Monkeypox is a rare disease caused by infection with the virus of the same name. Monkeypox virus belongs to the genus Orthopoxvirus of the family Poxviridae. This genre also includes:
- Variola virus (causes smallpox),
- Vaccinia virus (used in the smallpox vaccine) and
- The cowpox virus.
Monkeypox was first discovered in 1958 when two outbreaks of a smallpox-like disease occurred in colonies of monkeys used for research, hence the name "monkeypox."
During a period of efforts to eliminate the smallpox virus, the first human case of monkeypox was recorded in the Democratic Republic of the Congo in 1970. Since then, cases of monkeypox have been reported in people from several other West and Central African countries (Cameroon, Central African Republic, Côte d'Ivoire, Democratic Republic of the Congo, Gabon, Liberia, Nigeria, Republic of the Congo, and Sierra Leone) . But most of the infections have been in the Democratic Republic of the Congo.
Cases of monkeypox have occurred in people outside of Africa related to international travel or imported animals, including cases in Europe, the United States, as well as in Israel and Singapore.
The natural reservoir of monkeypox is unknown. However, African rodents and non-human primates are thought to harbor the virus and infect people.
What are the signs and symptoms of monkeypox?
In humans, the symptoms of monkeypox are similar to but milder than the symptoms of smallpox. Monkeypox begins with muscle aches, exhaustion, fever, and headache.
The main difference between the symptoms of smallpox and monkeypox is that monkeypox causes the lymph nodes to swell (lymphadenopathy), while smallpox does not. The incubation period (time from infection to symptoms) for monkeypox is usually 7 to 14 days, but can range from 5 to 21 days.
The disease begins with:
- Fever
- Headache
- Muscle pains
- Back pain
- Swollen lymph nodes
- Chills
- Exhaustion
Within 1 to 3 days (or more) after the first symptoms, the patient develops a rash, which often begins on the face and then spreads to other parts of the body. The lesions progress through the following stages before fall down:
- Macules
- Papules
- vesicles
- Pustules
- Crusts
The duration of the disease is usually 2 to 4 weeks.