The variation in the numbers of confirmed cases of H1N1 globally appears to depend on whether the countries are in the North or South hemisphere, with the temperate countries of the Southern hemisphere currently in their winter season. All countries except those in Sub Saharan Africa have reported extensive spread and the low numbers of cases reported in Africa may be due to the limited reporting that takes place in many countries. The WHO confirm that pandemic flu tends to spread rapidly in shanty towns and are watching for cases in these environments.
Australia and South America initially experienced rapid spread of the virus and, although it is still circulating, the numbers of cases are reducing.
In the temperate areas of the northern hemisphere the virus outbreak commenced earlier and whilst there is still spread to previously unaffected areas, the numbers of cases is also declining.
Tropical areas are now being affected and increasing numbers of cases are emerging in these countries. With the risk of further spread during the monsoon season community outbreaks are anticipated in highly populated areas of Asia and Africa.
The epidemiological behaviour of the H1N1 virus is still being evaluated but studies of past pandemics suggest peaks in recurrence with a predicted second wave affecting the northern hemisphere in the autumn.
The UK has released plans for a country wide vaccination programme and according to Sir Liam Donaldson, Chief Medical Officer, vaccination of priority groups will commence in October. Whilst cases are in a steep decline, there is a concern that there will be a brief increase in numbers when schools and universities re convene after the holiday period.
The USA also anticipates a second wave of the pandemic in the fall and is continuing with contingency planning and educational programmes to inform the population on how to minimise spread. The virus appears to affect similar age groups as in the UK and Europe with children and young adults being the most susceptible. As in the UK, the first batches of vaccine are also scheduled to be available in the USA in October.
The U.S. Centre for Disease Control and Prevention is following the WHO guidance on those groups who should receive H1N1 vaccine first. These populations include pregnant women, healthcare workers, parents and caregivers for children under 6 months old and people aged 6 months to 24 years.
The NHS Blood and Transplant service is encouraging people to donate blood in advance of the winter months to avoid the potential shortage that may arise if a significant number of blood donors contract H1N1 which prevents them from giving blood.
There have been a number of concerns raised by the media regarding the use of Tamiflu in children due to the lack of evidence that it reduces the incidence of severe disease in this group.
Doctors have been alerted by the Medicines and Healthcare Regulatory Agency that the use of Tamiflu in adults may increase the risk of stroke and there are also concerns that Tamiflu can interact with Warfarin, a drug that is used in thousands of patients to thin the blood.
FirstAssist is able to provide a service for employers to monitor the impact of swine flu on their employee’s sickness absence. Information on this service is available at: http://www.first-assist.com/shownews.aspx?ID=42
H1N1 Update