The Centres for Disease Protection and Control (CDC) says outbreaks of the new H1N1 swine flu continue to spread across the United States and the swine influenza virus is expected to spread to all 50 states and to cause many infections ranging from mild to severe.
According to acting CDC Director Dr. Richard Besser the pattern of disease is more important than the actual numbers and at present there are no signs of the virus abating.
Dr. Besser says though Mexican officials believe the worst is over, there was still significant transmission occurring there and as only about 10% of confirmed cases have a travel history for Mexico it suggests the virus is still passing very easily from one person to another.
Dr. Besser says the new virus appears very similar to seasonal flu and takes two rounds of tests to confirm a patient has the new H1N1 swine flu variety.
At present the influenza strain remains a mild one, with only 5% of cases needing hospitalisation and of the deaths which have occurred experts say some were suffering serious underlying health problems aside from the new virus.
Scientists at the CDC are examining many aspects of the new strain, including how long a patient is infectious after recovering, whether antiviral drugs like Tamiflu affect whether a person can spread the virus, whether healthcare workers are at risk of infection, how many people have been infected and do not know it, and how many cases of regular, seasonal H1N1 flu are still occurring.
Dr. Besser says the possibility remains that the virus could return in the cooler months in a more dangerous form and between now and autumn is of critical importance in terms of preparing for this possibility.
The Department of Health in Britain has conducted a survey on government action to control swine flu and included questions on whether the public believe the threat of the virus has been hyped up by the media in particular.
The survey was conducted to examine whether government messages on the virus were being understood and included questions on the dangers of swine flu, basic advice on hygiene and if people had stopped eating pork or were worried about pork products.
Leaflets giving information on swine flu and where to seek further advice, or help, are being distributed around the Britain which has to date had 34 confirmed cases.
The World Health Organisation (WHO) is not recommending travel restrictions related to the outbreak of the influenza A (H1N1) virus but does say people who are ill should delay travel plans and returning travellers who fall ill should seek appropriate medical care.
The WHO says these recommendations are prudent measures which can limit the spread of many communicable diseases, including influenza.