Historical story

Lecture by Roel Coutinho on the unpredictability of the spread of infectious diseases

Infectious diseases are back with a vengeance. Roel Coutinho, professor of epidemiology and infectious diseases at Utrecht University, recently gave a lecture about infectious diseases in the past and present in the Boerhaave museum. According to him, an epidemic is still impossible to predict, but major changes in society, such as in livestock farming, must be closely monitored.

Coutinho starts his lecture in the Boerhaave museum with the history of infectious diseases. He says that in 1850 almost everything was done in the Amsterdam canals:from washing your clothes to doing your needs. “It was a stinking mess. The poor living conditions also ensured that a disease such as Tuberculosis was spread quickly,” explains Coutinho.

Fortunately, from 1885 there is an improvement and there is a decrease in the number of infectious diseases. Around that time it became known how diseases were transmitted and improved hygiene played a major role in this decline.

At the beginning of the 1950s, antibiotics came on the market and various vaccines were also available against, among other things, diphtheria and polio. These changes reduced the number of epidemics.

New infectious diseases

Despite this, the numbers did not continue to fall. New diseases even emerged, such as HIV. Coutinho:"In 1981 there were only 5 cases of HIV infection, which is now unimaginable." The HIV virus had already passed from animals to humans in the Belgian colony of Zaire in 1910, probably by hunting monkeys. “Many men lived in this society and prostitution was common, so the virus spread from person to person. As a result, when French teachers were brought from Haiti to teach French in the African colony, the virus began to spread across the rest of the world.” Travel, animals and human contact are thus typical examples of factors that are important in the spread of infectious diseases.

On the other side of the world, in China, there is currently Influenza A (H7N9). It is yet another variation of the flu, such as the well-known bird flu (1997) or swine flu (2009). The flu is an illness caused by the influenza virus, but this virus can change (mutate). A virus multiplies in order to survive, but small errors can occur in the new virus. “Most organisms have a system that detects these errors and often corrects them, but viruses don't,” Coutinho explains. The change of the genes due to those small mistakes ensures that a new variant can arise in viruses.

Professor Roel Coutinho is also the author of the book 'The plagued man'. In this book he describes a number of infectious diseases, explains how we dealt with them, how we might get a grip on them, and how it is different every time.

Predicting the future

The emergence of new variants can ensure that people or animals become infected with this 'new' virus. Today, it has been agreed worldwide that an increase in new diseases must be reported, but an outbreak of an infectious disease is still difficult to predict. This is because there are so many – and often unexpected – factors at play.

The Q fever, which suddenly took off at the beginning of this century, started in goats in a village in Brabant, for example. Because there was a quota on the cow's milk to be produced, goats were used to produce milk. Goats do not get sick from this bacterium, but they did have miscarriages. The increase in goat farming and thereby an increase in the number of miscarriages in goats resulted in an enormous amount of bacteria that subsequently jumped to humans.

It is therefore important to detect any infectious diseases early. Especially within countries that are currently undergoing a drastic change, such as in the field of ecology, in living conditions or in society. However, it remains unpredictable whether and how a micro-organism will adapt to the environment and whether it will pose a danger to humans.

However, when an infectious disease is detected, measures must be taken to prevent it from spreading. For example, there is currently an outbreak of the Ebola virus in West Africa. This virus spreads through the body fluids of infected people, and if proper measures are not taken – such as poor hygiene and contact with patients – the virus can continue to spread.

But even if scientists think that a bacterium or virus is dangerous, practice sometimes shows that nothing is wrong. An example of this is the swine flu. After the alarm was raised on a large scale, the disease often turned out not to be dangerous for the most vulnerable group. Most elderly people had already come into contact with this flu variant, which made it easy for their body to clear up this virus. “A lot of research is being done and we are trying to make models, but we still can't see into the future,” said Coutinho.

Amazing models

Until June 1, the exhibition Amazing Models . is on display in the Boerhaave museum to see. The exhibition contains various anatomical models used in the 19 e century were created to study man. For example, the French doctor Louis Auzoux in the 19 e anatomical models made of papier-mâché for artificial dissection, because there was a shortage of corpses for medical students.

The impressive exhibition also contains models of infectious diseases that occurred during this time.