The Nebraska Department of Health and Human Services has detected Cache Valley virus (CVV) in a mosquito pool tested by the Nebraska Public Health Laboratory (NPHL). On August 6, 2024, the West Central District Health Department collected samples from a mosquito pool in Lincoln County as part of the DHHS mosquito surveillance program. Limited expanded testing of mosquito samples for CVV in addition to Jamestown Canyon virus (JCV) and LaCrosse encephalitis virus (LACV) began in 2024. This is the first positive CVV mosquito pool detected in Nebraska.
CVV is a virus endemic to the U.S. and spread to people by infected mosquitoes. Human disease from CVV is rare with only seven cases ever reported in the U.S. However, of the human cases that have been reported, all have resulted in serious neuroinvasive diseases such as encephalitis and meningitis with three of the seven cases resulting in death and the other cases reporting long-term effects.
CVV is also known to cause reproductive disease in animals, primarily sheep, but also cattle and goats leading to stillbirths and birth defects in those animals if they are infected in a specific period during pregnancy. CVV does not cause disease in adult animals. Sporadic animal cases of CVV infection have been reported in Nebraska previously making it a potential veterinary pathogen in the state. CVV is only transmitted to people and animals via mosquito bites and not by direct contact with infected animals. There is currently no treatment or vaccine for CVV disease in both people and animals. Preventing mosquito bites is the only way to reduce the risk of acquiring CVV disease.
In addition to the detection of CVV, West Nile virus (WNV) and JCV have also been detected in Nebraska mosquito samples during 2024. Although it is now late summer, individuals are highly encouraged to remain vigilant in protecting themselves against mosquito bites as mosquitoes will remain active until the first hard freeze.
Individuals can protect themselves by taking these preventative steps:
Use an EPA-registered repellent.
Wear protective clothing like loose-fitting, long-sleeved shirts, and pants.
Avoid dusk and dawn when mosquitoes are most active.
Check for standing water and water-holding containers once per week on your property and empty, drain, or treat with a mosquito dunk to prevent mosquitoes from breeding.
Additional resources can be found at https://dhhs.ne.gov/Pages/Mosquito-Borne-Diseases.aspx.
