What is an arbovirus?
“Arbovirus,” short for arthropod-borne virus, doesn’t refer to one particular virus. Rather, it refers to a type of virus transmitted via insects that bite and feed on blood.
This includes a large family of viruses. In fact, there are over 600 known arboviruses, and more than 80 of them are known human pathogens. The resulting illnesses can range from mild to severe.
On a global scale, dengue virus may be the most challenging, infecting 100 to 390 million people and leading to 12,500 deaths per year. It spreads mostly through mosquitos in underdeveloped, highly populated regions.
Some other arboviruses can lead to:
- Chikungunya fever
- Colorado tick fever
- Eastern equine encephalitis
- Japanese B encephalitis
- La Crosse encephalitis
- Powassan virus infection
- St. Louis encephalitis
- West Nile virus infection
- Western equine encephalitis
- yellow fever
- Zika virus disease
Many other serious diseases, such as malaria, Lyme disease, and Rocky Mountain spotted fever are spread through insects. But because they’re not viral infections, they don’t fall into the same category.
Who’s at risk
Blood-sucking insects, such as mosquitos, pick up viruses from birds or other host animals. The virus replicates inside the insect, but it doesn’t cause illness to the insect. The insect carries it around as it looks for its next meal. You become infected when the insect bites you.
Most arboviruses aren’t transmitted from person to person, usually making humans dead-end hosts.
A few exceptions are dengue fever and yellow fever, which can be transmitted from person to person through insect bites. Some, such as West Nile virus, Colorado tick fever, and dengue may be spread through blood product transfusions or organ donation.
Anyone can contract an arbovirus, no matter where they live. Your risk may be increased if:
- you live in or travel to a mosquito- or tick-infested area where outbreaks tend to occur
- it’s mosquito season
- you have a compromised immune system
- you’re younger than 10 or older than 60
Some people are asymptomatic, and others may have only mild symptoms. Because of this, arboviruses may be underreported.
Symptoms of infection
It’s not unusual for someone who’s infected to have no symptoms at all. If you do have symptoms, they can start anywhere from three days to two weeks after you’ve been bitten. They can be similar to those of a mild case of the flu, but severe, life-threatening symptoms can occur.
Arboviruses can cause different types of illness, such as:
- encephalitis, meaning inflammation of the brain
- febrile diseases, which involve a fever sometimes accompanied by rash
- hemorrhagic fevers, which cause damage to blood vessels, bleeding out of broken blood vessels, and fever
Other symptoms may include:
- general body aches
- cerebral edema, which can occur due to encephalitis
How it’s diagnosed
Your doctor will assess your symptoms and perform a physical examination to help determine what tests are needed. Be sure to tell your doctor if you’ve recently traveled outside the country or if you’ve been bitten by an insect. That information can offer clues about the type of virus you have.
Some of the ways your doctor can identify a specific virus include blood tests and cerebrospinal fluid testing through a spinal tap or lumbar puncture. If you have symptoms of encephalitis, your doctor may order an MRI of the head.
There are no specific medications or therapies to rid your body of an arbovirus. Treatment involves careful monitoring and symptom relief.
Get plenty of rest and drink lots of fluids to avoid dehydration. If your fever rises or your symptoms get worse, seek medical attention.
Depending on which virus you have and the symptoms it causes, your doctor may:
- monitor your blood pressure, heart rate, temperature, and respiration
- monitor for and control any bleeding
- administer intravenous fluid
- prescribe medication to reduce fever and pain
In the most severe cases, life support may be necessary, such as a breathing tube hooked to a mechanical ventilator.
The arbovirus must run its course. Most people make a complete recovery, although severe illness is possible. Neurologic damage or death can happen, but it’s not common.
There are many types and strains of arboviruses, so having had one doesn’t necessarily prevent you from becoming infected again. Taking preventative measures can reduce your risk of future infection.
Are there vaccines?
With a few exceptions, vaccinations aren’t available for most arboviruses.
For example, a vaccine for yellow fever is available. It’s recommended for people who are at least 9 months old who live in or will travel to high-risk areas in South America or Africa.
There’s also a vaccine for Japanese encephalitis. It’s recommended for people who live in the rural parts of Asia where the virus is common, as well as for travelers who plan to remain there for a long period.
Europe, Russia, and China have vaccines for tick-borne encephalitis, and a moderately effective vaccine for dengue fever is in use in some countries outside the United States.
How to prevent infection
The main method of prevention is insect control. Here are a few tips that can help lower your risk of being bitten.
To protect your home
- Reduce stagnant water, which is an attractive breeding ground for insects.
- Get rid of old tires, pots, and any containers that hold water, or empty them after a rain.
- If you have recycling containers outside, drill holes in the bottom for drainage.
- Empty wading pools and turn them over at night.
- Change the water in your birdbath at least twice per week.
- If you have a swimming pool or outdoor hot tub, keep it clean and chlorinated. Don’t allow water to pool on top of the covers.
- Inspect window and door screens to make sure you have a good fit, free of gaps. Repair or replace damaged screens.
- Keep shrubbery around your home under control.
- Clear your gutters of leaves and other debris.
To limit exposure when outdoors
- Cover as much of your skin as possible. Be especially careful at dusk and dawn when mosquitos are most active. At those times, it’s a good idea to tuck your pant legs into your socks.
- Wear light-colored clothing to help you spot ticks quickly.
- Use insect repellants when you’re in mosquito- or tick-infected areas.
To travel smart
- When planning a trip outside the country, ask your doctor if vaccinations are appropriate.
- When camping, cover your skin, use insect repellant, and sleep with mosquito netting.