There has been a sharp spike in dengue cases in Indonesia this year with more than 13,000 recorded so far, more than twice the number for the same period last year.
The number of deaths has also jumped - to 133 this month from 43 in January last year.
The Health Ministry attributed the spike to greater rainfall intensity as well as humidity, and the government has moved to implement measures to curb the spread of the viral disease.
January and February are forecast to be the peak of the rainy season on the archipelago this year.
"Water is abundant now. The humidity and temperature affect the mosquitoes, so they can live longer and their eggs hatch faster," said Ms Siti Nadia Tarmizi, the Health Ministry's director for vector-borne and zoonotic diseases, at a press briefing yesterday.
Dengue is transmitted through bites from the Aedes aegypti mosquito.
Increase in dengue cases in Indonesia this month, compared with the same period last year.
However, she said that the government had yet to declare a dengue emergency for the whole country despite the sharp rise in cases.
So far, only four regions - the city of Kupang and West Manggarai regency in East Nusa Tenggara, Kapuas regency in Central Kalimantan and North Sulawesi province - have declared a health emergency.
"Indeed, we've seen an increase (in cases) in January, but the figure is much lower compared with the average number in past years," said Ms Siti.
Official figures show that Indonesia recorded more than 120,000 dengue cases each year between 2005 and last year.
More than 1,000 people have died from the disease annually.
But 2016 was an exceptionally bad year with 204,171 cases and 1,598 fatalities.
Ms Siti said that to control the outbreak, the health ministry has distributed larvicide and fogging equipment to affected regions.
It has also raised awareness among communities to destroy mosquito breeding grounds by burying, draining and covering objects that can store water.
Ms Inda Mutiara, head of infectious, vector-borne and zoonotic diseases at the Jakarta health agency, was also at the news briefing. She said her office had, among other things, funnelled larvicide to all villages in the capital as part of its efforts to fight the disease.
Jakarta reported 430 cases of dengue in the first three weeks of this year, nearly four times the number for the same period last year, although no fatalities were recorded.