Detection of measles virus RNA in whole blood stored on filter paper

The purpose of this study was to evaluate the use of dried blood spots stored on filter paper as a means to provide specimens for virologic surveillance for measles virus (MV) in situations when the reverse cold chain is not available. Two single-step RT-PCR assays were evaluated for sensitivity of detection of MV nucleoprotein gene RNA. The more sensitive assay was then used to assess the stability of MV RNA in dried whole blood stored on filter paper. MV RNA was found to be stable in dried blood spots for up to 2 months at room temperature or 1 month at 37degreesC. As few as 100 infected human peripheral blood mononuclear cells (PBMC) per blood spot could be detected using a single-step RT-PCR reaction and ethiclium bromide detection. MV RNA was also detected in dried blood spots obtained from rhesus macaques after challenge with wild-type MV. In the rhesus samples, the single-step RT-PCR reaction could detect approximately 10(3) TCD50 per blood spot, while nested PCR detected 3 TCD50 per blood spot. The results of this laboratory-based study suggest that the use of dried blood spots stored on filter has the potential to improve virologic surveillance for MV in some areas, and they emphasize the need for continued testing underfield conditions. (C) 2002 Wiley-Liss, Inc.