Fourth measles case confirmed

A fourth case of measles has been confirmed in Canterbury.

A teenager from Rangiora in North Canterbury is the latest person to contract the disease. The case was confirmed yesterday by the Canterbury District Health Board (CDHB).

On Tuesday, authorities confirmed three people in Rangiora and Christchurch had contracted measles: a teen and a man and a woman in their 40s. None were thought to be fully immunised. People are considered immune if they have had two doses of measles, mumps, rubella (MMR) vaccine, have had the disease before, or were born before 1969.

It comes after an 18-year-old Dunedin student was confirmed as having measles on Friday. She was not thought to be immunised.

University of Auckland associate professor Nikki Turner, director of the Immunisation Advisory Committee, said historical vaccination issues were a bigger problem for the spread of measles in New Zealand than vaccine hesitation. ‘‘We did not vaccinate very well 15 to 20 years ago for a whole lot of reasons. So it’s a historical problem ... the people getting measles, they’re not young

Dr Helen Petousis-Harris

kids, because most of the young kids are protected.’’

Turner said it was possible people may not know if they were fully protected against measles.

The World Health Organisation (WHO)says vaccine hesitation, the refusal or reluctance to vaccinate, is one of 10 threats to global health. New Zealand is not exempt: despite years of increasing immunisation coverage, thousands of parents decline at least one of the many vaccines freely available to children.

Vaccinologist and University of Auckland lecturer Dr Helen Petousis-Harris said declines in vaccine uptake globally were often closely followed by measles outbreaks. ‘‘It’s sort of like the canary in the mine. It’s so super, super infectious that it’s highly sensitive to declines in coverage.’’

In 2017, New Zealand gained WHO-verification for successfully eliminating endemic measles and rubella for the first time, meaning no cases had originated in the country for the previous three years. However, people who caught the disease overseas still regularly brought it back.

The Health Ministry publishes data showing the number of children who have received all their age-appropriate immunisations by each milestone age. Of the 63,413 children who turned 5 last year, 55,800 (88 per cent) were fully immunised for their age. The parents of 3160 children in the cohort had declined at least one of the available vaccines.

Petousis-Harris said there had always been vaccine sceptics, but social media meant these groups were now better able to spread misinformation.

‘It’s so super, super infectious that it’s highly sensitive to declines in coverage.’