The state Department of Health says it’s investigating two suspected cases of dengue fever in East Maui.

The department said today it has confirmed that four people in Hawaii have contracted the viral disease so far this year. All four were infected by mosquitoes near their homes in the Pearl City area of Oahu.

The department has received 42 reports from doctors about possible cases of dengue fever around the state. The department has determined 13 of the cases to be negative.

Dengue fever is transmitted by mosquitoes in mostly tropical and subtropical areas.