In the hot summer, you can't hide from the favor of mosquitoes anywhere, Xiaobian's legs have long been bitten out of large and small bumps, and you can only wear the longest pants on the hottest day to cover the legs of the "red bean popsicle"!! Whenever I am tossed by mosquitoes and can't sleep at night, Xiaobian will think, why do the evil mosquitoes bite me alone?! Can't the rain and dew be evenly wet??!!
Not really! Today, Xiaobian is going to talk to you about a deadly disease transmitted by mosquitoes. There is no cure for the disease, and so far no vaccine has been found. Half of the world's population is at risk of contracting the disease, a major public health problem that affects many children. You can't predict whether you or him, or whether she will die of the disease.
This is one of the most terrible diseases in the world – dengue fever. Perhaps many people don't know about dengue fever and have never even heard of it, but this terrible disease is spreading rapidly, and more and more people are threatened by it every year. What is dengue fever? What are its symptoms? Are there any means to prevent it? In this issue of "Life Code", follow the editor to understand that everyone knows very little, but it is lurking around us with dengue fever!
Guest information for this issue
Dr. Stephen Whitehead, National Institute of Allergy and Infectious Diseases, Washington, D.C.
Dr. Remi Teyesu, Partner, Dengue Prevention and Control Centre.
Dr. Joan Lang, Sanofi Pasteur R&D Center.
Dr. Ruth Tugavin, Baguio City Hospital, Philippines.
Dr. Alex Mareiro, Philippine Department of Health.
Dr. Ferdinand Guzman, San Lazzaro Hospital, Manila.
What is dengue fever?
Like malaria, dengue is a mosquito-borne disease. But the dengue mosquito Aedes aegypti mosquito bites people during the day and is therefore more difficult to control. This mosquito grows in humid tropical areas, breeding in stagnant water, by sucking human plasma as a food source.
Dengue fever is mainly endemic in the tropics and subtropics, Asia and Latin America are the highest incidence of dengue fever in the world, and Guangdong, Hong Kong, Macao and other places in China are all endemic areas of dengue fever. However, the constant change in the global climate means that dengue can no longer be considered a tropical disease, and more and more countries are under threat.
In the 1970s, only 9 countries in the world reported domestic outbreaks of dengue fever, and today more than 120 countries have experienced dengue fever. Because there are no treatment options or vaccines, people have been suffering from dengue fever for decades.
What are the symptoms of dengue fever?
When the rainy season comes, dengue fever is the number one disease and the number one problem that health departments have to deal with.
Nosebleeds, vomiting, abdominal pain, these are all obvious symptoms of dengue fever, and in severe cases, patients with dengue fever develop internal bleeding and shock. The worst case for dengue fever is death from excessive blood loss, and if the patient loses too much blood, he will undergo irreversible shock. Dengue fever worsens further and is beyond doctor control, and even with the utmost support, patients are still at risk of dying.
Little mosquitoes, threatening the economy!
Dengue not only affects people, but also threatens the economy.
If dengue fever occurs in a city, especially in a big city, everything will come to a standstill. Both the economic and public health architecture can be undermined because of the sheer number of patients and its impact on the economy is significant, especially for emerging developing countries. Nearly $9 billion has been spent worldwide on a dengue health management system, which is undoubtedly a huge economic burden for developing countries.
Find a dengue vaccine!
The World Health Organization has set a goal of reducing dengue deaths to half of what it is today by 2020. Over the past 50 years, the rate of dengue virus infection has increased by 30 percent, meaning we need vaccines to achieve this goal.
So far, scientists around the world have been looking for a vaccine against dengue fever, but the search has been slow. Over the past few decades, other high-impact infectious diseases have found a vaccine to fight it – smallpox has been completely cured, polio has been largely eliminated, measles has found an effective cure... But year after year, scientists are still helpless in the face of dengue fever.
At the same time, the number of dengue diseases is still rising, and more and more families, because of dengue fever, have lost their loved ones and become no longer complete.
Scientists at the National Institutes of Health in Washington, D.C., believe they have made significant progress in developing a dengue vaccine. They are currently conducting initial testing of the dengue vaccine, which is the first time that the vaccine has been tested in humans, to make a preliminary assessment of the vaccine's safety and to see what negative effects the vaccine will have on the human body. The scope of the vaccine was small, with only 250 people taking part. The aim is to test to find out whether the vaccine is safe in humans, whether it is effective, and whether it can be widely used in countries infected with dengue fever.
Find a four-in-one vaccine!
Scientists around the world are working to find usable vaccines to tackle the complex disease of dengue in different ways. The city of Lyon, France, is the world's largest vaccine production site, home to a pharmaceutical company called Sanofi Pasteur, where experts have spent decades researching vaccines for dengue.
Dr. Joan Lang is the head of the research department and has spent his entire career researching dengue vaccines.
He told us that it is very difficult to find a vaccine against dengue because dengue has 4 different viruses, so what you need to find is a vaccine against 4 viruses, which not only needs to fight 4 viruses, but also to fuse 4 functions together. So a four-in-one vaccine needs to be developed from the start, because all four dengue viruses can cause dengue infection and cause serious illness leading to hospitalization and death. Finding a vaccine against a virus takes about 10 years.
Just as scientists struggle to fight the virus, dengue fever is spreading rapidly. Over the past 20 years, the number of hospitalizations of dengue patients has increased and is now a major public health problem. Dengue fever disasters have occurred in Brazil, Mexico, Colombia, Honduras and other places.
Dengue patients of all ages require ongoing tests, saline transfusions, blood tests, and, if necessary, blood transfusions. If a vaccine could be found, the situation would improve considerably.
Dengue fever is not a once-in-a-lifetime illness
For other infectious diseases, once infected, antibodies are produced and will not be infected a second time. And dengue fever is not a disease that only happens once in a lifetime, it is possible that you will get better this time and be infected more seriously next time.
A person who contracts dengue fever in childhood will be infected again in a few years, and in general, the second time will be more severe. This is very rare and is endemic to dengue fever.
When you are infected with dengue virus, let's say you are infected with dengue virus 1, the body will develop antibodies to dengue virus 1. These antibodies kill dengue virus 1, but if you are exposed to dengue virus 2, 3 or 4, the antibodies in the body will recognize these viruses as the same kind of dengue 1 virus, but they will not kill them. In the fight against vaccines, the four strains of the dengue virus compete with each other, hoping to become the main strain of the virus. As a result, it is very difficult to find a balance. It is precisely because of this peculiarity of the dengue virus that it is extremely difficult to develop a vaccine.
Dengue fever, the typical 21st century disease!
The problems caused by dengue fever are increasing, and the onset season of dengue fever is getting longer and longer in some tropical regions, such as Indonesia, due to climate change. 20 years ago, dengue always started during the rainy season, around November, December and January, but now it's different, and the rainy season basically lasts all year, which has a lot to do with global climate change.
More rain means more mosquitoes. If rainwater accumulates in one place for a long time and is relatively clean, it will become the favorite breeding place for mosquitoes carrying dengue virus. Mosquitoes like clean and static water beaches, and there is a lot of still water in the city, puddles, flower pots, buckets, paint cans... These can become sites for dengue mosquitoes to breed.
As more cities in developing countries have attracted a large number of mosquitoes carrying the dengue virus, they are breeding rapidly here, and we are the initiators.
Dengue fever is a typical "21st century disease" because mosquitoes carrying the dengue virus prefer the living environment of big cities, and a large number of people are crammed into a small living space. In addition, changes in the environment have also changed the living space of mosquitoes.
Dengue fever is constantly spreading through travel, migration and urbanization. If we carry the dengue virus, there may be a little mild low-grade fever and there is no discomfort, but when we go to other places, if we are bitten by local mosquitoes, then these mosquitoes will pass the virus on to other people. In other words, we become the ones who spread the dengue virus.
Nowadays, it is becoming more and more common to travel abroad or to travel abroad, and if we don't know we have the dengue virus, we will take it to the place where we go.
epilogue
Any place where Aedes aegypti mosquitoes may grow is at risk of erosion by the dengue virus. As the climate changed, the mosquito began to multiply in more and more parts of the world. This means that dengue fever is no longer a tropical disease, and more and more people are beginning to be exposed to this disease.
Little mosquitoes, never underestimate. When we have unexplained nosebleeds, vomiting, and abdominal pain, we must seek medical attention in time!
Editing: Pastoral, Montessori