Molecular Characterization of Lineage-IV Peste Des Petits Ruminants Virus and the Development of In-House Indirect Enzyme-Linked Immunosorbent Assay (IELISA) for its Rapid Detection".

ABSTRACT

Peste des petits ruminants (PPRV), a highly contagious viral disease, causes significant economic losses concerning sheep and goats. Recently, PPR viruses (PPRVs), have adopted new hosts and lineage IV of PPRVs represents genetic diversity within the same lineage. 350 samples, including blood, swabs, and tissues from sheep/goats, were collected during the 2020-2021 disease outbreaks in Pakistan. These samples were analysed through RT-PCR and three isolates of PPRV with accession numbers, MW600920, MW600921, and MW600922, were submitted to GenBank, based on the partial N-gene sequencing. This analysis provides a better understanding of genetic characterizations and a targeted RT-PCR approach for rapid PPRV diagnosis. An IELISA test was developed using the semi-purified antigen MW600922 isolate grown in Vero cells. The PPRV isolates currently present high divergence with the Turkish strain; conversely, similarities equivalent to 99.73% were observed for isolates collected from Pakistan. The developed indirect ELISA (IELISA) test demonstrated antibody detection rates at dilutions of 1200 for antibodies (serum) and 132 for antigens. In comparison to cELISA, high specificity (85.23%) and sensitivity (90.60%) rates were observed. In contrast to the virus neutralization test (VNT), IELISA was observed to be 100% specific and 82.14% sensitive in its results. Based on these results, serological surveys conducted for PPR antibodies using IELISA can be a more effective strategy on a larger scale. Furthermore, our results demonstrate a significant breakthrough in the research in terms of cost-effectiveness and storage efficiency, and the developed IELISA test is highly recommended for use in developing countries.

Peste des petits ruminants (PPRV) is a transboundary, highly contagious, and economically significant viral disease affecting small ruminants and wildlife. PPRV, a disease that only targets animals, is the focus of the Global Eradication Programme (PPRV GEP), which aims to eradicate the disease by 2030. Following the completion of the first phase of the GEP (2017­2021), Pakistan has initiated the second phase PPRV presence and the implementation of a control strategy. Rapid and accurate laboratory diagnosis is vital to the disease's effective control and eradication. In the present study, we have improved diagnosis by reverse transcriptase polymerase chain reaction (RT-PCR), which not only can detect low viral concentrations but also contributes to the genetic analysis of lineage-IV viruses. However, the development of cost-effective indirect ELISA (iELISA) may allow for the analysis of serum samples obtained from larger populations of small ruminants.