Many parts of our world are on track to record the highest number of measles cases in the last decade. Once thought to be disappearing from our developed world, measles is now re-emerging as a major threat and remains one of the most persistent of human viruses. Measles is an acute highly contagious childhood disease characterised by fever, conjunctivitis, cough, sore throat and general skin eruption. The virus has the ability to survive in the air or on physical surfaces for a number of hours. A single attack of measles provides life-long immunity.
Today measles cases are currently surging all around our world and the WHO has reported that cases rose by 300% in the first three months of 2019 compared with the same period in 2018. Should we be worried and if so, what should we do?
Australia has a long history of measles epidemics. Measles was most probably introduced into Australia in the late 1820s by soldiers and missionaries from England where the disease was endemic. Over the next 150 years, measles would become entrenched in Australia and epidemic outbreaks would become a regular event.
In 1834 a major epidemic broke out in Tasmania from where it spread to the whaling port of Port Molyneux in the South island of New Zealand where it was introduced to the local Maori population via the crew of a number of whaling vessels. In the 116 years after 1834 Australia experienced at least 30 major measles epidemics – the last occurring in 1950. Some of these epidemics were severe, such as the one that occurred in Victoria in 1898 which caused at least 60,000 cases and 100 deaths, or the one that took place in 1920 which lingered on until 1924 causing at least 40,000 cases and almost 500 deaths. The measles epidemic which took place in Sydney in 1866-67, however, remains one of the greatest childhood disasters in Australian history, when 80% of all children living in Sydney caught the disease.
In the 50 years after 1920, childhood deaths from measles substantially declined, from 50 per 100,000 to 0.6 per 100,000 in 1970. The period after 1950 saw the greatest decline in child mortality from the disease. Many children who grew up in the late 1940s/early 1950s would have experienced an attack of measles. For most it was a relatively mild disease of infancy, over in a few weeks and providing the sufferer with life-long immunity.
We may never know the real impact of these measles epidemics, particularly how they affected the Aboriginal population, but there is little doubt that they may have borne the brunt of the disease. What evidence there is suggests a series of severe epidemics among Aboriginal people in Bengalla near Goondiwindi in 1875, an outbreak in Inverell in 1888 and a series of epidemics in Central Australia and the Northern Territory in 1938, 1946 and 1948, all of which caused the deaths of thousands of Aboriginal people. By the 1950s measles had become a much more mild disease and while outbreaks continued over the next 70 or so years ,the number of child deaths markedly declined.
We currently face the re-emergence of measles epidemics in Australia, as well as throughout much of the developed world. In the developing world measles continues to wreak havoc. During 2018, 98 countries around the world reported an increase in measles cases, with 136,000 deaths being attributed to the disease. Madagascar has so far reported more than 117,000 cases of measles and more than 1,200 children have died over the last six months, while in the Philippines more than 21,000 cases of the disease and 315 deaths have occurred so far this year.
In the developed world, measles is also making a comeback. So far, 22 states in the USA have experienced measles cases, the most significant outbreak in 25 years, and only a few weeks ago the USA declared measles to be a national emergency, formally quarantining a number of Orthodox Jewish schools, as well as quarantining hundreds of staff and students who may have been exposed to the disease at two universities in California. As well, unvaccinated children have been formally barred from public spaces.
In Europe there have been more than 82,000 cases of the disease and 72 deaths over the last year, three times the number that occurred in 2017 and 15 times greater than the number in 2016. Japan is currently facing its most severe measles outbreak in a decade, largely because a particular religious sect has turned its back on medicine and vaccines. In the case of Britain only about 87% of all children have been vaccinated against measles, considerably below the WHO's recommended level, and possibly 500,000 children remain vulnerable to the disease.
In parts of the developing world the number of vulnerable young children is much higher. In India for example, almost three million young children have not been vaccinated and in Pakistan and Indonesia the number is at least 1.2 million. War and civil unrest can also play a role in helping the spread of the disease. In the Ukraine, for example, more than 53,000 cases of measles occurred in 2018 largely because war disrupted the country's vaccination program and the epidemic continues with 30,500 cases so far this year.
Much of this surge in measles cases is being caused by two critical factors. In the first place, there is what the WHO calls Vaccination Hesitancy, whereby parents opt out of vaccinating their children or simply let it slide. In Australia, large numbers of parents remain sceptical about routine vaccination against diseases like measles. Possibly because measles has been virtually absent from Australia for a number of decades, the new generation of parents have little understanding of its nature and the risks for children.
There is also a deep-seated belief by a number of people that their health and that of their children remains their personal responsibility and that the government and medical profession should not intervene in such matters. The basic problem with such an approach is that it does not appreciate the vulnerability of others and how that vulnerability can be influenced by the failure to vaccinate. The WHO's threshold for measles vaccination rates offering full protection is currently a vaccination rate of 90-92%. Australia's current fully immunised rate for five year old children currently stands at 96%, but there continue to exist significant areas that dip well below this. In NSW for example, the northern coastal area of Richmond Valley as well as Manly and the inner part of Sydney City all have vaccination rates below 90%. Such rates place many young children at risk.