111 kids sick; why authorities didn’t know

On Wednesday, one child at the school was sick. On Thursday, dozens more fell ill.

By Tuesday, 88 children and staff had been struck down by norovirus – later suspected to have spread through infected food handlers in the canteen at the private boys’ school.

As the cases rose above 100, still the boarding school remained open. Seven days after the first child started vomiting, boys aged 5 to 12 continued to walk through the gates, taking the acute form of gastroenteritis home to parents and siblings.

Three days later, the school closed. By then, 111 boys from the roll of 365 at Christchurch’s Medbury Independent School for Boys were sick – an infection rate of 30 per cent.

Health authorities are now using the incident last August as a case study of a public health crisis – and are warning schools, doctors and nurses to report highly contagious illnesses immediately.

And the Ministry for Primary Industries (MPI) is urging schools to prepare their own food control plans by June this year, when new regulations designed to prevent such outbreaks come into effect.

The infection rate at Medbury was higher than the largest known outbreak of norovirus on a cruise ship, the Explorer of the Seas, in 2014. In that case, 22 per cent of the ship’s 3050 passengers became ill.

The school says it dealt with the outbreak well, and is equipped to deal with crises in future.

Spread amplified

In its report, the Institute of Environmental Science and Research (ESR) said contaminated surfaces, food, and person-toperson contact at the school ‘‘amplified’’ the spread of the norovirus.

‘‘This was a rapidly spreading norovirus outbreak that needed prompt interventions by the public health authorities, which the school did not get in the first instance,’’ said Canterbury medical officer of health Alistair Humphrey.

‘‘There was some confusion in the school about what they should be doing. They had been told the outbreak would ‘burn itself out’, people would get infected and then it would stop and there was nothing they could do about it. That’s not true.’’

Humphrey said the school had told a nurse about the possible outbreak on Monday, five days after the first boy fell ill.

It took her two more days to notify the public health team.

Neither had any GPs raised the alarm – and with changes to the Health Act 1956 in force since January 2017, it was now compulsory for all health professionals to alert public health to a possible outbreak.

‘‘We have to remind doctors all the time. We have to say: If you don’t notify not only are you potentially putting people’s lives at risk, but you’re actually breaking the law,’’ Humphrey said.

‘‘There have been outbreaks before in parts of the country where a specialist has not notified public health, and that is concerning. If [a doctor] had seen a kid with meningococcal, not told us and, say, their brother or sister caught it and died, we would prosecute.’’

Medbury School were asked to comment, but declined interview requests. In a statement, the new headmaster, Ian Macpherson, said he had consulted with senior staff who were there at the time and they considered the crisis was dealt with quickly.

The school believed their notification duties were met when they told the nurse, Medbury School’s liaison to the Canterbury District Health Board, on the Monday.

There were 188 norovirus outbreaks confirmed by ESR in 2016. This is not a complete record of outbreaks, as not every crisis is reported. About 50 per cent were reported early enough to be tested and the pathogen identified.

Extremely infectious

ESR scientist Jill Sherwood said norovirus is a major cause of outbreaks in New Zealand, and the most common cause of vomiting and diarrhoea.

While not usually severe, it can be deadly for infants, the elderly and those with compromised immune systems, and is the cause of 50,000 child deaths globally each year.

Norovirus was extremely infectious, spreading rapidly through person-to-person contact and food, Sherwood said.

‘‘The bottom line is – if people actually follow good food handling advice, wash their hands and don’t go back to school while they’ve got diarrhoea, that’s the only way to break transmission. But it is difficult. The virus can survive on surfaces for days.’’

The Medbury outbreak was contained by the closure of the boarding school on Saturday August 12, for four days. Sports and social events were cancelled, the sick isolated, and MPI was called in to review food safety practices.

High risk sites

MPI food and beverage manager Sally Johnston said inspectors found food hygiene and preparation practices at the school were generally good.

But, under new laws set to affect schools and early childhood education centres where food is prepared and sold on-site from June this year, canteens will be considered ‘‘high-risk’’ sites.

In this case MPI helped staff create a food control plan – a measure which all school cafeterias will soon have to comply with.

‘‘It’s not about punishing schools and saying ‘ Don’t feed these kids’, it’s putting practices in place so they don’t get sick again,’’ Johnston said.

‘‘For us, it’s a change in tactic from saying ‘is your kitchen suitable’ to saying ‘are your practices suitable’.

‘‘Kitchens don’t make food, people do.’’