Trehalose improves PPR vaccine virus stability in diluent

Peste des petits ruminants (PPR) is a highly contagious disease that is considered a major threat to the small livestock industry. Although vaccination via live-attenuated PPR vaccine is a main controlling strategy in the endemic area, during PPR eradication process, the inactivated PPR vaccine (iPPRV) is recommended. This study aimed to compare the inactivation kinetics of the PPR virus via different inactivants and immunogenicity evaluations of the iPPRV formulated vaccine in mice. The vaccinal live PPR virus was inactivated by either H2O2 or binary ethylenimine (BEI (at two concentrations of 1 or 4 mM. Thereafter, the inactivated virus was formulated with different adjuvants, including aluminum hydroxide (AH), aluminum phosphate (AP), and a mixture of AH and AP that were intraperitoneally (IP) administrated (0.1 mL) to 90 BALB/c mice in a completely randomized design and 3×3 factorial arrangement (9 animals per group). The booster vaccination was carried out in all animals 21 days after the primary vaccination. Results showed that the PPR virus was successfully inactivated by all the inactivation agents; however, the time of complete virus inactivation was estimated to be 482, 295, and 495 min post-treatment initiation for 1 mM BEI, 4 mM BEI, and H2O2, respectively. The main effect of inactivant on antibody titers against PPR virus that was measured after 42days post-immunization in mice was significant (P<0.05); however, the adjuvant and interaction effect of inactivator×adjuvant were not effective(P>0.05). Inactivation by 1 mM BEI was associated with a higher antibody titer against PPR virus (P<0.05) in comparison with both 4 mM BEI and H2O2 (2.51 vs. 2.25 and 2.22, respectively). Meanwhile, there were no significant differences among the used adjuvants in terms of eliciting antibody response against PPR virus. In conclusion, the use of 1 mM BEI in combination of AH, AP, or a mixture of AH and AP was associated with a higher immune response against PPR virus in mice. However, the appropriate inactivation kinetic of the virus and immunogenicity associated with the use of H2O2, as well as its biocompatibility property and better cost-benefit, nominated H2O2 to be used in iPPR preparation; however, more investigations are required in target animals.

Peste des Petits ruminants (PPR) is a highly contagious trans-boundary animal disease associated with 100% morbidity and 80-90% mortality in goat herds. The study was carried out to assess the immune status against PPRV in unvaccinated and post vaccinated flock as well as immune response as it relates to age, sex and breed using a homologous tissue culture PPR vaccine produced by National Vaccine Production Laboratory, Kathmandu, Nepal. A total 276 blood samples were randomly collected from different regions of Parbat, Baglung and Myagdi districts with a population of 0.0189 million goats. Out of these, 214 goats were vaccinated one month earlier and 62 were unvaccinated. PPR antibody was detected by using competitive enzyme linked immunosorbent assay (c-ELISA) (ID Screen, PPR competition test kit, IDvet France). Of the unvaccinated goats, 25.8% (16/62) were sero-positive suggesting prior exposure to PPRV. In the vaccinated goats, 75.2% (161/214) were sero-positive and 2.8% (6/214) animals were doubtful, suggesting a significant proportion failed to respond to vaccination. The competition percentage (S/N%±SD) of post-immunization (49.19±32.19) were significantly (p&lt;0.01) lower in comparison to the respective unvaccinated mean titre (75.76±35.51). There is no significant effect of age, sex or breed on the antibody titre value in PPR vaccinated animals. The sero-prevalence of PPR in unvaccinated animals suggested that these flocks are in high susceptibility to PPR outbreak and needs an implementation of control measures to reduce economic losses. Vaccination will increase the proportion of animals with a protective antibody level, however more investigation needs to be done to determine why almost one-quarter of animals failed to seroconvert to vaccination. Further detailed study is needed to find out the risk factors responsible for low prevalence of antibody against PPRV in the immunized flock.

Aim:The work was conducted to diagnose peste des petits ruminants (PPR) outbreak through an in house developed indirect ELISA (thereafter referred as iELISA) its comparison with other available diagnostic tests and description of practical considerations in its development, utility and limitations.Materials and Methods:An outbreak resembled to PPR occurred in two different places of southern Gujarat viz. Vapi and Navsari, affecting 622 animals, including both goat (n = 476) and sheep (n = 146). Animals displayed the typical signs of PPR at Vapi; however diarrhea was the inconsistent feature in animals of Navsari. The affection caused morbidity of 100% and mortality were 73.68% (n = 392/532) and 56.67% (n = 51/90) in Vapi and Navsari outbreaks, respectively. Relevant ante mortem and post mortem samples were collected from representative animals. At the outset of the epidemic no kit was available with us, so agar gel immunodiffusion (AGID) was carried out and a commercial ELISA (cELISA) kit was ordered for making diagnosis through antibody demonstration. Meanwhile, an iELISA was developed in house using PPR vaccine as antigen and protein G conjugated HRPO antibody as detector. Histopathology and results of sandwich ELISA were also used to diagnose PPR virus (PPRV) in the outbreak.Results:The iELISA developed had detected PPRV antibodies in 22/24 samples (91.66%). Significant difference was observed in disease sensitivity pattern of two species by Chi-square test. While AGID failed to detect antibodies in any sample. Results were reconfirmed by comparing with commercially available cELISA kit.Conclusion:PPR is an economically important disease and for the rapid diagnosis of PPR the in house developed antibody capture iELISA can be a suitable cost effective alternative.

Experimental studies on immunosuppressive effects of peste des petits ruminants (PPR) virus in goats

Serological response to a live commercial vaccine of Peste des petits ruminants (PPR) virus administered to sheep and goats in Buchanan, the capital city of Grand Bassa County, Liberia was assessed in view of its importance for effective restocking of small ruminants in the city. Forty-four paired serum samples (pre- and post-vaccination) were collected from vaccinated sheep and goats during a nation-wide campaign for food security promotion from March to October, 2011. Sheep and goats were vaccinated against PPR in late April, 2011. Pre-vaccination samples were collected in mid-April, 2011. Post-vaccination samples were collected in mid-October 2011 from the same groups of sheep and goats (6 months after vaccination). Paired serum samples gathered were stored at -4 oC until tested. Competitive Enzyme Linked Immunosorbent Assay (c-ELISA) was used to determine antibody levels against PPR virus. Only 34(77.3%) out of 44 paired serum samples were adequate in quantity and quality for the test. Test results indicated 27(79.4%) out of 44 paired serum samples increased significantly in antibody levels from prevaccination to post-vaccination levels that were equal or above threshold of Percentage Inhibition (PI &gt; 50%) against PPR vaccine. The importance of these findings to effective veterinary services delivery for the control of this neglected animal disease in Liberia is discussed. The present seroconversion status against PPR virus is considered to be a milestone in rebuilding veterinary services systems in Liberia towards national efforts for food security after prolonged civil war (1989-2003) in the country.

Peste des petits ruminants (PPR) is a highly contagious viral disease of domestic and wild small ruminants and thus has serious socioeconomic implications. In Pakistan, during the year 2012-2013, estimated losses due to PPR were worth Rs. 31.51 billions. Close contact between infected and susceptible animals is an important route of transmission of PPR. Therefore, carrier animals play an important role in unnoticed transmission of PPR. The objective of the study was to investigate the detection of PPR virus in goats recovered from PPR. A suspected PPR outbreak was investigated and confirmed as PPR after analysing appropriate samples collected from infected animals using rRT-PCR. A longitudinal study was conducted over the period of 16 weeks to ascertain the detection of PPR virus (PPRV) in faecal samples of recovered goats. Ninety-six (96) faecal samples from each sampling were collected at 4, 8, 12, and 16 weeks after the outbreak. Faecal samples were analysed using rRT-PCR. Of 96 from each sampling a total of 46, 37, 29, and 25 samples were positive for PPR viral genome at 4, 8, 12, and 16 weeks, respectively, after recovery. Attempts were made for the isolation of PPR virus on Vero cells, but results were negative. These results indicated the detection of PPR viral RNA up to 16 weeks after infection. Therefore, these results may help in the future epidemiology of PPR virus shedding and possible role as source of silent infection for healthy animals especially when there is no history of any outbreak in nearby flock or area.

In this study, the ability of the combined vaccine against peste des petits ruminants (PPR) (Nigeria strain 75/1) and sheep pox (SPP) (NISKhI strain) to form a protective immune response for 12 months in Kazakh breed fine-fleeced sheep aged 6–12 months was demonstrated. The duration of the protective immunity of immunized sheep from PPR and from SPP was evaluated using a serum neutralization test (SNT), followed by testing of the resistance of vaccinated sheep to infection with the field strain Kentau-7 of the PPRV and the virulent strain A of the SPPV. The PPR antibody response was additionally measured by c-ELISA. A single immunization of sheep with a combined vaccine in a volume of 2.0 mL, containing the PPR and SPP vaccine viruses in the titers of 103.0 TCID50/mL, provided reliable protection of animals from two infections simultaneously for 12 months (observation period). At the same time, in sheep immunized with the combined vaccine, antibodies of PPRV persisted for up to 12 months, with slight fluctuations. The combined vaccine induced 100% clinical protection against the field strain of PPRV and the virulent strain of SPPV in immunized sheep for up to 12 months, while unvaccinated animals became ill with the manifestation of clinical signs specific to PPRV and SPPV.

Background and Aim:The peste des petits ruminants (PPR) is a highly contagious disease of small ruminants which negatively affects animal production and the socioeconomic status of farmers. Peste des petits ruminants virus (PPRV) encodes eight proteins, with the viral fusion protein (F) playing a role in virus virulence and stimulating an effective protective immune response. This study aimed to isolate and complete the identification of PPRV circulating in goats in different Egyptian governorates and perform molecular characterization of the PPRV F gene.Materials and Methods:Samples were collected from unvaccinated animals with clinical signs suggestive of PPR. A total of 256 sera were tested for the detection of PPRV antibodies using a competitive enzyme-linked immunosorbent assay (c-ELISA) kit, while 214 samples of blood buffy coat preparation, animal swabs (nasal, ocular, and saliva), and fecal and tissue samples were tested for the detection of the PPRV antigen using an antigen-capture ELISA kit. Molecular diagnosis, gene cloning, blast analysis, and phylogenetic analysis were performed for the molecular characterization of PPRV.Results:The seroprevalence results of PPRV antibodies in the tested sera showed a total of 67.9% positive samples. The rates of PPR antigen recorded by the antigen-capture ELISA in the swabs (nasal and ocular) and tissue samples were 44.3%, 46.8%, and 43.5%, respectively, with saliva swabs having the highest rate of PPRV positivity (76.4%) and fecal samples having the lowest (33.3%). Molecular characterization of the PPRV Vero cell culture revealed that the circulating PPRV strain belongs to the IV lineage. Blast analysis of the PPRV F gene showed 96.7% identity with the PPRV strain Egypt-2014 fusion protein (F) gene, KT006589.1, differing by 43 single-nucleotide polymorphisms.Conclusion:The results of this study indicate that the emerging PPRV belongs to the IV lineage among small ruminant animals. The findings also indicate the need for an innovative strategy to control and eliminate this disease based on a regularly administered and effective vaccine, a test to distinguish between infected and vaccinated animals, and the need for further study on the protein structure and PPRV F gene expression, which should help us to understand the molecular evolution of the virus and control and eliminate PPR disease.

Livestock production system, particularly in pastoral areas, is mainly constrained by rampant livestock diseases and seasonal feed and water shortages. In areas like Dassenech, bordering Kenya and South Sudan, this risks are pronounced due to the unavailability of appropriate prevention and control. The research was conducted with the objectives of identifying major rampant diseases and designing appropriate prevention and control strategies. A cross-sectional study was employed, conducted using both participatory epidemiology and conventional veterinary investigation. Spatial and temporal occurrence of diseases was assessed. The major five diseases in bovine were contagious bovine pleuro pneumonia (CBPP), septicemic pasteurellosis, anthrax, foot and mouth disease (FMD), and black leg, in that order of importance. Similarly, in ovine, "unknown recent disease," pneumonic pasteurellosis, brucellosis, peste des petits ruminants (PPR), and septicemic pasteurellosis were ranked, starting from the most important whereas in caprine PPR, contagious caprine pleuro pneumonia (CCPP), goat pox, brucellosis, and pneumonic pasteurellosis were ranked in that order of importance. The seroprevalence in bovine were found to be 97, 10, 18, and 15% for septicemic pasteurelosis, CBPP, FMD, and brucellosis, respectively. The seroprevalence of septicemic pasteurelosis, PPR, and brucellosis was 86, 49, and 3%, respectively, in ovine. The seroprevalence of caprine sera for CCPP, PPR, and brucellosis were 87, 42, and 0%, respectively. The prevention and control regimen, vaccination against CBPP, should be at the beginning of wet season, whereas, for FMD, it should be at the end of wet season in bovine. Brucellosis for bovine, if has to be applied, should be at the beginning of dry season. PPR vaccination for ovine should be at the beginning of wet season whereas, for caprine, it should be just before start of dry season. Furthermore, the efficacy of aforementioned vaccines and its protocol should be verified in local context. In conclusion, this finding is an alarm and requires preparation and implementation of appropriate disease prevention and control strategy in collaborated approach. Further studies have to be conducted, with particular emphasis in determining the epidemiology, and prevention and control options of FMD and brucellosis.

Influence of mutation in nucleoprotein of Peste-des-petits-ruminants virus (PPRV) isolated from 2016 Indian outbreak

Lyantonde District, Uganda, is a recognized hotspot for Peste des Petits Ruminants (PPR) outbreaks. However, the magnitude and risk factors of PPR in this area remain poorly characterized. This study aimed to determine the prevalence of PPR antibodies in goats and sheep and to identify associated risk factors in selected sub-counties of Lyantonde District. A cross-sectional serosurvey was conducted in July 2024 in three purposively selected sub-counties (Lyantonde, Lyakajula, and Kinuuka), chosen for their large small ruminant populations, high livestock trade activity, and active animal movement. Farms without a history of PPR vaccination were randomly selected, and simple random sampling was used to select study animals. Whole blood samples were collected from the jugular vein and analyzed using the ID Screen® PPR competitive ELISA kit to detect virus-specific IgG antibodies. Multivariate analysis was performed using Modified Poisson regression to identify risk factors associated with PPR seroprevalence. Adjusted prevalence ratios (aPRs), 95% confidence intervals (CIs), and p-values were reported. A total of 351 goats and sheep were sampled, with an overall apparent seroprevalence of 42.17% (n = 148). The Rogan-Gladen estimator gave a true prevalence of 44.27%, with goats showing a significantly (p = 0.046) higher prevalence (46.27%) compared to sheep (33.62%). Age was significantly associated with seropositivity. Animals aged > 1-3 years (aPR = 1.86; 95% CI: 1.16-2.97, p = 0.009), and > 3-5 years (aPR = 2.56; 95% CI: 1.54-4.24, p < 0.0001) had higher prevalence ratios compared to those < 1 year. Goats also had higher prevalence ratios than sheep (aPR = 1.59; 95% CI: 1.01-2.53, p = 0.046). Farms reporting wildlife interactions had a 43% higher prevalence ratio (aPR = 1.43; 95% CI: 1.07-1.91, p = 0.015), and acquisition of new animals from other farmers was similarly associated with higher prevalence ratios (aPR = 1.32; 95% CI: 1.02-1.71, p = 0.029). This study shows the high burden of PPR among small ruminants in Lyantonde district, with higher prevalence in goats than sheep and identification of risk factors associated with seropositivity. The study provides baseline evidence of PPR exposure and documents differences by species, age group, animal acquisition practices, and reported wildlife interactions. These findings contribute to improved characterization of PPR epidemiology in Lyantonde district and may inform the design of future surveillance and control activities aimed at reducing PPR burden.

The threat of peste des petits ruminants: progress in vaccine development for disease control

In December 2017, Peste des Petits Ruminants (PPR) emerged in Burundi (East Africa) and rapidly spread to five provinces (Gitega, Kirundo, Mwaro, Muramvya and Karuzi) in the country, causing severe disease and killing more than 4,000 goats in the province of Gitega alone. An initial outbreak investigation was conducted in December 2017 by the Burundi Government Veterinary Services and samples were collected for laboratory confirmation. A competitive Enzyme Linked Immuno-Sorbent Assay (cELISA: Chinese Patent No. ZL201210278970.9) supplied by the Lanzhou Veterinary Research Institute was used to test 112 sera and results showed around 37.5% positive samples. This high level of PPR positive sera in an animal population where PPR infection and vaccination had not been previously reported indicated the exposure of the animals to PPRV. Subsequently in January 2018, the laboratory tests conducted at the African Union-Pan African Veterinary Vaccine Centre (AU-PANVAC) laboratories following a joint investigative mission by the African Union-Interafrican Bureau for Animal Resources (AU-IBAR), AU-PANVAC and the East African Community (EAC) confirmed the presence of PPR in Burundi. Samples tested by conventional RT-PCR indicated the presence of the PPR virus (PPRV). Confirmatory isolation of the virus was also performed. Phylogenetic analysis revealed that the virus belongs to lineage III and shows a close relationship with PPRV isolates from Kenya in 2011 and Uganda in 2012. A possible explanation for the outbreaks of PPR in Burundi between December 2017 and February 2018 is presented.

Peste des petits ruminants (PPR), an economically important morbillivirus infection of sheep and goats, is widely distributed in sub-Saharan Africa, Middle East and western and southern Asia including Bangladesh. A small flock of Black Bengal goats contracted PPR following introduction of new animals. A pathological investigation was conducted on the outbreak, the viral RNA corresponding to F gene was detected by RT-PCR and the virus was isolated in Vero cells. Out of 37 goats 19 (51%) developed clinnical disease, of which 5 (13.5%) died. Goats under one year of age had highest morbidity and mortality with typical signs and lesions of PPR. Viral RNA should be detected in mesenteric and bronchial lymph node tissues. Typical cytopathic effects (CPE) in Vero cells following inoculation of lymph node tissue homogenate were visible at the third passage. However, the replication of virus in cel culture was detected by RT-PCR at the first and second passage in the absence of visible CPE. RT-PCR appears to be a very useful and sensitive tool not only for the detection of PPR virus in clinical samples but also for monitoring the growth or virus in cell culture following inoculation.DOI: http://dx.doi.org/10.3329/bvet.v28i1.8808 Bangl. vet. 2011. Vol. 28, No. 1, 1–7

ABSTRACTA study was conducted to evaluate mucoadhesive property and immunomodulatory effect of phytogenic gums from Boswellia frereana, Boswellia carteri andCommiphora myrrha on intranasal Peste des petits ruminants (PPR) vaccination in goats and sheep in an ex-vivo and in-vivo situations. Plant gums were purified, dried and compressed into 500gm tablets. Modified shear stress measurement technique was used on freshly excised trachea and intestine tissues of goat to measure peak adhesion time. Forty eight animals (24 goats and 24 sheep) were divided into eight groups (of 3 goats and 3 sheep) and immunized intranasally with gum-vaccine combinations in two ratios (1:1, 1:2). Antibody against PPR virus was measured on day 14, 28, 42 and 56 post vaccination using H-based PPR bELISA. The peak adhesion time of the different gums was transient. PPR virus antibodies were detected in all immunized goats and sheep but not in unvaccinated control. The best percentage inhibition was recorded for Boswellia carteri-vaccine combination group at a ratio of 1:1. Administration of Boswellia carteri-PPR vaccine combination through intranasal or subcutaneous route, elicited similar antibody titre, implying that the intranasal route may be used as a non-invasive alternative delivery in PPR vaccination of small ruminants.