Tiny blood-sucking, nocturnal bedbugs are making a dramatic resurgence, not only in Hawai'i but around the country.

"Three years ago, we were lucky if we did six bedbug treatments a year; now we're doing six a month," Xtermco pest control consultant Keith Yakabe said. "It's widespread, all over the place, from Hawai'i Kai to Nanakuli. We've even done a hospital, which had bedbugs in the sofa and chairs in a waiting room area."

The National Pest Management Association, which represents many of the country's pest control companies, reported in March that bedbug infestation nationally had increased 63 percent over the past four years and 43 states, including Hawai'i, had reported infestations.

That prompted Hawai'i lawmakers to pass a resolution ordering the state Health Department to conduct a prevention and public education campaign on bedbugs and to submit its findings and recommendations 20 days before the 2007 Legislature convenes.

The state Heath Department Vector Control Branch investigated 29 bedbug complaints — 14 at apartments, five at hotels, four at homes, one at a theater, another at a student housing building and four at miscellaneous housing areas — from July 2005 through June 2006, and the number represents "just a snapshot" of the problem, Vector Control program manager Greg Olmstead said.

"We may be seeing an increase in complaints as the public becomes more aware of bedbugs," Olmstead said.

The infestations are not just on land.

Observers with NOAA's Pacific Islands Regional Office have reported that 10 long-line commercial fishing vessels are infested with bedbugs.

"We normally try to get the boat owners to mitigate the problem, and they've been trying. They've been responsive, but it's difficult," said John Kelly, with the observer program.

"It's no secret that bedbugs are making a comeback," said Dan Suiter, an associate professor of entomology at the University of Georgia.

Before World War II, bedbug infestations were common in the United States, but they were virtually eradicated through improvements in hygiene and the widespread use of DDT in the 1940s and 1950s.

Bedbugs are tiny, brownish, flattened insects that feed exclusively on the blood of animals and humans. Their bites may cause itchy red welts or swelling.

Unlike mosquitoes, though, they are not known to transmit blood-borne diseases from one victim to another. They are extremely resilient and very difficult to exterminate. Experts say bedbugs are not necessarily an indicator of unsanitary conditions.

In the past four years, reports of bedbugs have significantly increased in U.S. cities, especially in hotels, hospitals and college dormitories — all places with high resident turnover.

Bedbugs are basically harmless, although their bites can cause swelling.

"There's absolutely no known cases of bedbugs transmitting diseases to human beings," said William "Bill" Kanour, Vector Control's new chief entomologist.

Last week, Vector Control posted a bulletin on bedbugs on its Web site. The bulletin is the first step in the planned public education campaign, which will include two different presentations to the community, to comply with the legislative mandate, said Olmstead.

According to the bulletin, the main reason for the spread of bedbugs is the decrease in the use of broad-spectrum pesticides, such as DDT, which previously kept them in check. "Now we're using targeted (pesticides) that bedbugs don't come in contact with," Kanour said.

Kanour cautioned residents returning from trips not to take their suitcases, which might be hiding bedbugs, from the car directly into their houses.

"What they can do is empty their suitcases outside and put them in a dark-colored plastic trash bag, tie up the bag and sit it out in the sun," Kanour said. "The dark plastic will hold in heat on a sunny day and kill any bedbugs."

One or two bedbugs in a home may be hard to spot, but by the time they are noticeable, there may be hundreds or tens of thousands of them, said Kanour, who recently retired from the Navy, where he was assigned to an environmental preventive medicine unit at Pearl Harbor.

"I saw one bed in a barracks room at Pearl Harbor where there were thousands in a mattress," he said. "They leave tell-tale signs because when they feed, they tend to load up and leave waste products like blood spots on the sheets."

Getting rid of a large infested area is time-consuming, Yakabe said.

Reach Rod Ohira at rohira@honoluluadvertiser.com.