Mpox (formerly monkeypox) is a viral disease caused by infection with mpox virus, a member of the orthopoxvirus family. In the United States, cases are generally uncommon but can occur, with most infections linked to international travel or imported animals. The illness often begins with fever, swollen lymph nodes, and a rash that progresses through raised bumps, fluid-filled blisters, and scabs. Mpox spreads mainly through close, personal contact, including skin-to-skin contact with lesions, contact with contaminated fabrics, and respiratory droplets during prolonged face-to-face exposure. Public health guidance emphasizes risk reduction, vaccination for eligible people, and early treatment to limit complications and further spread.
What mpox is and how it spreads
Mpox is a zoonotic disease caused by mpox virus, which is related to the variola virus that causes smallpox. Because of this relationship, vaccines developed for smallpox are cross-protective, although newer vaccines are preferred for mpox in the US. Historically, mpox has been rare in this country and has primarily been reported in travelers from regions where the virus circulates, including parts of Central and West Africa. Person-to-person spread is more common when there is prolonged close contact, such as household or intimate contact, but brief encounters generally pose low risk. Understanding how the virus transmits helps people make informed decisions about activities, testing, and medical care.
Routes of transmission
- Direct contact with infectious rash, scabs, or body fluids.
- Contact with objects and fabrics that have been contaminated, such as bedding, towels, or clothing.
- Respiratory secretions during extended face-to-face or intimate contact.
- Animal bites or scratches, or handling infected animals.
- Healthcare or laboratory exposures involving infectious material.
Understanding the difference between higher and lower risk activities is essential. Simple actions like talking with someone in an office, walking in a park, or using public transportation are not known to spread mpox. The virus does not spread easily through casual contact or short encounters, and it is not primarily considered a sexually transmitted infection, although it can spread during intimate physical contact. Clear, factual information about transmission supports better decisions about prevention, testing, and when to seek care.
Recognizing the symptoms of mpox infection
The clinical presentation of mpox can vary, and symptoms may resemble other illnesses, which sometimes leads to delayed diagnosis. Symptoms typically begin within three weeks of exposure, though the incubation period can range from one to four weeks. People may experience fever, chills, swollen lymph nodes, headache, muscle aches, backache, and fatigue before or alongside a rash. The rash often starts as flat red spots that become raised bumps, then fluid-filled blisters, and eventually scabs that fall off. Lesions can be painful or itchy and may appear in the genital, anal, or other areas, on the face, hands, feet, chest, or elsewhere on the body. Recognizing these patterns helps people seek timely care and reduces the chance of unknowingly exposing others.
Stages of the mpox rash
The progression of the rash is a key feature of mpox, though not everyone develops every stage. The order and timing can vary among individuals. People can be contagious from one day before the rash appears until the sores have fully healed and a fresh layer of skin has formed. Knowing the stages supports accurate identification and reinforces the importance of avoiding close contact while infectious.
| Stage | Visual description | Typical duration |
|---|---|---|
| Macules | Flat red spots | Hours to 1 day |
| Papules | Raised bumps | 1–2 days |
| Vesicles | Fluid-filled blisters | 2–4 days |
| Pustules | Pus-filled lesions | Several days |
| Scabs | Dried lesions that fall off | 1–3 weeks |
Current mpox situation in the United States
Since May 2022, the United States has experienced a larger outbreak of mpox than is typically seen, with cases reported across many states and territories. Transmission has predominantly affected some networks of close-contact social and sexual networks, but anyone with close contact can be at risk, regardless of gender or sexual orientation. Public health authorities have maintained vaccination and treatment access, surveillance, and guidance updates to help control the outbreak. Ongoing monitoring continues to support situational awareness, but long-term control is expected to rely on established tools such as vaccination, case investigation, and coordination with healthcare providers. Monitoring trends, vaccination coverage, and community awareness remains essential for reducing impact over time.
Testing, diagnosis, and medical care
Testing for mpox is usually considered for people with a compatible rash and known exposure, travel to affected areas, or who are part of groups at higher risk. A healthcare provider collects a sample from a lesion for PCR testing, which is the standard method to detect mpox virus DNA. Early diagnosis supports timely treatment and reduces the chance of spreading the virus to others. People who suspect they have mpox should contact a healthcare provider or local health department before going to a clinic or emergency department, so that appropriate infection control precautions can be in place. Diagnosis can help guide decisions about isolation, partner notification, and further medical management.
Vaccines, treatments, and risk reduction
Vaccination
Two vaccines are used in the United States for mpox protection. JYNNEOS (also called Imvamune or Imvanex) is preferred and is administered in two doses several weeks apart. ACAM2000 is an older smallpox vaccine that can be used under certain circumstances. Vaccination is recommended for people who have had recent exposure to mpox and for those at higher risk due to behaviors or occupations. Eligibility and availability vary by location, and people should check with local health departments or healthcare providers for current guidance. Vaccination after exposure but before symptoms appear can help prevent disease or lessen severity.
Treatment
Antiviral treatment, such as tecovirimat, may be recommended for people with severe disease, those at higher risk for complications, or certain others as determined by a healthcare provider. Most people with mpox recover without specific antiviral treatment, and supportive care such as pain management and skin care can help relieve symptoms. People who are immunocompromised or have certain skin conditions may be at increased risk for more severe illness and should seek prompt medical attention if they suspect mpox infection. Decisions about treatment are made in consultation with a clinician based on individual health circumstances.
Practical risk reduction strategies
- Avoid close skin-to-skin contact with people who have a rash or lesions consistent with mpox.
- Do not share items such as towels, bedding, clothing, or electronics that may have touched a rash.
- Practice good hand hygiene with soap and water or alcohol-based hand sanitizer.
- Check venue and event factors if considering participation in gatherings, and ask organizers about case management plans.
- Follow guidance from local and state health departments, especially if you are in a group at higher risk.
- Consider vaccination if you have had recent exposure or other risk factors; consult a healthcare provider.
When to seek care and what to expect
If you develop a rash or other mpox symptoms, contact a healthcare provider before visiting a clinic or emergency room. Advance notice allows the clinic to implement infection control measures and reduce potential exposure to others. A healthcare professional will evaluate your symptoms, ask about exposure history and activities, and determine whether testing is appropriate. If mpox is confirmed, public health officials may assist with contact tracing and recommendations to protect others. Isolation while infectious, wound care guidance, and monitoring for complications are important parts of managing mpox. Most people recover fully with time and supportive care.
Key facts at a glance
| Attribute | Verified detail | Source type |
|---|---|---|
| Typical incubation period | 1–4 weeks (commonly 7–14 days) | CDC guidance |
| Primary US 2022–2023 pattern | Outbreak predominantly affecting some networks of close-contact social and sexual networks, with cases in many other networks | CDC surveillance summaries |
| Vaccines available | JYNNEOS (2-dose series) and ACAM2000 (under certain criteria) | FDA-approved product information |
| Main mode of spread in the US outbreak | Prolonged close contact, including intimate and household contact | CDC transmission guidance |
| Contagious period | From one day before rash onset until all lesions have healed and a new layer of skin has formed | CDC case management guidance |
| High-risk groups during the recent outbreak | People with recent exposure, some networks with close intimate contact, and certain occupational or health circumstances that increase risk | CDC risk considerations |
Bottom line
Mpox in the United States remains uncommon in the general population but can affect anyone with close contact with an infectious person. The illness follows a recognizable pattern of fever, swollen lymph nodes, and a rash that progresses through distinct stages. Spread occurs mainly through prolonged close contact rather than casual interactions. For most people, the risk remains low if they avoid contact with suspicious rashes and follow public health guidance. Vaccination and, when needed, antiviral treatment are important tools for preventing and managing cases. Reliable information from health authorities, combined with practical precautions, supports ongoing risk reduction over time.