Swiss Re says media focus on swine flu has not threatened its successful placement of a $US75 million ($83.2 million) notes issue for extreme mortality risk in the US and UK.

The notes cover a five-year period ending in 2014.

With winter closing in on the northern hemisphere, the World Health Organisation (WHO) puts the global death toll from swine flu so far at 6770.

It says the early-onset winter influenza season continues to intensify across parts of North America and much of Europe, although there are early signs of a peak in disease activity in some areas of the northern hemisphere.