Evaluation of effectiveness of Mass Vaccination Campaign against Peste des petits ruminants in Chhattisgarh state, India

Flock level socio-economic and other associated risk factors for Peste des petits ruminants (PPR) exposure in sheep and goats in Madhya Pradesh state, India

To effectively control and eradicate PPR, the comprehensive understanding of risk factors associated with PPR exposure is vital. Hence, this study investigated socioeconomic and other associated risk determinants for PPR exposure at flock level in sheep and goats in a non-vaccination programme implemented Madhya Pradesh state India. A total of 410 sheep and goat flocks, comprised mostly of goats but also some mixed flocks, were surveyed during 2016 using a multistage random sampling procedure. Further, 230 blood samples were also collected from the farmers-reported PPR affected flocks and sera were tested using c-ELISA to confirm PPR exposure. The primary data on socioeconomic factors, farm management factors, health status, vaccination details and other epidemiological risk factors were collected from flock owners and descriptive statistics, chi-square analysis and logistic regression models were fitted to identify the significant risk factors for PPR incidence. The farmer's education, flock size, rearing pattern, and awareness of PPR vaccination were found to be significant pre-disposing risk factors for PPR exposure in the flocks. Hence, the control and eradication strategy need to be designed comprehensively considering the key social factors like education and vaccination awareness along with other flock level risk factors to eradicate PPR by 2030 in consonance with the global plan.

Simulating the Spread of Peste des Petits Ruminants in Kazakhstan Using the North American Animal Disease Spread Model

In this study, we simulated the potential spread of Peste des Petits Ruminants (PPR) between small ruminant (SR) farms in the Republic of Kazakhstan (RK) in case of the disease’s introduction into the country. The simulation was based on actual data on the location and population of SR farms in the RK using the North American Animal Disease Spread Model (NAADSM). The NAADSM employs the stochastic simulations of the between-farm disease spread predicated on the SIR compartmental epidemic model. The most important epidemiological indicators of PPR, demography of SR farms, and livestock management characteristics in the RK were used for model parameterization. This article considers several scenarios for the initial introduction of PPR into the territory of Kazakhstan, based on previously identified high-risk regions and varying sizes of initially infected farms. It is demonstrated that the duration and size of the outbreak do not depend on the size of initially infected farms but rather depend on the livestock concentration and number of farms in the affected area. This implies that the outbreak may affect the largest number of farms in the case of introduction of the disease into farms in southern Kazakhstan. However, even in the most unfavorable scenario, the total number of affected farms does not exceed 2.4% of all SR farms in the RK. The size of the affected area is, in most cases, no larger than an averaged 2-level administrative division’s size, which suggests the scale of a local epidemic. The chosen model provides ample opportunity to study the impact of different control and prevention measures on the spread of PPR as well as to assess the potential economic damage.

Towards Eradication of PPR: Disease Status, Economic Cost and Perception of Veterinarians in Karnataka, India

In this study, we assessed the PPR disease status, its economic cost, the financial viability of vaccination, and the perspectives of field veterinarians on the PPR vaccination programme implemented in Karnataka state, India. In addition to secondary data, cross-sectional surveys undertaken during 2016-17 (survey I) and 2018-19 (survey II) from 673 sheep and goat flocks and data collected from 62 veterinarians were analysed. The economic costs and perceptions of veterinarians were analysed using deterministic models and the Likert scale, respectively, and the financial viability of vaccination programmes under the best (15%), base (20%), and worst-case (25%) PPR incidence scenarios, considering two different vaccination plans (plan I and plan II), was assessed. The disease incidence in sheep and goats was found to be 9.8% and 4.8% in survey I and survey II, respectively. In consonance with the increased vaccination coverage, the number of reported PPR outbreaks in the state declined significantly. The estimated farm-level loss of PPR varied between the surveyed years. Even under the best-incidence scenario, under vaccination plan-I and plan-II, the estimated benefit-cost ratio (18.4:1; 19.7:1), the net present value (USD 932 million; USD 936 million) and the internal rate of return (412%) implied that the vaccination programmes were financially viable and the benefits outweighed the cost. Though the majority of veterinarians perceived that the control programme was well planned and rolled out in the state, a few of them disagreed or were neutral towards the plan per se, towards the coordination between functionaries, the availability of funding, and the programme acceptance by farmers. Despite many years of vaccination, PPR still persists in the Karnataka state for various reasons and in order to eradicate the disease, a review of the existing control programme with strong facilitation from the federal government is needed.

Assessment of post-vaccination immune response to peste des petits ruminants virus in small ruminants in the central and western regions of India

The cross-sectional serosurvey for post-vaccination assessment of peste des petits ruminants (PPR) virus (PPRV) antibodies in sheep and goats was carried out in different states in the central and western regions of India after the implementation of vaccination under the PPR control programme. The serum samples (n = 4687) were collected from sheep (n = 1539) and goats (n = 3148) from August 2017 to March 2018 at various epidemiological units (n = 301) of the studied regions using a stratified random sampling method and PPR competitive ELISA kit was employed to detect PPRV antibodies. The results revealed 34, 21, 52, 74, 68, and 65% of prevalence of PPRV antibodies in small ruminants in Madhya Pradesh, Goa, Chhattisgarh, Maharashtra, Gujarat, and Rajasthan states, respectively, with a difference in seropositivity in sheep and goats across the states in sheep (p < 0.01) and goats (p < 0.01). Further, this serosurvey revealed that 60% of the epi-units (n = 185) had > 50% prevalence of post vaccination PPRV antibodies across states due to variations in vaccination rates and patterns. The vaccination coverage and the reported outbreaks varied between the states in the studied regions. Due to continuous vaccination under the control program, the reported PPR outbreaks have progressively declined in most of the studied states, and the PPR risk areas are confined to a few districts and sporadically, outbreaks are reported indicating the effectiveness of vaccination. These findings provide valuable information on potential PPRV episystems, and will assist with activities regarding intensive surveillance, vaccination, biosecurity, and modification of policy decisions towards designing and implementing control and eradication measures. Further, the present situation necessitates continuous mass vaccination and active surveillance programs to make these regions free from PPR in consonance with the PPR Global Control and Eradication Strategy under the PPR Global Eradication Program.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-022-00796-6.

Prioritizing smallholder animal health needs in East Africa, West Africa, and South Asia using three approaches: Literature review, expert workshops, and practitioner surveys

Managing the health needs of livestock contributes to reducing poverty and improving the livelihoods of smallholder and pastoralist livestock keepers globally. Animal health practitioners, producers, policymakers, and researchers all must prioritize how to mobilize limited resources. This study employed three approaches to prioritize animal health needs in East and West Africa and South Asia to identify diseases and syndromes that impact livestock keepers. The approaches were a) systematic literature review, b) a series of expert workshops, and c) a practitioner survey of veterinarians and para-veterinary professionals. The top constraints that emerged from all three approaches include endo/ ectoparasites, foot and mouth disease, brucellosis, peste des petits ruminants, Newcastle disease, and avian influenza. Expert workshops additionally identified contagious caprine pleuropneumonia, contagious bovine pleuropneumonia, mastitis, and reproductive disorders as constraints not emphasized in the literature review. Practitioner survey results additionally identified nutrition as a constraint for smallholder dairy and pastoralist small ruminant production. Experts attending the workshops agreed most constraints can be managed using existing veterinary technologies and best husbandry practices, which supports a shift away from focusing on individual diseases and new technologies towards addressing systemic challenges that limit access to veterinary services and inputs. Few research studies focused on incidence/ prevalence of disease and impact, suggesting better incorporation of socio-economic impact measures in future research would better represent the interests of livestock keepers.

Temporal and Spatial Epidemiological Analysis of Peste Des Petits Ruminants Outbreaks from the Past 25 Years in Sheep and Goats and Its Control in India

This study was aimed to understand the temporal and spatial epidemiology of peste des petits ruminants (PPR) in India using national surveillance data available in the National Animal Diseases Referral Expert System (NADRES) along with its control plan undertaken. On analysis of the outbreaks/cases reports in sheep and goats in NADRES database from 1995 to 2019, it was observed that PPR features among the top ten diseases and stands first among viral diseases, and among reported deaths, PPR accounts for 36% of mortality in sheep and goats. PPR outbreaks occur round the year in all the seasons but are encountered most frequently during the lean period especially, in the winter season (January to February) in different regions/zones. The reported outbreaks have been progressively declined in most of the states in India due to the implementation of a mass vaccination strategic program since 2011. On state-wise analysis, the PPR risk-areas showed wide variations with different levels of endemicity. Andhra Pradesh, West Bengal, and Karnataka were the top three outbreaks reported states during 1995-2010, whereas Jharkhand and West Bengal states reported more outbreaks during 2011-2015 and 2016-2019 periods. The temporal and spatial distribution of PPR in India provides valuable information on the hotspot areas/zones to take appropriate policy decisions towards its prevention and control in different regions/zones of India. The study also identifies when and where intensive surveillance and vaccination along with biosecurity measures need to be implemented for the control and eradication of the disease from India in consonance with the PPR Global Control and Eradication Strategy.

Progress towards Eradication of Peste des Petits Ruminants through Vaccination

Peste des petits ruminants (PPR) is a transboundary viral disease that threatens more than 1.74 billion goats and sheep in approximately 70 countries globally. In 2015, the international community set the goal of eradicating PPR by 2030, and, since then, Food and Agriculture Organization of the United Nations (FAO) and World Organization for Animal Health (OIE) have jointly developed and implemented the Global Control and Eradication Strategy for PPR. Here, data from the United Nations Food and Agriculture Organization Statistical Database (FAOSTAT), the OIE World Animal Health Information System (WAHIS), Regional Roadmap Meetings, and countries' responses to PPR Monitoring and Assessment Tool (PMAT) questionnaires were analyzed to inform on current progress towards PPR eradication. OIE recorded the use of over 333 million doses of vaccine in 12 countries from 2015 to 2018, 41.8% of which were used in Asia and 58.2% in Africa. Between 2015 and 2019, a total of 12,757 PPR outbreaks were reported to OIE: 75.1% in Asia, 24.8% in Africa, and 0.1% in Europe. The number of global outbreaks in 2019 fell to 1218, compared with 3688 in 2015. Analysis of vaccine use and PPR outbreaks in countries indicates that disease control strategies, particularly vaccination campaigns and vaccine distribution strategies, still require scientific evaluation. It is imperative that vaccination is undertaken based on the epidemiology of the disease in a region and is coordinated between neighboring countries to restrict transboundary movements. Strengthening surveillance and post-vaccination sero-monitoring at the national level is also essential. The PPR vaccine stock/bank established by FAO, OIE, and other partners have improved the quality assurance and supply of vaccines. However, to achieve PPR eradication, filling the funding gap for vaccination campaigns and other program activities will be critical.

Towards eradication of peste des petits ruminants: post-vaccination evaluation in sheep and goats in Southern Peninsular India

The cross-sectional seroprevalence study of the peste des petits ruminants (PPR) in sheep and goats was carried out in the Southern Peninsular region of India to ascertain the prevalence of PPR virus (PPRV) antibodies at the epidemiological units (epi-units) level in the small ruminant population. The serum samples were collected from various epi-units (villages) in the different states and union territory (UT) in Southern Peninsular region using a stratified random sampling methodology from August 2017 to March 2018. A total of 6643 serum samples [sheep (n = 2785) and goats (n = 3858)] were collected from 360 epi-units and were screened by PPR competitive ELISA kit for the detection of PPRV antibodies. The results revealed that the seroprevalence of PPR in small ruminants in Telangana, Andhra Pradesh, Karnataka, Tamil Nadu, and Kerala states, and Puducherry UT was 87.0%, 66.4%, 64.3%, 47.8%, 11.4%, and 50.4%, respectively in the studied region. Further, the results of the chi-squared test revealed that the PPRV antibodies across different states and UT in the region were associated (sheep-χ² = 218.8, p < 0.01; goats-χ² = 827.1, p < 0.01), as all the states and UT adopted the PPR vaccination programme. The study also implies that the small ruminants in some of the epi-units (n = 102) had < 30% seroprevalence, which necessitates comprehensive intensive vaccination and active surveillance programmes to make this region as PPR free zone.

Seroprevalence study of peste des petits ruminants in sheep and goats in the northern region of India

Background and Aim:

Peste des petits ruminants (PPR) is a contagious, World Organization for Animal Health notifiable, economically important, transboundary morbilliviral disease of sheep and goats. Studying seroprevalence of PPR from different geographical areas under varying agro-climatic conditions may help in formulating effective and appropriate disease control strategies under the ongoing national PPR control program. The present cross-sectional study describes the prevalence of PPR virus antibodies in sheep and goats in the various epidemiological units in different states (Haryana, Himachal Pradesh [HP], Jammu and Kashmir [J&K], Punjab, Uttarakhand [UK], and Uttar Pradesh [UP]) of the northern region of India.

Materials and Methods:

A total of 5843 serum samples (sheep [n=2463] and goats [n=3380]) were collected by stratified random sampling method from 322 epidemiological units in the studied region during 2017-2018 and tested for PPR virus (PPRV) antibodies by competitive ELISA.

Results:

The results revealed that an overall seroprevalence of 44.05% (2574/5843) with 57.32%, 55.22%, 65.69%, 37.09%, 32.73%, and 29.35% prevalence of PPRV antibodies in small ruminants in Haryana, Punjab, UP, HP, J&K, and UK states, respectively. Further, Chi-squared test revealed an association of PPRV antibodies in goats (χ²=252.28, p<0.01) and sheep (χ²=192.12, p<0.01) across different states in the region.

Conclusion:

The seroprevalence in majority of the epidemiological units (n=130) in sheep and goats in the studied region had <30%. This necessitates comprehensive, rigorous, continuous vaccination and active surveillance programs for few more years to achieve the desired 70% seroprevalence level of PPRV antibodies in population and to make the northern region of India, as PPR free zone.

Seroprevalence of peste des petits ruminants in sheep and goats in Eastern India

The seroprevalence study of peste des petits ruminants (PPR) in small ruminants in Bihar and Odisha states in the Eastern region of India was carried out. A total of 1836 serum samples were collected from sheep (n = 648) and goats (n = 1188) from various epidemiological units (n = 112) in these states by a two-stage sampling plan during April 2017-March 2018. These samples were tested for the detection of virus antibodies by PPR competitive ELISA kit. The results revealed that the seroprevalence of PPR in sheep and goats in Bihar and Odisha states was 30.91% and 54.20%, respectively. Further, the chi-square analysis showed that the association exists between the presence of PPR virus antibodies in the goats (χ² = 93.28, p < 0.01) and between the states (χ² = 82.61, p < 0.01). This cross-sectional serosurvey also infers that the sheep and goats in most of the epi-units (n = 87) had < 70% of PPR virus antibodies prevalence. This warrants the intensive continuous mass vaccination program for a few more years to achieve the desired level of population immunity (epidemiological units protection level) and active surveillance to make these states free from PPR in the Eastern region of India.

Scorecard method for assessing the severity of peste des petits ruminants in sheep and goats

A methodology to assess the clinical severity of peste des petits ruminants (PPR) in sheep and goats in the field condition was developed using a scorecard by considering five specific cardinal clinical signs (pyrexia, oculo-nasal discharge, oral lesions, respiratory signs, and diarrhoea) of disease. The scores were assigned for the signs based on the severity of the disease that ranged from 1 (low) to 4 (high). The assigned weightage for signs, morbidity, and mortality was 0.75, 0.05 and 0.2, respectively summing up to unity. The scoring and weightages and guidelines were devised by Delphi technique based on the field investigation, field veterinarian's assessment and specific inputs from PPR experts. The estimated Weighted Score Index (WSI) was considered to classify the severity into mild (WSI < 40) or moderate (WSI 41-60) or severe (WSI > 60) form. This scorecard will help preliminarily to the extent for the identification of the suspected flocks with a required case definition at the first instance, before making decisions on what merits further field investigation. This is first of its kind of methodology to assess the disease pattern in small ruminants and could be used as a disease severity assessment tool in different geographical areas in endemic settings.

Toward peste des petits virus (PPRV) eradication: Diagnostic approaches, novel vaccines, and control strategies

Peste des petits ruminants (PPR) is an acute transboundary infectious viral disease affecting domestic and wild small ruminants' species besides camels reared in Africa, Asia and the Middle East. The virus is a serious paramount challenge to the sustainable agriculture advancement in the developing world. The disease outbreak was also detected for the first time in the European Union namely in Bulgaria at 2018. Therefore, the disease has lately been aimed for eradication with the purpose of worldwide clearance by 2030. Radically, the vaccines needed for effectively accomplishing this aim are presently convenient; however, the availableness of innovative modern vaccines to fulfill the desideratum for Differentiating between Infected and Vaccinated Animals (DIVA) may mitigate time spent and financial disbursement of serological monitoring and surveillance in the advanced levels for any disease obliteration campaign. We here highlight what is at the present time well-known about the virus and the different available diagnostic tools. Further, we interject on current updates and insights on several novel vaccines and on the possible current and prospective strategies to be applied for disease control.