Monkeypox

What is Monkeypox?

Monkeypox is a rare disease caused by the monkeypox virus. It leads to rash and flu-like symptoms. Like the better known virus that causes smallpox, it is a member of the family called orthopoxvirus.

Monkeypox was discovered in 1958 when two outbreaks of a pox-like disease occurred in groups of monkeys being used for research. It’s spread mainly through human contact with infected rodents, but can sometimes be spread through skin-to-skin contact with an infected person. There are two known types (clades) of monkeypox virus — one that originated in Central Africa and one that originated in West Africa. The current world outbreak (2022) is caused by the less severe West African clade.

Signs and symptoms

The incubation period (interval from infection to onset of symptoms) of monkeypox is usually from 6 to 13 days but can range from 5 to 21 days.

The infection can be divided into two periods:

the invasion period (lasts between 0–5 days) characterized by fever, intense headache, lymphadenopathy (swelling of the lymph nodes), back pain, myalgia (muscle aches) and intense asthenia (lack of energy). Lymphadenopathy is a distinctive feature of monkeypox compared to other diseases that may initially appear similar (chickenpox, measles, smallpox)

the skin eruption usually begins within 1–3 days of appearance of fever. The rash tends to be more concentrated on the face and extremities rather than on the trunk. It affects the face (in 95% of cases), and palms of the hands and soles of the feet (in 75% of cases). Also affected are oral mucous membranes (in 70% of cases), genitalia (30%), and conjunctivae (20%), as well as the cornea. The rash evolves sequentially from macules (lesions with a flat base) to papules (slightly raised firm lesions), vesicles (lesions filled with clear fluid), pustules (lesions filled with yellowish fluid), and crusts which dry up and fall off. The number of lesions varies from a few to several thousand. In severe cases, lesions can coalesce until large sections of skin slough off.

Vaccination

Vaccination against smallpox was demonstrated through several observational studies to be about 85% effective in preventing monkeypox. Thus, prior smallpox vaccination may result in milder illness. Evidence of prior vaccination against smallpox can usually be found as a scar on the upper arm. At the present time, the original (first-generation) smallpox vaccines are no longer available to the general public. Some laboratory personnel or health workers may have received a more recent smallpox vaccine to protect them in the event of exposure to orthopoxviruses in the workplace. A still newer vaccine based on a modified attenuated vaccinia virus (Ankara strain) was approved for the prevention of monkeypox in 2019. This is a two-dose vaccine for which availability remains limited. Smallpox and monkeypox vaccines are developed in formulations based on the vaccinia virus due to cross-protection afforded for the immune response to orthopoxviruses.

Prevention

Raising awareness of risk factors and educating people about the measures they can take to reduce exposure to the virus is the main prevention strategy for monkeypox. Scientific studies are now underway to assess the feasibility and appropriateness of vaccination for the prevention and control of monkeypox. Some countries have, or are developing, policies to offer vaccine to persons who may be at risk such as laboratory personnel, rapid response teams and health workers.

Reducing the risk of human-to-human transmission

Surveillance and rapid identification of new cases is critical for outbreak containment. During human monkeypox outbreaks, close contact with infected persons is the most significant risk factor for monkeypox virus infection. Health workers and household members are at a greater risk of infection. Health workers caring for patients with suspected or confirmed monkeypox virus infection, or handling specimens from them, should implement standard infection control precautions. If possible, persons previously vaccinated against smallpox should be selected to care for the patient.

Samples taken from people and animals with suspected monkeypox virus infection should be handled by trained staff working in suitably equipped laboratories. Patient specimens must be safely prepared for transport with triple packaging in accordance with WHO guidance for transport of infectious substances.

Preventing monkeypox through restrictions on animal trade

Some countries have put in place regulations restricting importation of rodents and non-human primates. Captive animals that are potentially infected with monkeypox should be isolated from other animals and placed into immediate quarantine. Any animals that might have come into contact with an infected animal should be quarantined, handled with standard precautions and observed for monkeypox symptoms for 30 days.

The monkeypox rash usually develops within one to three days after fever. However, some people may experience a rash or sores first, followed by other symptoms. Some people may also only develop a rash. Most people who have monkeypox recover without needing treatment within two to four weeks.

How common is monkeypox?

Monkeypox is rare. But the number of cases is increasing in Africa, as well as in regions that haven’t seen these infections before.

Who does monkeypox affect?

Anyone can get monkeypox. In Africa, most cases are among children under 15 years old. Outside of Africa, the disease appears to be more common in men who have sex with men, but there are numerous cases in people who don’t fall into that category.

How do you catch monkeypox?

Monkeypox is spread when you come into contact with an animal or a person infected with the virus. Animal-to-person transmission occurs through broken skin, like from bites or scratches, or through direct contact with an infected animal’s blood, bodily fluids or pox lesions (sores).

Monkeypox can spread from person to person, but it’s less common. Person-to-person spread (transmission) occurs when you come in contact with the sores, scabs, respiratory droplets or oral fluids of an infected person usually through close, intimate situations like cuddling, kissing or sex. Research is ongoing, but researchers aren’t sure if the virus is transmitted through semen or vaginal fluids.

You can also get monkeypox by coming into contact with recently contaminated materials like clothing, bedding and other linens used by an infected person or animal.

How do you prevent monkeypox virus?

A smallpox vaccine provides protection against monkeypox, but its use is currently limited to clinical trials. Prevention depends on decreasing human contact with infected animals and limiting person-to-person spread. The best way to help prevent spread the monkeypox virus is to:

• Avoid contact with infected animals (especially sick or dead animals).
• Avoid contact with bedding and other materials contaminated with the virus.
• Thoroughly cook all foods that contain animal meat or parts.
• Wash your hands frequently with soap and water.
• Avoid contact with people who may be infected with the virus.
• Practice safe sex, including the use of condoms and dental dams.
• Wear a mask that covers your mouth and nose when around others.
• Clean and disinfect frequently touched surfaces.
• Use personal protective equipment (PPE) when caring for people infected with the virus.

How long does monkeypox last?

Monkeypox normally takes about two to four weeks to run its course. If you are exposed to monkeypox, your provider will monitor you until the rash resolves.

How do I take care of myself?

If have monkeypox symptoms, there are over-the-counter medications that can help you feel better, including:

• Pain relievers and fever reducers. Medicines like ibuprofen (Advil®, Motrin®) and acetaminophen (Tylenol®) can help you feel better.
• Oatmeal baths. Soaking in a warm bath with colloidal oatmeal can relieve the dry, itchy feeling that comes with skin rashes.
• Isolate yourself if you’re infected. Avoid contact with others until all your lesions have scabbed.
• Cover single or local lesions. Use gauze or bandages to limit spread to others and the environment.
• Take good care. It’s important to stay home and rest when you’re sick, wear a mask around others and drink plenty of fluids.
• Avoid contact with pets (especially rodents).

When should I see my healthcare provider?

Call your healthcare provider if you:

• Feel sick with fever, aches or swollen lymph nodes.
• Have a new rash or sores.
• Have been in close contact with an infected person.

When should I go to the ER?

Seek medical care if you develop the following symptoms:

• Trouble breathing.
• New or worsening chest pain.
• Stiff neck.
• Are confused or can’t think clearly.
• Difficulty speaking or moving.
• Loss of consciousness.
• Seizures.