PETALING JAYA: A total of 45,901 dengue cases were reported this year, the Health Ministry said.

The figure was an increase of 11.9% from the 41,006 cases in 2009.

The number of dengue deaths also increased with 134 this year compared to 87 in 2009.

The ministry attributed the rise in cases and deaths to secondary infection by four different types of dengue virus or serotype.

Health director-general Tan Sri Dr Ismail Merican said a secondary infection was an infection that occurs during or after treatment of an existing infection.

He said there were four types of dengue serotype – DEN-1, DEN-2, DEN-3 and DEN-4 – that could cause dengue, and immunity against one of these types did not protect one against the other three.

“Patients who recover from infection with one serotype will not have protection against the other three,” Dr Ismail told The Star yesterday.

He said the four serotypes had existed not only in Malaysia, but globally, adding that previously, there were only DEN-1 and DEN-2.

“The existence of more dengue serotypes could be due to global warming, climate change and other factors,” he said.

Dr Ismail noted that there was no dominant serotype this year.

He said 26% of patients were infected by DEN-1, 29% DEN-2, 27% DEN-3 and 18% DEN-4.

He said the current rainy spell increased the chances of mosquito breeding and urged the public to destroy all potential breeding spots for Aedes by carrying out regular gotong-royong.

“The public must seek early treatment if they discover any dengue symptoms,” he said.

Retrieved online from http://thestar.com.my/news/story.asp?file=/2010/12/31/nation/7716328&sec=nation on Dec 31, 2010