Monkeypox is caused by a virus called orthopoxvirus. The virus was discovered in the late 1950s in a research laboratory in Copenhagen among monkeys imported from Singapore (hence the name). The first cases among humans were identified in the Democratic Republic of Congo in 1970. It has since been discovered that the largest reservoir of the virus is among rodents and squirrels on the African continent. The virus can be transmitted from animals to humans (a zoonotic disease), including through contact with infected rodents or by consuming undercooked meat. In May 2022, an outbreak among humans started in Europe and other parts of the world.
The disease is characterized by a rash, ranging from a few to many small pox-like skin lesions measuring 2-5 mm each. Individuals with monkeypox may also experience fever, swollen and tender lymph nodes, headache, fatigue, and muscle aches.
The rash is often localized to areas of skin contact, including around the mouth, hands, genitals, and around the anus. These skin lesions change over time, starting as red spots and progressing to fluid-filled or pus-filled lesions, and eventually crusted sores. The rash can be itchy and painful. Like any open sores, monkeypox lesions can become infected with other microorganisms such as Staphylococcus aureus and herpes viruses.
Recently, there have been increasing reports of monkeypox virus infections presenting as isolated pharyngitis or proctitis. Patients experience soreness and pain in the affected areas.
The typical course of the disease lasts from two to four weeks. However, children and immunocompromised individuals have a higher risk of prolonged and/or severe illness. There have been few deaths caused by the monkeypox virus.
Monkeypox is diagnosed by obtaining brush samples from the rash, which are sent for PCR testing. The virus can also be detected from throat and rectal swabs in some cases.
Monkeypox primarily spreads through direct contact (skin-to-skin or mucous membrane contact) over time among household members or individuals with intimate contact, regardless of sexual orientation. The virus is also found in the respiratory tract and can be released as large droplets, posing a risk of transmission at close range. Monkeypox can also, rarely, be transmitted indirectly through objects, textiles, and surfaces.
The time from exposure to onset of symptoms can vary. It is most commonly one to two weeks but can take up to three weeks.
An individual is contagious from the onset of symptoms until the scabs have fallen off and new skin has formed underneath.
Monkeypox is usually self-limiting, and most infected individuals recover without treatment within a few weeks. However, the pox lesions can leave pigmentation changes and scars on the skin. Treatment with antiviral drugs is recommended in some cases.
Monkeypox can partially resemble various sexually transmitted infections, including genital herpes, syphilis, and lymphogranuloma venereum (LGV). The skin lesions can also be confused with common conditions such as varicella (chickenpox), herpes zoster (shingles), and bacterial skin infections.
Transmission is largely associated with sexual activity. The risk of transmission can be reduced through safer sex practices.
The virus has been detected in the body for an extended period after recovering from the disease, but it is uncertain whether it represents live virus or dead virus remnants. Therefore, it is recommended to use condoms for 12 weeks after recovering from the disease.
Travelers to areas where monkeypox is endemic should avoid contact with rodents. It is also advisable to avoid consuming undercooked meat.
