Pandemic Influenza H1N1 2009 (swine flu) – Update

Pandemic Influenza H1N1 2009 (swine flu) – Update 184

Surveillance data from GP practices and Healthline for the week ending 30 April shows a continued increase in both the number of people calling healthline for free health advice on influenza-like illness, and visiting the doctor with an influenza-like illness. While numbers are still below baseline, this continued increase could signal the start of a higher level of pandemic influenza activity in New Zealand.

The number of people calling Healthline (0800 611 116) for advice is slightly higher than at this time last year.

Autumn is when colds and other viruses start to circulate in the community so it's timely to remember that we can all help reduce the spread of these by washing and drying hands frequently, covering coughs and sneezes, and staying home from work or school when you have symptoms of influenza.

It's also timely to remind those who are at greatest risk of complications for pandemic influenza, to seek medical advice as soon as they develop influenza-like symptoms. Young children are at higher risk of complications of pandemic influenza, as are women who are pregnant or recently pregnant, severely overweight people and those with serious underlying medical conditions.

Vaccine Supply

Air freight is now returning to normal, following the widespread closure of European airports in mid-April caused by the eruption of Eyjafjallajökull in Iceland. Those airport closures created a backlog for air freight, which delayed the delivery of seasonal flu vaccine from France to New Zealand over the past few weeks.

Large shipments of vaccine are now possible, with the first (of 108,000 doses) arriving in New Zealand today (Thursday May 6).

This enables our seasonal flu vaccine stockpile to return to a state where it is well stocked - and in the next week will enable us to resume advertising to encourage people to access the protection provided by seasonal vaccination.

Having a healthy stockpile will also enable GPs and other key providers in the community to resume scheduling "vaccination clinics" - a practice we advised against in recent weeks when vaccines were in short supply.

Studying the effects of H1N1

Solid progress is being made in two important studies which examine the true impact of pandemic influenza H1N1 in New Zealand last year.

The first of these is a Seroprevalence Study, which uses laboratory examination of randomly selected blood samples to estimate what percentage of the New Zealand population came into contact with H1N1 during 2009. This is important because people who were infected last year should have immunity to the virus this time around. The study also looks at differences in exposure by region, ethnicity, age group and other categories. This will help us understand much more about the first wave, and importantly will help identify how vulnerable New Zealanders are to a significant second wave. This study has now reached the peer review stage, and we hope to be able to release it in the weeks ahead.

The Ministry of Health also has a Pandemic Influenza Mortality & Morbidity Review Group which is reviewing the number of deaths that may be attributed to pandemic influenza. Their report will include the 35 deaths which have been established to date, and also looks at clinical records for other deaths where pandemic illness was present and may have been a contributing factor. Findings from this group are expected to be released around two months from now, once clinical review is complete.

Vaccination of children under the age of five

The Ministry of Health continues to gather data, and liaise with Australian health authorities, over the best approach to the issue of seasonal flu vaccination for children under the age of 5. This follows in the wake of Australian authorities beliving there had been "a spike" in admissions to hospital in western Australia within 24 hours of receiving the vaccine with symptoms such as febrile convulsions.

We have not seen a similar "spike" in New Zealand, prompting the Ministry's chief advisor on Child & Youth Health, Dr Pat Tuohy, to observe:

“All of the evidence which I’ve seen to date indicates that there has not been any perceptible increase in the overall rate of febrile convulsions occurring. (Also) There does not appear to be any difference between the number of people who return to their GP after receiving the 2010 seasonal flu vaccine, and the rate of re-presentation to GPs for other vaccines in previous years. The Ministry of Health's advice for New Zealand remains the same as it was on Friday last week: People, including children under 5, at risk of increased complications from flu should get a flu vaccine.”

The international picture

As at 30 April 2010, WHO reports it is continuing to actively monitor the progress of the pandemic. The current situation is largely unchanged since the last update. The most active areas of pandemic virus transmission continue to be in parts of West and Central Africa with some focal ares of activity in South and Southeast Asia. Pandemic influenza activity remains low in much of the temperate zone of both the northern and southern hemispheres. Since the pandemic began in April 2009, almost all countries have experienced outbreaks of pandemic influenza and over 17,919 laboratory-confirmed deaths have been reported worldwide.

For the WHO’s latest updates on the global pandemic, check their website: http://www.who.int/csr/disease/swineflu/en/

ENDS

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