<h1 class="pgc-h-arrow-right" > history of the epidemic</h1>
West Nile virus was discovered in December 1937 in the West Nile region of Uganda, Africa, hence the name.
In 1999, West Nile virus first appeared in the Western Hemisphere. In August, within a 4-square-mile radius of Queens, New York, 25 people were infected in just a few days, and patients presented with encephalitis, 7 of whom died. At that time, 62 people were infected in New York, and cases were found in 4 states except New York.
In 2000, West Nile virus spread from New York to 12 neighboring states.
In 2001, the virus spread westward and south from the East Coast, and was found in 23 states across the country and in Washington, D.C.
Between 1999 and 2001, there were 149 cases of West Nile virus infection in the United States, and in 2002, 4156 people infected with West Nile virus in 44 states, of which 284 died;
In 2003, there were more than 7,700 cases and 166 deaths.
On August 1, 2012, the U.S. Centers for Disease Control and Prevention reported that by the end of July, the center had received reports of West Nile virus infection, four of whom had died.
On August 12, 2012, according to data released by the Texas Centers for Disease Control and Prevention, the state has reported 351 cases of West Nile virus infection, of which 15 people have died.
On August 23, 2012, the U.S. Centers for Disease Control and Prevention said that West Nile virus had the largest outbreak in many parts of the United States. As of the 21st, 38 states in the United States have reported human infection cases, and the US Centers for Disease Control and Prevention has received a total of 1118 case reports, including 41 deaths.
According to the latest statistics released by the Greek Center for Disease Control and Prevention, two more people infected with West Nile virus died in Greece from August 2 to 8, 2019. Since 2019, a total of 35 People infected with West Nile virus have been identified in Greece, aged between 52 and 91.
disseminate
The virus has been detected from many kinds of mosquitoes: such as Aedes mosquitoes, Anopheles mosquitoes, pulmonas mosquitoes, lepidoptera mosquitoes, blue ribbon mosquitoes, mosquitoes from infected birds after absorbing blood containing the virus, the virus in the mosquito body after 10 to 14 days, the virus exists in the saliva glands of mosquitoes, can be through the bite of other animals or humans and spread the virus, the virus into the blood of animals or people, will enter the brain through the blood-brain barrier, causing encephalitis. There is no direct transmission between humans, poultry and birds, and researchers have found West Nile virus in overwintering mosquitoes, suggesting that the virus usually spreads to new places along the path of bird migration, based on experience in Europe and the Middle East.
Clinical symptoms
West Nile virus infection can be asymptomatic (asymptomatic), which makes up about 80% of the infected population and can also cause West Nile fever or severe West Nile disease.
About 20% of people infected with West Nile virus develop West Nile fever. Symptoms include fever, headache, tiredness, body aches, nausea, and vomiting, occasionally accompanied by a rash (of the trunk) and enlarged lymph glands.
Symptoms of severe illness (also known as neuroinfective disease, such as West Nile encephalitis or meningitis, or West Nile polio) also include headaches, high fever, neck stiffness, numbness, disorientation, coma, tremor, convulsions, muscle weakness, and paralysis. It is estimated that one in every 150 people infected with West Nile virus will develop a serious disease. People of any age group are at risk of developing severe illness, but people over the age of 50 and immunosuppressed people (e.g., organ transplant patients) are at the highest risk of developing severe illness after infection with West Nile virus.
The incubation period is usually 3 to 14 days.
Treatment and prevention
Treatment
Treatment of patients with neuroinfectious West Nile disease is supportive and usually includes hospitalization, intravenous fluids, respiratory support, and prevention of secondary infection. There is no vaccine available to humans.
Prevention
Reduces the risk of infection in humans
Due to the lack of vaccines, the only way to reduce human infections is to raise awareness of risk factors and educate people on how to take steps to reduce exposure to the virus.
Information on public health education should focus on the following main points:
Reduces the risk of mosquito transmission. Efforts to prevent transmission should first focus on protecting individuals and communities from mosquito bites through the use of mosquito nets, personal insect repellents, wearing light-coloured clothing (long-sleeved tops and trousers), and avoiding outdoor activities during peak bite times. In addition, community planning should encourage communities to eliminate mosquito breeding grounds in residential areas.
Reduces the risk of transmission from animals to humans. Gloves and other protective clothing should be worn when handling diseased animals and their tissues, slaughtering and plucking procedures.
Reduces the risk of transmission through blood transfusions and organ transplantation. In the event of an outbreak, after assessing the epidemiological status of the local/regional area, consideration should be given to restricting blood and organ donation and conducting laboratory tests in the infected area.
WHO's response
The WHO Regional Office for Europe and the WHO Regional Office for the Americas, together with country representative offices and international partners, actively support West Nile virus surveillance and outbreak response activities in Europe and North America, Latin America and the Caribbean, respectively.
Resources
1. West Nile virus – official of the World Health Organization
2. Greece has two new cases of West Nile virus deaths - from CCTV News
3. Get to know West Nile virus together – Chinese Center for Disease Control and Prevention official
The title image is from the pixabay.com, the authorization is based on the CC0 agreement, if there is infringement, please contact us to deal with it