Hawai’i’s Big Island is under a state of emergency, declared by Hawai’i County Mayor Billy Kenoi in early February. The island has 250 cases of the mosquito-spread virus confirmed since Oct. 29.

The declaration means people on the island will be allowed to resume disposal of old tires in landfills, since tires can collect water and serve as a breeding ground for mosquitos.

The dengue outbreak is the largest in Hawaii since the 1940s, reports NBC News. The disease causes flu-like symptoms and can develop into dengue hemorrhagic fever, which is often deadly.

Hawai’i Governer David Ige said he would not extend a statewide emergency declaration unless the outbreak spreads to other islands or expands to include other mosquito-spread diseases such as Zika, which is currently spreading in South and Central America as well as the Caribbean.

In January, a baby born with brain damage at an Oah’u hospital was the first case of the Zika virus in a birth on U.S. soil.