The difference is being attributed to a broader use in Wailea of zinc phosphide, a federally restricted rodenticide.

The limited success, however, has not stopped the spread of murine typhus, which is transmitted by fleas from infected mice. Health officials have confirmed a 13th case ­ this one from Kahului ­ of the flu-like infection.

"The numbers of mice in most areas have declined or leveled off," said Bruce Anderson, director for the state Department of Health. "However, there is still concern about the significant increase of mice in the Kihei/Wailea area on the island of Maui. This is where the majority of the murine typhus cases have been reported."

Monitoring and increased control efforts remain a priority, he said.

The department measured the population using specially baited sampling traps in both areas, said Janice Okubo, health department spokeswoman. In Wailea, the average for an overnight sampling has come down between June and the first few weeks of this month, from 56 mice caught overnight to 36.

The overnight average more than doubled in Keonekai in Kihei, from 19 in June to 49 so far this month.

Oats poisoned with zinc phosphide cannot be used in Keonekai because of cattle in the area.

"It would poison the cattle, so they have to be careful," Okubo said. "We are using it now, but only in baited stations and in very limited amounts."

The department is still waiting for word on its request for permission from the federal Environmental Protection Agency to use zinc phosphide in pastures, Okubo said.

The continued rise in murine typhus cases is no surprise, she said.

"We expected that because we had more mice," Okubo said. "But it hasn't been dramatic or anything."