The HSE is refusing to comment on reports that two people have been admitted to Letterkenny General Hospital with swine flu. Both are understod to know each other.
A spokesperson for the HSE has confirmed a general increase in the number of cases nationally, saying the increase was expected and is not a cause for alarm.
However, no regional breakdown is being provided.
The HSE says incidents of flu across the country are increasing, and this year, the predominant flu virus is the H1N1 virus also known as swine flu.
This flu virus mainly affects younger people and those with preexisting medical conditions, women who are pregnant or have been in the last 6-8 weeks are also particularly at risk.
While refusing to comment specifically on the Donegal situation, the HSE is reporting a major rise in people attending GPs and GP out of hours services with flu like illnesses, with most people then self medicating at home.
They say some people have been hospitalised, and a small number have been admitted to intensive care units. Latest figures show that in the week between the 13th and 19th of December, 30 positive swine flu specimens were detected, more than double the number in the previous week.
On December 21st, there were 14 people in hospital across the country, 3 of them in ICU. However, no geographic breakdown is being provided.