Signs and Symptoms of Monkeypox according to WHO

Signs and Symptoms of Monkeypox – Brimestone Academy Inc.

Monkeypox is a viral zoonosis (a virus transmitted to humans from animals) with symptoms similar to those seen in the past in smallpox patients, although it is clinically less severe. With the eradication of smallpox in 1980 and subsequent cessation of smallpox vaccination, monkeypox has emerged as the most important orthopoxvirus for public health. Monkeypox primarily occurs in central and west Africa, often in proximity to tropical rainforests, and has been increasingly appearing in urban areas. Animal hosts include a range of rodents and non-human primates. (Posted by WHO, 19 May 2022)

Monkeypox virus is an enveloped double-stranded DNA virus that belongs to the Orthopoxvirus genus of the Poxviridae family. There are two distinct genetic clades of the monkeypox virus: the central African (Congo Basin) clade and the west African clade. The Congo Basin clade has historically caused more severe disease and was thought to be more transmissible. The geographical division between the two clades has so far been in Cameroon, the only country where both virus clades have been found. (Posted by WHO, 19 May 2022)

• Transmission (zoonotic) can occur through direct contact with the blood, body fluids, or cutaneous or mucosal lesions of infected animals.
• Human-to-human transmission can occur through close contact with respiratory secretions, skin lesions of an infected person or newly contaminated material. Transmission of droplet respiration particles often requires long-term face-to-face contact, which puts health workers, family members and other people close to active cases at high risk.

The incubation period (the time from infection to the onset of symptoms) for monkeypox usually ranges from 6 to 13 days but can range from 5 to 21 days.

The infection can be divided into two periods: (according to World Health Organization)

• 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.

• Vaccines used during the smallpox eradication programme also provided protection against monkeypox. Newer vaccines have been developed of which one has been approved for prevention of monkeypox
• Monkeypox is caused by monkeypox virus, a member of the Orthopoxvirus genus in the family Poxviridae.
• Monkeypox is usually a self-limited disease with the symptoms lasting from 2 to 4 weeks. Severe cases can occur. In recent times, the case fatality ratio has been around 3–6%.
• Monkeypox is transmitted to humans through close contact with an infected person or animal, or with material contaminated with the virus.
• Monkeypox virus is transmitted from one person to another by close contact with lesions, body fluids, respiratory droplets and contaminated materials such as bedding.
• Monkeypox is a viral zoonotic disease that occurs primarily in tropical rainforest areas of central and west Africa and is occasionally exported to other regions.
• An antiviral agent developed for the treatment of smallpox has also been licensed for the treatment of monkeypox.
• The clinical presentation of monkeypox resembles that of smallpox, a related orthopoxvirus infection which was declared eradicated worldwide in 1980. Monkeypox is less contagious than smallpox and causes less severe illness.
• Monkeypox typically presents clinically with fever, rash and swollen lymph nodes and may lead to a range of medical complications.
  (Posted by WHO, 19 May 2022)

Reference: World Health Organization, May 2022