Dr Lees said as far as he was aware the baby was in good health at birth.
The baby's grandmother, Charmaigne, who is on a medical benefit but looking for work, said she had rented the Housing New Zealand Property for three years. Hamish and Ashley lived in one room. Charmaigne slept in the lounge with two grandchildren, a 16-year-old girl and a 13-year-old boy, who slept on mattresses on the floor.
Charmaigne became their legal guardian when she moved into the property and has been on the list for a larger house for two-and-a-half years.
In March, she gave up her own bedroom for her son, 27, his partner, 20, and their 16-month-old baby. The son works fulltime as a manager in Tauranga and had been unable to find a rental.
Earlier this year Charmaigne invited a friend, aged 32, and her friend's two children 13 and 5 to live with them.
"Her youngest was due to start school, and they had no home, and were in a campsite so I wanted to give her a bit of stability for the kids."
Charmaigne said she had health problems, including two artificial hips, acute arthritis and fibromyalgia. Despite this, she was keen to "get out and work" and her and her friend recently did a course to get their class 2 and wheels, tracks and rollers driving licences.
Ministry of Social Development Social Housing Deputy Chief Executive Carl Crafar said Charmaigne had been on the Social Housing Transfer Register since January 2014. "At the time of her application she listed five people as living in her current house, including herself.
"We first became aware of the baby's illness on Monday - as a result we applied a rheumatic-fever fast-track to the application making the family a priority for placement in a larger social housing property. We are working with Housing New Zealand to identify an appropriate four-bedroom property in one of their preferred suburbs ... Staff are working with Charmaigne and her family to see what further assistance can be provided while a suitable property is identified.
"We would also encourage any other occupants to contact us to discuss their housing situation and any support we can provide."
Fears for boy's ongoing health
The baby's 18-year-old mother, Ashley, had been scared she would lose her son to meningococcal meningitis. She was horrified his sickness could have been brought on by where they were living,
"I don't want to take him back to that crowded house ... I'm terrified he would get sick again," she said.
His 53-year-old grandmother, Charmaigne, said it was distressing to watch their boy suffering tests, included a lumbar puncture, which revealed the deadly disease.
"Luckily the docs had put an IV into him straight away ... it was hard watching them try to get the line into his poor wee hand. A baby's vein is 10 times smaller than an adult's."
She said the baby was now stable but not out of the woods and would remain in hospital until next week.