A statewide increase in field mice, especially on Maui, may be contributing to the increase of typhus cases because fleas on the infected rodents are spreading the disease, said state epidemiologist Paul Effler.

"It's serious," Effler said. "To prevent more and more cases coming, people need to be getting on the fleas and getting on the rodents that transport it to the home."

Overall, 12 typhus cases have been confirmed in Hawai'i. Ten of the cases occcurred on Maui ­ six of them with ties to Kihei, where it appears to have been hit the hardest. One case each has been reported on O'ahu and Kaua'i.

Effel said murine typhus is endemic to the islands, and in a previous year, Hawai'i had a high count of 10 confirmed typhus cases.