Overview

Venezuelan equine encephalitis (VEE) is a viral disease that is transmitted by mosquitoes and it can pose significant risks for pregnant women and their unborn babies.¹ VEE can cause serious illness in infected individuals and may also cause complications in pregnant women and the foetus. This article will cover what VEE is, how it is transmitted, its symptoms, and how to manage and be aware of it during pregnancy.

Understanding Venezuelan equine encephalitis

VEE virus is responsible for causing Venezuelan equine encephalitis disease. While many outbreaks of this disease occur in equines like horses, donkeys, mules, and zebras, humans can also be infected with this virus.¹ The majority of these outbreaks occur in Central and South America, including countries such as Venezuela, Colombia, Peru, Ecuador, Costa Rica, Mexico, and the United States.^1,2 

The virus is primarily spread by mosquitoes. VEE in humans occurs when a mosquito bites an infected animal and then bites a human.¹ 

In an infected individual, VEE can cause inflammation in the brain (encephalitis), leading to serious illness.¹ This illness can affect anyone, but pregnant women are particularly at risk because it can be dangerous for both the mother and also the unborn baby. When a pregnant woman gets VEE, the virus can pass through the placenta and into the developing baby. This can potentially cause birth defects or other complications. 

Symptoms and possible complications of Venezuelan equine encephalitis

VEE can cause a range of mild to severe symptoms. Some common symptoms include:³

• Fever
• Headache
• Muscle pain
• Fatigue

In more severe cases, individuals may experience symptoms such as:³

• Nausea
• Vomiting
• Confusion
• Seizures
• Inflammation of the brain (encephalitis)

Encephalitis is a serious complication, and can lead to long-term neurological problems or even death. Between 4% to 15% of infected individuals will develop neurological disease of some kind. Seek appropriate medical attention if you experience symptoms of VEE or believe you may have been exposed to the virus. 

Risks of Venezuelan equine encephalitis in pregnancy

If you are pregnant and you contract VEE, there is a higher chance of experiencing severe illness and complications because pregnancy causes changes in the immune system.^3,4 The common symptoms of fever, headache, muscle aches, and fatigue, and symptoms can be adverse in pregnant women. Additionally, severe cases of VEE can lead to neurological symptoms such as confusion or seizures, which poses a serious risk. 

VEE is dangerous for the unborn baby as the virus can cross into the placenta and infect the foetus. This can lead to:

• Miscarriage
• Stillbirth
• Pre-term birth
• Birth defects such as brain damage, developmental delays, and neurological abnormalities⁴

These risk are highest in the first trimester as this is the time when the baby is undergoing important development. In the later stages, the infected mother can pass VEE to the baby during childbirth or through breastfeeding.⁴ Luckily, there are various preventative measures that women can take to avoid becoming infected with VEE.

Precautions for pregnant women

If you are pregnant, you should take extra precautions to protect yourself and your baby against VEE because of the risks that can happen. Here are some essential precautions to consider.⁵

Avoid travelling to high-risk areas 

If possible, avoid travelling to regions where there are reported outbreaks of VEE, or where the virus is known to be prevalent. These areas are often tropical or subtropical regions of Central and South America, where there is a higher risk of mosquitoes transmitting the virus.

Use mosquito repellent 

If you live in or are travelling to an area where there are risks of VEE transmission, use insect repellents containing DEET, picaridin, or oil of lemon eucalyptus to help protect against mosquito bites.⁵ Applying repellent to exposed skin and clothing can help reduce the likelihood of mosquito bites.

Wear protective clothing 

Ideally, wear long-sleeved shirts, long pants, and socks when outdoors, especially during dawn and dusk when mosquitoes are most active, and it is an important measure if you are pregnant.⁵ Wearing light-coloured clothing can also help deter mosquitoes.

Use mosquito nets 

When sleeping or resting indoors in areas with a high risk of VEE transmission, using mosquito nets or screens on doors and windows can help prevent mosquitoes from entering living spaces. Additionally, you can put mosquito netting over the sleeping area to protect you as you sleep.

Eliminate mosquito breeding sites

Taking steps to reduce mosquito breeding sites around their homes, like removing any standing water from containers, gutters, and flowerpots where mosquitoes can lay eggs is important.

Stay informed 

It is important to stay informed about VEE outbreaks and public health advisories issued by local authorities or healthcare providers. One should also follow recommendations for prevention and seek medical attention promptly if symptoms develop.

Management and treatments for Venezuelan equine encephalitis

There is currently no specific antiviral treatment or vaccination that is widely available for VEE in humans.⁶ Therefore, management of this disease primarily is supportive care to help alleviate your symptoms and prevent further complications. If you are pregnant, it is important to seek medical attention and treatment as quickly as possible.

Healthcare providers may prescribe medications to manage symptoms such as fever, headache, muscle aches, and nausea.³ Pregnant women should follow their healthcare provider's recommendations for over-the-counter medications that are safe to use during pregnancy. Additionally, making sure that you are hydrated properly is essential to prevent any dehydration that can occur while being sick with VEE, especially if you experience any vomiting or diarrhoea. Drink plenty of fluids, including water electrolyte solutions, and clear soups, which can help replenish any lost fluids and electrolytes. These should also help calm any nausea symptoms. 

Finally, it is important to get plenty of rest with VEE if you have become infected. This will help support your immune system to fight off the virus and aid in your recovery. Getting enough rest can also help with any fatigue that you experience during the illness. 

Be sure to check in frequently with your healthcare provider to watch for any potential complications that can occur, like neurological symptoms. This is important for both the mother and the unborn baby. While your immune system is weakened during illness, it is possible to develop secondary bacterial infections such as pneumonia or urinary tract infections. However, you can avoid this through practising good hygiene such as proper handwashing with soap and water, and avoiding close contact with any individuals infected with respiratory infections.

FAQs

Can Venezuelan equine encephalitis be transmitted from person to person?

No, VEE cannot be transmitted directly from person to person. It primarily spreads through the bite of infected mosquitoes.

How is Venezuelan equine encephalitis diagnosed?

VEE is generally diagnosed by your healthcare provider using a combination of symptoms, medical and travel history, and laboratory testing. If someone has the characteristic symptoms of VEE and was recently in an area where VEE is common, then the doctor may order tests to further confirm this. These tests may include blood tests to look for signs of the virus or imaging scans to check for any brain inflammation or other abnormalities.¹

Can Venezuelan equine encephalitis affect the developing baby?

Yes, VEE can affect the developing foetus if the mother becomes infected during pregnancy. The virus can cross into the placenta and cause developmental defects.^3,4

What are the potential long-term effects of Venezuelan equine encephalitis on the baby?

The potential long-term effects of VEE on the baby may include developmental delays, cognitive impairments, or neurological deficits.^3,4

Summary

In summary, Venezuelan equine encephalitis (VEE) is a serious viral infection that has a significant risk for pregnant women. The virus is transmitted through mosquito bites and causes severe flu-like symptoms, neurological complications, and potential developmental issues in the foetus. Pregnant women may experience more intense symptoms than others. The virus also increases the risk of miscarriage, stillbirth, or pre-term birth. There are several preventative measures to minimise these risks, including using insect repellent and wearing protective clothing. Be sure to get an early diagnosis and appropriate management to help prevent these complications from occurring.