Be careful outside this year!
West Nile virus cases have reached record levels in the US. Climate changes causing heat waves and droughts are thought to be among the reasons, with higher temperatures fostering faster reproduction of both the mosquito and the virus. As Reuters reported:
A total of 1,590 cases of West Nile virus, including 66 deaths, were reported through late August this year in the United States, the highest human toll by that point in the calendar since the mosquito-borne disease was first detected in the country in 1999, health officials said on Wednesday. The toll is increasing quickly. “We think the numbers will continue to rise,” said Dr. Lyle Petersen, director of the U.S. Centers for Disease Control and Prevention’s Division of Vector-Borne Infectious Diseases.
Over 70 percent of the cases have been reported from six states (Texas, South Dakota, Mississippi, Oklahoma, Louisiana, and Michigan) and over 45 percent of all cases have been reported from Texas, but the virus has been encountered in 46 states.
West Nile Virus is a flavivirus commonly found in Africa, West Asia, and the Middle East. It is closely related to St. Louis encephalitis virus which is also found in the United States. The virus can infect humans, birds, mosquitoes, horses and some other mammals. Since 1999, West Nile virus has been identified in more than 200 species of birds found dead in the United States. The Center for Disease Control explains that West Nile mostly spreads by Infected Mosquitoes. Mosquitoes become infected when they feed on infected birds.
The disease is primarily transmitted by Culex pipiens mosquitoes, also known as common house mosquitoes, and the only preventive measure is to avoid being bitten. Infected mosquitoes can then spread WNV to humans and other animals when they bite. In a very small number of cases, WNV also has been spread through blood transfusions, organ transplants, breastfeeding and even during pregnancy from mother to baby.
There is no treatment for West Nile infection, and no vaccine.
The CDC outlines that West Nile Virus causes:
- Serious Symptoms in a Few People. About one in 150 people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent.
- Milder Symptoms in Some People. Up to 20 percent of the people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.
- No Symptoms in Most People. Approximately 80 percent of people (about 4 out of 5) who are infected with WNV will not show any symptoms at all – but people over 50 are most at risk of getting severely ill.
What can you do to protect yourself?
- When you are outdoors, use insect repellent containing an EPA-registered active ingredient.
- Many mosquitoes are most active at dusk and dawn. Be sure to use insect repellent and wear long sleeves and pants at these times or consider staying indoors during these hours.
- Eliminate standing water where mosquitoes can lay eggs
- Install or Repair Window and Door Screens
- Support Community-Based Mosquito Control Programs
The problem is serious, even if it hasn’t hit the Mass Hysteria and Apocalyptic levels described in Ghostbusters.