestic small ruminants, namely sheep and goats. This study aimed to employ a methodical approach to evaluate the regional occurrence of PPR in small ruminants in Pakistan and the contributing factors that influence its prevalence. A thorough search was performed in various databases to identify published research articles between January 2004 and August 2023 on PPR in small ruminants in Pakistan. Articles were chosen based on specific inclusion and exclusion criteria. A total of 25 articles were selected from 1275 studies gathered from different databases. The overall pooled prevalence in Pakistan was calculated to be 51% (95% CI: 42-60), with heterogeneity I2 = 100%, τ2 = 0.0495, and p = 0. The data were summarized based on the division into five regions: Punjab, Baluchistan, KPK, Sindh, and GB and AJK. Among these, the pooled prevalence of PPR in Sindh was 61% (95% CI: 46-75), I2 = 100%, τ2 = 0.0485, and p = 0, while in KPK, it was 44% (95% CI: 26-63), I2 = 99%, τ2 = 0.0506, and p < 0.01. However, the prevalence of PPR in Baluchistan and Punjab was almost the same. Raising awareness, proper surveillance, and application of appropriate quarantine measures interprovincially and across borders must be maintained to contain the disease.

Sero-Prevalence and Associated Risk Factors of Peste Des Petits Ruminants in Dera and Gerar Jarso Districts of Oromia Region, Ethiopia

Introduction

Peste des petits ruminants is a transboundary disease of major economic importance and imposes significant constraints on small ruminant production.

Methods

A cross-sectional study was employed in Dera and Gerar Jarso districts of the North Shewa zone, Oromia Region from February 2021 to March 2022, to estimate the antibody of PPRV and assess the associated risk factors. Blood samples (n = 662) were collected from sheep and goats. Cluster sampling strategy was employed to collect the data. Villages/Kebeles and individual small ruminants were randomly selected, while households were designated using a systematic random sampling method.

Results

An overall individual animal and flock level sero-prevalence was 10.3% (95% CI = 8.2-12.8) and 100% (95% CI = 96.3-100), respectively, from the c-ELISA test result. A sero-prevalence of 11.2% (95% CI = 8.7-14.4) in Dera and 8% (95% CI = 5-12.7) in Gerar Jarso districts was recorded.

Discussion

Flock size, age, sex, communal grazing, and watering system, new small ruminant introduction into a flock, and mixed rearing were significantly associated with PPR sero-positivity in sheep and goats. The chance of PPR occurrence in goats was 4 times (OR = 4; P = 0.000) more than sheep. Female sheep and goats were more likely to be sero-positive to PPR by 3 times (OR = 3.2; P = 0.003) than males. The newly introduced small ruminants had 4 times more odds (OR = 4.4; P = 0.000) of sero-positivity than animals being born at home. Small ruminants kept under communal grazing and watering system were nearly 12 times (OR = 11.5; P = 0.024) more likely sero-positive than privately managed small ruminants. Likewise, sheep and goats reared together were almost 9 times (OR = 9.4; P = 0.000) a higher chance of being sero-positive compared with separately reared small ruminants.

Conclusion

The finding of PPR virus antibodies in small ruminants from all study areas indicates endemic circulation of the virus. The implementation of regular vaccination could minimize the occurrence of PPR.

Prevalence, Risk Factors for Exposure, and Socio-Economic Impact of Peste Des Petits Ruminants in Karenga District, Karamoja Region, Uganda

Peste des petits ruminants (PPR), a disease caused by small ruminant morbillivirus (SRM), is highly contagious with high morbidity and mortality. Controlling PPR requires a proper understanding of the epidemiological dynamics and impact of the disease in a range of geographical areas and management systems. Karenga district, located in the pastoral region of Karamoja in northeastern Uganda, and in the vicinity of Kidepo Valley National Park, is characterised by free cross-border (South Sudan and Kenya) livestock trade, communal grazing, and transhumance. This study was conducted from November through December 2020 to determine the seroprevalence of anti-SRM antibodies, the risk factors associated with the occurrence, and the socio-economic impact of PPR in Karenga. A total of 22 kraals were randomly selected from all administrative units, and 684 small ruminants (sheep = 115, goats = 569) were selected for serum collection using systematic random sampling. Exposure to SRM was determined using a competitive enzyme-linked immunosorbent assay. The overall true seroprevalence of SRM antibodies was high, 51.4 (95% confidence interval [CI] 45–52.6). Multivariate logistic regression for risk factors showed that seroprevalence varied significantly by location (26.8% to 87.8%, odds ratio (OR) ≤ 14.5). The odds of exposure to SRM were higher in sheep (73.9%) than in goats (43.8%) (OR = 1.7, p = 0.08), and seropositivity was higher in animals greater than two years old (65.5%; OR = 11.1, p < 0.001), or those one to two years old (24.7%; OR = 1.6, p = 0.2), compared to small ruminants less than one year old (16.1%). Using participatory epidemiology approaches (semi-structured interviews, clinical examinations, pairwise ranking, proportional piling, impact matrix scoring) with 15 key informants and 22 focus groups of pastoralists, PPR was the second most important small ruminant disease: relative morbidity 14%, relative mortality 9%, and case fatality rate 78%, and impacted productivity mainly in terms of treatment costs, mortality, marketability, and conflicts. These findings provide evidence to support the implementation of disease surveillance and control strategies to mitigate the impact of PPR in Karamoja and other pastoral areas in eastern Africa.

Global ecological niche modelling of current and future distribution of peste des petits ruminants virus (PPRv) with an ensemble modelling algorithm

Peste des petits ruminants (PPR) is a highly contagious transboundary viral disease of sheep and goats that negatively impacted the farmers and pastoralists' livelihood in Africa and Asia. To overcome the disease's consequences, the OIE and FAO are collaborating efforts to eradicate the disease once and for all. We developed a predictive model that delineates suitable territories for the virus globally in support of this eradication programme. To achieve this, we used an ecological niche modelling with an ensemble algorithm. AUC-ROC curve, true skill statistics (TSS) and Kappa values were used to evaluate the model's performance. A TSS value greater than 0.7 was used to pool outputs of the nine model. The ensemble model has better performance than individual models by every evaluation metrics (Kappa = 0.82, TSS = 0.88 and ROC = 0.99). Annual minimum temperature (24.92%), annual maximum temperature (21.37%), goat density (18.03%) and solar radiation (14.04%) have the highest overall contribution in the ensemble model. The model indicates that India, Mongolia, Iraq, Iran, Afghanistan, Nepal, Tanzania, Uganda, Kenya, Sudan, Angola, Nigeria, DRC, Ghana, Sierra Leon, Southern Spain, France, Albania, Montenegro, Macedonia, Italy, Armenia and Azerbaijan are highly suitable for PPRv. In 2040, suitable territories for PPRv will diminish, indicating the odds are with us in eradicating disease by 2030. We believe that this model can be used as an epidemiological tool to facilitate the global eradication programme of the disease set by the OIE and FAO.

Seroepidemiology of Peste des Petits ruminants in sheep and goats in the selected district of Horu Guduru Zone, Western Ethiopia

Peste des Petits Ruminants (PPR) is an acute, highly contagious, economically important transboundary viral disease of small ruminants. The objectives of this cross-sectional study were to estimate the seroprevalence and associated risk factors of PPR in small ruminants in selected districts of Horo Guduru Zone, Western Ethiopia. A total of 806 blood samples, corresponding to 124 flocks comprised of 387 sheep and 419 goats, were collected using multi-stage sampling. The sera were tested using competitive Enzyme-Linked Immunosorbent Assay (c-ELISA). A pre-tested questionnaire was used to collect data on potential risk factors for PPRV infection. Pearson's Chi-Square and logistic regression analyses were used to see the association of the seroprevalence with potential risk factors. The flock-level overall seroprevalence of PPR was 27.42% (95% confidence interval [CI]: 19.79-36.15%). An overall animal level seroprevalence of 5.71% (95% CI: 4.21-7.54%) was recorded with 6.98% (95% CI: 4.65-10.00%) seroprevalence in sheep and 4.53% (95% CI: 2.75-6.99%) in goats. There was a significant association between the seroprevalence and risk factors that were sharing common grazing land (P = 0.032), the introduction of newly purchased animals into the flock (P = 0.011), and uncontrolled animal movements in goats (P = 0.018). Sharing common grazing land with other flocks in goats (P = 0.026) and midland altitude in sheep (P = 0.029) were the other predictors of PPR. The seropositivity in unvaccinated small ruminants suggests the circulation of the virus. Therefore, awareness creation, vaccination, strengthening the disease surveillance system and large-scale epidemiological and molecular studies are suggested.

Peste des petits ruminants (PPR) in Africa and Asia: A systematic review and meta-analysis of the prevalence in sheep and goats between 1969 and 2018

BACKGROUND

Peste des petits ruminants (PPR) is a prevalent viral disease of sheep and goats that impacts productivity and international animal trade. Despite the substantial economic consequences related to PPR, little is known about the prevalence of this disease at the broad geographical levels.

OBJECTIVE

The present study aimed to use a systematic approach to assess the regional prevalence of PPR in sheep and goats, and the associated factors that contribute to prevalence estimates.

METHODS

Published articles on PPR in sheep and goats were searched in PubMed, Web of Science, Scopus, Google Scholar and the reference lists of articles reporting the prevalence from 1 January 1969 to 31 December 2018. Articles were selected using inclusion and exclusion criteria. Since the heterogeneity among the studies was significant, pooled prevalences were estimated by a random effect meta-analysis model.

RESULTS

Data on the prevalence of PPR were obtained from Africa and Asia, where the pooled prevalence estimates were 40.99% (95% CI: 37.20%-44.79%) and 38.43% (95% CI: 35.64%-41.22%) respectively. Overall, the estimated pooled prevalence at Africa-Asia level in sheep was 39.31% (95% CI: 35.75%-42.88%) and in goats was 39.57% (95% CI: 36.66%-42.48%). Significant heterogeneity (I²  > 80%) was noted in most pooled estimates.

CONCLUSION

The results on the regional prevalence estimates of PPR presented here will be useful in raising awareness and advocating for Governments to engage in initiatives to eradicate PPR and prevent it from spreading to other continents.

Transcriptional Profiles of Murine Bone Marrow-Derived Dendritic Cells in Response to Peste des Petits Ruminants Virus

Background: Peste des petits ruminants virus (PPRV) is the causative agent of PPR, which can cause an acute, highly contagious and fatal disease of sheep and goats, resulting in significant economic losses for commercial animal husbandry due to its high mortality and morbidity. As professional antigen-presenting cells, dendritic cells (DCs) play a unique role in innate immunity. This study aimed to gain a deeper understanding of the transcriptional response of bone marrow-derived dendritic cells (BMDCs) stimulated with PPRV. Results: Transcriptional profiling was performed using RNA sequencing. Herein, we reported that compared to untreatedBMDCs, 4492 differentially expressed genes (DEGs) were identified following PPRV stimulation, out of these DEGs 2311 were upregulated and 2181 were downregulated, respectively. A total of three gene ontology (GO) term clusters of biological process, cell component and molecular function were significantly enriched in 963 GO terms in the PPRV-stimulated BMDCs. These GO clusters were related to inflammatory response, cell division and vacuole, anchoring junction, positive regulation of cellular component and nucleoside binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of DEGs were enriched in a chemokine signaling pathway, protein processing in endoplasmic reticulum, cell cycle and mTOR signaling pathway. Additionally, identified DEGs of BMDCs were further validated by qRT-PCR and the results were in accordance with the change of the genes. This study suggested the effects of PPRV stimulation on the maturation and function of BMDCs. Conclusion: We found that the dramatic BMDCs transcriptome changes triggered were predominantly related to an inflammatory response and chemokine signaling pathway.

Epidemic and evolutionary characteristics of peste des petits ruminants virus infecting Procapra przewalskii in Western China

Due to the migration or transboundary spread of domestic and wild animals, peste des petits ruminants virus posed a high potential threat to them. In this study, we initially detected that a class of animal named Procapra przewalskii was infected with peste des petits ruminants virus (PPRV ChinaGS2018) in Gansu province. According to phylogenetic relationships analysis, we found that ChinaGS2018 comprised of 15,954 nucleotides and was classified into IV genotypes. In addition, indirect immunofluorescence assay (IFA) showed that ChinaGS2018 could infect isolated primary goat tracheal epithelium cells (GTC). Comparing with full-length genome sequences revealed that ChinaGS2018 strain has high identity to the reference complete genomes (87.16-99.55%) at the nucleotide level. Multiple sequence alignment showed that F protein has the highest identity of 99.8%, and H protein has the highest nucleotide substitution ratio. Our study also suggested this strain may be transmitted from Xinjiang, China. Along with the migratory of Procapraprzewalskii, this wild ruminant infected with PPRV can pose a huge threat to other wild ruminants and domestic ones. This is the first report describing infected with PPRV which will provide insights into the epidemiology and pathogenesis of this important virus.

Proteomic analysis of murine bone marrow derived dendritic cells in response to peste des petits ruminants virus

Peste des petits ruminants virus (PPRV) poses a great threat to livestock husbandry, especially goat farming due to its high mortality and morbidity. Dendritic cells (DCs), as the principal stimulators of naive Th cells were widely used in antigen processing and presenting. In the previous study, we tested the effects of PPRV on murine bone marrow derived dendritic cells (BMDCs) including surface markers and cytokines. While the aim of this study is to detect the proteomic profile of BMDCs stimulated with PPRV towards key proteins involved in. Following PPRV stimulation, 110 differentially expressed proteins (DEPs) were identified through iTRAQ labelling with LC-MS/MS approach, of which 94 DEPs were up-regulated and 16 DEPs were down-regulated, respectively. Among them 15 out of 110 DGPs were related to innate immune system, three were involved in cell apoptosis, RPS15a and Smox were related to translation of viral mRNA. Additionally, western blot analysis showed identical results to iTRAQ analysis. There will be profound significance for understanding antigen-presenting of BMDCs after stimulation with PPRV.