An increase in cases has been seen at emergency rooms on O'ahu for a couple of months, said state Department of Health communications director Janice Okubo. Dr. Marian Melish, pediatric infectious disease specialist at Kapi'olani Medical Center for Women and Children, said doctors in Honolulu have seen a jump in cases since May.

Melish did not have the latest figure for reported viral meningitis cases but said the number of cases appears to be about three to four times higher than usual. "There are at least two or three a day," she said.

Melish, who is also a professor of pediatrics at the John A. Burns School of Medicine at the University of Hawai'i, said there appears to be no concentration of cases in a specific area or association with any particular activity.

"We have been seeing a large number of children, several times more than we see in most years," Melish said. She said this outbreak is unusual in appearing more in school-age children, teens and young adults, while it's usually concentrated on infants.

Melish said people who have fever, headache and/or a stiff neck should be evaluated to make sure it's not the more serious bacterial meningitis.

She said her patients tell her that they could tell something was different about this illness. "They all tell me it's the worst headache they've ever had," she said.

On Kaua'i, the outbreak has brought an estimated 50 to 60 children and a few adults to the Wilcox Memorial Hospital emergency room and family physicians in the past few days.

"We've seen half a dozen in the last week, and there have been probably 10 times that many at the emergency room," said Dr. Bob Wotring, head of pediatrics at Wilcox. Most are treated and sent home, but some — those who are unable to keep fluids down— have been admitted to the hospital, he said.

Wotring said doctors recommend that parents bring children in for checkups if they display the symptoms. While antibiotics will not help a viral infection, some doctors may place patients on antibiotics until they are sure the disease is not bacterial.

There are many different viruses that cause viral meningitis, a term that refers to the irritation of the lining of the brain. The main disease-causing virus in this outbreak appears to also involve intestinal distress.

Viral meningitis, which normally clears up by itself in 10 days or so, is not tracked by the state Health Department, so the agency doesn't know exactly how many cases there have been.

Maui and the Big Island have not seem a similar increase in cases, according to officials.

At Hilo Medical Center, Infection Control Director John Halloran said there have been less than a half-dozen cases of viral meningitis this year, which is about normal. Halloran said viral meningitis is seasonal, with a few cases normally cropping up in July, August and September.

On Maui, Dr. Scott Hoskinson, infectious disease specialist and hospital physician for Kaiser Permanente, said he has seen only a couple of cases this year.

Okubo recommended that sick children be kept home from school or summer activities, where they could infect others.