Causes
As mentioned above, the cause of yellow fever is the yellow fever virus, which is transmitted by mosquitoes. This mosquito is therefore also called yellow fever mosquito, but the disease can also be transmitted by other mosquitoes. Other ways of getting infected with yellow fever, for example through the air or water, are still unknown.
When the yellow fever virus enters the body through the mosquito bite, the viruses usually first attack the lymph nodes near the bite site. The viruses can multiply in the lymph nodes and then spread throughout the body via the bloodstream, often attacking the heart, liver, bone marrow, brain and kidneys. The viruses invade the cells of the various organs and multiply again there, eventually causing the cell to die.
This results in the damage to the organs characteristic of yellow fever, such as liver failure or bleeding in the gastrointestinal tract. Especially the infestation of the heart can be dangerous, as it can lead to cardiac arrest. However, due to the simultaneous damage to several organs (multi-organ failure), life-threatening situations can also occur in all other organs, which cannot always be treated adequately. A detailed overview of all tropical diseases can be found under the article: Overview of tropical diseases
Diagnosis
The diagnosis of jaundice is based on the clinical picture of the patient’s symptoms. In the early stages, however, it is still difficult to distinguish the disease from other, more harmless conditions. The combination of fever, jaundice and bleeding from mucous membranes and the gastrointestinal tract often results in a diagnosis only in the second stage.
In order to find a diagnosis, it is particularly important that the patient is asked to travel to areas at risk of yellow fever and to have sufficient vaccination protection against yellow fever. In the laboratory, the virus can be reliably detected in the blood up to the 10th day of the disease and ensures the diagnosis. In addition, antibodies against the virus can be detected in the blood.
In the autopsy, characteristic changes can be detected in the liver preparation. During the course of the disease, however, the removal of tissue (biopsy) from the patient is not permitted (contraindicated), as this may cause additional bleeding.
