Yellow fever | Symptoms | Treatment | Vaccination

Description Of Yellow Fever

Yellow fever is a serious viral infection transmitted by a species of mosquito ( Aedes ). This infectious disease occurs in equatorial Africa as well as in Central and South America

Yellow fever signs and symptoms

 Yellow fever occurs only in tropical Africa and South America. In severe cases, yellow fever ends fatally in more than every other case. For this reason, a preventive yellow fever vaccine against the infection is very important. When entering and leaving the country, it is even mandatory. Here you can read all the important information about yellow fever.
Yellow fever disease begins three to six days after infection with a first fever. A second episode - after a seemingly healthy phase - leads to severe hepatitis, in which approximately 20% of patients die. A causal, medicinal therapy of yellow fever is not possible.

Occurrence Of Yellow Fever

Tropical physicians annually report about 200,000 yellow fever diseases and 30,000 deaths worldwide. About 90 percent of them are in Africa. Every suspicion, every illness and every death by yellow fever is notifiable. Nevertheless, the World Health Organization (WHO) estimates that there is a high level of unreported cases. This means that even more people get yellow fever, but these cases either not reported or not recognized as such.
Yellow fever virus is endemic in some areas of Africa and Central and South America :

Africa
Kenya , Tanzania , Angola , Equatorial Guinea , Ethiopia , Benin , Burkina Faso , Burundi , Ivory Coast , Gabon , Gambia , Ghana , Guinea , Guinea-Bissau , Cameroon , Republic of the Congo , Democratic Republic of the Congo , Liberia , Mali , Niger , Nigeria , Rwanda , Zambia , Sao Tome & Principe , Senegal , Sierra Leone , Somalia , Sudan , Togo , Chad , Uganda and Central African Republic

Central and South America:
Bolivia , Brazil , Ecuador , French Guiana , Guyana , Colombia , Panama , Peru , Suriname , Venezuela , Trinidad and Tobago


The number of epidemics has risen since the early 1980s. In other countries, the risk of introducing yellow fever virus is thought to be possible because of the presence of appropriate vectors and suitable primate hosts (including Asia, where no yellow fever has ever been reported, but the " Aedes " carrier mosquito is also native to Asia).
pathogen

Yellow fever virus, an arbovirus of the family Flaviviruses
infection

Female mosquitoes transmit the virus when monkeys pass from human to human (so-called jungle yellow fever) or from person to person (so-called city yellow fever). The mosquitoes sting during the daytime . The transmission takes place at altitudes up to 2,500 meters .

The yellow fever virus affects humans and monkeys. In jungle and forest areas, monkeys are the main reservoir of infection, with mosquito bites transmitting the virus from monkey to monkey. The infected mosquitoes can also sting people who are in the forest areas, resulting in sporadic cases or minor outbreaks. In urban areas, monkeys are not involved in the transmission, the infection is transmitted by mosquito bites from person to person . The introduction of an infection into the urban area can lead to large yellow fever epidemics. In the humid savanna regions of Africa, both transmission paths occur. Mosquitoes infect both monkeys and humans, which can lead to local outbreaks.

Incubation Period of Yellow Fever Virus

3 - 6 days
course

After mosquito bites and transmission, the virus multiplies in the organism. A rapid increase in fever is associated with severe general symptoms (headache, muscle pain, nausea), often accompanied by slowing pulse and conjunctivitis. After a short recovery of perhaps one day, the patient enters the phase of organ involvement: liver and kidney failure poison the organism, coma and death are - in severe cases - in up to 50% of cases the result (the mortality of uninoculated tourists higher!).

Hemorrhagic yellow fever leads to skin and organ bleeding. In addition to these severe forms with liver involvement (yellowing symptoms, hence the name), it also leads to mild diseases, even symptom-free courses are possible. Children are favored, but their mortality is lower.

Against yellow fever there are no drugs and causal therapy . The treatment is intensive care and refers to the symptoms.
Passive protection

Avoid mosquito bites at all times of the day and night . The exposure prophylaxis (protection against insect bites / bites) with mosquito nets and a repellent should definitely be used in endemic areas
vaccine

Vaccinated with a special vaccine strain. These "live" but attenuated viruses do not cause disease. The vaccine is propagated on hatched chicken eggs and then cleaned. Traces of chicken egg white may be included. The vaccine is injected into the muscle or under the skin. The vaccine is extremely effective (protection rate close to 100 percent), while the disease can be fatal in unimmunized adults. The vaccine is recommended to all travelers (with some exceptions) who visit countries or areas with yellow fever risk. For domestic travel in countries of the yellow fever zones of Africa and South America, vaccination is recommended to anyone leaving the urban environment, even if these countries have not officially reported cases of illness.
application

First vaccination at least 10 days prior to entry, vaccination only with authorized vaccine doctors possible, because the vaccine is very sensitive and an authorized vaccination certificate must be issued.
vaccination

Vaccination is strongly recommended when traveling in high risk areas and is required by high risk countries. According to the WHO, vaccination after a single vaccination is life-long unless vaccinated at the same time as a measles vaccine. However, not all countries have accepted this new regulation and continue to insist on a vaccination that is no more than 10 years old. Exactly information on the entry requirements can be found here.
The live vaccine is only given to approved vaccination centers and the vaccine protection occurs after about 10 days and is almost 100%. In addition to the vaccination protection is always to ensure effective mosquito protection

Side effects / Contraindications of Yellow Fever vaccine

The vaccine is usually well tolerated, occasionally appear reddening, swelling or flu-like symptoms. In rare cases, neurological vaccination reactions (meningitis) are described.

Pregnant women, egg whites allergic patients and patients with immunodeficiencies should not be vaccinated.
Remarks

After stay in yellow fever countries without vaccine protection, entry into other countries can be denied. For medical reasons, there is the possibility of a vaccination exemption, which must be certified by government agencies, but not necessarily recognized by all countries. Prior contact with the embassy is recommended.


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