Measles comes every twelve years

Dutch biblical belt

The Dutch Bible Belt is home to a religious group of about 250,000 faithful. Every twelve years, measles starts, and every time 2,500 people become sick. The researchers badyzed why.

KRAKOW. Every twelve years or so, a measles epidemic affects about 2,500 people in the Dutch Bible Belt.

In this religious community, fewer people are vaccinated against the measles virus than would be necessary to permanently prevent the spread of the virus. Polish and US scientists have studied the circulation in more detail (Biosystems 2019; 3 (177) 16-23).

The pace is due to the fact that the number of unvaccinated people increases slowly until there are enough potential victims of the disease. Then the virus can spread. After about a year, the pathogen disappears first.

One reason is that many people who have survived the disease are now immune. It is only with new births that the number of people who can catch the virus is increasing again. A new wave of illness begins.

Goal: to eradicate measles!

Until about half a century, measles was prevalent in almost everyone. The number of cases was therefore relatively constant, write the researchers of the College of Medicine Bartosz Lisowski Jagiellonian in Krakow.

With the introduction of measles vaccine – in the 1960s and 1970s in the western world and since 2000 in many developing countries – the number of diseases had decreased considerably.

In 1980, 2.6 million people died of the virus, compared with less than 90,000 in 2011. Meanwhile, even the eradication of measles seemed possible. Today, this goal has evolved in the distant future, said the researchers.

One of the reasons is that in many European countries the proportion of children vaccinated is less than 95% today – which is considered necessary to stop the spread of viruses in a group.

This is partly due to the increasing number of people who consider that vaccinations are superfluous and even dangerous for health. On the other hand, wars or refugee movements have led children to not be vaccinated as planned.

In three years, three measles outbreaks

The consequences of this on the spread of the measles virus, the Lisowski team is now studying in the Dutch Bible Belt, a corridor of about 200 kilometers long and several kilometers wide, ranging from Middelburg to the south West to Zwolle in the east of the country.

Around 250,000 Dutch people live in a strict reform, mainly in about thirty medium-sized cities. Some of these people do not consider vaccinations as natural and reject them. The majority – estimated at around 60% – but children are still vaccinated.

Since the introduction of vaccination programs in the Netherlands in 1976 through 2016, researchers have reported three measles outbreaks in the Bible Belt that lasted about a year and affected approximately 2,500 people each. The gap between homes – the last in 2013/14 – was twelve years each.

Before the introduction of vaccination programs, the virus was as prevalent in the religious community as in the rest of the country, the researchers said.

Sufficient new "victims" for the virus

The number of diseases was about constant. After that, the situation changed: the number of unvaccinated people in Protestants was high enough that the virus found enough new "victims" to spread among the group, especially among schoolchildren about ten years old.

The researchers remember that measles is essentially worse than a permanent spread of the virus. Those who have survived the disease are immune to it for life – they can no longer get sick.

But whoever has not fallen ill as a child risks becoming an adult at the next outbreak. Measles is often more serious in the elderly, the researchers write.

In fact, more and more adults have been diagnosed with the three epidemics in the biblical belt, the number of admissions to the hospital has increased. What is happening in the biblical belt may well be an example of what is threatening elsewhere in the future. In 2015, for example, there was a measles outbreak with 1243 cases registered in Berlin.

He was fired from two sources: one by children of parents who refuse to be vaccinated; on the other hand by refugees, for example from Syria or the former Yugoslavia, where health systems collapsed because of wars.

Disturbing development

Declining immunization rates would not bring the developed world back directly into the era of the great epidemics of the 19th century, the researchers say. First, local epidemics will be increasingly affected.

Viruses should adapt to new realities and evolve in a way that they could spread better among the small group of sentient humans.

For example, they may be more contagious before the first symptoms appear, which increases their risk of transmission. It was a worrying development and if the trend did not reverse, it would take a small step forward to the black middle ages. (AP)

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