Strong health systems, along with immunization efforts, are critical to fighting diseases around the world.
Measles, once a common, fatal childhood disease that has been "cut off" from many parts of the world, including the United States, Canada, and Europe for almost two decades, is back on the global health agenda. Measles cases globally increased nearly 300% in the first quarter of 2019 compared to the first quarter of 2018, according to surveillance data covering 190 countries released last week by the World Health Organization.
More than 112,000 cases were reported to begin this year, as opposed to just over 28,000 since early 2018. This year also saw a significant gain over 2017. Although not yet close to the shocking levels of the mid-20th century, when tens of millions of children became infected and millions died, the trend for new measles infections appears to be inexorably and frustratingly on the rise.
This trend places children under the age of 10, particularly in poor and conflict-affected regions around the world, at increasing levels of totally preventable risk.
THE HIGHLIGHTS OF GLOBAL MEASURES
One of the most common explanations in the media for the resurgence of measles has to do with a set of beliefs that promote reluctance to follow up with infant vaccinations. The WHO, earlier this year, called this emerging reluctance one of the "top ten" global threats to global health.
The spread of misinformation about child vaccination is leading to a wave of what the World Health Organization calls "vaccine hesitation." Over time, declining trends to follow evidence-based public health recommendations can threaten long-established success practices that have improved children's health since the mid-twentieth century.
In parts of California, New York and Washington, for example, there is evidence that relatively small outbreaks have been correlated with reduced rates of vaccination due to misinformation against the vaccine combined with the new introduction of the virus, often through travelers.
Overall, however, how can the resurgence of the disease be explained? Undoubtedly, the world needs to remain vigilant in the face of any possibility that the consensus around child vaccination will be hampered by increased "vaccination." However, a large number of people around the world still do not have access to the vaccines they both desire. and need.
MEASURES, CONFLICTS AND HEALTH SYSTEMS
In addition to the effect of vaccine hesitation, we need not go beyond the country's own data on the locations and growth trends of measles cases.
Almost all the huge jump in measles cases from 2017 until the beginning of this year is attributable to a handful of places. This year, almost two-thirds of the total reported cases of global measles are attributable to just two countries: Ukraine and Madagascar. These two countries are highly instructive as to the real reasons why we should pay attention to measles as something like a "canary in the coal mine" to the underlying weaknesses of public health systems.
Let's start with Ukraine, which may seem, at first glance, the most intriguing.
Why would a middle-income country on the periphery of Europe, with a historically reliable and almost universal public health system, suddenly become a kind of propaganda boy for the unbridled spread of infectious childhood diseases for which there is immunization? The answer is quite simple: conflict.
Before 2014, Ukraine maintained a 95% measles vaccination rate, generally considered the gold standard level for herd immunity. Then the conflict erupted between Ukraine and Russia. As a result, the budget of the Ministry of Health of Ukraine was frozen and measles vaccination purchases ceased largely by the end of 2015. By 2016, Ukraine's vaccination rate fell to only 41%, one of the highest rates of the planet.
In the following years, the vaccination rate in Ukraine returned to be close to its pre-conflict levels, with about 91% coverage reached last year. But the damage was already done. A cohort of several Ukrainian children had lost their immunity to the disease. Combined with the widespread disruption of the primary health care system and the physical effects of conflict in a large number of communities, measles quickly settled again and began to spread.
Part of the migration of measles from the Ukrainian epidemic has apparently become international, with cases in New York, Israel and other sites tracked directly to index cases of travelers from Ukraine.
Elsewhere in places in Yemen to Nigeria, it is also possible to detect the highly negative impact of the conflict on the basic capabilities of the health system and on rates of measles infection. The lessons of the Ukrainian measles epidemic, as with those other countries, are not just the fact that it does not take much to fundamentally disrupt a well functioning health system and produce an otherwise preventable outbreak. Disruptions in health systems in one country, due to high levels of global mobility through air travel, can be quickly noticed in many parts of the world.
THE DANGER OF SUB-FUNDING HEALTH CARE
The current situation in Madagascar, where Direct Assistance continues to respond with local partners, including the Ministry of Health, is quite different from that of Ukraine. Madagascar is one of the least developed countries, with a Human Development Index (HDI) that ranks 161st out of 189 countries measured. Its public health budget has been under constant pressure for many years simply because of the tradeoffs needed to manage multiple emerging health threats to rapidly changing communities. As a result, the measles vaccination rate in Madagascar fell to one of the lowest in the world, at 58%.
Vaccination is not the only element of the health system that leads to an increased likelihood of measles contagion. Poor nutrition leads to weakening of children's immune systems and decreased ability to resist infection. This is one of the main reasons why Direct Relief has helped in the delivery of high doses of vitamin A to strengthen the immune system of vaccinated and unvaccinated children.
Weak primary care systems also present challenges to ensure that all children are seen regularly by a physician and that suspected cases of measles are quickly identified and treated. Combined with low vaccination rates and persistent malnutrition, poor primary care and disease surveillance can allow cases to multiply well before there is a chance to identify and intervene.
THE KINDLING THAT APPEARS AN OUTBREAK
Measles is well suited for epidemics, given the weaknesses of the system. The rate of reproduction of measles, the number that epidemiologists use to measure the likelihood of an infected person infecting others in the absence of countermeasures, is very high.
A systematic review in The Lancet from 2017 confirmed an average reproduction rate of 18, with considerable variation observed depending on contextual factors, including poverty and strength of health systems. This means that a single measles infection can produce at least 18 new infections in the absence of countermeasures. Likewise, measles is infectious for 7 days before the individual becomes symptomatic, which means that infections can easily spread without being detected. This surprising rate of transmission, including challenges with early detection, is what constantly threatens to turn measles outbreaks into epidemics in exponential growth.
In addition to advocating the central value of public health and the practice of mass vaccination, we still have a long way to go to achieve the genuine universality of vaccine access, not to mention health care interventions that maximize children's chances of resis- tance infectious diseases. This lack of equitable access threatens the most vulnerable in these countries, above all else. But this threatens communities far beyond their borders, given the flow of global commerce and travel.
Weak primary health systems, born of conflict, poverty or, as is often the case, a combination of both, remain among the greatest threats to human health everywhere.