Measles under the microscope

According to the World Health Organisation (WHO) cases of measles have continued to climb across the world in recent years. Data from 2019 shows a rise of 300% in reported cases in the first three months of the year compared to the same time period in 2018.

The disease is one of the most contagious in the world, caused by a virus in the paramyxovirus family. Unvaccinated children are the highest at-risk population, followed by unvaccinated pregnant women. The danger is a non-immune person passing the disease to a vulnerable member of the community.

The most common symptoms are fever, a dry cough, runny nose, sore throat, inflamed eyes, tiny white spots found inside the mouth and a skin rash made up of large, flat blotches that often flow into one another

A suspected measles case will be referred for a pathology test to confirm infection. A pathology laboratory will perform a test called an IgM capture EIA on a sample of the patient’s blood. In Australia, the lab will also report any confirmed cases to the National Notifiable Diseases Surveillance System which monitors outbreaks.

Even in developed countries, an outbreak can be deadly. The virus remains active and contagious in the air or on infected surfaces for up to two hours. It can be transmitted by an infected person from four days prior to the onset of the rash to four days after the rash erupts. In severe cases, complications can result in hospitalisation and patients can end up suffering from lifelong disabilities including blindness and brain damage.

Entirely preventable

Despite the potentially devastating effects, the disease is almost entirely preventable through a safe and affordable vaccination program. No specific antiviral treatment exists for the measles virus, which is why prevention is key to controlling the spread.

Spokesperson for Pathology Awareness Australia, Dr Petra Derrington said;

‘With global vaccination, we have the power and the ability to eradicate this illness which is deadly to babies who are not yet immunised and to the immunocompromised, particularly those in developing countries. Nonimmune people with the infection will spread this potentially deadly disease widely. The decision not to vaccinate your child has far reaching implications on other lives, not just the lives of your own family.’

According to the WHO, global vaccination coverage for the first dose has stagnated at 85%, 10% short of the optimal coverage needed to prevent outbreaks. Given its preventability, governments and health organisations across the world have conducted response operations to bring country-wide outbreaks under control.

Clusters of unvaccinated people 

Even with coordinated efforts, a clear trend in data remains, indicating the rise of measles. Concerningly, countries that are known for their overall high vaccine coverage have also been affected, including parts of the United States of America where the disease has spread quickly among clusters of unvaccinated people.

The re-establishment of measles transmission in several countries where it was previously eliminated, particularly in neighbouring regions, comes as a wake-up call to countries such as Australia.

Dr Derrington added,

‘Parents refusing to vaccinate their children are the cause behind the resurgence of measles in many developing countries.’

Closer to home, New Zealand has recently experienced a severe measles outbreak. The upsurge in measles during 2019 was the largest the country had seen in over 20 years, placing New Zealand as the second highest in the Western Pacific region at 152.4 per million, with only the Philippines having higher rates at 612.1 per million.

From January 2019 to September 2019, there were over 1,500 confirmed cases in New Zealand with over a third of infections resulting in hospitalisation. An outbreak which some sources have referred to as a pandemic.

New Zealand was verified by the WHO as having eliminated endemic measles in October 2017, having demonstrated the absence of local transmission for more than three years. However, it was acknowledged at the time there was a risk of further transmission due to known immunity gaps across the population.

Measles in Australia

In Australia, there were 286 cases of measles recorded in 2019, almost three times as many as in 2018. Measles remains a common illness in many destinations popular with Australia travellers and 58% of the measles cases in 2019 were acquired overseas, indicating the importance of immunisation and monitoring the unvaccinated. The Australian government continues to encourage Australians to ensure they are fully protected against measles prior to overseas travel, and more recently has included New Zealand as a hotspot to watch.

The elimination of measles is not an easy battle. Not only does the first dose of the measles vaccine need to reach 95% coverage globally, but the coverage of the second dose also needs to increase to cover children who do not have full immunity. Global coverage of the second dose of the vaccination is currently at 67%.

As international travel is once again on the horizon, it is important to remember that one imported case could be enough to spark a large outbreak among those not immunised or under-immunised. Elimination status is no easy feat and the localised outbreaks that currently occur in Australia could threaten Australia’s elimination status.

Effective public health and primary care actions are instrumental in keeping community transmission at bay. However, given the figures from not only across the world but right next door, early detection and management is essential of any imported measles cases that may occur in the future.

References

https://www.who.int/news/item/15-05-2019-new-measles-surveillance-data-for-2019

https://www.who.int/news-room/fact-sheets/detail/measles

https://www.immune.org.nz/sites/default/files/publications/Turner2019NZMJ_A%20measles%20epidemic%20NZ%20editorial.pdf

https://www1.health.gov.au/internet/main/publishing.nsf/Content/ohp-measles-outbreaks-2019.htm

https://www1.racgp.org.au/ajgp/2020/march/measles-elimination-in-australia

http://www9.health.gov.au/cda/source/rpt_3.cfm

 

 

 

 

 

 

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