Questions surround Tamiflu-resistant H1N1 viruses

Although uncertainty still surrounds the origins of the four drug-resistant H1N1 cases recently identified at the Medical Center, officials are not greatly concerned that the virus will become widespread.

The cases are resistant to Tamiflu, a drug used to treat seasonal flu and swine flu, but are no more severe than the Tamiflu-susceptible virus, according to the Centers for Disease Control and Prevention. The confirmed cases of Tamiflu-resistant swine flu are responsive to Relenza, another medication used to treat the virus.

More than 50 cases of drug-resistant H1N1 virus have appeared globally since the spring, according to the World Health Organization.

Members of the CDC’s Epidemic Intelligence Service are interviewing physicians, nurses, family members and at least one patient at the hospital to figure out the source of the four drug-resistant swine flu cases, said Dr. Joseph Govert, director of the Medical Intensive Care Unit.

“There is an investigation at this point to try to understand whether the strain of the virus is the same in all four cases or whether they are individual cases that developed a resistance to Tamiflu after having taken it,” he said.

Dr. Daniel Sexton, director of the Duke Infection Control Outreach Network, said in a Nov. 20 CDC statement that appropriate infection control procedures were practiced in the unit where the cases occurred. None of the employees working with the patients contracted the virus, he said.

All four patients with the virus were in an isolated unit of one floor at Duke Hospital when they contracted the strain, the news release said. The patients were very ill with “underlying severely compromised immune systems and multiple other complex medical conditions,” the release states.

The news release also said there is no reason for “hospital-wide” concern, and that despite these four cases, the number of hospitalizations for H1N1 in the state have declined in the past several weeks.