The study involved typing dengue viruses from 136 patients under 15 years old who were admitted to Pathum Thani Provincial Hospital between May 1999 and April 2000.
A total of 44 dengue virus strains were isolated, accounting for a 32.4% isolation rate, with the breakdown as follows: 18 DEN-1, 18 DEN-2, 7 DEN-3, and 1 DEN-4.
The isolation rate of dengue viruses declined as the number of days since the onset of symptoms increased, notably from day 4 to day 8.