Journal of Virological Methods 117 (2004) 97–99 Short communication Use of whole blood dried on filter paper for detection and genotyping of measles virus Mar´ ıa del Mar Mosquera a,∗ , Juan E. Echevarr´ ıa a , Sabino Puente c , Félix Lahulla b , Fernando de Ory a a Centro Nacional de Microbiolog´ ıa, Instituto de Salud Carlos III, Carretera de Majadahonda-Pozuelo s/n, 28220 Majadahonda, Madrid, Spain b Hospital Regional de Bata, Bata, Equatorial Guinea c Hospital Carlos III, Madrid, Spain Received 19 August 2003; received in revised form 8 December 2003; accepted 9 December 2003 Abstract PCR, and two different ELISAs were used to detect measles virus on blood dried on filter paper samples from Equatorial Guinea. Sensitivity was 40% by PCR, 57.1% by indirect ELISA and 86.7% by  chain capture ELISA. Genotype B3 was found in two positive samples by PCR. © 2003 Elsevier B.V. All rights reserved. Keywords: Measles; Polymerase chain reaction; Genotyping; Blood dried on filter paper Laboratory diagnosis of measles virus infection is usu- ally done by detection of specific IgM in serum sam- ples. Recently, the use of blood samples dried in filter paper have been described as a potential good alterna- tive, useful both for specific IgM (De Swart et al., 2001; Helfand et al., 2001; Riddell et al., 2002), and PCR (De Swart et al., 2001; Katz et al., 2002) for situations when serum cannot be easily obtained and stored. However, these studies were made under well controlled laboratory condi- tions. The present study shows results on samples obtained in a tropical area without adequate conditions for serum extraction and storing. Two commercial kits were used for the detection of measles virus specific IgM based either on indirect (Dade Behring, Germany) or  chain capture (Chemicon USA) ELISA, and a multiplex nested reverse transcription PCR (RTMNPCR), designed for simultaneous detection of measles virus, rubella virus and parvovirus B19 (Mosquera Mdel et al., 2002), with the aim of diagnosing measles virus on dried blood samples. Genotyping measles virus was attempted on positive samples by sequencing a fragment of 456 bp corresponding to the COOH terminus on the nucleoprotein coding region amplified previously by ∗ Corresponding author. Tel.: +34-1-5097901; fax: +34-1-5097966. E-mail address: mmosquera@isciii.es (M.d.M. Mosquera). a different reverse transcription nested PCR, currently un- der evaluation. Sequences were obtained with an automatic sequencer and compared with reference strains of measles virus genotypes. For this purpose, phylogenetic distance analysis of the aligned sequences was undertaken by the neighbor-joining algorithm as unrooted tree tested with 1000 bootstraps using the MEGA (Molecular Evolutionary Genetics Analysis, Tempe, Arizona, USA) software. Twenty samples were taken from 19 patients (age: 3 months–7.5 years) from a measles outbreak occurred in Equatorial Guinea from February to May of 2001. The specimens were taken during the first 3 days after the exan- thema. The samples were collected at the Hospital Regional de Bata in a period of 4 weeks on May and maintained at room temperature (22–30 ◦ C with a relative humidity of 90%) until they were sent to the laboratory in Spain. Finally, they were stored at 4 ◦ C until tested, no more than 2 months later. All samples were tested by RTMNPCR, 14 by indirect ELISA, and 15 by  chain capture ELISA. One circular filter paper piece of 3 mm in diameter cor- responded to 1 l of serum (Evengard et al., 1988). In each serological assay, the adequate volume of dilution buffer was used to reach the corresponding dilution (1:40 in indirect ELISA and 1:200 in the capture assay). Serological tests were carried out according to manufacturer’s instructions. Both tests included antigen and control antigen wells each 0166-0934/$ – see front matter © 2003 Elsevier B.V. All rights reserved. doi:10.1016/j.jviromet.2003.12.004