Monkeypox virus belongs to the Orthopoxvirus genus which also includes variola virus (which causes smallpox), vaccinia virus (used in the smallpox vaccine), and cowpox virus, among others.

Transmission occurs when an individual comes into contact with the virus from an animal, human, or materials contaminated with the virus. The virus enters the body through broken skin (even if not visible) or through the respiratory tract (eyes, nose, or mouth). Human-to-human transmission is thought to occur primarily through skin-on-skin, intimate personal contact. The virus also can be transmitted by large respiratory droplets requiring prolonged face-to-face contact.

The natural reservoir of monkeypox remains unknown. However, African rodents and non-human primates (like monkeys) may harbor the virus and infect people.

Burden

Monkeypox was first discovered in 1958 when two outbreaks of a pox-like disease occurred in colonies of monkeys kept for research. The first human case of monkeypox was recorded in 1970 in the Democratic Republic of the Congo during a period of intensified effort to eliminate smallpox. In Africa, monkeypox has been shown to cause death in as many as 1 in 10 persons who contract the disease.

The US declared a public health emergency for monkeypox on August 4, 2022, signaling new urgency as cases rise in the US.

According to the Centers for Disease Control and Prevention (CDC), thousands of cases have been reported in the US, particularly among men who have sex with men. CDC is urging US healthcare professionals to be alert for patients who have rash illness consistent with monkeypox, regardless of travel history, risk factors, or gender or sexual orientation.

In humans, the symptoms of monkeypox are similar to, but milder than, the symptoms of smallpox. Monkeypox symptoms include:

Rash on the hands, feet, chest, face, mouth, or on or near the genitals or anus. The rash may start out looking like pimples or blisters and may be painful or itchy.
Fever or chills
Swollen lymph nodes
Exhaustion
Muscle aches, backache, headache
Respiratory symptoms (e.g., sore throat, nasal congestion, or cough)
Symptoms usually start within 3 weeks of exposure to monkeypox. Within 1 to 3 days (sometimes longer) after the appearance of fever, the infected individual develops a rash. The rash can appear anywhere on the body, often on the trunk, genitals, or buttocks. The illness typically lasts for 2−4 weeks.

Monkeypox infection can be prevented by:

Avoiding close, skin-to-skin contact with the monkeypox rash
Avoiding contact with objects and materials that a person with monkeypox has used (such as bedding, towels, clothing, or eating utensils or cups)
Washing hands with soap and water or using an alcohol-based hand sanitizer after contact with infected animals or humans
Avoiding contact with animals that could harbor the virus (including animals that are sick or that have been found dead in areas where monkeypox occurs) and any materials that have been in contact with a sick animal
Isolating infected patients from others who could be at risk for infection
Monkeypox is not considered a sexually transmitted disease, but it can be transmitted through close physical contact, which includes sexual contact. CDC recommends limiting the number of sexual partners to reduce the risk of exposure. If you or a partner think you may have monkeypox, avoid kissing, touching, or sex of any kind (oral, anal, or vaginal) while you are sick.

CDC recommends vaccination for people who have been exposed to monkeypox or may be more likely to get monkeypox. The preferred vaccine to protect against monkeypox is JYNNEOSTM , an attenuated live virus vaccine. Vaccine supply is limited; vaccines may be available through state and local health departments.

Currently, there is no proven, safe treatment for monkeypox virus infection, and treatment focuses on relieving symptoms. Pain management is critical. The majority of patients recover from monkeypox, but it may take 2-4 weeks for the rash to disappear.

Smallpox vaccine, antivirals, and vaccinia immune globulin (VIG) may be used to control the monkeypox outbreak in the US. An experimental antiviral drug (tecovirimat or Tpoxx) is available in the US under “compassionate use.”

If you think you may have monkeypox, talk to a healthcare professional as soon as possible.

Updated August 2022

Source: Centers for Disease Control and Prevention