Summary:
West Nile virus (WNV) is spread by mosquitoes. An individual’s exposure to mosquitoes increases their risk of getting infected. Generally, West Nile virus spreads to humans and animals by infected mosquitoes. In fact, infected mosquitoes spread this virus to people and other animals by biting them. Most cases occur during warm weather, typically June through September when mosquitoes are most active. Many infected individuals don’t feel like they have developed any signs or symptoms. However, the individual might experience mild symptoms such as a headache and fever, which is referred to as West Nile fever. It is also possible that some people develop more dangerous signs and symptoms resulting in the need for urgent medical help.
Fact table:
| Formal binomial name of microbe: | Flaviviridae |
| Gram stain (gram positive, gram negative or neither): | Neither |
| Is the microbe mobile or immobile? | Immobile |
| Primary habitat? (Where is the organism normally found or prefer to live?) | Mosquito |
| Can the organism infect humans? | Yes |
| Can the organism infect other species? If so, which ones. | Yes, horses and other mammals |
| Documented cases of antimicrobial resistance? | Yes |
| Number of infections per year in the US | 2,544 cases |
| Number of infections per year in the world | N/A – data only available for U.S. |
Description:
West Nile virus is the leading cause of mosquito-borne disease in the United States. West Nile virus can affect people and animals. It spreads by a bite from an infected mosquito, but keep in mind that contact with infected people or animals doesn’t spread this virus. People are most likely to develop West Nile virus due to age and specific medical conditions. For example, being older puts someone at a higher risk, as does having certain diseases such as cancer, diabetes, hypertension, and kidney disease.
8 out of 10 people that are infected with West Nile virus don’t develop any symptoms and don’t feel sick. However, about 20% of people develop a mild infection including: fever, headache, body aches, vomiting, fatigue, and skin rash. These mild symptoms usually resolve on their own or last just a few days. Less than 1% of infected people experience serious infection signs and symptoms causing a neurological infection, including inflammation of the brain (encephalitis) and the membrane surrounding the brain and spinal cord (meningitis). The signs and symptoms of neurological infections include: high fever, severe headache, stiff neck, disorientation or confusion, tremors or muscle jerking, seizures, and partial paralysis or muscle weakness. These symptoms can stick around for weeks or months so it is crucial to seek medical help right away. In fact, these infections can lead to hospitalization or death. About 1 in 5 people who are infected develop a fever and other minor symptoms like headaches, body aches, etc. In addition, about 1 out of 150 infected people develop a serious and sometimes fatal illness.
There are no vaccines present to treat West Nile virus. However, there are over-the-counter pain relivers that can be used to reduce fevers and other symptoms. It is important for an individual to talk with their health care provider if they believe they have this well-known virus. The best way to prevent West Nile virus is to drain anything that holds water, wear long-sleeved shirts and long pants to prevent mosquito bites, and use mosquito repellent while outside. “As we have said from the beginning, people of all ages – in all areas of the state should be aware of the simple, common-sense precautions they can take to reduce exposure to mosquitoes,” said Department o Community Health Chief Medical Executive, David R. Johnson, M.D.“
News articles:
Sidney Herald addresses the importance of how to prevent West Nile virus. It mentions that there are four D’s of West Nile prevention that should be followed to reduce the chance of mosquito bites. These steps include: DEET – using insect repellent such as DEET or picaridin; drain – draining standing water around an individual’s house to prevent mosquito breeding; dawn/dusk – mosquitoes are most active during dawn and dusk so stay inside or take precautions during these times, and dress – when possible, wear long-sleeved shirts and pants to protect bites from happening.
WQAD 8 highlights that Illinois tested positive for the West Nile virus of 2019 in the village of Wayne. It explains that there hasn’t been any human cases reported in 2019, until this specific case happened in May. However, in 2018 there were 176 human cases that included 17 deaths.
Bismarck Tribune summarizes the prevention of West Nile virus. The North Dakota Department of Health wants to remind individuals that preventing mosquito bites is the most effective way to avoid the West Nile virus. There hasn’t been any human cases of West Nile reported in North Dakota this year of 2019, but keep in mind that there is always a risk of developing the virus anytime mosquitoes are active. Therefore, in order to avoid mosquito bites, use insect repellent, wear protective clothing that doesn’t show skin, limit outdoor activities, install screens on windows and doors, and keep your grass short.
References:
“1st West Nile virus-positive mosquitoes found in Illinois”; wqad.com; https://wqad.com/2019/05/24/1st-west-nile-virus-positive-mosquitoes-found-in-illinois/
“Health department pushes prevention of West Nile virus”; bismarcktribune.com; https://bismarcktribune.com/health-department-pushes-prevention-of-west-nile-virus/article_7912309e-a4f6-516a-b05f-0619b0c9ac4b.html
“Michigan West Nile Virus Update: Total Human Cases 379”; michigan.gov; https://www.michigan.gov/mdhhs/0,5885,7-339-73970_71692_8347-52941–,00.html
“State officials suggest steps to prevent West Nile Virus”; sidneyherald.com; https://www.sidneyherald.com/news/state-officials-suggest-steps-to-prevent-west-nile-virus/article_269fca28-8dec-11e9-a396-b303e606d772.html
“Symptoms, Diagnosis, & Treatment”; cdc.gov; https://www.cdc.gov/westnile/symptoms/index.html
“West Nile virus”; mayoclinic.org; https://www.mayoclinic.org/diseases-conditions/west-nile-virus/symptoms-causes/syc-20350320