Epidemiologic features of rotavirus infection in Taiwan: a review

Group A rotaviruses are a major cause of severe gastroenteritis in children under 4 years of age worldwide. Group A rotaviruses have been identified in many animal and bird species; they are antigenically complex, and multiple serotypes infect humans. Reassortant rotavirus vaccines are now available that confer protection against severe illness due to rotavirus serotypes G1-4. Before vaccines are introduced, it is necessary to establish their efficacy and to establish a baseline for future surveillance strategies. The purpose of the present review is to describe current knowledge of the diversity of rotavirus in Taiwan. The present review is based on the available published studies and data from China Medical College Hospital (Taiwan). In Taiwan, rotavirus has been detected year-round, with the epidemic peak swinging from November-December in 1984 to January-March in 1988-95 and then back to December-March in 1996-99. Most affected patients are under 2 years of age. Only group A rotavirus has been found. Neither group B nor group C rotavirus have been identified. G1 strains have been the predominant strains except for the year 1992-93, when G2 strains were prevalent. There has been no G4 strain detected in published studies. The electropherotype 'baba' has been observed every year. Five other electropherotypes have been sporadically found. Half of the strains that have been studied were genotype P[8] and their VP7 serotype was G1 or G3. All genotype P[4] strains have shown serotype G2. It is expected that the reassortant rotavirus vaccine will be effective in prevention of severe illness caused by rotavirus in Taiwan.