Yellow Fever

Description

One of the most common infectious diseases in tropical, central and southern Africa is yellow fever, which often leads to death if left untreated.

It occurs constantly as jungle or bush fever. In cities epidemics are possible, one speaks of urban yellow fever. Worldwide, 200,000 people fall ill each year, 30,000 of whom succumb to the infection.

Yellow fever is caused by a representative of the flaviviruses. The natural hosts of the virus are monkeys. From them, pathogens are transmitted to humans via mosquitoes. In the phenomenon of urban yellow fever, humans are simultaneous hosts. However, direct infection from person to person is not possible.

There is an incubation period, which is 3 to 6 days. The contagious period is estimated to be the first week of illness.

At the beginning of the disease, flu-like symptoms appear. If yellow fever takes a mild course, there are no further symptoms, which is why yellow fever is often not recognized as such.

Typical is a high fever phase of 3-4 days, accompanied by nausea, (blood) vomiting, headache, back pain and yellowish discoloration of the skin. This is followed by a fever-free phase of 1-2 days.

Subsequently, high fever occurs again and the disease fully develops. Bleeding from the skin and mucous membranes usually occurs. Neurological symptoms such as meningitis, or kidney or liver failure can also follow. In such a severe course, patients often die within a week.

Within the first 5 days, the pathogens can be detected in the blood, then by specific antibodies.

In mild cases, yellow fever is often mistaken for influenza or other febrile illnesses. Severe cases strongly resemble other hemorrhagic fevers, such as Ebola.

Yellow fever can only be treated symptomatically, special therapies are not available. The main focus of the treating physician is on sufficient fluid intake and intact blood clotting.

The chances of recovery depend very much on the severity of the yellow fever. In about 10% of cases, the liver is damaged during the 2nd fever phase. There may also be severe bleeding from mucous membranes and the digestive tract.

Children and adolescents under 14 years of age have the lowest mortality. The highest mortality rate is 50% in adults between 20 and 30 years of age.

Yellow fever can only be prevented with a vaccination. Vaccinations may only be given by state-approved yellow fever vaccination centres. It should be given at least 10 days before departure and is recommended for every trip to an epidemic area.

Infants under 6 months of age should not be vaccinated. Pregnant women are advised against vaccination.

Once vaccinated, protection lasts for 10 years.

Anyone who has already been infected with yellow fever is immune to a new infection for life.

Yellowfever is under no circumstances to be confused with jaundice! The latter colloquially refers to hepatitis (infection of the liver), medically a yellowish discoloration of the skin.