Monkeypox: Symptoms, Causes, Treatment, and Complications

What is Monkeypox?

Monkeypox is a viral disease caused by the Monkeypox virus, which belongs to the Orthopoxvirus genus. This genus also includes the viruses responsible for smallpox and cowpox, making monkeypox closely related to these better-known diseases. Despite this relation, monkeypox is generally less severe than smallpox and rarely fatal, though it can still cause significant illness, especially in vulnerable individuals.

The virus spreads when a person comes into contact with an infected animal, human, or contaminated materials. Transmission can occur through bites or scratches from animals, direct contact with bodily fluids, or exposure to contaminated objects like bedding or clothing. Human-to-human transmission is less common but can happen through respiratory droplets during prolonged face-to-face contact or close physical contact with infected individuals.

Once inside the body, the virus multiplies and triggers a variety of symptoms, most notably a characteristic rash that progresses through multiple stages, from macules to papules, vesicles, pustules, and finally scabs. The incubation period, or the time between infection and the appearance of symptoms, typically ranges from 5 to 21 days.

History and Background of Monkeypox

Monkeypox was first identified in 1958 when two outbreaks of a pox-like disease occurred in colonies of monkeys kept for research, which is how the disease received its name. Despite this initial identification in monkeys, subsequent research revealed that monkeys are not the primary natural hosts. Instead, the virus is believed to circulate mainly among rodents and other small mammals in certain regions of Central and West Africa.

The first known human case of monkeypox was reported in 1970 in the Democratic Republic of Congo, during a period when efforts to eradicate smallpox were ongoing. Since then, the disease has been primarily confined to rural areas of Central and West Africa, where humans come into closer contact with wildlife. For decades, monkeypox remained relatively rare outside these endemic regions, with most cases linked to animal exposure rather than human-to-human transmission.

However, the early 21st century saw notable changes in the disease’s pattern. Sporadic outbreaks began appearing outside Africa, first in the United States in 2003, when imported exotic animals from Africa transmitted the virus to humans. In recent years, global travel and trade have increased the risk of monkeypox spreading to non-endemic countries, drawing international attention.

Causes and Transmission of Monkeypox

Monkeypox is caused by the Monkeypox virus, a member of the Orthopoxvirus genus. This virus is closely related to the smallpox virus but is generally less severe in humans. The primary cause of monkeypox is infection with this virus, which can enter the human body through direct contact with infected animals, contaminated materials, or, in some cases, through human-to-human transmission.

The natural reservoirs of the virus are believed to be certain species of rodents and small mammals, such as squirrels, Gambian pouched rats, and dormice, which carry the virus without necessarily showing symptoms. Humans typically contract the virus when they come into close contact with these infected animals, either through bites, scratches, or handling of animal meat.

Symptoms and Clinical Presentation of Monkeypox

The first signs usually appear within 5 to 21 days after exposure, which is the incubation period of the virus. Early symptoms include fever, intense headache, muscle aches, back pain, and profound fatigue. Some patients may also experience swollen lymph nodes, a feature that distinguishes monkeypox from similar viral illnesses such as chickenpox or smallpox. Swollen lymph nodes often occur in the neck, armpits, or groin and may persist throughout the illness.

A few days after the onset of fever, a distinctive rash emerges, typically starting on the face before spreading to other parts of the body, including the palms of the hands and soles of the feet. The rash progresses through multiple stages. Initially, it appears as flat, red spots known as macules. These then evolve into raised bumps called papules, which subsequently fill with clear fluid to form vesicles. The vesicles eventually become pustules, which are filled with thick, yellowish fluid. Finally, the pustules dry out, form scabs, and eventually fall off as the skin heals. The entire rash progression usually lasts two to four weeks. In addition to the rash, patients may experience other systemic symptoms such as chills, sore throat, and general malaise.

Diagnosis of Monkeypox

The diagnostic process begins with a detailed medical history, including potential exposure to infected animals or contact with individuals showing symptoms. Information about recent travel to endemic areas or interaction with wildlife can provide important clues. Physicians also examine the characteristic rash, noting its distribution, progression, and appearance of lesions at different stages—macules, papules, vesicles, pustules, and scabs.

Polymerase chain reaction (PCR) testing is the most reliable method, detecting viral DNA from samples collected from skin lesions, swabs, or crusts. Other laboratory tests may include serological assays to detect antibodies against the virus, although these are less specific and more useful for retrospective confirmation.

Treatment Options for Monkeypox

Currently, there is no specific, universally approved antiviral treatment for monkeypox, and management primarily focuses on supportive care and symptom relief. Most cases of monkeypox are mild and self-limiting, resolving within two to four weeks without the need for intensive medical intervention.

Supportive care : Patients are encouraged to rest and maintain adequate hydration to prevent dehydration caused by fever, sweating, or loss of appetite. Pain and fever can be managed with over-the-counter medications such as acetaminophen or ibuprofen, while antihistamines may help reduce itching associated with the rash. Proper skin care is important to prevent secondary bacterial infections; lesions should be kept clean and covered, and patients should avoid scratching.

Vaccines developed for smallpox, such as the Modified Vaccinia Ankara (MVA) vaccine, can provide protection against monkeypox and may be recommended for high-risk populations or as post-exposure prophylaxis to reduce disease severity.