Encephalitis is the brain infection that is met in several forms, like La Crosse, West Nile, Eastern Equine, etc. This disease is peculiar to the USA, and the scope of territories where the patients with such diagnosis can be met is constantly growing. Being very rare disease, in up to 60% of cases Eastern Equine Encephalitis (EEE) leads to fatal outcome. Those who survive, experience serious impact of the CNS.
EEE is transmitted by Culiseta melanura species of mosquitoes. They can be called as a ‘bridge vector’ spreading infection from one species to another by cross biting. This means that such a mosquito can bite an infected bird, and then bite a human, transmitting EEE from birds to people. Also EEE can be transmitted to horses or other animals.
The symptoms of Eastern Equine Encephalitis are experienced in 2 – 10 days after the bite of mosquitoes that was infected. The severe symptoms, like stiff neck, fever, lethargy are usually very difficult to bear. The most harmful symptom that can occur when infected with EEE, is the brain inflammation that can lead to death. To avoid the worst consequences, it is highly recommended to ask for medical help as soon as first symptoms appear.
Dengue disease is met in tropical territories and it can be spread by Aedes aegypti mosquito. These insects attack mostly on daytime, and they prefer humans to animals. The other infection transmitter is Aedes albopictus or ‘tiger mosquito’. People bitten by infected insects can experience various disorders starting from viral influenza to different fatal diseases like hemorrhagic fever.
Until 1970’s there were no cases of dengue in America, till the infection appeared in Cuba and was spread around the Caribbean region. In 1981 there was one more wave of disease, and this time infected people experienced one of the hardest symptoms – hemorrhagic fever. There was about 300 000 of infected people with more than one thousand deaths. Mostly they were children. In 1998 the Barbados Island also struggled from dengue epidemy.
Dengue becomes more and more dangerous infection as for its consequences and epidemic scale, and soon it can overcome malaria that is the most popular human infection transmitted by mosquitoes.
Malaria can occur when transmitting a malaria parasite from the infected person to another. The transmitters of this disease are Anopheles mosquitoes that bite at night. Malaria is typical for tropic and subtropical territories.
The common symptoms for malaria are high fever, head and muscle aches and sickness. It is often confused with flu on the early stages. As a rule, first symptoms appear in 6-7 days after the bite of infected insect. In some cases people can experience malaria in a few months after a bite when travelling around tropic countries.
When going there, you can protect yourself from malaria by taking special anti-malaria drugs and using repellents against mosquitoes. According to numerous studies, about 40% of the population of the planet is at the group of risk to catch malaria. The statistics shows that annually malaria becomes the reason of more than one million of human deaths.
WEST NILE FEVER
West Nile Fever is displayed in high temperature, headaches, rash and sickness.
The more severe symptoms that can occur in case of West Nile Virus infection are torpor, neck stiffness, coma, blindness, palsy. A patient can experience these symptoms for weeks or even permanently.
The period after bite when the symptoms begin to release, is three to fourteen days. As opposite to Eastern Equine Encephalitis, in 4/5 of cases there are no any symptoms at all, and only 20% of infected people feel mild or severe symptoms of WNF disease. Mostly they are children or people with auto-immune disorders.
Yellow jack or yellow fever is transmitted by Aedes aegypti. There was no case of such disease in the USA, but it occurs rather often in South America and Africa. The symptoms are typical for most of mosquito-transmitted fevers and include fever, head and back aches, sickness and retching. Sometimes patients with yellow jack can experience jaundice. As the most severe display of the disease, the infection can affect blood, kidneys and liver, and can lead to death.
The transmission is similar to Malaria: a mosquito bites an infected person and then bites another one, transmitting parasites. The patient with yellow fever can get a therapy only against the symptoms, but there is no treatment against the disease itself. When infected once, the human body produces immunity against yellow fever. The disease distribution can be limited using vaccination.