Dengue is the world’s most widespread illness, which is transmitted by mosquitoes. And the most underrated. Especially in Asia, more and more people are infected. Why is this so? Here are some answers.
Dengue breakouts in Asia, more violent?
Yes, but not only there. In the past 50 years, says the WHO, has verdreißigfacht the number of Dengue cases. 50 to 100 million people are infected – according to estimates, every year. Especially in Southeast Asia, South America, tropical Africa and also in Australia.
Because there, in tropical and subtropical climates, feel the mosquito Aedes most comfortable with. It transfers a bite, the Dengue Virus to humans. Meanwhile, half of all people in the world in Dengue-prone areas can expect to live. Before 1970, the tropical disease from nine countries, was known today, it is widely used in over 100 countries. The sharp increase relates primarily to Laos, and the Philippines.
Click here to read: The most dangerous diseases that mosquitoes transmit
Why the increase?
Jonas Schmidt-Chanasit from the Bernhard-Nocht-Institute for tropical medicine in Hamburg, says the Dengue Virus is one of the fastest-spreading pathogen in the world. And he warns that Dengue will dramatically underestimated. Because often, the disease is quite harmless, like a cold. In the worst Case, it ends deadly. Especially dangerous is when the symptoms are not interpreted properly, the disease is not detected or with other infections such as Malaria is confused. So can spread the Virus sound.
Also, the proof is not easy. In the case of Malaria a drop of blood is sufficient under the microscope in order to detect the rather large excitation, the tiny Dengue virus can only be done with a blood test exposed.
A particularly severe increase of Dengue is always in the rainy season and in urban areas. Because the mosquitoes need moisture so their larvae can grow to sharp Virus-Vectors approach.
The more water, the more larvae and, finally, mosquitoes are invading with your virus proboscis about people. Larvae need for your development more than a puddle of water. You are abound to find, especially in cities. In tin cans, water puddles, old author tyre, plastic bags. And Stechgelegenheiten in cities well enough. Especially because Dengue mosquito is active during the day. Unlike the nocturnal Malaria mosquito, in front of the people very effectively with anti-malaria bed nets can protect.
Other reasons for a rise in Dengue cases: the globalisation and climate change. On the plane, on container ships, by tourists and business travelers with Dengue be dragged-mosquitoes all over the world. As the climate changes – in many places it will be warmer and more humid – survival of the mosquitoes where they were previously frozen. Thus, also in Europe, especially in southern countries, more and more Dengue mosquitoes. This Trend will intensify.
Why are the viruses, particularly in Asia to be so aggressive?
Firstly, because the Asian viruses are much more virulent than their American Relatives. And secondly, because it is in Asia, only a Virus, but four subtypes, called serotypes. A Patient suffering from a Virus, it develops antibodies that make him a life long immune to the Dengue Virus. Often the initial infection is harmless.
The Patient being infected at some point later with a different subtype, can pass the disease dramatically, says tropical medicine, Schmidt-Chanasit: “a severe course of the antibodies, which have formed after the first infection, are not quite innocent. Because, you can amplify the disease by other viruses sometimes.”
This is exactly what makes the development of a protective vaccine is so difficult. Because the vaccine must be against all of the pathogen types of the Dengue Virus to be effective. A type of virus is not covered, it can come, according to experts, to a series of infections, and in the case of infection with a particularly severe course.
There is, however, a vaccination, or?
Yes, there is, but it is controversial. The vaccine is Dengvaxia, he was developed by Sanofi-Pasteur. A prerequisite for this vaccination, however, is that the people have had a previous Dengue infection. As for people who had pre-vaccination never Dengue fever, there is an increased risk of developing a particularly severe Form.
The Philippines were the world’s first country to Dengvaxia began to mass vaccination. After several deaths, the country has prohibited, however, at the beginning of the year, the Import, sale and distribution of the vaccine permanently.
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