Even though right now Zika virus is on the forefront of all the mosquito-borne diseases, there are others, that are common, too, and that can cause as much damage as Zika. And one of these less known mosquito-borne diseases is the St. Louis encephalitis virus.
St. Louis encephalitis virus or SLEV for short is a a diseases transmitted by mosquitoes. The beginnings of this virus can be seen around 1933, when there was an encephalitis epidemic in and around St. Louis, Missouri. At the time over 1,000 people contracted this virus, and the then newly created National Institute of Health determined that it was a new strain of the encephalitis virus, giving it the name St. Louis encephalitis virus in reference to the place where it originated.
This virus is a Flaviviridae family virus, meaning that the virus is mainly spread with the help of vectors, insects like mosquitoes and ticks that are infected with the virus (by biting a bird that is infected in SLEV’s case), and because humans are natural hosts for it, there is a big chance that you will get the virus if an infected mosquito or tick bites you. Luckily, humans cannot transmit this virus to other humans, because unlike Zika, SLEV is not transmittable with bodily fluids, so you could say that humans (and domestic mammals like dogs, pigs and such) are dead-end hosts for the SLEV virus.
Which mosquito species transmit SLEV?
The St. Louis Encephalitis virus is transmitted only by the Culex genus mosquitoes. The Culex mosquitoes can be differed from other mosquitoes by their looks. Characteristics that indicate that the mosquito is indeed a Culex mosquitoes are a medium size body in brown color (some Culex mosquitoes also have lighter markings on their abandonment, wings or legs), clearly defined head, thorax and abdomen and that these mosquitoes stay parallel to the surface and don’t stick their abdomens up in the air when they are resting.
SLEV symptoms and treatment
Although usually less than 1% of infected people show any symptoms at all if they have contracted SLEV, there are those who aren’t that lucky and who will began to experience some symptoms after 5 to 15 days after an infected mosquito or tick has bitten them, since that is the incubation period for this encephalitis strain. The main symptoms for St. Louis encephalitis are sudden fever, dizziness, headache, nausea and malaise or just general feeling of being ill. And although these are pretty common symptoms, if you feel like they only intensify over time from the moment you started feeling them, then you might have SLEV. The main treatment for this encephalitis is treatment of symptoms, because there is no vaccine or specific treatment just for this disease. But if you think, that you have SLEV but you figure that you shouldn’t go to the doctor, since the doc will threat only the symptoms, you are wrong, because there have been cases that mild, untreated SLEV case turns into severe illness resulting in central nervous system infection or even coma.
If you live outside the United States, Canada or Mexico, then you can rest assured that you won’t be getting the St. Louis encephalitis virus, since it affects only these regions, mainly the U.S. with a couple of cases of SLEV in Canada and Mexico. How often do Americans suffer from SLEV? Annually close to 130 people are diagnosed with this encephalitis in the U.S., which might seem like a large number, however if we compare it to the over 324 million residents that live in the United States, then St. Louis encephalitis virus is not really something you should worry about.
How to avoid SLEV?
There are multiple things you can do to avoid contracting the St. Louis encephalitis virus. Firstly you can take safety measurements yourself to protect your body from mosquito bites by not only using mosquito repellent, but also by wearing clothing that doesn’t allow for mosquitoes to touch your skin. And secondly you can also make sure that your home, back yard and other areas that you frequent aren’t mosquito traps. You can use a mosquito fogger or mosquito yard spray to fog or spray your yard so the mosquitoes aren’t around when you spend time around your house, you can put up mosquito screens or nets on your windows, doors and such, that will prevent mosquitoes from getting inside of your home, and you can also make sure that these insects aren’t breeding in your area, by dumping all the standing water or using mosquito dunks in those water reservoirs that you cannot drain.