CDC Recommends Preventative Action Amid Rising Cases of West Nile Virus

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West Nile virus (WNV) is the leading cause of mosquito-borne disease in the continental US and is most commonly spread to people via a bite from an infected mosquito. Cases occur during mosquito season, which begins in the summer and continues through the fall. According to the Centers for Disease Control and Prevention (CDC), at least 216 cases of WNV were detected in a total of 33 states in 2024.^1,2

As of August 25, 2024, Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases and former chief medical advisor to the president of the United States, was hospitalized after contracting WNV. Although he is currently recovering at home, both Fauci and a spokesperson have noted it may take weeks for him to reach a full recovery.^2-4

“I just have to rest,” said Fauci regarding his recovery process in an interview with NBC News. “The good news is I’m absolutely going in the right direction. The sobering news is that it’s going to take weeks and weeks to get back to normal. That’s the history of WNV. It just wipes you out so badly.”⁴

In addition, a teenager from St. Louis County, Missouri suffered rare complications from WNV that has left him paralyzed and on a ventilator. His father had reported that his initial symptoms, which consisted of headaches and dizziness, began in early August.⁴

The CDC notes that severe complications because of WNV are rare, with about 1 in 150 people experiencing symptoms that impact the central nervous system (eg, inflammation of the brain or meningitis or inflammation of membranes surrounding the brain and spinal cord). Additional symptoms of severe illness can include headache, disorientation, neck stiffness, and paralysis, with recovery taking weeks to months. The CDC warns that in some cases, some of these effects may be permanent; however, approximately 70% to 80% of human WNV infections are considered subclinical or asymptomatic.^4,5

Additionally, the CDC warns that WNV should be considered in any individual who has an acute febrile or neurologic illness who has had recent exposure to mosquitoes, blood transfusion, or organ transplantation—particularly during the summer months—as well as infants born to mothers infected with WNV during pregnancy or while breastfeeding. The incubation period for WNV is typically 2 to 6 days; however, in immunocompromised individuals, it can range from 2 to 14 days or up to several weeks.⁵

Any clinical management available to patients with WNV is considered supportive, according to the CDC. For example, patients who have severe meningeal symptoms typically require pain control for their headaches and antiemetic therapy, or rehydration for any nausea and vomiting associated with their disease. Other supportive treatments can include close monitoring for the development of increased intracranial pressure and seizures in patients with encephalitis. The CDC notes that various drugs have been evaluated or empirically used for WNV; however, to date, none have shown specific benefit.⁶

Currently, there are no licensed vaccines or medicines that are able to prevent WNV infection, meaning that the prevention of the disease is dependent on community-level mosquito control programs that reduce exposure to infected mosquitoes. Additionally, the CDC recommends that the best way to prevent WNV is to practice precaution against mosquito bites, which can include the use of insect repellent, wearing long-sleeved shirts and pants, treating clothing and other gear when needed, and taking steps to control mosquitoes both indoors and outdoors.^6,7

REFERENCES

1. About West Nile. Centers for Disease Control and Prevention. May 15, 2024. Accessed August 29, 2024. https://www.cdc.gov/west-nile-virus/about/index.html

2. Diaz, J. Fauci Recovering From West Nile Virus Infection. The New York Times. August 25, 2024. August 29, 2024. https://www.nytimes.com/2024/08/25/us/fauci-west-nile-virus-hospitalized.html

3. Hetter K. What to know about West Nile virus, the illness that sickened Dr. Anthony Fauci. CNN. August 29, 2024. Accessed August 29, 2024. https://www.cnn.com/2024/08/29/health/west-nile-virus-cases-wellness/index.html

4. Burke M. Missouri teenager left paralyzed and on a ventilator from West Nile virus. NBCNews.com. August 29, 2024. Accessed August 29, 2024. https://www.nbcnews.com/news/us-news/missouri-teenager-left-paralyzed-ventilator-west-nile-virus-rcna168761

5. Clinical signs and symptoms of West Nile virus disease. Centers for Disease Control and Prevention. May 15, 2024. Accessed August 29, 2024. https://www.cdc.gov/west-nile-virus/hcp/clinical-signs/index.html 

6. Treatment and prevention of West Nile virus disease. Centers for Disease Control and Prevention. May 15, 2024. Accessed August 29, 2024. https://www.cdc.gov/west-nile-virus/hcp/treatment-prevention/index.html

7. Preventing West Nile. Centers for Disease Control and Prevention. May 15, 2024. Accessed August 29, 2024. https://www.cdc.gov/west-nile-virus/prevention/index.html