Below are some of the latest numbers around the epidemic of measles in New Zealand, and the outbreaks in Australia which are currently linked to New Zealand via infected
Measles is a vaccine-preventable disease caused by a highly transmissible respiratory virus called measles virus (MeV). When given as two (or three for the very young) doses, the measles vaccine is a highly effective way to prevent disease due to MeV infection.
The measles vaccine is a much safer option to develop immunity than gaining immunity by getting infected by MeV.
Don’t forget measles makes you less immune to other stuff
I recently wrote about a poorly discussed outcome of getting ill with measles; immune amnesia.[2,3]
Not only can a measles infection make you sick, put you in hospital and trigger complications like pneumonia, sepsis and encephalitis, but it can also suppress your immune response to other disease-causing viruses and bacteria. And it can remove the immune defences you had painfully built up from past illnesses. The outcome? You’re left exposed. You may end up getting sick all over again due from infections you were able to fend off – until you got measles. It’s a like a bad morning after but instead of you not knowing what you did last night, it’s your immune response that’s forgotten what it did!
Where are the infections
Cases have been occurring all over Australia this year. The public data in the graphs below – which start from April – highlight a sudden upturn in recent weeks, driven by multiple outbreaks on the eastern (Queensland) and western (Western Australia) coasts of Australia.
I’ll use a definition of an outbreak as being 1 onward transmission from an infected traveller in a country that has been declared free of endemic MeV transmission (like Australia and New Zealand).
Who is getting infected?
A range of age groups are being infected but the bulk sits among newborns and those who didn’t get both doses of vaccine for reasons
- because they weren’t doing that back in the day
- because they didn’t complete the full course in their childhood
- because of issues around costs and access to vaccination
- because they can’t be vaccinated
- because they were too busy to find the time,
- because they forgot to get a second dose or can’t remember whether they did or not
- because they are hesitant or fearful about this and perhaps other vaccines
- because they just don’t care
- because they actively avoid all vaccination (in Australia, this is a minority)
Most cases and the highest rates are among males, except in the 10-14-year-olds age group. You can also see that among the older age groups, when measles was rampantly transmitting, cases are few because immunity is high. But as we will learn from the New Zealand data, getting infected at any age is also associated with a decent risk of being admitted to hospital. Vaccination is a much safer way to get that immunity.
What about measles in New Zealand?
New Zealand is experiencing its biggest measle epidemic of the past 11 years-worth of data shown below. Perhaps even longer. We can see this thanks to the public and beautifully prepared weekly reports from the NZ Ministry of Health and the Institute of Environmental Science and Research (ESR) put out.[5,6]
While it looks like their epidemic has peaked, New Zealand is still seeing over 80 new measles cases a week, so it has a long way to go to quell this infectious wildfire.
Cases are being seen in similar age groups to those seen Australia – kinda everyone (see below).
Most of the activity is in and around Auckland – New Zealand’s largest (but not capital) city in the north of the North Island.
What is really clear among the data is that the majority – 85% of cases for which this information is known –
Just 4% were partially vaccinated and 11% were fully vaccinated. Cases in these people, sometimes called “breakthrough” cases, do happen. These illnesses could be due to vaccination that didn’t result in immunisation. More
- prolonged exposure to another infectious person
- lots of contact with infectious surfaces
- high viral loads
…the kind of interactions you’d find in a family setting.
Measles embers drifting around the Pacific
Buit Australia isn’t the only country seeing cases arrive via travel across its island boundary. Both Tonga [8,9] and Samoa [10,11] have outbreaks linked to the kiwis and Fiji is on alert. I’d strongly suspect that there will also be a fair few cases in Japan – which already outbreaks[13,14] – because of its current Rugby World Cup mass gathering.
Vaccination work to prevent disease, save lives and stop the spread. It can also be used with 72 hours after exposure to prevent disease.
Talk to your friends. Stop measles. Keep your immune memories intact.
- Could Measles virus and Ebola virus be working together in the DRC?
- Measles and Immune Amnesia
- Measles leaves you vulnerable to a host of deadly diseases
- Measles Immune Suppression: Lessons from the Macaque Model
- Public Health Surveillance NZ MOH & ESR | Measles reports https://surv.esr.cri.nz/surveillance/WeeklyMeaslesRpt.php
- ESR (the Institute of Environmental Science and Research), New Zealand’s Crown Research Institute
- Measles spreads to Tonga from New Zealand
- Tonga’s Health Ministry issues measles alert
- NZ ‘could have protected’ Samoa from measles
- Vaccine expert says Samoa measles epidemic ‘our worst fear’
- Measles alert: Fiji offers free measles vaccines
- Irish rugby fans warned over measles outbreak in Japan
- Measles in Japan (IDSC)