With flu season in full swing, an employers' group is calling on employers to send staff home if they show symptoms of an illness.
A large number of influenza cases are being reported, with the Canterbury District Health Board (CDHB) saying late last month that it was treating between 35 and 48 patients in Christchurch hospital every day with the illness or symptoms.
The number of influenza vaccines handed out also far exceed the number distributed at this point last year, and Paul Jarvie, the Employers and Manufacturers Association (EMA) employment relations and safety manager, says it's impacting employers.
"We are getting quite a few calls through our call centre that people are having the flu and it is quite hard on them," Jarvie told The AM Show.
"We hear from [the Ministry of Health] that the flu virus has come down earlier, which is unexpected, but it is also very aggressive, so people are getting the flu, but getting it very quickly and badly.
"I think people are taking more and more leave as they are getting sicker."
The flu is quite a serious problem and you shouldn't underestimate it.
Jarvie said his message to employers was that "if people are sick, then send them home".
"We don't want sick people at work… It is actually infecting other people.
When you sneeze, you are sneezing at about 130km/h and it blows it out about 3 metres. It is better to stay home during the first week and rest up," he said.
Cutting off the spread of illness was important to ensuring businesses can get back to running as normal quicker without sick people bringing down productivity.
"Anytime an employee is away, you lose productivity, and given that our country is made up of a very large number of small employers, having one person away really hurts.
"If you are a large employer then there is a lot more ability for the company to have some back-up, so it is about productivity."
While the law does allow employers to require a medical certificate from an employee's doctor, Jarvie said most employers are happy to take the worker's word for it as long as that isn't abused.
Last month, Pharmac said that the number of vaccines distributed was already higher than the number of vaccines distributed in 2016 and 2017, and nearly as many as the total of last winter, when 1.3 million were given out.