There is no evidence that the troublesome strain of HIV is spreading rapidly, but its appearance underscores the need for renewed emphasis on safe-sex practices, officials in the Seattle-King County public health department said Thursday.
"There may be more cases we don't know about," said Dr. Bob Wood, the agency's HIV/AIDS program director.
"We are still working to learn more about these individuals and the virus they have contracted," said Dorothy F. Teeter, interim director of the department. "We are concerned for these individuals and their partners and are continuing our investigation."
The same genetic strain of HIV was found over a 15-month period in all four men, methamphetamine users who each had multiple partners, but none is known to have had sex with any of other three, officials said.
"That's highly unusual," said Dr. Peter Shalit, who treats HIV/AIDS patients and directs HIV/AIDS research at Swedish Medical Centre.
One possibility is that there is a new strain of multi-drug-resistant HIV that is spread more easily than previous drug-resistant strains, "definitely a scary prospect," Shalit said.
"There's no evidence that this has spread outside of King County," said Dr. Patrick Sullivan, chief of the behavioral and clinical surveillance branch at the Centers for Disease Control and Prevention in Atlanta.
But the center also hasn't compared this strain with ones outside King County because the center studies disease from a population, not an individual, perspective, he said Friday in a telephone interview.
One man in New York, diagnosed with HIV in December 2004, was found to have a multi-drug-resistant type of HIV and he too had multiple, anonymous sexual partners, a history of methamphetamine use and had sex with men, according to the CDC.
Nationally, 2 percent to 3 percent of the HIV strains that people are infected with may be resistant to two to three classes of drugs, Sullivan said.
While at least 100 King County residents die of AIDS annually, there is evidence of declining condom use and other safe-sex practices among gay drug users especially, said Wood, who is gay and has medically managed his own HIV infection for more than 20 years.
"There's a lot of complacency," he said. "People need to know that some of these new infections may be impossible to treat."
Seattle was among the first metropolitan areas in the country to begin a surveillance program for multi-drug-resistant HIV in 2003.
Since then, doctors and other health care providers have been asked to test routinely for drug resistance in anyone who is HIV-positive and to report any indication of multi-drug-resistant strains.
Before Thursday, health officials had identified 12 cases of multi-drug-resistant HIV in the county, none as resistant to anti-viral drugs as the most recent four.
None of the four men has experienced any symptoms, Wood said , but experts fear that drug-resistant HIV could progress to AIDS much faster than typical HIV.
In addition, Dr. Robert D. Harrington, director of a Harborview Medical Center clinic for HIV patients, said treatment for those who are resistant to several types of drugs could cost more than twice as much as the $15,000 a year that is needed for typical HIV.Copyright 2007 Associated Press.