At least eight more people have died from dengue fever in less than a month, prompting health officials to warn people to be vigilant in preventing the disease.

The latest deaths bring the toll of the mosquito-borne illness to 24. Health officials are asking people to clean out containers and places of standing water, where the mosquitoes breed, and they are distributing a chemical additive that kills mosquitoes in cisterns.

The total number of dengue infections has risen to nearly 7,000, up from around 2,000 last year, which is a common discrepancy, because in some years, the disease is relatively dormant.

“2014 was the year of relief time, in terms of dengue fever; the number declined dramatically,” Leang Rithea, manager for the Ministry of Health’s dengue program, said.

This year, however, the disease has surged, especially in the provinces of Siem Reap, Kampong Thom, Kampong Cham, Kandal, Battambang and Oddar Meanchey, as well as Phnom Penh, he said.

Keo Vannak director of the Tbong Khmum provincial health department, said that he has seen the number of dengue infections in his province increase and that his health officials are busy educating people about the disease.

“We are still campaigning and continuing to educate people,” he said. “We remind people in the community to prevent dengue infection.”

Infections can remain high through the dry season if people do not get rid of sites for standing water, he said.