Mass on-campus testing of students is to begin again at the University of Limerick after 50 students were referred for Covid-19 testing yesterday - up from just under five two weeks ago.

A further round of on-campus testing comes after concerns by both the UL authorities and HSE Mid-West community healthcare about the spread of the virus arising from social household mixing in the Castletroy area, the suburb adjacent to the university campus.

Students can register online to be tested at a facility to be run from Thursday to Sunday next by the community healthcare team and the National Ambulance Service.

The Department of Public Health Mid-West is encouraging all students to avail of the mass testing this week, in order to protect themselves, their households and communities. They do not have to show symptoms to get a test, which is free.

Students who availed of the mass testing earlier this month are also encouraged to register for a test, as infection since being tested is still possible.

Dr Marie Casey, specialist in public health medicine, said Public Health Mid-West has noticed a series of behavioural patterns that are contributing factors to the increase in cases in the area.

"We have seen evidence of multiple household clusters arising out of continued social mixing. Since the B117 variant has become the dominant strain in Ireland, single cases are escalating quickly to whole households being infected and then quickly spreading to others.

"Students have a unique risk profile as they live in large households, travel to and from their family homes, and may have a part-time job. Because many will present no symptoms, the level of risk multiplies when they breach their social bubble or socialise with others outside their household.

"There are continued small and larger social gatherings, many of which we only discover during follow-up calls with cases and their close contacts."

"Our contact tracers are seeing new positive cases identifying an excessive number of close contacts outside their households.

"This is problematic as, largely speaking, you're only close contacts should be your own household. We are also noticing that some people are building wider 'social bubbles', whereby some people within the same household are exposed to separate social settings, such as visiting partners or classmates.

"While we are managing an outbreak among the student population, we are seeing similar patterns of inter-household and family outbreaks in housing estates and communities across Limerick and in the midwest. This is due to increased levels of social mixing," Dr Casey said.

Dr Ronan Ryder, Director of the Student Health Centre at UL, said that the service referred fewer than five patients for testing this day two weeks ago, but this rose to 50 on yesterday.

"I really feel that the vast majority of the student population have done exceptionally well to protect themselves since Christmas.

"However, when case numbers start to rise, it does take some time to bring them back under control, so I am encouraging all students in the Castletroy area to avail of testing, and to avoid household visits and socialising so that we can manage this disease in our community," said Dr Ryder.

Dr Ryder added that even if phone lines are busy, every student will be accommodated, and that their service will be open every Saturday and Sunday over the next two weeks to facilitate the increased level of demand.