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West Nile Virus

West Nile Virus (WNV) is a mosquito-borne disease that was first seen in North America in 1999. The most serious manifestation of West Nile Virus infection is fatal encephalitis (inflammation of the brain) in humans and horses, as well as mortality in certain domestic and wild birds. Cases of West Nile Virus in New Mexico have occurred every year since 2003. West Nile Virus infections in humans occur seasonally, with the peak of cases in late summer and early fall.

The risk of acquiring West Nile Virus can be reduced by:

  • Using insect repellent
  • Reducing the amount of time spent outdoors at dusk and dawn when mosquitoes are most active
  • Having screens on your doors and windows to keep mosquitoes out
  • Emptying or eliminating water holding containers (where mosquitoes lay their eggs) such as tires, flower pots and buckets

Frequently Asked Questions

This list of frequently asked questions explains about the virus, how people get infected, how it is transmitted, symptoms, treatment, and what to do if you get bitten by a mosquito.


Fact Sheet

This fact sheet explains what West Nile Virus is, what the symptoms are, how the infection is spread, how long people are contagious for, what treatments are available, how you can protect yourself and your family, and more.


Manual for Investigation

This comprehensive West Nile Virus Manual for Investigation provides all the information required to investigate West Nile Virus cases including a summary of the disease, agent details, mode of transmission, period of communicability, incubation period, diagnosis, treatment, surveillance, control measures, and more.


Case Reporting Form

Use this Arbovirus Case Reporting Form to report cases of West Nile virus to NMDOH.


Diagnosis & Laboratory Testing Recommendations

Our West Nile Virus Diagnosis and Laboratory Testing Recommendations for medical providers publication describes the recommendations for diagnostic testing, considerations for when to test for West Nile virus, and more.


Activity in New Mexico

There have been no human cases of West Nile Virus in New Mexico in 2018.

There were 33 Human Cases of West Nile Virus in New Mexico in 2017 and six Human Cases of West Nile Virus in New Mexico in 2016.

See the following news releases for more information:


New Mexico Case Data

Case data from previous years are archived below for historical reference.

Cumulative