The disease cannot spread among humans. Only infection-carrying mosquitoes spread the disease to humans. The main symptoms of yellow fever are a high temperature, a slow pulse , albuminuria, jaundice , congestion of the face, and hemorrhage, or bleeding.
These symptoms usually improve after a few days, but around 15 percent of people enter a second stage, or toxic stage. The symptoms are more severe, and they may be life-threatening. Between 20 percent and 50 percent of people who develop toxic stage symptoms die within two weeks. Within 7 to 10 days, yellow fever is fatal in around half of all people who enter the toxic phase.
It is transmitted by mosquito bite, usually the Aedes aegypti mosquito. The mosquito becomes infected by biting an infected human or a monkey. An infected mosquito is a source of infection for the rest of its life. The flavivirus is believed to be endemic among monkeys that live in the tree tops of the jungle, known as the jungle canopy, in many parts of Africa and the Americas.
If the infected mosquito passes the flavivirus on to a person who is in the jungle, that person may become a source of infection when they return to their community. They can go on to infect other people. Anybody who travels to an area where the yellow fever virus is present is at risk of becoming infected.
These areas include parts of Africa, especially sub-Saharan Africa, tropical South America, and some parts of the Caribbean. Travelers should check if the area they are visiting requires a vaccination. A yellow fever vaccine taken 10 to 14 days before traveling provides effective protection from the disease.
Diagnosis will be confirmed after the doctor detects the signs and symptoms and carries out a blood test. A blood test may reveal the virus, or it may detect antibodies that the body produces when the virus enters the body. A blood test may also reveal a drop in white blood cells, or leucopenia, another sign of infection. As a consequence, a valid certificate, presented by arriving travellers, cannot be rejected on the grounds that more than ten years have passed since the date vaccination became effective as stated on the certificate; and that boosters or revaccination cannot be required.
Individual country certificate requirements should be checked on our Country Information pages. Public Health England has published guidance for health professionals managing clinical incidents or adverse vaccine associated events related to yellow fever vaccination Read more.
From 15 October to 3 November , a total of 42 suspected cases of yellow fever were reported, mostly among nomadic settlers. Eleven out of the 42 suspected cases, including three PCR positive cases, have died. Source: WHO. As of 6 October , a total of seven human cases have been laboratory confirmed. To date no deaths have been reported. Source: PAHO. As of 7 October , a total of 10 confirmed epizootics of non-human primates araguato monkeys have been reported in Venezuela: 7 in Monagas and 3 in Anzoategui.
On 1 October , the World Health Organization reported that from 1 January to 31 August , a total of 1, suspected yellow fever cases were reported in Local Government Areas across 36 States and the Federal Capital Territory. Home Diseases in Brief Yellow fever. Yellow fever.
The risk of contracting YF is determined by the following factors: Travel destination. The mosquitoes that spread the infection are found in towns, cities and rural areas.
They mainly bite during the day. Mosquitoes can also spread other serious illnesses, such as malaria and dengue. If you're travelling to an area where yellow fever is found, try to avoid being bitten, even if you have been vaccinated. Read more about how to prevent insect bites. See a doctor straight away if you get symptoms of yellow fever while travelling in an area where the infection is found. If you get symptoms after recently returning from one of these areas, contact a GP or NHS for advice as soon as possible.
Tell them exactly where you have been travelling, whether you think you have been bitten by a mosquito, and what symptoms you have. The virus is spread to people by the bite of an infected mosquito. Yellow fever is a very rare cause of illness in U. Illness ranges from a fever with aches and pains to severe liver disease with bleeding and yellowing skin jaundice.
There is no medicine to treat or cure infection. To prevent getting sick from yellow fever, use insect repellent, wear long-sleeved shirts and long pants, and get vaccinated.
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