Influenza A / H1N1 swine flu pandemic

A pandemic is an ongoing worldwide epidemic caused by a new virus, afflicting those who lack immunity to that virus. The three flu pandemics in the 20th century were in 1918, 1957 and 1968. The current situation with swine flu is reaching a critical stage and the decision to raise the threat level further from the current stage 5 level may not be long away. Nevertheless, media hype and increased awareness nowadays makes it easy to level the accusation of exagerration to various media outlets.

The 2009 swine flu outbreak in the United Kingdom started in April 2009, with an outbreak of a new strain of influenza known as "swine flu". The virus was identified as a re-combination of various strains of Influenza A virus, subtype H1N1. The origins of this new strain are uncertain. The virus has been shown to be transmitted between human raising concerns about the possibility of a pandemic.

What is the attack rate?

The attack rate is expected to be about 70% in young children and up to 50% in adults. Most adults affected in Europe are young however this may just affect the type of traveller to Mexico, where the outbreak started. Swine flu is highly contagious. In the event that anti-virals need to be administered on a widespread basis then some governments advise infected patients having a "flu friend", so that the infected individuals are less likely to pass on the virus to healthcare workers or others. A flu-friend might collect anti-virals or other supplies for an infected patient.

How can the infection rate be reduced?

Wash your hands at least 10 times daily - there is some evidence that this may limit transmission.

How effective are antiviral drugs?

Antivirals such as Tamiflu reduce the duration of infection by a day, and reduce shedding of the virus. The drugs however do not prevent the initial infection. Tamiflu is also known by its other name - Oseltamivir.

What about a vaccine?

This takes about six months.

Is travel to North America safe?

Visit http://www.fco.gov.uk/en/travelling-and-living-overseas/swine-flu
for more information.

Article for UK public health visitors forum (233023-a)