Hantavirus infection is notifiable in Germany and can take a severe course. Successful therapies depend on the form of hantavirus infection.
What is hantavirus infection?
Hantavirus infection is an infectious disease that can be caused by various forms of hantavirus. Hantavirus infection is found worldwide in varying degrees; for example, the infection is relatively widespread in Southeast Asia. Cases of hantavirus infection also occur in Europe: A relative accumulation can be observed here, for example, in the Balkans or in parts of Scandinavia. Hantavirus infection was named after the South Korean river Hantan, where many soldiers contracted the virus during the Korean War in the 1950s. In Germany, a hantavirus infection has been notifiable since 2001. According to the Robert Koch Institute (a federal institute familiar with infectious diseases, among other things), hantavirus infection was one of the five most common viral diseases subject to mandatory reporting in Germany in 2007.
Causes
Predominantly, hantavirus infection is transmitted to humans by rodents. Although infection can also occur from person to person, this is comparatively rare. Transmission of hantavirus infection by rodents occurs primarily through excretions of the animals; the pathogens of hantavirus infection are then ingested by humans through the respiratory air. Because of this source of transmission, persons who frequently come into contact with potential excretions of appropriate rodents are at particular risk:
For example, individuals who are employed as hunters, foresters, or soldiers and therefore spend a comparatively large amount of time in forests that are home to rodents are at higher risk of hantavirus infection.
Symptoms, complaints, and signs
Hantavirus infection can manifest itself with very nonspecific symptoms. Usually, flu-like symptoms such as sudden onset of high fever with chills, headache, and aching limbs are initially apparent. The eyes are often extremely sensitive to light, and visual disturbances are also possible. Occasionally, cough, sore throat, diarrhea, vomiting and abdominal pain occur. Depending on the type of pathogen, the infection may spread to the kidneys or lungs: If the kidneys are involved, blood is often seen in the urine, and the volume of urine also decreases significantly. Large amounts of protein can be detected in the urine. Other alarming signs are minute hemorrhages (petechiae) in the skin, mucous membrane and conjunctiva of the eyes, as well as a significant drop in blood pressure. In a severe course, the progressive infection leads to complete kidney failure. In rare cases, inflammation of the heart muscle (myocarditis), inflammation of the thyroid gland (thyroiditis), inflammation of the liver (hepatitis) or dysfunction of the central nervous system may occur in the course of a hantavirus infection. Possible signs of pulmonary involvement include severe coughing and increasing shortness of breath, which can develop into life-threatening acute respiratory distress syndrome (ARDS). The course of hantavirus infections varies greatly, often going unnoticed due to the mild symptoms or being mistaken for a harmless cold. Severe courses, especially those with life-threatening respiratory tract involvement, are rare in Europe.
Diagnosis and course
To diagnose hantavirus infection, a diagnostician often first collects data on a patient’s occupation and daily environment. This can serve as an initial risk assessment with respect to hantavirus infection. Further sources of information for the diagnostician for the diagnosis of a hantavirus infection are the so-called clinical (i.e. the observable or currently present) symptoms of a patient and various laboratory values (such as blood values). The course of a hantavirus infection can vary greatly depending on the form of hantavirus and on the patient. In severe cases, hantavirus infection can be fatal. The incubation period (i.e., the time between infection and the first noticeable symptoms) of hantavirus infection can be approximately 1-5 weeks.Possible first symptoms of a hantavirus infection are, for example, fever, chills, muscle pain or pain in the area of the lumbar spine. Depending on the form of a hantavirus infection, coughing, vomiting or diarrhea may also occur. Severe cases manifest themselves, for example, in kidney inflammation or bleeding of the gastrointestinal tract.
Complications
Hantavirus infection can cause death of the patient in the worst case. Without treatment, this does not result in an automatic healing process. The affected person suffers from fever and pain in various regions of the body due to this infection. Thus, muscles and joints ache and there is a stabbing headache that can spread to the back. Likewise, abdominal pain occurs, and sometimes even diarrhea or vomiting. The patient may also suffer from an irritating cough and usually also develops conjunctivitis. The patient’s everyday life is made more difficult and the affected person feels tired and weary. Active participation in life is usually not possible due to the symptoms of hantavirus infection. Furthermore, rapid infection of other patients may occur. In the worst case, inflammation of the kidneys may occur, and renal insufficiency may develop. If left untreated, this can lead to the death of the patient. Treatment takes place with the aid of medication and is usually successful if started early. Further complications do not occur. After treatment, the affected person is usually immune to hantavirus infection.
When should you see a doctor?
Hantavirus infection is treated symptomatically. Depending on the type of virus and the infected person’s defenses, there may be no symptoms of illness at all to life-threatening symptoms. In the case of an infection with the hantaviruses found in North and South America, there is a risk of severe pneumonia with pulmonary edema, which requires medical monitoring and treatment. Therefore, it is advisable to consider the possibility of hantavirus infection and seek immediate medical attention when visiting the Americas in the event of sudden onset of pulmonary symptoms. Asian and European strains of hantavirus, if the course of infection is severe, can cause HFRS (hemorrhagic fever with renal syndrome); medical attention is also essential in these cases. If symptoms of the first phase appear, such as high fever, chills, headache and pain in the limbs, red eyes, nausea, abdominal and/or back pain, then there is a risk of the onset of a further, possibly life-threatening phase of the infection, at the end of which kidney failure may occur. The doctor must be consulted already in the case of the above-mentioned symptoms of the first phase. Moreover, infection with hantavirus is notifiable, although it is not always recognized by the physician or affected person in the case of a mild course or due to its flu-like symptoms.
Treatment and therapy
The successful therapy of a hantavirus infection depends, among other things, on the diagnosed form of hantavirus infection and on the symptoms present. It often makes sense to have a hantavirus infection treated in clinics that are equipped with an adequate intensive care unit if necessary. For the pure symptom treatment of a hantavirus infection, analgesics (drugs to fight pain) or so-called antipyretics (to fight fever) are used, among others. If an affected person is found to have an infection-related impairment of the kidneys, the therapy of a hantavirus infection may include, for example, checks on the fluid balance and, if necessary, balancing of the fluid balance. If, in the course of a hantavirus infection, the kidneys fail to function, possible therapeutic steps include hemodialysis (i.e. blood washing outside the body with the aid of an ‘artificial kidney’). If the lung function is impaired during the course of the hantavirus infection, one therapy step may be ventilation in an intensive care setting. After successful therapy of hantavirus infection, the affected person usually has immunity to the treated form of hantavirus infection.
Outlook and prognosis
Statistically, hantavirus causes death in rare cases in Europe. Viruses from rodents are rarely aggressive here.The situation is different in Asia and South America. Scientists there have not only identified far more dangerous pathogens. Rather, the climatic conditions there also offer good living and spreading conditions. The hygienic conditions allow contact with rats and mice and their excreta. The infection with the hantavirus usually subsides without residual damage. A medically prescribed therapy provides improvement in a short time. Only the so-called Hantavirus Pulmonary Syndrome has a mortality rate of 50 percent. In most cases, death is caused by organ failure. Anyone who observes the usual hygiene standards in Europe is unlikely to come into contact with infected rodents. People at risk work almost exclusively in agriculture. After successful control of the virus, people remain immune to the pathogen for decades. To date, no vaccine exists for the prevention of hantavirus. Overall, it can be stated that an infection with hantaviruses in Germany usually takes a good course. The prospect of complete cure is to be classified as very favorable in view of the less aggressive pathogens.
Prevention
Although no approved vaccination against hantavirus infection exists yet, appropriate preventive measures can reduce the risk of hantavirus infection. For example, if sites are cleaned of mouse or rat droppings (such as barns or attics), wetting the droppings beforehand or wearing respiratory protection can reduce the risk of hantavirus infection.
Follow-up
In most cases of hantavirus infection, the measures or direct options for follow-up care are severely limited. The focus is on early detection and treatment of the disease to prevent further complications or upset. The earlier the disease is detected by a doctor, the better the further course of the disease usually is. Therefore, affected individuals should seek medical attention at the first symptoms or signs of hantavirus infection. In most cases, this infection is treated by taking medication. In doing so, those affected must ensure that they take their medication regularly and in the correct dosage. Side effects or interactions should also be taken into account. In case of questions or uncertainties, a doctor should always be contacted first. Furthermore, regular control of the internal organs is also very important in the case of hantavirus infection, whereby especially the kidneys should be controlled. In some cases, the affected persons are dependent on dialysis. In this case, the care and support of one’s own family or friends is also often necessary to properly alleviate the symptoms. Possibly, this infection also reduces the life expectancy of the affected person.
This is what you can do yourself
A hantavirus infection is always treated with medication. The administration of analgesics and anapyretics can be supported by the affected person by a number of measures. First and foremost, bed rest is important. Since it is a classic viral disease, the typical measures can be taken. For example, it helps to adjust the diet and to stop eating foods that could irritate the gastrointestinal tract. In addition, the body temperature should be measured regularly. If there is a sudden rise or fall in fever, a doctor should be consulted. The sufferer should also drink plenty of water and compensate for any loss of fluids and nutrients with supplements. In severe cases, the sufferer must go to a hospital. After intensive medical care, the body is very weakened and should be rested for at least two to three weeks. This should be accompanied by close monitoring by a physician, as complications can only be ruled out by regularly checking the patient’s blood values and general state of health. If signs of a renewed outbreak of the hantavirus infection become apparent after treatment, the responsible physician must be consulted immediately.
