Browsing by Author "Lahikainen, Elina"

Rotaviruses are double-stranded RNA-viruses. They are members of the family Reoviridae and are the cause of severe gastroenteritis in young humans and animals. Primary infection is the most severe and reinfections usually produce only mild symptoms. Worldwide about 600 000 children die every year from rotavirus infection, and this figure represents about 5 % of all deaths in children younger than five years. Virtually all children will be infected by the time they reach one year of age. Because primary infection is so severe, rotavirus vaccines have been developed. Surveillance studies are needed to monitor the vaccine impact on circulating viral strains. It is important to know whether some strains disappear and new strains, possibly from animals, emerge. This rotavirus genotyping study is part of a long-term European surveillance study, which tries to define and monitor rotavirus types circulating in Europe. Proteins VP4, VP6 and VP7 are the primary antigens of rotaviruses. Rotavirus is classified into serogroups A-G based on inner layer protein VP6. Group A-C rotaviruses are human pathogenes. Most human rotavirus diseases are caused by group A rotavirus. The group A rotaviruses are further classified into G and P types based on the outer layer proteins VP4 and VP7. 15 G and 14 P types have been identified in humans. In this study we established G and P types for 200 rotavirus samples by using nested-PCR. Materials consisted of stool samples originated from HUSLAB virology department and Kuopio University Hospital. Rotavirus positive stool samples taken from children during years 2005-2007. RNA was extracted from stool suspensions and it was translated to DNA and amplified by nested-PCR. As first step RNA was transcripted to cDNA by reverse transcription. cDNA was amplified from gene segment areas that code for VP4 and VP7 proteins. As second step these PCR-products were amplified using G and P type-specific primers. Final PCR products were G and P typed by using agarose electrophoresis. We find that most common G types in 2005-2007 were G1 and G9; other G types was also found. Most common P type was P[8], which constituted 90 % of all viruses. The most common G and P combinations were G1P[8] and G9P[8]. In epidemic season 2006-2007 the most common G types in Helsinki were G1 and G9. In Kuopio predominant stains were G2 and G9. The most common G and P combinations in epidemic season 2006-2007 were G1P[8] and G9P[8] in Helsinki and G9P[8] and G2P[4] in Kuopio. In recent years the most common G types in Europe have been G1-G4 and G9. Finnish genotype distribution is mainly congruent with G and P types in other European countries.