Nearly half of the 9,000-plus new HIV infections in Thailand each year are people aged between 15-24 years old, according to the Department of Disease Control.

Dr Suchada Jiamsiri, chief of the Division of Aids and Sexually Transmitted Infections, Ministry of Public Health's Department of Disease Control, said infections among this age group have been a trend for several years.

The highest rates used to be among sex workers and the group of men who have sex with other men, said Dr Suchada, who was speaking with the Bangkok Post for World Aids Day, which occurs on Friday.

Dr Suchada said these rates show that young people have paid less attention to the disease and ignored the use of condoms.

She said that the young are likely to care more about the prevention of an unwanted pregnancy at their age, such as by using birth control pills, which have been effective in reducing the number of teenage mothers, but it seems that the condom is the last choice due to perceptions that it will make sex less fun.

"We have a strong concern about this trend, and we have tried our best to raise their awareness about condom use," she said.

Dr Suchada said the department's latest survey found that 77.8% of female middle school students and 59.1% of male students use condoms, and the numbers are 77.6% and 72.5%, respectively, among vocational school students.

She said the department has closely worked with civil society to send a strong message that HIV/Aids can be prevented by having safe sex.