An outbreak of norovirus at a Central Otago sports event and a second at a social gathering in Queenstown has prompted the Southern District Health Board (SDHB) to issue a warning.
At least 20 cases of the virus have been reported in the region over the past fortnight, the DHB said.
The virus had been identified in two large outbreaks.
More than 20 people were affected at a sporting event in Central Otago due to contaminated water.
A second outbreak had been identified at a social gathering in Queenstown.
A SDHB spokesperson said no-one had been hospitalised as a result of the outbreak.
Norovirus is highly-infectious and spreads easily from person to person.
SDHB Medical Officer of Health Dr Marion Poore said the "community-based" nature of the outbreaks was unusual.
“Norovirus outbreaks are more commonly associated with situations where people are living or working closely together, such as schools, colleges or residential care facilities," Dr Poore said.
Although the acute illness is generally over within 24 to 36 hours, people with norovirus are infectious for at least three days after the symptoms stop and on some occasions for up to two weeks.
Symptoms may include nausea, vomiting and diarrhoea, stomach cramps, headache, low-grade fever, chills and muscle aches.
The virus can survive on contaminated surfaces even after cleaning with some disinfectants.
“With the start of the holiday period we ask everyone to be thorough with all personal hygiene, safe food preparation, and cooking," Dr Poore said.
More information is available on the Ministry of Health website.
