Hawaii Governor David Ige declared a state of emergency on Friday amidst an outbreak of dengue fever. According to the Associated Press, there have been more than 250 confirmed cases on Hawaii’s Big Island.

The declaration also applies to the Zika virus, although there have not yet been any locally-transmitted Zika cases in Hawaii.

“We are doing everything we can to be prepared, to be proactive, to prevent vector borne diseases here in Hawaii,” Ige said at a press conference. The mosquitos that carry dengue can also carry the Zika virus, which is present on several Pacific Islands, including American Samoa.

Per the Department of Health, 231 of the confirmed cases are residents of Hawaii Island and 24 are visitors: 209 are adults and 46 are children.

Outbreaks of dengue are rare in Hawaii, BuzzFeed News reports:

This is the first outbreak in the Hawaiian Islands since 2011, when four people were infected on Oahu with a local strain of dengue fever. In 2001, an outbreak in Hawaii infected 153 people, predominately in East Maui. Dengue is not normally present in Hawaii and occurs mainly in Asia, Africa, the Caribbean, and the South Pacific. It was likely transmitted via travelers coming through the islands, as happened in Hawaii in 2001 and 2011.

An official with the Centers for Disease Control and Prevention said Nov. that visitors to the islands should not cancel plans. “This isn’t a huge outbreak compared to elsewhere,” said Dr. Lyle Petersen, director of the CDC’s Division of Vector-Borne Diseases, on Nov. 20. In comparison, Peterson said as many as 400 million people are infected yearly around the world. He said in Puerto Rico, where the disease is endemic, that 95% of the population has been infected at some point.

Declaring a state of emergency may help the state acquire more funding for preventative measures, and will also empower state officials take more aggressive steps to preventing the outbreak’s spread.