Orthopoxvirus

What are orthopoxviruses?

Orthopoxvirus is a genus (grouping) of viruses that cause a raised, bumpy rash. They’re zoonotic diseases, which means they can infect animals and humans. Orthopoxviruses infect mammals like cows, cats and small rodents, but they sometimes spread to people, too. Smallpox — which is eradicated (no longer spreads) — and mpox are the only orthopoxviruses that spread between humans.

Examples of Orthopoxvirus

Some types of orthopoxviruses include:

• Akhmeta virus.
• Alaskapox virus.
• Camelpox virus.
• Cowpox virus.
• Horsepox virus.
• Mpox virus.
• Vaccinia virus (used in smallpox vaccines).
• Variola virus (the virus that causes smallpox).

What are the symptoms of orthopoxviruses?

If you have an orthopoxvirus, a raised, well-defined, bumpy rash is usually the most recognizable symptom. The rash goes through several stages, starting out flat, becoming raised (papules) and fluid-filled (vesicles), and then, finally crusting over. This happens over a few weeks. The rash is sometimes painful and itchy. Depending on the virus, it can show up in different places on your body. You might have a rash on your:

• Hands, especially your palms.
• Soles of your feet.
• Anus (butthole).
• Genitals (penis or vagina).

Other symptoms of orthopoxviruses include:

• Muscle aches.
• Swollen lymph nodes.

How do orthopoxviruses spread?

Orthopoxviruses can spread either through animal-to-person or person-to-person contact. You can get orthopoxviruses from infected animals through bites, scratches or direct contact with their blood, bodily fluids or rash.

You can also get orthopoxviruses through close contact with someone who’s infected. This includes:

• Contact with respiratory droplets (from coughing, sneezing or talking).
• Contact with fluid from sores.
• Intimate contact, like kissing and sex.

Mpox is the only Orthopoxvirus that currently spreads from person to person (smallpox can spread from person to person, but has been eradicated since 1980). Other orthopoxviruses, like Alaskapox and camelpox, spread from contact with infected animals.

What animals carry orthopoxviruses?

Mammals that carry orthopoxviruses include:

• Domestic animals, like cats and dogs.
• Red-backed voles and shrews carry Alaskavirus.
• Small animals, like squirrels, rats and mice carry mpox.

Some orthopoxviruses can be transmitted to animals through insects, like ticks.

How are orthopoxviruses diagnosed?

A healthcare provider might suspect that you have an orthopoxvirus based on the appearance of a rash and other symptoms. They might test a sample of your blood, fluid from the rash or tissue from your skin to diagnose orthopoxvirus.

How are orthopoxviruses treated?

Healthcare providers don’t often treat orthopoxviruses, unless you’re very sick. Sometimes, they treat orthopoxviruses like mpox with antiviral medications created to treat smallpox. Vaccinia immune globulin (VIG-IV), a type of antibody treatment, is also sometimes an option.

Can orthopoxviruses be prevented?

You can get vaccinated against some orthopoxviruses if you’re at high risk of being exposed to one. Vaccines are available for mpox and smallpox. You can also reduce your risk of orthopoxviruses by:

• Wearing protective equipment (like gloves and a mask) if your job or hobbies put you in contact with animals that could carry orthopoxviruses.
• Avoiding contact with infected animals or people. This includes dead animals.
• Avoiding contact with bedding and other materials contaminated with an orthopoxvirus.
• Thoroughly cooking all foods that contain animal meat or parts.
• Washing your hands frequently with soap and water.
• Practicing safe sex, including the use of condoms and dental dams.
• Using personal protective equipment (PPE) when caring for people infected with an orthopoxvirus.

What can I expect if I have an orthopoxvirus?

If a provider diagnoses you with an orthopoxvirus, they’ll let you know how to manage symptoms at home and what to do if symptoms become severe. Avoid other people while you have symptoms to limit the risk of spreading the virus.

Most orthopoxviruses are uncommon in humans. And since the eradication of smallpox, most cases of orthopoxviruses aren’t fatal.

When should I see my healthcare provider?

Talk to a healthcare provider if you think you’re at high risk for exposure to orthopoxviruses. They can help you understand your risk and what kind of preventive measures you can take.

See a provider if you:

• Have a new rash or sores.
• Feel sick with fever, aches or swollen lymph nodes.
• Have been in close contact with a person or animal who’s infected with an orthopoxvirus.

When should I go to the ER?

Go to the emergency room if you have signs of serious illness, including:

• High fever (over 103 degrees Fahrenheit/40 degrees Celsius).
• Severe or sudden shortness of breath.
• Chest pain.
• Severe vomiting or diarrhea.
• Confusion or other mental changes.
• Persistent weakness or dizziness.

Is chickenpox an orthopoxvirus?

No, chickenpox doesn’t belong to the genus Orthopoxvirus. Varicella-zoster, the virus that causes chickenpox, is a member of the herpes virus family.