Published Monday, 27 February 2012
Last year’s peak was 263.5 cases per 100,000 of the population. (© Pacemaker)
The number of people reporting flu to their GP has jumped from almost 17 in 100,000 of the population to almost 26 per 100,000.
A statement from the PHA said: "Laboratories are now detecting more flu which also suggests that flu viruses are starting to circulate".
The PHA says this figure is low compared to last year, but since it could indicate the start of flu season, they have warned at-risk groups to take vaccinations.
These include over-65s and their carers, newly-pregnant women and children with medical conditions ranging from asthma to diabetes.
Dr Richard Smithson said: "We have seen a small rise in the number of seasonal flu cases.
"Receiving the seasonal flu vaccine is the best way to protect yourself and others from getting the virus. So, if you are in an 'at-risk' group, get the vaccine now - it's still not too late.
"There are still some people who have not been vaccinated and we would urge them to get the vaccine now.
"In particular, women who have become pregnant recently and may not have had the vaccine, should get the flu jab as soon as possible."
There has been a high uptake rate for the vaccine - including almost 60% of pregnant women - but some are still missing out.
Dr Smithson added: "We know that flu can have serious consequences for both a pregnant mother and her baby.
"However, there is a wealth of evidence to show that the vaccine is safe and effective at all stages of pregnancy and that it also protects both mother and baby for the first few months after birth, a particularly vulnerable time."
© UTV News