Chikungunya fever is a (sub)tropical viral disease transmitted by mosquitoes and manifested by pronounced joint pain and high fever. The course and prognosis are good for chikungunya fever, which rarely occurs in Germany.
What is chikungunya fever?
Chikungunya fever is a (sub)tropical disease from the hemorrhagic fever spectrum that occurs rarely in Germany and is due to a viral infection resulting from a bite by infected mosquitoes of the genus Aedes. The viral disease is most common in sub-Saharan Africa, the Indian subcontinent, and the islands of the Indian Ocean. Following the mosquito bite, the first characteristic symptoms manifest themselves after an incubation period of about one to twelve days, such as high fever, pronounced joint pain that makes it impossible to walk upright, as well as lymph node edema (swelling), pain in the limbs, headache, fatigue, and/or gastrointestinal complaints. In addition, a skin rash may be observed in about half of those affected and minor mucosal and skin bleeding in a quarter. Infections with Chikungunya fever are notifiable in Germany.
Causes
Chikungunya fever is due to infection with the chikungunya virus (CHIKV), which belongs to the alphavirus genus. Although from a theoretical point of view several different mosquito species can transmit the virus, so far only the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus), which also transmits dengue fever and yellow fever, have been proven to be definite carriers of chikungunya fever. Except in a few documented individual cases, the pathogen is not transmitted directly from person to person (via the blood route), but is transmitted to humans by the bite of a mosquito that had previously been infected by the pathogen-carrying hosts (primates such as monkeys, rodents, humans). In addition, transmission from pregnant women infected with chikungunya fever to the unborn child could also be observed (diaplacental transmission).
Symptoms, complaints, and signs
In chikungunya fever, the primary symptom is a very high fever. This fever also has an extremely negative effect on the quality of life of the affected person and reduces it. Patients also continue to suffer from permanent fatigue and exhaustion, so that they cannot actively participate in everyday life. Likewise, very severe headaches occur, which cannot be relieved with the help of painkillers. If Chikungunya fever is not treated, conjunctivitis also occurs, which in the worst case and especially if left untreated, can lead to complete loss of vision. Those affected also suffer from pain in the joints and muscles and are therefore unable to engage in physical activity. There are significant restrictions in movement, so that most patients are dependent on outside help in their daily lives. In chikungunya fever, the affected person’s joints usually swell considerably and there is bleeding or reddening of the skin. The skin may also be affected by a rash. Chikungunya fever can be treated relatively easily in most cases. However, it happens in some cases that the joint pain subsides only after several months and thus does not disappear immediately.
Diagnosis and course
In the early stages of illness, chikungunya fever is difficult to distinguish from other tropical febrile illnesses such as dengue fever or malaria. For the diagnosis of Chikungunya fever, the stay of the affected person in one of the endangered areas as well as the typical symptoms of the viral disease, especially pronounced pressure pain in one or both wrists, gives first information about a possible disease. In addition, in the first three to five days, the pathogen of Chikungunya fever can be detected directly in a blood analysis or by culturing in the laboratory. In the later course of the disease (eighth to tenth day), a diagnosis can be made by detecting antibodies specific for chikungunya fever (IgM, IgG). The prognosis for Chikungunya fever is good and the viral disease usually heals spontaneously after one to two weeks.Only in isolated cases (about five to ten percent) does the joint pain subside again only after months or years.
Complications
In most cases, chikungunya fever resolves on its own. However, joint pain can often continue for several weeks, and patients feel tired and listless. A small percentage of infected individuals may also suffer from joint pain for several months or even years. Very rarely, Chikungunya fever has a fatal course. On average, about four out of every 100 infected persons die from the disease, and the risk of a fatal course is somewhat higher in children. In some patients, however, serious complications such as meningitis, cardiovascular failure or lung failure occur time and again. Furthermore, the tropical disease can also lead to liver inflammation (hepatitis) or severe neurological disorders. Especially in young children, Chikungunya fever can also affect the nervous system or the liver. An increased risk for a severe course of the disease has especially people with heart failure, blood sugar disease or high blood pressure, newborns and people older than 65 years. Pregnancy is also a dangerous risk factor, as the mother can transmit the disease to the child.
When should you see a doctor?
People about to travel to India, Southeast Asia or Africa should get vaccinated against the chikungunya virus as a precaution. A doctor should be consulted immediately if an infection is suspected. A typical warning sign that requires medical clarification is the strong fever, which is usually associated with chills, headache and aching limbs. Characteristic are especially the severe joint pains. People returning home from vacation who experience severe pain in the arms and legs should talk to their family doctor. The same applies if skin rashes or conjunctivitis suddenly appear that cannot be attributed to any other cause. A severe course of Chikungunya fever is unlikely, but rapid treatment allows the symptoms to subside more quickly and without complications. Parents, children and pregnant women should always see a doctor if they suspect a serious illness. This is especially true if bleeding is observed – a sign of the so-called hemorrhagic course, which can be fatal if left untreated. If the symptoms do not subside after three to four days at the latest, a visit to the doctor is required.
Treatment and therapy
Against the Chikungunya fever exists so far no effective vaccine for the causal therapy of the viral disease. Only in recent years has the disease, which has been known since the 1950s, been brought into focus by affected travelers returning to the Western world, so that clinical pilot trials for vaccine protection are only now taking place. Accordingly, therapeutic measures for those affected by chikungunya fever have so far been limited to reducing symptomatic symptoms. Non-steroidal anti-inflammatory drugs and analgesics (painkillers) as well as antipyretic and anti-inflammatory drugs are used to minimize joint pain, which can be severe, and may need to be administered over a longer period of time. Physical measures may be supportive to minimize joint symptoms typical of chikungunya fever, especially if these do not subside over a prolonged period. In addition, in some cases to prevent dehydration (drying out) due to high fever, infusions are used to improve fluid balance. Furthermore, those affected by chikungunya fever should avoid taking acetylsalicylic acid at all costs. Acetylsalicylic acid impairs the function of platelets, which are present in lowered concentrations in chikungunya fever.
Outlook and prognosis
In most cases, chikungunya fever can be well treated, resulting in a favorable course of disease and complete recovery. Especially if diagnosed early, there are usually no particular complications. If the disease is discovered later, it can cause further inflammation, such as liver inflammation or pneumonia, if it is not treated. Neurological disorders may also occur. Chikungunya fever very rarely leads to the death of the patient and especially without treatment.A severe course of the disease often occurs only in people of advanced age or in people with acute illness, which weakens the immune system. If Chikungunya fever occurs during pregnancy, the disease can also be transmitted to the child and infect the child. Since the disease cannot be treated causally, only the symptoms of the fever are treated with the help of medication. As a rule, the symptoms subside after about a week. Only in a few cases do the affected suffer from the severe joint pain for several months and require intensive medical treatment.
Prevention
Since no vaccine against chikungunya fever exists to date, the disease can only be prevented by exposure prophylaxis. This includes mosquito repellent and wearing long-sleeved clothing when in areas at risk. Since the pathogen-transmitting mosquitoes are also active during the day, long pants and shirts should be worn at night as well as during the day. Those already affected by chikungunya fever have lifelong immunity.
Aftercare
Because the chikungunya virus cannot be fought directly, there is no common aftercare or follow-up treatment. During treatment, only the symptoms are treated. During this time, bed rest is especially important. Once the fever is over, it is important to slowly get going again. The circulation might not be up to speed yet after a longer period of lying in bed. It is also important to drink enough after the fever. During the fever one loses a lot of water, which has to be returned to the body afterwards. A doctor must check whether further painkillers are necessary after the fever. Physiotherapy is often prescribed after the treatment to counteract any persistent joint pain. After symptoms are relieved and the fever is reduced, the doctor will check to see if blood counts are back in the normal range and determine what other possible follow-up services are needed. Patients should be careful not to overexert themselves after the illness and gradually and slowly return to their normal daily routine. A fever like Chikungunya fever, depending on its severity, can be very debilitating to the body and immune system and can cause blood pressure to plummet.
Here’s what you can do yourself
According to current medical knowledge, no drug is available that directly combats the viral pathogen of chikungunya fever, so only symptomatic treatment is possible. The first symptoms of chikungunya virus disease are high fever and severe, sometimes unbearable muscle and joint pain, which can be relieved by antipyretics and painkillers. Paracetamol and non-steroidal anti-inflammatory drugs such as ibuprofen or naproxen have proven to be effective. Aspirin and other salicylates, on the other hand, are not recommended because they can worsen the effects of chikungunya fever by causing severe bleeding due to inhibition of platelet clotting. In some cases, Chikungunya fever is accompanied by a rash that usually resolves on its own, so there is no need for treatment. To aid in the healing process, it is advisable to stay on bed rest and drink plenty of water to counteract dehydration and mineral loss associated with the high fever. After the fever has subsided, light exercise is advisable to accustom the muscles and joints to strain again. So far, there is no vaccination against Chikungunya fever, which is transmitted by mosquitoes of the Aedes genus mainly in Asia and Africa. Accordingly, prophylaxis is only possible in the form of appropriate protective clothing and repellents.
