Philippine health authorities declared a national alert on Monday, after the number of dengue cases almost doubled since last year.

A total of 456 people have died of dengue in the Philippines in the first half of this year, which was a 39% increase on the same period last year. It is the first time the authorities have called a national alert because of dengue.

Health Secretary Francisco Duque III said "the objective is very clear — we want to raise awareness among the public and more importantly in communities where signs of early dengue increase are evident."

Cases of the illness are 85 percent higher than at the same time last year, the health authorities warned. This year, 106,630 people have contracted dengue compared to 57,564 in 2018.

Duque said the health department had issued a "code blue" in response to the huge increase.

He urged the public to seek medical help if they notice any of the symptoms. Dengue's main signs include a fever for more than two days, severe joint and muscle pain, and nausea.

Early detection "crucial"

"When there is hemorrhage, internal bleeding, the heart is affected, the other organs are similarly affected. Early detection is so crucial," he said.

According to the World Health Organisation (WHO), early detection and access to good care can reduce dengue fatality rates to below 1%.

The Philippine government suspended the vaccine for dengue, Dengvaxia, from schools in 2017, after the manufacturer revealed it provoked huge side-effects.

The French pharmaceutical company Sanofi admitted that people who took the drug suffered worse side effects after taking the medication.

Dengvaxia was withdrawn in 2017 after it's manufacturer admitted it could have side-effects

Vaccine distrust

Experts have connected the scandal with growing distrust of any vaccine in the Philippines. The number of people who took vaccines dropped from 70% to 40% in 2018.

Dengue is the fastest moving infectious disease in the world, with around half a million people currently infected with the illness.

jns/rc (EFE, dpa)