Is mankind a disease

Epidemics - ineradicable scourges of humanity?

Reinhard Güll

Whether plague, cholera, tuberculosis or influenza, hardly anything has affected people more than infectious diseases, which are often colloquially referred to as epidemics, in the course of their developmental history besides the incisive wars. For millennia, they have caused the deaths of even more people than the wars that raged at the same time. Nothing was more ruthless than the deadly scourge of infectious diseases. Neither kings nor beggars were spared from them. No social class could have felt safe from its immense power. During the Thirty Years' War in Europe, more people were recalled to the afterlife by the plague than by the immediate events of the war. Many infectious diseases around the world have lost none of their horror to this day.

Again and again, infectious diseases are in the public eye, despite immense medical advances. In many parts of the world they are still one of the most significant causes of death. Infectious diseases continue to pose enormous challenges to health systems around the world. Effective protective measures against infections are made even more difficult in countries with poor hygienic conditions and limited access to clean drinking water. Infectious diseases accompany human history as a bad omen, as the following brief historical overview shows.

The horror and hardship caused by infectious diseases led to the first written documentation in early antiquity. As early as 1550 before the birth of Christ, a papyrus text in Egypt described an illness associated with coughing, pain and infirmity. It was probably tuberculosis. This papyrus is considered to be one of the oldest medical texts and shows the horror that tuberculosis, which is still considered very dangerous today, must have triggered back then. Tuberculosis - formerly known as consumption in Germany - is an infectious disease caused by the bacterial species Mycobacterium tuberculosis. Tuberculosis primarily affects the lungs. From there, the infection can spread through the bloodstream to other organs - such as the bones, urinary tract, intestines, and skin. The infection usually occurs through inhalation of infected droplets of saliva.

Until the discovery and use of antibiotics, the disease was fatal in most cases. In 1900, tuberculosis was still the leading cause of death in the USA. In the period 1902/1904, 285,918 people with tuberculosis were registered as entrances to general hospitals in the German Reich. The Gartenlaube, the illustrated paper with the highest circulation in Germany at the time, denounced the conditions caused by tuberculosis in issue 1 of the 1891 volume as follows: “The seventh part of mankind succumbs to pulmonary consumption that, to let numbers speak in their brutal sobriety, in Germany every year an average of 160,000 people fall victim to this hitherto unbridled disease, and that most of them are at an otherwise fully developed age. ”How badly tuberculosis raged can still be seen decades later. According to the cause of death statistics, 3,608 people died of tuberculosis in Württemberg in 1923; that was 9.9% of all deaths. In Baden, 3,913 or 12.1% of all deaths died of tuberculosis in the same year. Worldwide, tuberculosis still represents a huge threat. With currently around 2.5 million deaths each year, tuberculosis causes the largest number of infectious disease victims in addition to AIDS.

Another ancient document reports that the Jewish king Azariah around 750 BC. Was attacked by leprosy, whereupon he was banished from the city walls until the end of his life. At that time, leprosy was understood to mean various diseases associated with rashes, including probably leprosy. Leprosy is a chronic bacterial infection and causes disfiguring spots and lumps on the skin, as well as nerve damage. In Africa, Asia and South America, where this disease occurs more frequently today, the infected people are housed and treated in leprosy wards. Leprosy is not eradicated today, but it can be controlled. Because of the antibiotic treatment options, leprosy has now almost disappeared in countries with developed health care. However, the disease is still a serious problem in many countries in Asia, Africa and South America. The majority of those currently infected live in India today. According to the WHO, around 213,000 people were infected with leprosy in 2008.

As early as 323 BC After conquering Mesopotamia, at the height of his power, Alexander the Great succumbed to a sudden fever at the age of 33, most likely malaria, an endemic infectious disease that has long imposed a high death toll on mankind. Malaria is also called malar fever or intermittent fever and is a disease caused by unicellular parasites of the genus Plasmodium. The disease occurs mainly in the tropical and subtropical areas by the bite of a female mosquito of the genus Anopheles. Typical symptoms are high, recurring to periodic fever with chills, discomfort and cramps in the gastrointestinal tract. In children, malaria can quickly lead to coma and death. According to the WHO, almost 1 million people die of malaria every year, around half of them are children under 5 years of age. 90% of all sick people live on the African continent. According to the Robert Koch Institute, the number of malaria cases worldwide is estimated at 300 to 500 million cases each year.

The first big known smallpock wave - also known as the "Antonine Plague" - attacked the city of Rome in 166. The virus epidemic depopulated and destabilized the Roman Empire in the following two decades. Even Emperor Marcus Aurelius probably succumbed to this disease. The smallpox pathogens in humans are viruses of the genus Orthopoxvirus, they are the largest and best-known animal viruses. The peoples of newly discovered continents were also quickly afflicted by these treacherous pathogens. The European conquerors brought smallpox with them to America, where it caused devastating epidemics among the Indians that resulted in millions of deaths. Smallpox cases were still occurring in Europe in the 1950s and 1960s, for example in Heidelberg in 1958 (18 cases of the disease, two of which were fatal). At the onset of the disease, there is a severe feeling of illness, back pain with fever and chills and catarrh in the throat. A biphasic fever is typical for smallpox: after 1 to 5 days the fever falls and rises again after a day, after which the typical skin symptoms appear, which were also eponymous for this disease. There is no cure for smallpox; only a preventive vaccination offers protection. The vaccination can still develop its protective effect if it is carried out up to about 5 days after the infection. There have been no cases of smallpox since the last known case of illness in Somalia in 1977. In Germany, the last case occurred in Hanover in 1972. Consistent vaccination and control programs by the WHO and other health organizations meant that in 1980 the world was declared smallpox-free by the WHO.

In Constantinople, in 542, the Justinian Plague - a plague epidemic brought from Africa to the entire Mediterranean region - killed tens of thousands of people within a few weeks. 1347 the plague brought from Asia reached Sicily. Within a few years, the so-called »Black Death« spread across Europe and killed an estimated 20 million people, which corresponded to a third of the European population at the time. This should not remain the only plague epidemic in Europe. Until the early modern period, the continent was repeatedly ravaged by plague epidemics. In the Thirty Years' War, for example, more people died from the plague than from direct effects of the war. From today's medical point of view, it is not clear whether these epidemics were all caused by the plague bacterium yersinia pestis, which was only discovered in 1894. The causes could also have been a hemorrhagic fever, smallpox, typhus, cholera or typhoid. In the past, the term plague was often equated with the term epidemic regardless of the causative agent type. Even today, around 2,000 people worldwide fall ill with the plague every year. Your chances of recovery are quite good compared to previous centuries. A good 90% of those infected survive the disease.

Only in the course of the 19th century did doctors and scientists track down the pathogens of many infectious diseases, which had been mysterious until then. Advances in the medical field and greatly improved hygiene have largely banished the previously terrible epidemics, at least from the industrialized countries. In Great Britain, Edward Jenner carried out the first successful vaccination against smallpox in 1796. Names like Max von Pettenkofer, Rudolf Virchow, Robert Koch and Emil von Behring are closely associated with the successful fight against epidemics in the 19th century. Many infectious diseases lost their horror as a result of the scientific findings of these and other researchers. Nonetheless, the threat to mankind from infectious diseases remains high, as new or changed pathogens keep appearing and the necessary hygienic standard, which is essential as an indispensable basic protection against infections, is still not guaranteed worldwide.

In addition to the infectious diseases described above, there were and are many more that threaten humanity in the past and in some cases still today. Examples are cholera, typhus, diphtheria, yellow fever, polio, syphilis and sleeping sickness. Newly discovered pathogens also spread fear and horror. A previously unknown fever epidemic occurred in 1976 on a tributary of the Congo, the Ebola River. Of the 318 infected, 280 died. Only through strict quarantine measures were teams of experts able to contain the epidemic. The Ebola River gave its name to the new, extremely dangerous pathogen, the Ebola virus. In 1981, the Bulletin of the United States Disease Protection Agency reported five young men with a fungal infection of the lungs. The rare condition was only known from immunocompromised patients. The bulletin quickly caused a stir. It was the first description of AIDS in the medical literature. A previously unknown serious lung disease developed in the Chinese province of Guangdong in 2002. A new type of virus was identified as the causative agent of this "Severe Acute Respiratory Syndrome" - SARS for short - which subsequently spread mainly in Southeast Asia, but also in Canada and other countries. A new type of flu virus spread from pigs to humans in Mexico in 2009 and caused a worldwide wave of the disease. Internationally, measures have been taken to monitor the pathogen and a wide-ranging vaccination campaign has been started.1

The Spanish flu, a form of influenza, is an example of the devastating consequences an epidemic can trigger. Influenza, also known as real flu, is an infectious disease in humans caused by viruses of the genus influenza virus A or B. Influenza viruses enter the human body through the lining of the airways, mouth and eyes. The first symptoms appear after an incubation period of a few hours to days. The symptoms are relatively unspecific and can therefore be confused with many other acute respiratory diseases. The main symptoms of influenza are: high fever, chills, headache and body aches, severe tiredness, tears in the eyes, dry cough, loss of appetite, nausea and vomiting. Usually symptoms last 7 to 14 days. However, a general feeling of weakness and loss of appetite may occur for a few weeks after this. Often it is not the viruses themselves that are dangerous in influenza, but the bacterial secondary infections that follow an influenza illness. Bacteria can penetrate the body more easily, multiply and there lead to further life-threatening diseases, since the organism is already weakened due to the fight against the influenza viruses. Influenza in its most severe form can lead to primary flu-related influenza pneumonia in people who are previously ill, immunocompromised or have no vaccinations, which can be fatal within a few hours.

The origin of the Spanish flu pandemic was in Kansas, USA, in 1917. Historians have identified Haskell County as the origin of the deadly influenza. The doctor Loring Miner had treated patients with unusually severe flu symptoms there in January and February 1918. His alarm call to the local health authorities went unheard. After three residents of Haskell County were drafted into the US Army in late February, the disease spread quickly. 3 weeks later, 38 recruits were dead and 1,100 were seriously ill.

The American soldiers deployed in Europe during the First World War brought the flu to the European continent. The virus quickly spread across Europe and then around the world. Due to press censorship, there was hardly any reports of the swelling flu epidemic in the warring states of Europe. However, this did not apply to Spain, which was not involved in the World War. Here it was difficult to suppress the news, especially since in Madrid in May 1918 every third inhabitant was sick. This is how the new epidemic got its name: "Spanish flu". Because of the bizarre secrecy among the warring nations, all sorts of names were circulating here among the war opponents, for example "Flemish fever" among the British and "lightning catarrh" among the Germans. Unlike usual, this form of flu primarily killed people between the ages of 20 and 40 and not the elderly, the sick and small children. The authorities in Germany did not improve the situation by taking half-hearted measures. Schools were closed to prevent the spread of the flu virus, but cinemas and theaters remained open because the government feared that without such distraction, riots could break out. So it happened that in 1918 around 7,300 people in the Kingdom of Württemberg died as a result of the direct consequences of influenza. In the Grand Duchy of Baden the death toll was 8,400.

The number of deaths in Germany as a result of the direct consequences of the Spanish flu was over 186,000. One can count on the same number of flu victims who died as a result of the indirect consequences of the influenza infection because their bodies are too weak due to other underlying diseases to develop enough defenses against the disease. All in all, an estimated number of more than 300,000 fatalities from the Spanish flu for the whole of Germany can be regarded as very realistic. Especially since it was not just a wave of illness. The first flu attack in May and June 1918 was followed in October by a second, even more violent wave in Europe and from there all over the world. The "Spanish flu" became a pandemic, from the United States to Europe to remote regions of Russia and India, where there were an estimated 17 million victims. The deadly disease raged as far as West Africa and the Philippines. The number of people who were infected with the virus at that time is estimated at 500 million. That corresponded to a third of the world population at that time. According to recent projections by medical historians, the epidemic claimed around 50 million lives in the following two years, which was more than three times the number of 15 million people killed in the World War.

The main reason why the pathogen causing the Spanish flu was so dangerous was that the immune systems of many affected patients overreacted at the time. Modern medical knowledge suggests that the pathogens of the Spanish flu multiplied particularly quickly and that, in an excessive reaction of the immune system, not only the viruses but also healthy body tissue were attacked, which among other things led to fatal bleeding in the lungs.2

Today, many diseases that caused the worst epidemics in human history are considered curable or eradicated. No one in Europe has been infected with the plague since the beginning of the 18th century. With consistent vaccination programs, many epidemics that were once threatening could be stopped. Thanks to the use of antibiotics, the treatment of bacterial infectious diseases has also improved significantly.

Although it has been possible to contain many diseases, new pathogens have emerged in recent decades that have the potential for new epidemics. Here we only want to point out the incurable HIV infections that led to 2,370 fatalities in Baden-Württemberg up to 2010. When and where a new influenza virus will appear, which can spread into a pandemic, cannot of course be predicted. The danger that humanity could be decimated by an infectious disease in the foreseeable future generally remains.

1 Source: Robert Koch Institute Berlin.

2 The data listed in this chapter are based on various WHO publications.

The frequent occurrence of infectious diseases is referred to as epidemic, pandemic or endemic, although these three terms cannot always be distinguished because there is often a smooth transition between them.


An epidemic is understood to be the temporal and local accumulation of a disease within a human population. In a narrower sense, it is an unusually high number of cases of an infectious disease. From the medical point of view, one speaks of an epidemic when the number of new cases of the disease increases significantly within a certain period.


In terms of definition, a pandemic is very similar to an epidemic; it is not restricted to one particular area. The difference to the epidemic lies in the spread and distribution across countries and entire continents.


Endemic refers to the permanent contamination of a society because certain pathogens are present here and cannot be completely eradicated. Anyone in a certain area is more or less likely to get sick. A typical example of an endemic in tropical countries is malaria.