Coronavirus precautions help keep measles out
Covid isn’t the only virus that managed isolation has helped keep out of New Zealand.
We’ve had no measles cases for more than a year, on the back of an epidemic which was dying down as the first coronavirus cases arrived.
But there’s potential for outbreaks to flare again as travel restrictions ease, a public health specialist says.
There have been no confirmed measles cases in Waikato since the end of the 2019 epidemic, Waikato DHB medical officer of health Dr Richard Hoskins said.
‘‘Basically, we flatlined in 2020.’’ With Covid came lockdowns, social distancing, restricted entry to New Zealand and isolation of those coming in, Hoskins said.
‘‘I can’t say, hand on heart, that [the absence of cases] is because of our precautions due to Covid. But it’s most likely that the precautions that we have taken for Covid have significantly decreased the chances of importing [cases].
‘‘There’s just no credible pathway for it to get into New Zealand at the moment.’’
And there haven’t been any cases in all of Aotearoa since February 2020.
Back in 2019, a global increase in cases led to ‘‘imported cases and resulting outbreaks’’ on our shores, a Ministry of Health statement said.
Case numbers were dropping before travel restrictions and quarantine for Covid began, but those measures lowered the risk of new cases getting in.
The big question on Hoskins’ mind, especially with some measles outbreaks around the world, is what happens when we go back to more or less unrestricted international travel.
‘‘It’s most likely that the precautions that we have taken for Covid have significantly decreased the chances of importing [cases].’’
Dr Richard Hoskins
Waikato DHB medical officer of health
Measles immunisation rates have fallen a bit, there is an existing immunity gap for measles in Aotearoa, and vaccinators are busy delivering Covid vaccines.
Measles is about five times more infectious than the current circulating types of Covid, Hoskins said, but that’s tempered by the fact more people are immunised. ‘‘Should there be a measles case in New Zealand, all the medical officers of health will know about it within 24 hours and, if you like, be on guard.’’
In recent years, Waikato has had an outbreak of 50-odd cases in 2016, and no confirmed cases in 2017. There was a case at the end of 2018, Waikato’s own outbreak early in 2019, and the region was ‘‘swept up in the epidemic that was 2019’’, reaching about 50 cases.
Waikato has also been without mumps for more than a year, although the ministry said there had been ‘‘sporadic cases’’ nationally. In Hamilton, a night out in Hood St led to about a dozen mumps cases in late 2019, and the tail of that outbreak stretched to early 2020.
The national outbreak was probably ‘‘petering out’’ anyway, Hoskins said, but, again, Covid restrictions would have limited the chance for spread.
Unlike measles, mumps is endemic, meaning infections are not from ‘‘imported’’ cases, the ministry said.
Sporadic cases have been picked up, but it’s a decrease in the number reported since May 2020. Those cases may have been mumps, Hoskins said, but there didn’t seem to be a chain of transmission and databases show they were all diagnosed through blood tests.
That’s less definitive than a PCR test – the style used for Covid – where a positive means it’s ‘‘absolutely mumps and couldn’t be anything else’’, he said.