KEY POINTS:
Badminton officials have suspended play for 24 hours at an international tournament in Christchurch after a stomach bug cut a swathe through a large number of competitors.
Since Saturday, more than 80 people at the trans-Tasman under-17 tournament -- players, coaches and tournament officials -- have succumbed to a bug causing vomiting and diarrhoea.
Public health officials called in to try to identify the source of the outbreak met tournament officials this afternoon after diagnosing the gut-wrenching stomach bug norovirus as the most likely cause.
Canterbury medical officer of health Alistair Humphrey said tonight a second wave of infection that hit tournament participants overnight was "characteristic of a norovirus infection".
Highly infectious, norovirus causes vomiting and diarrhoea. It is spread through contact with infected people, and contaminated food and eating surfaces.
Generally it is present in the community in various strains and outbreaks are periodically linked to institutions, such as hospital and rest homes, and where people are confined in close contact with each other.
Wards in hospitals in Christchurch and Dunedin have been closed this year through norovirus outbreaks.
Dr Humphrey told NZPA tonight a shared dinner during the June Bevan Badminton Trophy tournament opening ceremonies on Good Friday was the "prime suspect" as the infection's source.
While norovirus was not primarily a food-borne infection, it was likely something happened at that event where an infected person passed on the infection to many others.
"We are questioning the caterers and we will be analysing all the data collected from questionaires from the tournament participants to see if there's any common link between them all," Dr Humphrey said.
About 74 people had been affected in the first wave of norovirus on Saturday and Sunday. A further 12 had become ill last night, he said.
Tournament organisers had decided this afternoon to halt the competition for 24 hours to allow those affected to fully recover.
"It's not spread beyond the tournament, but the officials running the competition felt that, given they had enough time, they would rather suspend competition for 24 hours to help break the chain of infection," Dr Humphrey said.
Public health officials had contacted counterparts in Australia where several norovirus outbreaks had been reported at sporting events, and would continue to monitor the current situation here.
Most of those affected in the first wave were recovering well, he said.
Earlier today, tournament director Lyndsay Dick, told NZPA the tournament scheduled to run until Saturday had not been badly affected -- "although that's probably starting to happen now".
Ms Dick, who had also been affected by the bug, said officials were waiting for health officials to "make a call".
"We're carrying on at this stage, but today will be the difference between whether we carry on or not."
- NZPA
