Monkeypox was first identified in 1958 among monkeys used for laboratory studies.

The first human case was reported in 1970 in a nine-month-old boy in Zaire, present-day Democratic Republic of Congo.

Since then, monkeypox has become endemic in the Democratic Republic of Congo and has spread to other African countries, primarily in Central and West Africa.

The first recorded outbreak outside Africa occurred in the United States in 2003, and since 2018, cases have been reported in various countries across Europe, North America, and Australia.

The majority of confirmed cases outside endemic regions involve men who have sex with men (MSM), as noted by health authorities.

Recently, North Macedonia confirmed its first case of monkeypox, coinciding with reports of a new variant of the monkeypox virus detected in Europe.

Health organizations have reiterated that monkeypox remains a concern for public health globally.

Monkeypox is caused by a virus that belongs to the Poxviridae family, in the Orthopoxvirus genus, which also includes variola virus (responsible for smallpox), vaccinia virus, and cowpox virus.

There are two distinct genetic clades of monkeypox virus: the Central African clade (Congo basin) and the West African clade.

The Congo basin strains have demonstrated higher transmissibility and have been associated with more severe clinical presentations.

The natural reservoir of monkeypox is still unknown, although African rodents are suspected to play a significant role in transmission.

The virus has been found in several other animals, including squirrels, Gambian rats, dormice, and various species of monkeys.

Transmission of monkeypox can occur from animals to humans or between humans through direct contact (including bites or scratches, contact with bodily fluids or lesion material, and respiratory droplets); sexual contact is also a possible route.

Indirect transmission may occur through consumption of inadequately cooked meat or contact with contaminated objects and clothing.

Human-to-human transmission typically requires prolonged face-to-face contact with an infected individual.

Vertical transmission is also possible, where the virus can cross from mother to fetus through the placenta or during close contact during and after delivery.

The average incubation period lasts from 6 to 13 days, but it can vary between 5 and 21 days.

Infected individuals are contagious from one day before the onset of rash until 21 days after the initial symptoms or until all lesions have crusted over and other symptoms have resolved.

During the incubation period, affected individuals are not contagious.

Clinically, monkeypox symptoms are similar to smallpox but are generally milder.

Initial symptoms include fever, chills, headache, muscle and back pain, fatigue, and sometimes cough and sore throat.

The main distinguishing feature of monkeypox compared to smallpox is the swelling of lymph nodes (lymphadenopathy).

Lymph nodes may become enlarged in the neck, armpits, or groin, observed on either side of the body.

Within 1 to 3 days (or longer) after the onset of fever, the patient develops a rash, typically beginning on the face (in 95% of cases) and then spreading to the extremities (with palms and soles involved in 70% of cases) and other parts of the body, including the oral mucosa, genitalia, conjunctiva, and cornea.

The rash stage concludes with crusting, which eventually falls off, sometimes leaving scars or pigmentation changes.

The illness usually lasts between 2 to 4 weeks.

In diagnosing the disease, other conditions accompanied by rashes must be considered, such as varicella (chickenpox), measles, bacterial skin infections, scabies, and syphilis.

The presence of lymphadenopathy may be a clinical characteristic distinguishing monkeypox from chickenpox and smallpox.

Potential complications include encephalitis, severe dehydration due to vomiting and diarrhea or difficulty drinking due to lesions in the mouth, tonsillitis, pharyngitis, eyelid swelling, and conjunctivitis.

Respiratory tract complications are rare.

The diagnosis of monkeypox is confirmed using polymerase chain reaction (PCR) testing, which is the primary laboratory test due to its sensitivity and specificity.

Samples are typically taken from skin lesions (blood or fluid from vesicles and pustules, and crusts), and a biopsy can be performed when feasible.

Currently, there is no specific treatment for monkeypox; management is symptomatic and usually leads to complete recovery.

Preventive measures include avoiding unprotected contact with wild animals, particularly sick or dead ones; proper cooking of animal products; and hand hygiene after contact with infected individuals or animals.

Patients with monkeypox should be isolated, whether in healthcare settings or home conditions, with monitoring and supervision of contacts.

Vaccination remains critical.

The smallpox vaccine (first-generation) is approximately 85% effective in preventing monkeypox but is no longer widely available.

A newer vaccine based on a modified live vaccinia virus was approved in 2019 specifically for monkeypox prevention.

This two-dose vaccine is available in limited quantities, primarily for individuals at high risk of exposure, including laboratory workers and first responders.