Eastern Equine Encephalomyelitis

By | June 10, 2022

Eastern equine encephalomyelitis is a zoonotic disease. This inflammation affects both the spinal cord and the brain. Pathogens are viruses that occur on the east coast of Canada and the USA and are transmitted by mosquitoes. Individual cases have also been reported in Thailand and the Philippines. The number of reported human deaths is low.

What is Eastern Equine Encephalomyelitis?

The technical term for eastern equine encephalomyelitis is Eastern Equine Encephalomyelitis, or EEE for short. This means that it can be transmitted from animals Рin this case the horse Рto humans. If left untreated, the viral disease can also lead to death in humans. According to the animal epidemic ordinance, there is an obligation to report to the competent animal epidemic authority and the health department. The disease is transmitted by midges or mosquitoes. For what is the definition of herniated intervertebral disc, please visit healthknowing.com.

Adult insects feed on plant sap that contains sugar. In order for the eggs to mature, female midges need blood. With their stinging and sucking mouthparts, they are able to take in the blood that is vital for their offspring. They adapt to environmental conditions and climate change, among other things, is contributing to their occurrence also spreading to areas outside of Canada and the USA.


It’s just a barely noticeable sting and horse or human is infected. Mosquito plagues mainly occur in years that are particularly favorable for the hatching of the eggs. Of the many species, there are only about 50 that have been researched to the point where they can be considered carriers of pathogens. There are about 60 viruses that are found in mosquitoes and are mainly of importance in veterinary medicine.

Some of these viruses can also be transmitted to humans. This includes the Eastern Equine Encephalitis Virus, which is transmitted by the biting midge Culiseta melanura. Not only mosquitoes are considered as carriers. Wild birds and rodents are also considered hosts. Although cases have so far only been reported in eastern Canada and the USA, the disease can also spread to Europe. Anyone who becomes infected while traveling to the affected areas can infect other people when they return.

Symptoms, Ailments & Signs

As an inapparent or silent infection, it is not noticed by the patient. He is then free of symptoms, but the symptoms can still appear years after the infection due to stress or a weakened immune system. At the onset of the disease, symptoms include conjunctivitis, headache, and fever with muscle aches and body aches.

Other signs are general nausea, spasmodic vomiting and delirium. If meningitis occurs, patients often fall into a coma and die. The fatality rate in humans is between 30 and 50 percent. After a sudden onset of the disease, there is a brief improvement in the general condition. This only lasts for a few days and cramps, stiff neck and signs of paralysis in the extremities appear. The symptoms are partly identical to meningitis and other meningitis.

Diagnosis & course of disease

Virological diagnostics are carried out in the laboratory. For this purpose, the virus is grown on a suitable carrier. The correct diagnosis is made much faster if direct virus detection is provided. This is done through the serological examination of the blood. The examination of the liquor can also be used to detect and determine the viruses.

Horse owners should also pay attention to the examination of their animals. While Eastern equine encephalomyelitis is prevalent overseas, there is no guarantee that it will not occur in Europe. Every suspicion must be investigated and there must be no unprotected contact with the animals.

It is important that the correct diagnosis is made. There are two other similar encephalomyelites whose symptoms and disease course are similar to Eastern. Since they are caused by other pathogens, their existence must also be documented. These viruses have to be treated completely differently.


In most cases, this disease is diagnosed late and thus treatment is delayed. Those affected suffer from a significantly weakened immune system, which often leads to infections and inflammation. Conjunctivitis or severe headaches can also occur and are accompanied by fever.

There is also pain in the muscles and limbs. As the disease progresses, disturbances of consciousness also occur, leading to confusion or delirium. If the disease is not treated, the meninges become inflamed. In some cases this leads to death.

Various symptoms of paralysis or sensory disturbances can also occur and have a very negative effect on the patient’s everyday life and quality of life. Treatment of the disease is carried out with the help of drugs. In serious cases, however, surgical interventions are necessary.

Since the disease cannot be completely cured, the patient’s life expectancy is usually reduced. The relatives or parents of the patient can also be affected by psychological complaints or depression.

When should you go to the doctor?

People who have anything to do with horses should consult a doctor in the event of health changes or abnormalities. If you experience nausea, vomiting, or diarrhea, you should be concerned. A decrease in physical performance, headaches, increased body temperature and impairment of the muscular system indicate a health disorder. Medical tests are necessary to clarify the cause. Mobility restrictions, joint pain, cramps or stiff neck are further indications that should be followed up. Immediate action is required in the event of signs of paralysis.

In acute cases, an emergency service must be alerted so that no further complications arise. If the person concerned can no longer move without symptoms or without the help of other people, he must be examined and treated by a doctor. Inner irritability, fatigue or exhaustion indicate a health impairment. If the symptoms persist for a long time or if they increase in intensity, action must be taken as quickly as possible. In rare cases, if the disease progresses unfavorably without medical care, the affected person may die prematurely. Therefore, a doctor should be consulted at the first sign. If the inner stress experience increases or if the person concerned has a weak immune system, you must react as quickly as possible.

Treatment & Therapy

Therapy aims to treat the symptoms. It is important that the fever is reduced and that an antiepileptic is given in the event of seizures. Spasms can be reduced with muscle relaxants. If cerebral edema occurs, it presses on important areas of the brain and relief is imperative. Possible interventions are the installation of a shunt system or trepanation.

Both measures serve to rapidly drop the intracranial pressure by draining the brain water. However, they are only possible if the general condition of the patient allows it. The shunt installation puts less strain on him than the trepanation. It is already used in infants with hydrocephalus (water on the head). The liquor shunt permanently drains the brain water from the head to the abdominal cavity.

For this purpose, a small catheter is implanted, which can be controlled via a valve system. After the symptoms have subsided, removal is unproblematic and those affected can live without the CSF shunt. Patients always need intensive medical care.


Vaccination of horses is possible in risk areas. They are treated with an inactivated vaccine. For them, the risk of infection is then extremely low. A human vaccine is also available for overseas travel to the affected areas. According to experts, the viruses of the eastern equine encephalomyelitis are among the biological weapons of terrorists and dictators.

It is therefore of fundamental importance that vaccines are developed that can be used across the board. So far there are only serums that have many side effects. But that shouldn’t be a reason to forgo immunization if you’re planning a trip to risk areas.

You can do that yourself

As part of self-help, travelers who will be moving to Canada, the USA, Thailand or the Philippines should provide sufficient information in advance about the living conditions there. The occurrence of regional diseases and necessary precautionary measures must be researched in advance. The hygiene standard there should also be found out.

If you have any questions or are unclear, employees of the Federal Foreign Office or a doctor can provide further assistance. In some cases, sufficient protective vaccinations should be considered and carried out in consultation with the doctor treating you. Protection against insects, especially mosquitoes, should be planned sufficiently before you start your journey.

If health problems occur after an insect bite, a doctor should be consulted. It is advisable not to wait until you return home. Necessary assistance measures can already be initiated on site or the cause can be clarified. If the person concerned is back at his or her home town, a doctor should also be consulted immediately. Fever can be reduced by using cold compresses. Eating should also be optimized to reduce diarrhea and vomiting.

Since the disease leads to premature death in severe cases, a doctor should always be consulted if the symptoms increase.

Eastern Equine Encephalomyelitis