City and state officials are urging residents to eliminate mosquito-breeding grounds and to protect themselves from mosquito bites after the state Department of Health said it is investigating four possible cases of imported Zika virus, dengue fever, and chikungunya on Oahu.

Department of Health Director Virginia Pressler said the four cases were reported to the Department of Health on Thursday, and all were acquired in Latin America or other Pacific Islands. Pressler said there have been no cases of locally-acquired mosquito-borne illnesses on Oahu and the four cases are no longer active.

Samples were sent to the Centers for Disease Control and Prevention for identification, but results could take months.

Zika and dengue fever are spread by the same type of mosquito when the mosquito bites an infected person and bites another person. Zika is linked to birth defects. All three illnesses can produce symptoms similar to a fever with muscle aches and pains.

“This could become a serious health issue for our island and we must all do our part in the ‘Fight the Bite’ campaign,” said Mayor Kirk Caldwell, referring to the state’s efforts to stop the spread of mosquito-borne illnesses. “If you feel ill with flu-like symptoms, please seek medical attention, especially if you’ve traveled to another part of the world recently.”

He said knowing about a case is also helpful in fighting the spread of the illnesses.

To prevent mosquitoes from breeding, officials urged residents to eliminate standing water, fix leaky outdoor faucets, clean gutters, and treat bromelids and other plants that hold water.

Caldwell said if you see a neighbor with standing water, volunteer to dump it out. If the neighbor cannot be reached, call the city’s Department of Permitting and Planning at 768-8117 for assistance.

The city is also inspecting all city facilities for standing water and taking appropriate action to prevent mosquitoes from breeding, city officials said.