What is yellow fever?
Yellow fever (yellow fever) is an acute hemorrhagic disease caused by the Viscerophilus tropicus virus from the flavirivirus family .
How can you get yellow fever?
The yellow fever virus is spread to humans through the bites of infected mosquitoes belonging to the genera Aedes and Haemogogus . Mosquitoes become infected with this virus when they feed on the blood of infected monkeys living in tropical rainforests, and then, in turn, can infect other monkeys and humans through bites. People infected with the ZHL virus, in turn, can infect mosquitoes within 5 days of the appearance of symptoms of the disease. Unfortunately, human infection can occur not only as a result of encounters with infected insects in tropical rainforests, but also in cities: epidemics occur when people infected by mosquito bites bring the virus into densely populated areas with a high population density of mosquitoes of the genera Aedes and Haemogogus and with lack of immunity to this disease in the majority of the population . In such conditions, mosquitoes spread the virus from one person to another (the so-called urban yellow fever). The disease does not spread through person-to-person contact.
In which countries can you get infected with the yellow fever virus?
Yellow fever virus can be infected in tropical and subtropical zones of South America and Africa. A list of countries where transmission of the yellow fever virus has been recorded can be found here .
How soon after infection will the first symptoms of the disease appear?
The incubation period (time from infection to the first manifestations of the disease) is 3-6 days.
What are the symptoms of the disease?
The disease may be asymptomatic, but if symptoms do occur, the most common are fever, chills, intense headache, back pain, muscle pain, nausea and vomiting, fatigue, and weakness. Most patients recover from these symptoms in about 3-4 days. However, about 15% of people develop a more severe form of yellow fever after a temporary relief of the condition lasting from several hours to a day. In such cases, the patient develops severe fever, jaundice (yellowing of the skin and the sclera of the eye, due to which the disease got the name "yellow" fever), delirium (delirium), convulsions, bleeding (from the eyes, mouth, nose, or gastrointestinal tract). . This condition can lead to infectious-toxic shock and liver and kidney failure. Approximately 20 to 50% of people who develop a severe form of the disease die.
How to treat the disease?
There is no specific treatment for yellow fever. If possible, the patient should be hospitalized for symptom relief and observation. Rest, rehydration (preventing dehydration), and the use of painkillers and antipyretics can relieve symptoms. The use of certain medications – aspirin or other nonsteroidal anti-inflammatory drugs (such as ibuprofen and naproxen) – should be avoided because they increase the risk of bleeding.
How to protect yourself from yellow fever?
Yellow fever can be prevented with a highly effective vaccine that is safe, affordable and has been used worldwide for over 80 years. In most cases, one dose is enough to form lifelong protection against the disease. After the introduction of the vaccine, an adequate immune response is formed in 80-100% of the vaccinated in 10 days and in 99% of the vaccinated - in 30 days. You should also not forget about other methods of protection against insect bites: repellents and clothes that cover the body as much as possible. The use of mosquito nets on the bed has limited effectiveness because some mosquitoes carrying the ZL virus are active during the day.
Is it possible to get vaccinated against yellow fever in Ukraine?
In Ukraine, the vaccine Stamaryl is registered for the prevention of yellow fever. Adults and children aged 9 months and older are given one dose of vaccine (0.5 ml). The vaccine should be used at least 10 days before visiting an endemic zone to form an adequate immune response. Vaccination for the prevention of VL is not included in the National Vaccination Calendar, so if necessary, it can be carried out at your own expense.
Before traveling to which countries should you be vaccinated against yellow fever?
You should get vaccinated against yellow fever before traveling to countries (or certain regions of certain countries) where the yellow fever virus is endemic . Also, some countries require documentary confirmation of vaccination against rabies to enter their territory (this information should be clarified on the official website of a specific country at the stage of travel planning, because the requirements for entry change periodically; you can also use the service from the Ministry of Foreign Affairs of Ukraine). Vaccination must be done no later than 10 days before the trip, in order to have time to develop immunity to yellow fever.
What are the features of vaccination against yellow fever?
The vaccine against yellow fever is a live attenuated vaccine, so before making a decision on vaccination, it is necessary to take into account the absolute and temporary contraindications to the introduction of live vaccines, which are detailed in the order of the Ministry of Health No. 2070 . According to the order, administration of live vaccines is contraindicated:
pregnant women;
patients with a high level of immunosuppression (see clause 5.6 of the Order );
patients with some types of primary immunodeficiency (see clause 5.7 of the Order );
persons after organ transplantation.