Monkeypox in the United States: current status, transmission, and what to know

What is monkeypox and why it matters in the United States

Monkeypox is a viral zoonotic disease caused by the monkeypox virus, a member of the orthopoxvirus family. In the United States, cases have remained relatively rare but are taken seriously because of the potential for localized clusters and meaningful health impacts, especially among people who are immunocompromised. The 2022 international outbreak prompted rapid public health responses, including expanded testing, vaccination, and outreach; since then, case levels have declined substantially, though sporadic detections continue. Understanding the current picture helps clinicians, public health professionals, and community members make informed decisions about testing, vaccination, and risk reduction without unnecessary alarm.

Key definitions and terminology to know

Clear terminology supports accurate communication about monkeypox in the United States. Key terms include orthopoxvirus (the viral genus), zoonotic spillover (animal-to-human transmission), case (a person with confirmed infection), contact (a person with epidemiclogic exposure), and post-exposure prophylaxis (PEP, measures taken after exposure to reduce risk). Correct use of these terms supports consistent public health guidance, clinical decision-making, and community understanding.

Orthopoxvirus classification and related diseases

Monkeypox virus belongs to the genus orthopoxvirus, which also includes variola (smallpox), vaccinia (used in smallpox vaccines), and cowpox. Within orthopoxvirus, monkeypox divides into two clades: the Congo Basin (Central African) clade and the West African clade. The West African clade has been responsible for most recent international cases and tends to be associated with less severe disease compared to the Congo Basin clade.

Current status in the United States

As of the most recent national summaries, monkeypox cases in the United States remain uncommon compared with historical peaks seen during periods of international exportation. Public health agencies continue to detect cases through routine surveillance, targeted testing among people with compatible symptoms and risk factors, and contact tracing. The majority of recent cases have been identified in people who reported close, often intimate, contact with someone who has monkeypox or who sought testing due to symptoms. Context matters: ongoing, high-level transmission is not occurring broadly in the population, but preparedness and vigilance remain important.

Notable details and recent trends

While case counts fluctuate, the United States has reported substantially lower numbers than during the peak of the 2022 response. Wastewater surveillance and genomic sequencing continue to support situational awareness, helping public health officials detect changes early. Clinicians should maintain a moderate index of suspicion for monkeypox in patients with compatible rash illness, particularly among those with recent travel or close contact with a known case, regardless of geographic location.

How monkeypox spreads in the U.S.

Monkeypox is not a classic respiratory virus; it spreads primarily through direct contact with infectious lesions, scabs, or body fluids, and via prolonged face-to-face contact with infectious respiratory droplets. In the United States, most transmission has occurred within close social or sexual networks, often through skin-to-skin contact during intimate activity. It is important to note that monkeypox is not considered a sexually transmitted infection in the traditional sense, but sexual activity can facilitate the type of close contact that spreads the virus. Other routes, such as contact with contaminated linens or clothing, can also play a role in household or institutional settings.

Situation examples that raise concern

• Prolonged skin-to-skin contact with a person who has a monkeypox rash, even if the rash is covered by clothing.
• Sharing items such as towels, bedding, or sex toys that have touched infectious lesions.
• Occupational exposure among healthcare or lab workers without appropriate personal protective equipment.

Recognition and testing guidance

Key symptoms of monkeypox include fever, headache, muscle aches, swollen lymph nodes, chills, exhaustion, and a rash that progresses through stages including macules, papules, vesicles, and pustules. The rash may appear on or near the genitals, anus, hands, feet, chest, face, or mouth. In the United States, clinicians should consider testing for patients with a compatible rash and relevant exposure history, including travel to areas with ongoing transmission or close contact with a person who has monkeypox. Public health departments and commercial laboratories can coordinate testing; results typically return within a few business days.

When to test

• New or unexplained rash with or without fever in the past three weeks.
• Close contact with a person who has suspected or confirmed monkeypox.
• Multiple or widespread lesions, lesions in areas not typically explained by other causes, or severe illness.

Vaccines, treatment, and prevention measures

In the United States, vaccines and antiviral treatments are available for monkeypox and can reduce severity when provided early. The JYNNEOS (also referred to as MPXV-BN) vaccine is preferred and can be used for post-exposure prophylaxis and pre-exposure protection in higher-risk groups. Smallpox vaccine ACAM2000 is another option but is used more selectively due to a higher rate of side effects. Antiviral treatment, such as tecovirimat, may be considered for people with severe disease or those at high risk for complications. Non-pharmaceutical interventions include avoiding close contact with infectious individuals, not sharing personal items used by someone with monkeypox, and practicing good hand hygiene.

Practical steps for clinicians and community members

For clinicians, maintaining vigilance means assessing monkeypox in the differential diagnosis for patients with compatible rash and fever, regardless of travel history, and promptly consulting public health authorities for testing and vaccine access. Isolation of cases, careful environmental cleaning, and clear communication can limit household or institutional spread. For community members, reducing risk involves limiting close skin-to-skin contact with people who have rashes resembling monkeypox, avoiding shared linens or utensils, and seeking timely testing if symptoms develop. Public health resources should be consulted for up-to-date vaccine eligibility and guidance.

When to seek medical care and public health support

People who suspect they may have monkeypox should contact a healthcare provider or local health department before visiting a clinic or emergency department, so that appropriate infection control measures can be implemented. Public health departments can assist with testing, vaccine access, contact tracing, and guidance on isolation. Reporting to health departments helps ensure accurate situational awareness and supports timely public health interventions. Early clinical recognition and coordination with public health are key components of an effective response.

Summary and outlook

Monkeypox in the United States currently represents a low but significant threat, with sporadic cases and localized clusters rather than widespread community transmission. Understanding transmission routes, recognizing typical symptoms, and using vaccines and treatments appropriately are central to minimizing impact. Continued collaboration between clinicians, public health officials, and communities supports rapid detection and containment. Staying informed through reliable public health sources ensures that responses remain proportionate, effective, and grounded in the best available evidence.