So far this year, there have been nine confirmed cases of West Nile virus. According to disease experts, the virus is circulating more compared to the previous summer.
As of June 25, the CDC has confirmed human cases in several states including Arkansas, Arizona, Maryland, Kansas, Mississippi, Michigan, and Tennessee. The virus has also been detected in at least 18 states across humans, birds, mosquitos, and other animals.
Out of the nine human cases, five were neuroinvasive, meaning the individual developed severe disease in which the brain or the membranes surrounding the spinal cord become inflam
Currently, there are no effective treatments or vaccines for the West Nile virus, meaning those with severe disease can only receive supportive care such as pain medications or fluids.
Approximately 80 percent of those infected with the virus will not develop any symptoms. A small portion of people, however, may develop a fever, in addition to body aches, headache, vomiting, diarrhea, joint pain, or a rash.
Given how similar the symptoms are with those of other viruses, many cases of West Nile go undiagnosed.
In the United States, up to several thousand cases are reported each year, the majority of which happen between August and September.
According to press officer for the CDC Kate Fowlie, West Nile virus activity is now occurring earlier compared to previous years, meaning individuals should take the proper steps to protect themselves from mosquito bites.
Increasing temperatures due to climate change have also increased the spread of the West Nile virus as mosquitos are able to breed faster and survive for longer periods of time.
Scott Weaver, the director of the Institute for Human Infections, said more mosquitos will be able to survive the winter if the months are warmer. They will also be able to breed and multiply quicker if the spring months are warm.
These factors have led to the increase of other mosquito-borne illnesses such as dengue fever, which can cause symptoms high fever, severe headaches, swollen glands, pain behind the eyes, nausea, vomiting, and joint pain.
According to Weaver, mosquitos that carry the West Nile virus tend to be the most active in central areas such as Colorado and Texas. Regions with lower temperatures such as the Northwest don’t tend to see as much activity, which makes sense seeing as how the virus replicates slowly if the temperature is not high enough.
Officials from Douglas County also said in a news release that this year’s mosquito population is much higher compared to last summer. Last month, they announced that one individual, a blood donor, tested positive for the virus.
The Texas Department of State Health Services also announced one confirmed case in the Houston area, and are expecting the number to go up as summer continues.
In Springtown, Texas, a man died of West Nile virus in late June. According to his wife, he had tested positive for the virus not long before his death.
While it’s hard to predict epidemics of West Nile, many counties have come up with innovative approaches to deterfine the location of infected mosquito populations. For example, Clark County, Nevada, is using drones to locate mosquito breeding sites.
Scott County, Illinois, has also asked the public to call in dead bird sightings as they may indicate the presence of the virus as birds are natural hosts for the West Nile.
