Dengue fever is a viral disease that can occur both as an epidemic and sporadically. Because of its mode of transmission, it occurs only in tropical and subtropical areas.
What is dengue fever?
Dengue fever is also called bone-crushing or dandy fever. It is caused by the dengue virus. This is transmitted by bites from certain types of mosquitoes when they are infected with the virus. Infection with dengue fever resembles the course of a severe flu or diseases with similar symptoms, so diagnosis is not very easy. The main areas of distribution of dengue fever are South and Central America, some parts of Africa, Southeast Asia, and some islands in the Pacific Ocean. In the USA and Europe, dengue fever is one of the most frequently imported diseases. This is due in particular to the increased travel by Europeans and North Americans. Dengue fever has four subtypes, but these can occur locally at the same time. Patients who have passed through an infection with one of the subtypes are immune to further illnesses of this subtype. However, infection with one of the other three subtypes can still occur. This is then usually worse than the first illness with dengue fever.
Causes
Causes of dengue fever are the so-called dengue viruses, which are transmitted by bites of infected mosquitoes of the species “Aedes”. However, only primates and mosquitoes are known to carry the dengue virus. The female mosquito ingests the virus when sucking blood from an infected victim. If the concentration of the virus in the blood is high enough, it can multiply in the mosquito’s stomach. The virus then enters the mosquito’s blood system and saliva. When bitten again, the virus is transferred with the saliva into the bloodstream of the primate or human.
Symptoms, complaints, and signs
The first symptoms of dengue fever appear about 2 to 14 days after the affected person has been bitten by an Aedes mosquito. At first, nonspecific signs reminiscent of the flu form. It is typical for dengue fever that the first symptoms are non-specific. For example, most of those who contract the disease initially suffer from pain in the head and joints. Some patients also experience a rash on the skin that resembles rubella. They also experience itching all over the body. However, some people do not experience any symptoms at all, which is especially true for children. In most cases, the symptoms of dengue fever last for about seven days. If there is a loss of appetite and nausea, they can even last for several weeks. As a rule, however, the symptoms of the disease recede again without serious effects. However, dengue fever can sometimes be much more severe. Thus, the symptoms are much more pronounced in a further episode of the disease. Doctors distinguish between dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). In dengue hemorrhagic fever, there is a risk of serious bleeding complications because the amount of platelets in the body decreases. As a result, there is a risk of life-threatening bleeding. If dengue shock syndrome is present, it is possible that blood pressure will be derailed, which in turn will result in the heart being unable to ensure adequate blood flow in the organism. As a result, essential organs such as the kidney and brain are affected.
Diagnosis and progression
Infection with dengue fever initially leads to high fever, which is also often accompanied by chills. Furthermore, there is pain in the limbs, head, muscles and joints. The incubation period is about three to fourteen days. A red rash on the face or a rash on the arms and legs is also possible in the first days of infection. Other flu-like symptoms include sore throat, runny nose, cough, dizziness and nausea. After a few days, there is initially a short fever-free period, followed by a few more days with a fever that is not quite as high. In a more severe form of dengue fever, there is a disturbance in blood clotting. This leads to internal bleeding, especially in the gastrointestinal tract, large fluid losses and circulatory collapse. This form of the disease is called dengue hemorrhagic fever.A diagnosis of dengue fever is initially possible on the basis of the symptoms that occur and the patient’s medical history. The diagnosis is confirmed by an antigen test, in which certain pathogens are detected in the blood. It is important in the diagnosis of dengue fever to exclude other tropical diseases, such as malaria, yellow fever, or Lassa fever.
Complications
Usually, dengue fever progresses without further complications. If medical care is provided and the patient is treated properly, the disease heals without further damage in 99 out of 100 people affected. The risk of complications occurring is increased if patients are not adequately hydrated. Children under the age of twelve are also more prone to complications than older sufferers. Dengue fever can be particularly dangerous if the affected patient has already suffered from this disease once or several times. For reasons that have not yet been confirmed, the course of dengue fever is more severe if the patient already carries the dengue virus. The combination of dengue shock syndrome, or DSS, and dengue hemorrhagic fever, or DHF, is particularly dangerous. These patients must be treated in the intensive care unit. If left untreated, the mortality rate is over fifty percent. In dengue hemorrhagic fever, it is possible for the patient to develop meningitis. However, this complication is rare. About as unlikely but not impossible is inflammation involving the heart and coronary arteries. Complications that can occur in DSS are shock symptomatology and circulatory failure.
When should you see a doctor?
Dengue fever is a tropical viral infection transmitted by the Aedes mosquito. Those who become infected and ill after a mosquito bite initially develop symptoms similar to those of a harmless cold. Headache, joint pain and pain in the limbs are typical. However, because dengue fever can cause much more serious complications than a normal cold, sufferers should see a doctor immediately if they develop flu symptoms after returning from a risk area. This applies all the more if the typical symptoms are joined by a skin rash and itching. Risk areas include in particular Thailand, the Philippines, India, Cambodia, Brazil and Cuba as well as the Maldives. The Aedes mosquito is not native to Europe. The only known exception is the Mediterranean island of Madeira, which belongs to Portugal. If dengue fever has been diagnosed, those affected should monitor the course of the disease and immediately consult the attending physician or a hospital as soon as the first signs of complications appear, as these can become life-threatening. The first signs of a severe course of the disease are, for example, abdominal pain and vomiting as well as a sudden drop in body temperature or blood pressure. Dengue fever is not contagious, so those affected need not fear infecting their social environment. The latter also do not have to see a doctor as a precaution. Nevertheless, the disease is notifiable. This is taken care of by the attending physician.
Treatment and therapy
Treatment of dengue fever is adapted to the patient’s condition. In this regard, there is no specific therapy. Rather, the physician tries to alleviate the symptoms and thereby facilitate the patient’s recovery. Consideration is given to the use of agents that reduce fever and have an analgesic effect. However, painkillers based on acetylsalicylic acid must not be used, as these inhibit blood clotting. This can be dangerous when dengue hemorrhagic fever sets in. The patient should keep strict bed rest during the disease, then healing can be expected after about two weeks. In the severe form of the disease and massive circulatory collapse, inpatient hospitalization may be necessary. In this case, an isotonic solution is administered to the patient via an infusion to compensate for a major fluid deficiency and prevent further fluid loss. It is also possible to administer blood plasma or blood protein if dengue fever is severe.
Outlook and prognosis
Dengue fever is a very serious disease that absolutely must be treated by a doctor. In the worst case, death can occur if dengue fever is left untreated.Those affected primarily suffer from the symptoms of flu or a cold, with severe pain in the limbs and also nausea. Furthermore, the disease leads to internal bleeding and thus, in the further course, to circulatory collapse. The patient may also lose consciousness and injure himself. Due to the disturbed blood coagulation, severe bleeding also occurs in case of injuries. In most cases, the course of dengue fever is positive if the disease is treated correctly. In this case, those affected depend on treatment with the help of medications that support recovery. In most cases, simple bed rest is sufficient to overcome dengue fever. No particular complications or long-term damage occur, so the patient’s life expectancy is also unaffected by this disease. As a rule, recovery takes about two weeks.
Prevention
To prevent dengue fever, mosquito bites must be prevented. This can be done by wearing long clothing or using insect repellents and mosquito nets. Although a vaccine against dengue fever is currently in clinical trials, it is not yet available.
Follow-up
After completing medical treatment and regular blood tests during dengue fever, special care should be taken by the patient to replenish his fluid balance sufficiently. This is because it was severely affected during the infection and will lead to fewer complications and bleeding tendencies if the patient is re-infected. A further dengue fever infection can lead to an increased risk of complications in most patients. Therefore, it is extremely important to protect against it from the outset. Before traveling to regions endangered by the virus, one should obtain detailed information and, if necessary, seek medical advice. During your stay in these areas and countries, you should urgently take all available protective measures to avoid being bitten. These include insect repellent spray, long clothing that covers the arms and legs, and mosquito nets for the bed to prevent mosquito bites at night. The transmitting mosquito is active around the clock, so you need to protect yourself adequately from its bite at all times of the day and night. If one was already infected and suffered dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) in the course of the disease, which were treated with intensive medical care, it is important to weigh up whether one wants to expose oneself to the high risk of a renewed infection and thus the risk of a complication-rich course of the disease or to avoid those endangered travel destinations completely in the future.
What you can do yourself
Dengue fever is a very serious viral infection, the symptoms of which sick people should not under any circumstances independently Therapieren. If dengue fever is suspected, a doctor must be consulted immediately. There is no vaccine available against dengue fever pathogens. Preventive measures therefore consist in particular of avoiding the bite of the Egyptian tiger mosquito (Aedes aegypti), which transmits the pathogen. The precautionary measures here are the same as for other blood-sucking insects. Those in a high-risk area should prefer light-colored clothing that covers arms and legs. In addition, highly effective chemical insect repellents should be used. Since the protective effect of such preparations usually lasts only a few hours, they must be applied several times a day. A mosquito net can be helpful at night. People who have contracted the disease should take it easy, avoid strenuous physical activity and sports. This applies even if only mild symptoms appear. Acute fever episodes can also be treated with mild home remedies in addition to the measures prescribed by a doctor. Cold calf compresses are particularly effective for fever. Under no circumstances should acetylsalicylic acid (ASA), which is contained in many over-the-counter medicines for headaches and fever and also in natural medicines made from willow bark, be taken without consulting a doctor. Affected persons should only use painkillers that have been prescribed by a doctor or handed out at the pharmacy after explicit reference to dengue fever.
