Krakow (DPA) – Every twelve years, he comes to the Dutch Bible Belt to a measles outbreak with about 2,500 patients.
In this religious community, fewer people are vaccinated against measles virus than would be necessary to permanently prevent the spread of the virus. Scientists from Poland and the United States have already examined the circulation more closely and presented their results in the journal BioSystems.
The established rhythm occurs because the number of unvaccinated people is slowly increasing until there are enough potential victims of the disease. Then the virus can spread. After about a year the pathogen disappears first. One reason: Many people who have survived the disease are now immune. Only with newborns the number of people who can catch the virus increases. A new wave of diseases has begun.
They suggest that the situation observed in the Biblical Belt in other cities and regions may happen in the future, for example if the number of opponents of vaccination in one city increases.
About half a century ago, measles were common in almost the entire world, so the number of cases is relatively constant, researchers at Bartos Lisovski Medical College in Krakow (Krakow) write. 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 has dropped significantly. In 1980, 2.6 million people died of viral disease, and in 2011 they were under 90,000. R Meanwhile, eradication of measles even seemed possible. Today, this goal has moved to the distant future.
One reason: In many European countries, the proportion of vaccinated children today is less than 95 percent – the rate that is considered necessary to stop the spread of viruses in the group. This is partly due to the growing number of people who consider vaccination to be unnecessary or even harmful to health. On the other hand, wars or the movement of refugees have led to children not being vaccinated as expected.
The consequences of the spread of the measles virus, Lysovski's team, who has now studied in the Dutch Bible Belt, a corridor that is about 200 kilometers long and several kilometers wide, passes from Middelburg to the southwest to Zvol to the east of the country. There live about 250,000 strictly reformed Dutch, mainly in about 30 medium-sized cities. Some of these people do not consider the vaccinations to be natural and therefore reject them. The majority – about 60% – but the children are still vaccinated.
Following the introduction of the vaccination programs in the Netherlands in 1976 to 2016, researchers reported that there were three outbreaks of measles in the Bible Belt, which lasted about a year, affecting about 2500 people. The difference between the outbreaks – the last one to happen in 2013/14 – was twelve years each.
Prior to introducing vaccination programs, the virus was widespread in the religious community as well as in the rest of the country, researchers explain. The number of diseases is approximately constant. The situation then changed: The number of unvaccinated people was only high enough among Protestants that the virus found enough new "victims" to spread to the group, especially among the ten-year-old students.
The recurrence of measles is worse than the persistent spread of the virus, researchers continue. Those who have survived the disease have been immune to it for life – they can not get sick again. But anyone who did not become a child is likely to be in adulthood at the next outbreak. Ordinary measles are often heavier in old age, the researchers write. In fact, more and more adults were diagnosed with the three outbreaks in the Biblical Belt, with the number of hospital hosts increasing.
What is happening in the Bible Belief can be an example of what threatens elsewhere in the future. In 2015, for example, there was an outbreak of measles with 1243 registered cases in Berlin. He is fired from two sources: one of the children of parents who refuse vaccinations; on the other hand, refugees, for example, from Syria or the former Yugoslavia, where health systems collapsed due to the wars.
Dropping vaccinations will not lead to the development of developed countries since the time of major 19th-century epidemics, researchers said. First, local outbreaks will appear. Viruses are expected to adapt to the new realities and to evolve in a direction where they could better spread among the smaller group of susceptible people. For example, they may be more contagious before the onset of the first symptoms, increasing their chances of transmission. It was an alarming development, and if the trend did not change, it would take a small step toward the dark Middle Ages.
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