At least 40 Virginia nursing home operators and employes flew to Honolulu for five days of sand, sun and surf at their annual national convention last fall, aware that federal and state taxpayers would pick up much of the tab.

They did -- paying up to $1,350 a person for the trip. The event underwritten by the government was the 30th anniversary convention of the Washington - based American Health Care Association, the nation's largest nursing home group.

Officials said they were unsure how many convention-goers have asked that their expenses be paid. But under federal health care guidelines adopted by Virginia and most other states, the nursing home group could bill most expenses of the trip to federal health insurance programs for the poor and elderly as "costs related to patient care."

The reason: sandwiched in the five-day Honolulu conference were 18 hours of educational sessions on topics such as antitrust law, labor relations and drug reaction.

"Of course it was fun, but it was also very educational," said Vivian V. Hewett, administrator of the Woodbine Nursing and Convalescent Center in Alexandria. "They had seminars every day of the week and they were excellent."

But besides the seminars, the convention package included optional golf, tennis and deep-sea fishing tournaments, an all-day scenic tour of Oahu's north shore, a "Pearl Harbor cruise with lunch," and an evening show that promised "you'll dine in beautiful surroundings and see a show by one of Hawaii's top male entertainers!"

"We can't help it if people went to have fun in Hawaii," said Michael Codel, the American Health Care Association's public affairs director. "Hawaii is a state. It's not like they went off to the Riviera."

Codel added, "If anybody thought this was a big political issue, I'm sure they would have jumped on it by now, and no one ever has."

Virginia's chief Medicaid auditor did question the properiety of the trip, leading officials to limit reimbursement to a maximum of $1,350 a person. That means the state's total payment could reach $54,000, about 56 percent of which comes from federal funds.

Medicaid officials in the District of Columbia and Maryland said today that their departments would also likely allow reimbursement for the convention, but could not say how much money was involved.

Federal guidelines also allow nursing homes to be reimbused for the costs of belonging to the Health Care Association and its state branches, which are considered among the nation's most effective lobbying groups both on Capitol Hill and at state legislatures. The cost of attending the group's annual three-day conference in Washington, which includes a congressional reception on the Hill, also can be reimbursed, under the guidelines.

Association officials and nursing home operators contend the primary purpose of the annual conventions -- which in past years were held in San Diego, New Orleans, Houston and Orlando, Fla., as well as a previous outing in Honolulu in 1974 -- is educational.

Federal health officials say most, but not all, states have adopted the guidelines for use in their state-operated health programs. The only example they cited was Michigan, which five years ago adopted a policy banning reimbursement for conferences held outsife the continental 48 states.

State officials say that because of the guidelines, they must allow the expenses even though some officials question them.

"They tell me it's allowable under federal regulations, so what are you going to do?" said Norbert Lassahn, Maryland chief of Medicaid invoice processing, who said he was surprised to learn from a reporter that the trips were reimbursable.

In Virginia, chief Medicaid auditor Stephen R. Roizen laid down a set of conditions last June for nursing home operators who went to Hawaii. Roizen said only one person from each home could attend, and limited the reimbursement to $1,350, based on tourist-class air fare and the cheapest available accommodations.

When Virginia Health Care Association executive Robert Seiler wrote to complain about the restrictions, Roizen responded with a letter citing the requirement that the conference by primarily educational, and noted:

"I cannot believe that this [education] is the primary purpose of the national convention and, therefore, feel that the guidelines proposed are most liberal."

Roizen said he said no way of calculating total public payments for the convention because nursing homes will include the expenses in their administrative costs reported to the state and not as a separate item. State auditors may examine receipts from the convention during an examination of each home's books. Those audits usually occur every three years, Roizen said.

Federal officials contend states are not required under their guidelines to reimburse conventioners for the trips.

"A state could look at this and decide the convention was not a reasonable expense and just throw it out," said Milton Dezube, health program analyst for the new Department of Health and Human Services (formerly HEW).

In 1975, then-HEW secretary Casper Weinberger called Medicated reimbursement of the association's three-day Washington conference "an abuse of taxpayers' money" and asked for new federal regulations to prohibit the practice. The regulations were never drawn up, health officials said today, because it was decided to leave discretion over the payments to indivdual states.

Under present federal guidelines, the government aslo reimburses owners for annual dues of $3.85 per nursing home bed to the association, which boasts 7,500 members with 650,000 beds -- a total of more than $2 million a year. The associations's Codel said the money went for salaries for the group's 30-member staff, which includes a three-member government services section. Codel said the section advises federal health officials and members of Congress on proposed laws and regulations but denied that the group's activitives constitute "lobbying" -- an assertion some congressional staff members scoffed at.

"They sure as hell do lobbying and they're very effective," said a staff member of the House Select Committee on Aging, who asked not to be identified. "They're a significant force in this town and they throw their weight around a good deal."

In Virginia, the 150-member state Health Care Association's dues also are reimbursable under Medicare and Medicaid.The state group is more candid about its lobbying effort, which includes and annual reception for legislators at one of Richmond's most luxurious hotels. This year, the association reported spending more than $9,000 for lobbying.

The association's major legislative work this year involved opposing a state Senate resolution requiring the Virginia Health Department to reevaluate its system of paying for nursing home sales. Critics charge the present system can give a windfall profit to owners. The bill died in a House committee after Seiler and another association lobbyist spoke against it.