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.

Gelana M ，Gebremedhin EZ ，Gizaw D 《-》

Sero-prevalence and associated risk factors of peste des petits ruminants and contagious caprine pleuro-pneumonia in goats and sheep in the Southern Zone of Tanzania.

A retrospective Sero-prevalence analysis was conducted in 2012 in order to find out whether contagious caprine pleuro-pneumonia (CCPP) and peste des petits ruminants (PPR) had already been introduced in Mtwara and Lindi regions of Southern Tanzania by 2007 and 2009. A total of 477 randomly selected sera from a bank of 3500 small ruminant samples that were collected as part of Rift Valley Fever surveillance of 2007 in Mtwara and Lindi regions were used in this study. Seroconversion was also evaluated in the 504 sera that were collected in 2009 as part of disease outbreak investigations in Tandahimba and Newala districts of Mtwara region. Seroconversions to CCPP and PPR were tested using competitive ELISA. In addition, information on different variables available in the existing surveillance forms gathered during sampling was used in the analysis of risk factors associated with seropositivity to the two diseases. The overall seroprevalence of CCPP for the sera of 2007 and 2009 in goats was 52.1% (n=447) and 35.5% (n=434) respectively; while in sheep the seroprevalence was 36.7% (n=30) and 22.9% (n=70) respectively. Seroconversion to PPR in goats and sheep was 28.7% (n=434) and 35.7% (n=70) respectively based on the sera of 2009. However, no antibodies were detected in the 2007 sera. Mixed infections were detected in 7.4% (n=434) of the goat and 12.9% (n=70) of sheep samples. Significant risk factors associated with seropositivity to CCPP in 2007 included introduction of new animals in flocks (OR=3.94; 95% CI 1.86-8.36; p<0.001) and raising animals in government farms (OR=4.92; 95% CI 1.57-15.76; p=0.02); whereas, seropositivity to CCPP in 2009 increased with introduction of new animals in flocks (OR=18.82; 95% CI 8.06-43.96; p<0.001), raising animals in government farms (OR=4.04; 95% CI 2.69-6.42; p<0.001) and raising animals in Newala district (OR=2.35; 95% CI 1.53-3.62; p<0.001). On the other hand, predictors for seropositivity to PPR in 2009 were introduction of new animals in flocks (OR=2.83; 95% CI 1.73-4.62; p<0.001) and communal grazing of animals (OR=7.60; 95% CI 1.77-32.58; p=0.01). Therefore, these results show that CCPP was already circulating in goats in the southern zone by 2007 and that PPR was probably introduced thereafter. Their presence in this emerging animal keeping area in Tanzania calls for improved surveillance and control systems.

Mbyuzi AO ，Komba EV ，Kimera SI ，Kambarage DM ... -  《-》

Seroprevalence, distribution and risk factor for peste des petits ruminants (PPR) in Algeria.

Peste des petit ruminants (PPR) is a highly contagious and infectious viral disease of small ruminants with severe socio-economic implications. The disease was first reported in the Southern part of Algeria in 2011 and by February 2012 it has reached the central part of the country. Estimating national prevalence, distribution and identification of risk factors remains a key component in understanding the epidemiology and control of the disease. The present study was carried out between January and June 2014, to include a detailed description of flock and within-flock seroprevalence and risk association between PPR seropositivity and various flock management factors in Algeria. A total of 150 flocks randomly sampled across the country were investigated and 4552 serum samples were collected from 3336 sheep and 1216 goats, respectively. C-ELISA was used to detect the presence of antibodies in small ruminant animals as an indicator of PPRV exposure. The results showed an overall true flock seroprevalence of 30.45% [95% CI 23.76-37.14] with a mean of the true within-flock prevalence as 29.87%±2.11. The mean of the true within-flock prevalence in mixed flocks (12.93%±1.85) was however found to be significantly higher than sheep flocks (5.74%±1.06). Also the mean of the true within-flock prevalence was found to be significantly higher in adult (35.36%±3.13) compared to young animals (21.83%±2.47) and in females (33.11%±2.87) compared to males (22.14%±2.31). The univariate analysis revealed that PPR overall flock seroprevalence was significantly higher (P<0.20) in large flock (50.61%) than in small flock (33.33%), in mixed flock (56.7%) than in sheep flock (35.35%) and in the flocks that had contact with other flocks (46.5%) compared to those who had not (30.6%). However the differences among studied regions and grazing system were not statistically significant. For the risk factor analysis, univariate analysis of variables followed by a multiple logistic regression identified mixed flocks [OR=2.64, 95% CI 1.30-5.38; P=0.007] and contact with other flocks [OR=2.27, 95% CI 0.99-5.21; P=0.053] as risk factors in the spread of the disease. In conclusion, this study revealed a high seroprevalence of PPR in Algerian small ruminants, therefore the establishment of early warning systems and comprehensive implementation of control measures are advocated to improve animal welfare and reduce economic losses.

Kardjadj M ，Kouidri B ，Metref D ，Luka PD ，Ben-Mahdi MH ... -  《-》

Epidemiology of peste des petits ruminants in selected districts of Borena zone, Ethiopia.

Peste des petits ruminant (PPR) is a contagious disease caused by the peste des petits ruminants virus (PPRV). The disease poses a significant economic threat to small ruminant production in Ethiopia, particularly to the striving pastoral production system. A cross-sectional study was conducted to estimate the seroprevalence and associated risk factors of PPR in the small ruminants of the Borena Zone. A total of 384 serum samples were collected randomly from sheep and goats and examined for the presence of PPRV antibodies using competition enzyme-linked immune sorbent assay (c-ELISA). Additionally, a retrospective analysis of five years of outbreak data was performed to provide insight into the spatial and temporal distribution of the disease. The seroprevalence of PPRV antibodies in nonvaccinated, vaccinated, and unknown vaccination status of small ruminants in this study was found to be 32.1%, 68.8%, and 45.5%, respectively. Multivariable logistic analysis revealed a statistically significant association between PPRV seropositivity and several factors, including age, animal origin, flock size, and veterinary services status. A retrospective analysis revealed 53 PPR outbreaks in the Borena Zone from 2018 to 2022, exacerbated by low vaccination coverage relative to the at-risk animal population. The study revealed significant gaps in current vaccination efforts, with herd immunity levels falling below the FAO-WOAH recommended threshold of 80%. Despite Ethiopia's ambitious goal to eradicate PPR by 2027, the frequent outbreaks and insufficient herd immunity highlight the inadequacy of the existing strategies. To effectively move toward eradication, Ethiopia must align its approach with the global PPR eradication framework, which emphasizes a comprehensive strategy that includes diagnostics, surveillance, prevention, and the establishment of a robust veterinary regulatory system, rather than relying solely on vaccination. Overcoming logistical challenges, improving vaccination coverage, and optimizing the timing of vaccination campaigns, especially in hard-to-reach areas, will be crucial for reducing outbreaks and making progress toward eradication.

Kumbe A ，Negussie H ，Getachew Y ，Alemu B ，Alemayehu G ，Girma S ，Sibhatu D ，Emiyu K ，Waktole H ，Leta S ... -  《BMC Veterinary Research》

Seroepidemiology of peste des petits ruminants virus in small ruminants in selected districts in Northwest Ethiopia.

Peste des petits ruminants (PPR) is one of the most severe diseases of small ruminants, causing the loss of millions of dollars annually. A cross-sectional study was conducted to determine the seroepidemiology of peste des petits ruminants virus (PPRV) in unvaccinated sheep and goats in selected districts in Northwest Ethiopia. The study was designed to investigate the epidemiology of PPRV in unvaccinated sheep and goats and risk factors in the study areas. A multi-stage sampling was used to select study districts, villages and households with a random sampling approach. Study animals (403 sheep and goats) older than 5 months were selected with a systematic random sampling approach. From the animals, blood samples were aseptically collected and PPRV antibodies from the serum were analysed with enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence of antibodies to PPRV was 32.5% in both species. It was higher in goats with a prevalence of 34.7% than in sheep (28.3%). District, herd size, sex, animal origin and grazing management were significantly associated with seropositivity of animals to PPRV antibodies. If an animal was from the Dangur district, it had 2.6 times higher chance of being positive than in the Dibati district (OR = 2.6, p = 0.01 and 95% CI = 1.2- 5.6). Herd size was also significantly correlated with the seropositivity with (OR = 4, p = 0.001, and 95% CI = 1.8-9). Also, male animals had 1.7 times higher chance of being positive than females. Further, if an animal comes from the market, it has 2.7 times higher chance of being positive compared to animals born and raised on the farm. The seropositivity indicates that the disease is circulating in the study areas. Hence, preventive approaches, like vaccination campaigns and strict biosecurity measures, are highly advised to avoid the catastrophic impact of the diseases if an outbreak occurs.

Abesha H ，Teshome Y ，Alemu YF ，Dejene H ，Tarekegn ZS ，Assefa A ... -  《Veterinary Medicine and Science》