One case of swine flu reported amid Christmas influenza spike

The sharp increase in flu cases was reported in the two weeks leading up to Christmas Eve.

According to the PHA GP consultation rates for flu or flu-like illnesses across the North "increased steadily from 8.2 per 100,000 population in week 49 to 10.1 per 100, 000 population in week 50 doubling to 20.7 per 100,000 population in week 51".

This was worse than the same period last year but is still below the health authority's own "pre-epidemic threshold".

"The NI GP consultation rate in both weeks 50 and 51 are marginally higher than the same period in 2016/17 (8.7 and 13.2 and per 100,000 population, respectively)," it said.

"Rates still remain below the pre-epidemic Northern Ireland 2017/18 threshold of 22.58 per 100,000 population. The number of positive influenza laboratory detections increased from 26 in week 49 to 56 in week 50 and to 85 in week 51, 2017.

"At this point in the season there have been a total of 112 detections of influenza A(H3), 61 of influenza B, 53 of influenza A (typing awaited), and 1 detection of influenza A(H1N1) 2009," it added.

The latter A(H1N1) 2009 strain refers to the flu virus that mutated from pigs and infected humans during the 2009 'swine flu' pandemic.

There was also a rise in out-of-hours (OOH) GP consultations for flu from 4.7 per 100,000 population in week 49 to 8.9 per 100,000 population in week 50 and 17.9 per 100,000 population in week 51, 2017.

And people receiving care in hospital wards were also affected.

The PHA indicated that "the number of detections of influenza from hospital wards reported to PHA increased significantly from a total of 25 detections in week 49, to 69 in week 50 and 43 in week 51, 2017."

It said: "There were eight cases reported in Intensive Care Units (ICU) with laboratory confirmed influenza in weeks 50 – 51 giving a total of ten cases this season to date. One death was reported in weeks 50 – 51 among ICU patients with laboratory confirmed influenza."

There were eight confirmed cases of influenza in ICUs over the fortnight.

"There was one death reported in ICU patients with laboratory confirmed influenza, this is the first death reported in ICU this season with confirmed influenza.

"There have been ten confirmed case of influenza in ICU reported this season to date, of which six have been typed as influenza A(H3), one influenza B and three influenza A (typing awaited)," said the PHA.