What Is Mpox?

Mpox (formerly known as monkeypox) is a rare disease caused by a zoonotic virus. This means it can be spread from animals to humans.

Mpox is caused by a virus that is closely linked to the virus that causes smallpox. While its symptoms often mimic those of smallpox, mpox is likely to be less severe.

The mpox virus is spread through close contact with a diseased person, diseased animal, or objects that contain the virus. It can also infect an unborn baby whose mother has the disease.

There is no approved treatment for mpox, so care generally involves symptom management. However, because of genetic similarities to smallpox, antiviral drugs used to treat smallpox may be used to treat mpox infections.

This article discusses mpox symptoms, causes, diagnosis, and treatment.

Types of Mpox

Mpox occurs from one of two viral clades, which originate in different geographic regions. A clade is a group of organisms that have a common ancestor.

The disease can be categorized into one of two groups: either the Congo Basin clade or the West African clade. The Congo Basin clade causes more severe symptoms, resulting in up to 10% mortality (rate of death). The less harmful West African clade results in about 1% mortality, and is the outbreak experienced in 2022.

Mpox Symptoms

An mpox infection usually starts with symptoms that can be mistaken for the flu or many other common infections. Symptoms usually last between two and four weeks before you feel better, though severe illness (lasting longer) can sometimes occur.

The disease may begin without symptoms. However, it usually starts with the following symptoms that can occur between five and 21 days after infection:

• Fever
• Intense headache
• Muscle aches
• Backache
• Swollen lymph nodes
• Chills
• Fatigue

After about one to three days, a rash or lesions appear. The lesions usually begin on your face, then spread to other areas, including the palms of your hands and the soles of your feet.

Mpox lesions follow a predictable set of stages similar to those that occur in smallpox. These stages are:

1. Macules (flat, discolored lesions)
2. Papules (lesions have progressed from flat or raised)
3. Vesicles (lesions filled with clear fluid)
4. Pustules (raised bumps filled with yellow fluid)
5. Scabs (hard, crusty patches that fall off as healing begins)

Transmission

The virus that causes mpox is spread through close physical contact with an infected person or animal. It can also be transmitted from contaminated materials to humans. Also, an infected mother can pass the virus to her unborn baby.

Human-to-human transmission typically occurs from close contact with an infected person's respiratory secretions, skin lesions, or contaminated materials. An infected person is considered contagious when they develop symptoms until their blisters scab over and dry.

While mpox is not regarded as a sexually transmitted infection (STI), the virus can be spread during intimate contact that occurs during sexual activities.

Transmission from animals to humans usually occurs in one of the following methods:

• Getting bitten or scratched by an infected animal
• Preparing or eating meat from an infected animal
• Using products made from infected animals

Diagnosis

When there is a known outbreak, mpox can be diagnosed by symptoms that include a rash that begins in your mouth before moving to your face, extremities, and the rest of your body. The presence of swollen lymph nodes can be used to distinguish mpox from other diseases.

A laboratory test can provide a definitive diagnosis of mpox. The test uses polymerase chain reaction (PCR), which detects DNA (genetic material) from the virus to confirm the diagnosis. Samples taken from the lesions or their fluids provide the most accurate results.

Treatment

There are no specific treatments for infections of the mpox virus. However, patients may benefit from therapy with antivirals made to treat smallpox. This option is usually reserved for immunocompromised people who become infected. This type of treatment includes the following antiviral drugs:

• Vistide (cidofovir)
• Tembexa (brincidofovir)
• Tpoxx (tecovirimat)

A vaccine called Jynneos was approved in 2019 for the prevention of smallpox and mpox. This two-injection vaccine is up to 85% effective in preventing mpox. Jynneos can also be effective in preventing the onset of mpox when it's administered within four days of exposure.

Prognosis

Mpox is usually a self-limiting (tends to go away on its own) disease that usually runs its course in about 14 to 21 days. However, it's possible for some people to experience severe symptoms and require medical treatment.

Severe cases are most likely to occur among children. Factors such as the extent of viral exposure, the patient's health status, and the presence of underlying immune deficiencies can lead to complications that include the following conditions:

• Secondary infections
• Bronchopneumonia
• Sepsis
• Encephalitis
• Infection of the cornea, leading to blindness

Coping

Contact your healthcare provider if you develop symptoms common with mpox. In its early stages, mpox can mimic many other types of infections, such as chicken pox. Getting an accurate diagnosis is key to receiving the right treatment for your condition.

If you are diagnosed with mpox, follow the advice of your healthcare provider regarding treatment. If you seek medical attention early, you may be able to reduce or prevent infection by getting the vaccine.

Your provider can also guide you in preventing the transmission of mpox to other household members and to the public.

Summary

Mpox is a rare disease that can be spread through close contact with a diseased person, diseased animal, or objects that contain the virus. It can also infect an unborn baby whose mother has the disease.

Mpox usually resolves on its own within two to four weeks. Problems are rare, and often limited to children and those with other health problems.

A Word From Verywell

Your risk of contracting mpox is relatively low. Mpox is not well-known in the United States, and getting a diagnosis with this new infectious disease can cause anxiety.

While it may not be familiar to the U.S. population, the virus has been active in Africa since 1958. Your treatment plan is based on the medical community's experience and success in treating African patients for more than six decades.

Since the disease is usually self-limiting, you can look forward to feeling better within two to four weeks. While you're sick, maintain your body's needs for proper hydration and nutrition to promote healing.