Filter paper is a simple and cost-effective transport medium for serological diagnosis of Peste des petits ruminants

Peste des petits ruminants (PPR) is a highly contagious disease caused by peste-des-petits-ruminants virus. Following the successful eradication of the related rinderpest virus, a program to control and eradicate PPR was launched by the FAO and OIE. PPR is today present in many tropical countries where maintaining the cold chain for sample transportation is one of the major barriers for timely processing. Transport of samples on filter paper is a simple and cost-effective method, however validation and optimization is required to fully adapt this approach. The objective of this study was to evaluate and validate the use of filter paper in serological diagnosis of PPR. Blood samples (serum and filter paper) were collected from sheep and goats in both Tanzania and Pakistan and analysed using a PPRV-specific cELISA. The positive proportion was 10.7% in Tanzania and 80% in Pakistan when performing the analysis on serum. These results were then considered as reference and compared to the results from the filter papers analysed by the same cELISA. According to the statistical analysis the cut-off for a positive results for samples stored on filter paper was adjusted from < 50 % competition percentage to < 84% in Tanzania and to < 69% in Pakistan.These results demonstrate that filter papers are an acceptable and cost-effective transport method of whole blood samples for later use in serological analysis.