Swine flu- strain resistant to Tamiflu spreads between UK hospital patients
Three appear to have acquired the infection in hospital, the National Public Health Service for Wales (NPHS) said.
Two of the five have recovered and have been discharged from hospital, one is in critical care and two are being treated on the ward.
The service said the resistant strain does not appear to be more severe than the swine flu virus circulating since the spring.
All patients on the unit have been tested and patients diagnosed with Tamiflu-resistant swine flu have been given other antivirals.
Patients have been isolated or are being cared for in a designated area for influenza cases.
Cardiff and Vale University Health Board has put appropriate infection control measures in place on the unit, the NPHS added.
Staff and patients have been offered swine flu vaccinations, and patients due to come into the unit for treatment are being warned to get the jab from their GP.
Close contacts of the patients are being warned to make sure they are treated quickly if they show any symptoms.
Dr Roland Salmon, director of the NPHS Communicable Disease Surveillance Centre, said: “The emergence of influenza A viruses that are resistant to Tamiflu is not unexpected in patients with serious underlying conditions and suppressed immune systems, who still test positive for the virus despite treatment.
“In this case, the resistant strain of swine flu does not appear to be any more severe than the swine flu virus that has been circulating since April. For the vast majority of people, Tamiflu has proved effective in reducing the severity of illness.
“Vaccination remains the most effective tool we have in preventing swine flu so I urge people identified as being at risk to look out for their invitation to be vaccinated by their GP surgery.”
It comes after it was announced that more than 3million healthy children under five across the UK are to be offered the swine flu jab.
Parents will be invited by their GPs to bring their children into surgeries, with vaccinations expected to start in December.
Health ministers across the UK agreed children aged six months to five years should be included in the next phase of the vaccination programme after GPs have finished vaccinating at-risk groups, including people aged six months to 65 with conditions like asthma, diabetes and heart disease. Pregnant women and frontline health workers are also currently being given the jab.
Figures released on Thursday showed an estimated 53,000 new cases of swine flu in England in the last week, down from 64,000 in the week before. In Scotland, the figure was 21,200, down from about 21,500 in the previous seven days.
The rate of flu-like illnesses diagnosed by GPs in Wales dropped to 36 cases for every 100,000 people from 65.8 the previous week.
Seven swine flu-related deaths were recorded in Wales in the previous week, taking the total to 21.
Wales’s Chief Medical Officer Dr Tony Jewell said people with suppressed immune systems were designated as a priority group for vaccination because they were known to be more susceptible to the virus.
“We have stringent processes in place for monitoring for antiviral resistance in the UK so that we can spot resistance early and the causes can be investigated and the cases managed,” he said.
“Identifying these cases shows that our systems are working so patients should be reassured.
“Treatment with Tamiflu is still appropriate for swine flu and people should continue to take Tamiflu when they are prescribed it.
“It’s also important that good hygiene practices are followed to further prevent the spread of the virus.”
Meanwhile, Norwegian health authorities said they had discovered a potentially significant H1N1 mutation that could be responsible for causing the severest symptoms.
The mutated virus was found in the bodies of two people who died of the virus, although medics do not believe it has been transmitted between humans.