Mpox, formerly known as monkeypox, is a zoonotic disease caused by a DNA virus in the Orthopoxvirus genus, related to smallpox but less severe. First identified in 1958 during pox-like outbreaks in research monkeys, it got its name from these early cases.

The first human case of Mpox was recorded in 1970 in the Democratic Republic of the Congo (DRC). Since the eradication of smallpox in 1980 and the end of global vaccination, Mpox has steadily re-emerged in Central, Eastern and West Africa.

The virus has two main clades (strains): Clade I, mostly found in Central and East Africa, and Clade II, in West Africa. Cameroon is the only country known to harbour both clades. Clade II was responsible for the 2022 outbreak. Now, a new strain, Clade Ib, spreads more easily between people and may cause more severe symptoms, making it the current strain of concern. The mpox cases can now be seen spreading outside of the African continent in Sweden and the Philippines.

Person-to-person transmission of mpox can occur through direct contact with infectious skin or other lesions such as in the mouth or on genitals; this includes contact which is

• face-to-face (talking or breathing)
• skin-to-skin (touching or vaginal/anal sex)
• mouth-to-mouth (kissing)
• mouth-to-skin contact (oral sex or kissing the skin)
• respiratory droplets or short-range aerosols from prolonged close contact

The virus then enters the body through broken skin, mucosal surfaces (e g oral, pharyngeal, ocular, genital, anorectal), or via the respiratory tract. Mpox can spread to other members of the household and to sex partners. People with multiple sexual partners are at higher risk.

Animal to human transmission of mpox occurs from infected animals to humans from bites or scratches, or during activities such as hunting, skinning, trapping, cooking, playing with carcasses, or eating animals. The extent of viral circulation in animal populations is not entirely known and further studies are underway.

People can contract mpox from contaminated objects such as clothing or linens, through sharps injuries in health care, or in community setting such as tattoo parlours.

After exposure, it may be several days to a few weeks before you develop symptoms. Signs of mpox include:

• Fever.
• Rash.
• Swollen lymph nodes.
• Chills.
• Headache.
• Muscle aches.
• Fatigue.

The rash starts as flat, red bumps, which can be painful. Those bumps turn into blisters, which fill with pus. Eventually, the blisters crust over and fall off. The whole process can last two to four weeks. You can get sores on your mouth, face, hands, feet, penis, vagina or anus.

Not everyone with mpox develops all the symptoms. Different ways you might experience symptoms include:

• Only a rash (no other symptoms), or other symptoms developing later.
• Flu-like symptoms, then a rash. Some people don’t get a rash at all.
• A rash can be widespread, but some people only a have few bumps or blisters.

You can have mpox and not know it. Even if you don’t show many signs of infection, it’s possible that you can spread still spread it to others through prolonged close contact.

Identifying mpox can be difficult as other infections and conditions can look similar. It is important to distinguish mpox from chickenpox, measles, bacterial skin infections, scabies, herpes, syphilis, other sexually transmissible infections, and medication-associated allergies. Someone with mpox may also have another sexually transmissible infection such as herpes. Alternatively, a child with suspected mpox may also have chickenpox. For these reasons, testing is key for people to get treatment as early as possible and prevent further spread.

Detection of viral DNA by polymerase chain reaction (PCR) is the preferred laboratorytest for mpox. The best diagnostic specimens are taken directly from the rash – skin, fluid or crusts – collected by vigorous swabbing. In the absence of skin lesions, testing can be done on oropharyngeal, anal or rectal swabs. Testing blood is not recommended. Antibody detection methods may not be useful because they do not distinguish between orthopoxviruses.

The goal of treating mpox is to take care of the rash, manage pain and prevent complications. Early and supportive care is important to help manage symptoms and avoid further problems.

Most people with mpox will recover within 2–4 weeks. Things to do to help the symptoms and prevent infecting others:

Do

• stay home and in your own room if possible
• wash hands often with soap and water or hand sanitizer, especially before or after touching sores
• wear a mask and cover lesions when around other people until your rash heals
• keep skin dry and uncovered (unless in a room with someone else)
• avoid touching items in shared spaces and disinfect shared spaces frequently 
• use saltwater rinses for sores in the mouth
• take sitz baths or warm baths with baking soda or Epsom salts for body sores
• take over-the-counter medications for pain like paracetamol (acetaminophen) or ibuprofen.

Do not

• pop blisters or scratch sores, which can slow healing, spread the rash to other parts of the body, and cause sores to become infected; or
• shave areas with sores until scabs have healed and you have new skin underneath (this can spread the rash to other parts of the body).

To prevent spread of mpox to others, persons with mpox should isolate at home, or in hospital if needed, for the duration of the infectious period (from onset of symptoms until lesions have healed and scabs fall off). Covering lesions and wearing a medical mask when in the presence of others may help prevent spread. Using condoms during sex will help reduce the risk getting mpox but will not prevent spread from skin-to-skin or mouth-to-skin contact.

Available vaccines for Mpox include JYNNEOS® and ACAM2000™, both effective in reducing the risk and severity of Mpox infection. JYNNEOS® is a third-generation vaccine based on a live, attenuated orthopoxvirus known as Modified Vaccinia Ankara (MVA). It is preferred due to its favourable safety profile and ease of administration.

JYNNEOS® is administered as a two-dose series, with the second dose given four weeks after the first.  Maximum protection is achieved two weeks after the second dose. It is recommended for those at high risk of exposure, such as individuals with multiple sexual partners or those who have had close contact with someone infected with Mpox. ACAM2000™ is also available but is generally reserved for healthy, non-pregnant adults when JYNNEOS® is not suitable

Source: Department of Health, Australia

The best time to receive the Mpox vaccine is before exposure, but if someone is exposed, vaccination within four days can significantly reduce the risk of developing the disease. Even after vaccination, individuals should continue practising infection control measures to prevent the spread of Mpox. Side effects from the vaccines are usually mild, such as pain at the injection site, muscle aches, and fatigue, though serious reactions, while rare, can occur.