Persistence of infectious peste des petits ruminants virus in clinical materials and environmental matrices

Аннотация

Background and Aim. Peste des petits ruminants (PPR) is a major transboundary infection causing substantial economic losses in sheep and goat farming. For epizootic surveillance and laboratory diagnostics, data on the persistence of peste des petits ruminants virus (PPRV) in clinical material and environmental matrices are essential, yet remain limited. This study aimed to quantitatively assess the persistence of infectious PPRV in clinical material and selected environmental objects and to determine the effect of key physicochemical factors on the loss of infectivity.
Materials and Methods. Infectious virus was recovered from organs/tissues of deceased animals, excretions/secretions from diseased animals, and residual drinking water after storage under controlled conditions. Virus infectivity was assessed after isolation in a susceptible primary lamb kidney cell culture and quantified by titration (TCID₅₀). Stability was evaluated under different temperature regimes, desiccation, extreme pH values, freezing (−10 °C and −50 °C), and lyophilization under vacuum and non-vacuum packaging.
Results. Under isolator conditions (14-16 °C, ~80% relative humidity), infectious virus was generally recoverable from carcass material and secretions mainly within the first 24-48 hours and was not recoverable after 48 hours. Freezing markedly prolonged infectivity: virus-containing material retained infectious activity for 6.5 ± 0.5 months at −10 °C and up to 24 months at −50 °C (observation period). Lyophilized material stored under vacuum at −10 °C remained infectious for at least 18 months with a substantial reduction in titre, whereas non-vacuum storage resulted in loss of infectivity within 3-5 days. In model matrices, infectivity declined rapidly at positive temperatures, during drying, and at extreme pH values; heating to 80 °C/boiling caused immediate inactivation.
Conclusion. PPRV infectivity in clinical material and environmental matrices is strongly determined by temperature, pH, and desiccation, while freezing and properly packaged lyophilization provide prolonged preservation. The results support practical recommendations for sampling, storage, and transport of material for PPR laboratory diagnostics.