Tropical diseasesSafari in Africa, sightseeing in Bangkok – Germans' desire for vacations in faraway countries is unquenched. Many travelers, however, know little about the diseases that threaten tropical and subtropical regions.
By Sine Maier-Bode
Paradise for parasites
Tropical diseases are infectious diseases that occur primarily in tropical and subtropical regions. Many of these diseases are contagious. Viruses, bacteria and parasites – the pathogens of various diseases have chosen the tropics because they find a little paradise there.
Not only the climate, which is also appreciated by tourists, is good for them. It is mainly poverty that causes many infectious diseases to be impossible to eradicate. There is a lack of money, a lack of medicines, and most importantly, a lack of clean water.
For a long time, physicians believed that they had conquered tuberculosis. It was once one of the most deadly diseases in Europe. Especially the 19. The nineteenth century was considered the "century of consumption". There was no knowledge of the disease yet. Staying at an air spa was recommended as a therapy.
Thomas Mann described in his novel "The Magic Mountain" a sanatorium of the fine kind, which will probably shape our ideas of what it might have been like there for a long time to come.
Alexandre Dumas, in turn, in his novel "The Lady of the Camellias" created the ideal of a devoted lover and sufferer. Tuberculosis has been stylized into a romantic disease. Since many artists succumbed to consumption, at that time it was also considered a disease of sensual and sensitive people.
In fact, it has always been a disease of poverty. Narrow living conditions, as created by industrialization, promoted the spread of the pathogen in Europe at that time. A pathogen that can be transmitted from one person to another in a flash by droplet infection.
In 1882, Robert Koch discovered the tubercle bacilli; since the mid-20th century, the primary. At the end of the twentieth century, the disease is curable. However, the fact that tuberculosis has been able to decline in rich countries thanks to growing prosperity and modern medicines has meant that it has been neglected for a long time.
Today, every third person in the world carries the tuberculosis pathogen, 90 percent of whom live in developing countries.
The disease does not always break out. Old, sick and weakened people are particularly at risk, because their immune systems cannot withstand the "tubercula" cannot withstand. Every year, around ten million people worldwide contract tuberculosis.
In the poor areas of the USA, in Russia and in many countries of Eastern Europe, new pathogens have emerged that are resistant to current antibiotics.
Fresh air cure against consumption
Always new viruses
Middle of the 20. The beginning of the twentieth century was a time of medical discoveries. Antibiotics and newly developed vaccines drove away epidemics that had plagued mankind for centuries.
For a long time, physicians were sure that the time of the great epidemics was over – until the HI virus appeared in the early 1980s, which still leads to many deaths worldwide today (HI = human immunodeficiency).
Although there are now some drugs that can help delay AIDS, the immunodeficiency disease caused by the HIV virus, there is still no cure for it.
The HI virus is not the only virus that has found its way to humans. Corona, BSE, Ebola, dengue fever – there are numerous viral diseases, some of which have appeared out of nowhere. Their pathogens, the viruses, have probably been present somewhere for a long time, well hidden in the jungle or in some other place difficult for humans to reach.
Viruses are not living organisms, but DNA or RNA information, respectively, pieces of genetic material. In order to exist, they need a host, a living being. If they want to exist for a long time, they should not harm this creature.
Thus, many viruses become dangerous only when they leave their original host – when they pass from animals to humans. The fact that this happens again and again is also a consequence of the change in man's interaction with nature.
Death from Ebola
Dormant pathogens in the rainforests
Humans are penetrating ever further into hitherto unexplored areas. Almost seems to awaken sleeping spirits. They are clearing the forests. Lure the animals out of hiding.
With the animals, the new viruses come into contact with humans. Actually, they reside in mice as in Hanta virus, in guenons as in Marburg virus, in mosquitoes as in dengue virus, or in bats as in Ebola virus.
When the Ebola virus first broke out in central Africa in the 1970s, people were terrified of an entirely new disease and had no idea how it had been transmitted to humans.
Today, it is known that the regions affected by the disease are home to bats, which are unaffected by the virus. Presumably it is from there to monkeys. Then transferred to humans.
Whoever falls ill with Ebola dies an agonizing death. Very few people survive the infection. Since the first outbreak, the disease has occurred at least six more times in different locations in Africa.
Many viruses are artists of adaptation. They can alter their genetic makeup, making it difficult for medical professionals to develop a drug against them.
Hiding places for viruses
Worms and other parasites
malaria is the best known tropical disease for long-distance travelers. And yet, very few people know that their pathogen is a parasite: Plasmodium falciparum. The Anopheles mosquito is only their carrier. And it is far from being the only parasite in the tropics. Parasites feel particularly at home in the warm, humid air.
Everywhere teems with plasmodia, trypanosomes, protozoa, larvae, flukes and worms. They all have only one thing in mind: They want to settle down in bodies to feed on them. They are a problem for tourists only if they do not protect themselves from them. Therefore, the first commandment is: "Cook it, peel it or forget it"!"
Where money for sanitation is lacking, waters are quickly polluted with feces. And because the water is a breeding ground for all kinds of pathogens in hot temperatures, you should be able to say no to fruit and salad and refrain from swimming in stagnant water.
If you also protect yourself from mosquito bites and get vaccinated if necessary, nothing should happen to you on vacation.
The situation is quite different for many inhabitants of the tropics. They have no money for medicine and they have no choice: they have to fish in the dangerous waters, they have to wash there, and often enough they get their drinking water from there.