Dengue cases in the Philippine capital region of Metro Manila are down by almost 41 percent on year to 1,638 for the Jan. 1 to March 22 period, the local health department said Friday.

Figures released by the Philippine Department of Health (DOH) showed that Manila recorded the highest dengue cases at 363, followed by Quezon City with 302; Las Pinas, 139; Pasig City, 133; Caloocan City, 118; Paranaque City, 108; and Taguig City, 103. The DOH recorded five deaths due to dengue.

"The decline in dengue cases means that residents of Metro Manila are now more cautious and concerned about the disease," DOH Undersecretary Ted Herbosa said.

The dengue virus is transmitted by infected female Aedes aegypti mosquitoes. According to the World Health Organization, symptoms of dengue include high fever, severe headache, pain behind the eyes, muscle and joint pains, nausea, vomiting, swollen glands or rash.

Meanwhile, the DOH said it has been spraying water-based permethrine to eliminate Culex quinquefasciatus mosquitoes which were observed to be proliferating in some parts of Metro Manila.

Culex quinquefasciatus mosquitoes or "household mosquitoes" is not as harmful as the Aedes aegypti as it does not carry the dengue virus, the DOH said.