Misdiagnosis of meningococcal disease is common as there are so many possible symptoms, the head of The Meningitis Foundation Aotearoa New Zealand says.
Ben Brown, 18, an apprentice plumber, died from the infection at Whangarei Hospital on Saturday - just days after he was admitted to the intensive care unit.
His death came a week after a 14-month-old Northland toddler died at Starship Hospital of the disease.
The teenager's father, Darren Brown, has asked the coroner to investigate why his son had been sent home twice by medical professionals in the days leading up to his death.
Founding co-director of The Meningitis Foundation Aotearoa New Zealand Paul Gilberd said unfortunately cases of patients being sent home from hospital is common, as meningococcal disease is hard to diagnose.
"It presents in just so many different ways.
"It is very hard to train clinical staff effectively in all of the signs because it just presents in so many different ways.
"You can get a stiff neck, you can get a headache, a fever, you could be vomiting, light sensitivity, drowsiness or confusion, joint pain, you could be fitting, and any one of those things could be on its own or with others and it is very hard for clinical staff, sometimes even right up to the late dangerous stages.
"Sometimes, people make mistakes, misdiagnose and send people home. They do everything can, but it is just a very nasty disease. If you know something is amiss [but the hospital wants to discharge you] you've got to be firm about it, because it can be life or death."
Mr Gilberd said it was vital people seek medical attention as soon as possible, even though the symptoms on their own can appear minor.
"It can present like flu. That's the nature of this disease, it is a very nasty and very dangerous disease," he said.
"What you learn about meningitis is the speed people deteriorate - that's the real feature."
"What we always say to people is see your GP immediately. If your GP is not immediately available, see another doctor or go straight to hospital emergency centre."
Mr Gilberd said young people and Maori and Pacific Islanders are most at risk, however it is indiscriminate.
"The problem is the actual infection lives in the backs of the throats of about 15 per cent of the population at any one time. So it is very hard to know where it is going to pop up," he said.
"We all need to be vigilant, because it is in us. The chances are you walked past 10 people on the street this morning who have got meningitis in the back of their throat. If they just happen to sneeze and you just happen have a weak immune system it can be as simple as that."
While there are many precautions people can take - not sharing bottles, covering your mouth while coughing and sneezing, not sharing body fluids - but vaccination is the most effective precaution, Mr Gilberd said.
"The ultimate way to protect yourself from this disease is to get a vaccination. If you are worried about it go and get a jab, because there are very effective vaccinations available in New Zealand to prevent people getting the main 13 serotypes [of meningitis].
"There's an extreme amount of empirical evidence to show that immunising through vaccination is the most effective way of managing this disease."
The foundation, which was formed this year, does not yet have a website, but Mr Gilberd recommended people visit meningitis.com.au for more information.