Fever is by definition an increase in body temperature above 38 ° C. It may be due to both an infection and a central regulatory disorder. However, bacterial or viral infections are usually the main cause of fever.
Fever in itself is not contagious, but the pathogen that causes the fever can be transmitted to more people.
Every disease can have different symptoms, with fever being just one of many possible. It arises when the body's own cells of the defense are activated and trigger an inflammatory reaction. Or, to put it another way, fever is nothing but a reaction of the immune system to kill pathogens. The increase in temperature means above all that the defense process is in full swing and that the infection has not yet been sufficiently contained by the body's own cells.
It can be determined only by measuring the body temperature - whether under the tongue or rectally. Affected individuals can also gauge how sick they feel based on the severity of other existing symptoms. The more symptoms associated with a disease in addition to the fever, the higher the risk of infection in principle. But even temperatures above the days during the recovery process should be seen as critical in terms of work ability, since even a minimal increase in body temperature is still an incompletely healed infection. In order not to unnecessarily infect his colleagues, the affected person should first return to work without fever.
Conversely, this also applies to only a slightly increased body temperature at the beginning of an infection. This period of time until the right outbreak is perhaps even the most dangerous for contagion. In the meantime, the invading pathogens multiply in the body and, for example, affect the mucous membranes of the affected person. Until the immune system identifies the pathogens as pathogenic and mobilizes and regenerates cells of the body's own defense, the person affected only suffers from subfebrile (= just below the fever limit of 38 ° C) temperatures. The affected person may feel a little bit less well, but not really sick.
For the pathogens, this means optimal propagation conditions, as contact with other people is usually not avoided. The slight feeling of "glowing" or "inner heat" should therefore be taken as seriously as the right fever in terms of virility.
As already mentioned, strictly speaking, any fever with its accompanying disease is contagious. But it is not the temperature increase that is contagious. Rather, it is the pathogens that trigger them. Thus, the fever is a good indicator of the healing process of an infection. If the affected person is again fever-free and has no further serious complaints, he is no longer considered to be contagious. On the other hand, every fever increase as well as any stagnant fever is classified as potentially infectious.
For workers or children visiting public institutions, this means staying away from work or school until a full recovery has occurred. This protects the others from possible infection and the affected person himself from possible deterioration or delay in his healing process. For too early stress can weaken the immune system. The best estimation parameter here is the own sense of illness in combination with a follow-up of the body temperature. As annoying and unpleasant as it seems. If there is no fever for more than two days according to the fever measurement, there is no longer a risk of infection.
Especially the incubation period is a highly contagious phase when fever accompanied by sore throat, runny nose, hustlers, headache, vomiting or diarrhea. For example, if pathogens enter the body via the mucous membrane, they will find an optimal nutrient medium. As a result, they multiply rapidly. Those affected notice this as a decrease in performance, drowsiness and slightly elevated body temperatures. In itself, however, they have no real disease value.
With further manifestation of symptoms such as sneezing or cough, the pathogens can then easily be transmitted via droplet infection. One speaks of a disease but only when the mucous membrane visibly inflamed and it comes to other symptoms. However, the risk of infection is highest in the symptom-poor incubation period. Social contacts are not avoided during her stay - and that's what makes the risk of infection so great.
Nettle fever is caused by the popularly known "hives". It is a skin disease that can have many causes. Their physical expression, however, is independent of the cause. The name suggests that this disease is characterized by wheals and redness on the skin, as they usually occur after contact with a nettle (also: stinging nettle).
They also have the same symptoms as a strong itching and a feeling of heat on the skin. The accompanying fever is explained by the inflammatory reaction caused by the disease. However, it is usually not contagious. This is due to the fact that the wheals are not caused by pathogens.
Rather, there are factors such as stress, sunlight or drugs that lead to an allergic reaction. The immune system is thus activated as in a normal infection, but it is directed against the consequences of physical stimuli or ingredients and not against components of bacteria or viruses. Thus, no transmission can take place and infection is excluded as long as the person does not suffer from an additional infection.
The 3-day fever is a typical childhood disease, characterized by three days of persistently high fever. With the rapid de-fever on the fourth day, a characteristic skin rash occurs on the whole body. The disease is caused by herpes viruses. In itself, infections with herpes viruses are very contagious with sufficient body contact with the person concerned.
However, one has to keep in mind that the prevalence rate in the population with this virus is very high. In principle, a child with a 3-day fever is highly contagious during the fever interval. Theoretically speaking, most parents have been in contact with the herpes virus before and are no longer bothering with their sick children. However, kindergartens and schools should not be visited during the illness phase, especially since the high fever causes a tremendous feeling of illness among those affected.
Dengue fever is a serious tropical disease. It is transmitted by mosquitoes to humans. Infection from person to person is not common. The only possible infection here is in the transmission of infested blood products. In another way, a victim can not, for example, infect his family with the virus. Nevertheless, the fever is no less dangerous, as it can lead to life-threatening symptoms in those affected.
The combination of the high body temperature and the effect of the virus on the blood components, as a rule leads to serious circulatory problems. Those who want to protect themselves from the virus must act prophylactically. There is no vaccine. Using mosquito repellent and mosquito nets is the only effective way to prevent disease. If you want to visit or visit a patient, you should be aware of the environment. On the one hand, a mosquito repellent should be applied when staying in endemic areas and on the other hand, care should be taken not to come into contact with blood products or objects contaminated with blood.
Mediterranean fever is a genetic disease. It is characterized by repetitive fevers with accompanying symptoms such as joint or muscle pain. In this case, pathogens such as bacteria or viruses are irrelevant. The cause lies in an altered genetic material of the person concerned. Contagion is therefore excluded, since only "internal factors" lead to fever.
Rheumatic fever develops after infection with streptococci. It is important to know that the rheumatic fever is not caused by a re-infection with the bacteria, but in response to the endured. The previously pathogenic bacteria are therefore generally not found here. Rather, it is the lasting effect of the infection that leads to a fever. Namely, due to the similarity of bacterial components and endogenous traits, the body erroneously starts an autoimmune reaction. This causes the fever and can additionally damage heart valves or the kidneys.
Rhematic fever is not contagious. Only the underlying infection of the upper airways by bacteria (streptococci) is contagious. This can be transmitted by a droplet infection or smear infection.