Mpox, also known as monkeypox, is an infectious disease caused by the monkeypox virus (MPXV). It can cause a painful rash, swollen lymph nodes, and fever. Most people recover fully, but some can get very sick.

Anyone can get mpox. It spreads through contact with infected people (through touch, kissing, or sex), animals (when hunting, skinning, or cooking them), and materials (like contaminated sheets, clothes, or needles). Pregnant people can pass the virus to their unborn baby.

If you have mpox, it’s important to tell anyone you’ve been close to recently. Stay at home until all scabs fall off and new skin forms. Cover any lesions and wear a well-fitting mask around others, and avoid physical contact.

The monkeypox virus was discovered in 1958 in Denmark in research monkeys. The first human case was in a nine-month-old boy in the Democratic Republic of the Congo in 1970. Mpox can spread from person to person or from animals to people. After smallpox was eradicated in 1980 and smallpox vaccinations stopped, mpox became more common in parts of Africa. A global outbreak occurred in 2022–2023.

Mpox spreads through direct contact with infectious skin or lesions, face-to-face contact, skin-to-skin contact, mouth-to-mouth contact, and respiratory droplets. The virus enters the body through broken skin, mucous membranes, or the respiratory tract.

Symptoms of mpox typically start within a week but can begin 1–21 days after exposure and last 2–4 weeks. Common symptoms include rash, fever, sore throat, headache, muscle aches, back pain, low energy, and swollen lymph nodes. The rash starts as flat sores, which turn into blisters, dry up, and fall off. Some people may have only a few lesions, while others may have hundreds.

People with mpox are contagious until all sores heal and a new layer of skin forms.

Mpox and the New Clade I Variant
Mpox is a viral infection spread mainly through close, skin-to-skin contact, including sexual activity. It can also spread through contact with rashes, scabs, body fluids, or contaminated items like clothing or bedding. Common symptoms include fever, chills, swollen lymph nodes, sore throat, and a painful or itchy rash. A more severe strain, Clade I Mpox, was recently identified in Southern California, confirming local community spread. While overall risk remains low, those at higher risk—especially gay, bisexual, and other men who have sex with men, as well as transgender, nonbinary, and immunocompromised individuals—should stay informed and get vaccinated. The two-dose JYNNEOS vaccine provides protection against both Clade I and II Mpox strains.