Twelve more possible cases of dengue fever have been reported by physicians to the state Department of Health since two confirmed and two unconfirmed cases were announced last week.

The confirmed cases were from two people who live in the same Pearl City neighborhood, and were the first known Hawaii cases of locally contracted dengue fever since a 2001 outbreak in which 153 people were infected with the mosquito-borne viral illness.

The Health Department is awaiting blood sample test results from the Centers for Disease Control on the two suspected cases from Pearl City, as well as the 12 new cases, a spokeswoman for the department said.

The two Pearl City cases involved adults who contracted it in February.

The Health Department issued an alert to Oahu physicians, advising them to consider the potential for dengue infection in patients with compatible symptoms, to request laboratory testing and to report all suspected cases.

Symptoms usually begin five to six days after a patient is bitten by an infected mosquito, but the onset can range from two to 15 days. Symptoms include a sudden fever, severe headaches, pain behind the eye, joint and muscle pain and rash — typically on hands, arms, legs and feet three to four days after the fever starts.