O'ahu's latest swine flu victims did not have contact with any of the first three patients and appear to have contracted the disease here, state health officials announced yesterday.

The two most recent infected adults have not left the island, but did come in contact with one another, state Health Department spokeswoman Janice Okubo said.

That means they likely contracted swine flu — H1N1 influenza A — from someone else in Hawai'i who has not yet been diagnosed.

"Now that we have two people that have not traveled, that are in the community, we need to be more diligent about how we interact with people that have any signs or symptoms of a respiratory illness," said Dr. Matthew Bankowski, an assistant professor of pathology at the University of Hawai'i's John A. Burns School of Medicine and laboratory director for clinical and molecular microbiology and infectious disease for Diagnostic Laboratory Services Inc.

The first three cases of swine flu on O'ahu were a married Army couple and an unrelated school-age child. The soldier had traveled to Texas and the child had been in California — states with confirmed cases of swine flu.

In the two latest cases, one patient is recovering at home and has been in self-isolation, Okubo said. The other is being treated at home, she said.

"We can expect to see more confirmed cases as this nationwide outbreak continues," state epidemiologist Dr. Sarah Park said.

The latest cases were discovered by reviewing the more than 100 lab tests sent to the state Health Department every day, Okubo said.

ENHANCED SCRUTINY

Before this week, state health officials would normally receive positive results for influenza A and then run additional tests for specific strains of influenza A. If they could not identify the strains as a known type of seasonal flu, they would then test for swine flu, for which no vaccine was produced, Okubo said.

Starting this week, health officials have been testing for swine flu first. They're even reviewing influenza tests before the results get back to the doctor who ordered them.

"Our staff has been back-tracking, reviewing and analyzing hundreds of test results from commercial clinical laboratories to identify all specimens that were identified as influenza A that may not have been properly reported and may potentially be novel influenza A rather than seasonal influenza A," Park said in her statement.

With any positive results for influenza A, health officials also have begun contacting the patients directly this week to suggest they stay home. Health officials are also asking for the names of anyone the flu sufferer has been in contact with, Okubo said.

"We'll have that information ready so that if they are confirmed (for swine flu), we can jump on that," Okubo said. "We already know where they've been and whoever they've been in contact with."

PRICIER TESTING

The Health Department now wants physicians to order more costly molecular testing for all suspected influenza patients, regardless of whether they have traveled recently.

Doctors more often use an in-office "rapid test" that has been known to produce false negative and false positive results, Dr. Bankowski said.

"Molecular testing takes longer, is more expensive, but more exact," he said. "Molecular testing is the preferred method. It is the most sensitive and the most specific."

At a price of at least $100 per test, Bankowski said molecular testing is three times the cost of the in-office test.

"These two cases indicate that there is at least limited community transmission of the novel influenza A (H1N1) virus on O'ahu," state health director Dr. Chiyome Fukino said in a statement. "Because the two individuals saw medical providers, followed doctor's orders and remained at home while sick, they reduced the chance of others from becoming ill."