The first case of West Nile fever virus isolation from human blood was recorded in Uganda in 1937. Further studies have shown that the causative agent of this disease is a representative of the flavovirus group. Most often, this disease affects residents of the Mediterranean countries (especially Egypt and Israel), India, Indonesia, Corsica. Also proved the presence of natural foci of the disease in Turkmenistan, Kazakhstan, Armenia, Azerbaijan, Moldova, Astrakhan, Volgograd, Omsk and Odessa regions.
The carriers of the disease are insects, most often mosquitoes and ticks. How to determine that a person has West Nile fever? Symptoms of the disease will largely depend on the form of the disease.
General symptoms
The incubation period of fever in its various forms proceeds differently. Moreover, about 80% of those infected do not experience any symptoms at all. Some patients report weakness and poor appetite. Almost always a person infected with the virus suffers from diarrhea or vomiting. In other words, his condition is characterized by a pronounced general intoxication. There are 3 forms of the course of this disease.
Neuroinfectious form
West Nile fever, the symptoms of which occur in the largest number of patients, is called neuroinfection. The following manifestations are characteristic of it:
- chills;
- weakness;
- vomiting not associated with meals several times a day;
- arthralgia;
- toxic encephalopathy (manifested in severe headaches, dizziness, hallucinations, tremors, etc.).
The disease lasts from 7-10 days and up to several weeks. However, it is noted that even after some time a person can feel weakness, insomnia, depression and even memory impairment.
Flu-like form
How does West Nile flu-like fever manifest itself? Its symptoms are largely similar to the manifestation of many viral infections:
- chills;
- pain in the eyeballs;
- conjunctivitis;
- cough;
- loose stools;
- enlarged liver and spleen;
- meningism.
Exanthematous form
The rarest variety of the course of the disease. This is West Nile fever, the symptoms of which may also include the appearance of a different type of rash, such as roseola or scarlet fever. The most characteristic manifestations of this form:
- catarrhal manifestations;
- fever;
- sore lymph nodes.
West Nile Fever: Diagnosis and Prevention
The manifestations of this disease are largely similar to the symptoms of other flavoviruses, so conventional blood and urine tests are not enough for this. It can be detected by donating blood for PCR or viral antigens. Despite the fact that the course of the disease is benign and has an almost complete absence of residual effects, it is easier to avoid than to treat.
Prevention of West Nile fever includes a number of measures aimed primarily at protecting against mosquito bites (wearing long sleeves, using “deterrent” chemicals) and destroying their potential nesting (cleaning ditches, sewage pools).