Monkeypox infection is a viral zoonotic (animal to human transmission) disease caused by the monkeypox virus which is part of the Orthopoxvirus genus of viruses, which includes smallpox (variola virus). The monkeypox virus was first identified in 1958 in monkeys, which is how the name was derived, and the first case in people was recorded in 1970 in the Democratic Republic of the Congo during the smallpox eradication efforts.
Historical genetic testing has shown that the monkeypox virus mutates slowly over time and having received a smallpox vaccination within the prior 3 years is estimated to be 85% effective in preventing monkeypox infection. However global vaccination for smallpox stopped in the 1970s when smallpox was eradicated globally. Since the 1990s the number of monkeypox cases has steadily increased as detection has improved. Global travel has increased the spread of diseases, children are no longer being vaccinated for smallpox, and adults experience waning immunity over time.
As of May 24, 2022 there is currently an outbreak of Monkeypox with 250 confirmed and suspected cases reported in 16 countries including the regions of North America, Europe, and Australia. Approximately 1/3 of infected people required hospitalisation, suggesting there are more cases where people have milder symptoms and have not sought medical care.
Reservoir:
The natural reservoir is not established but believed to involve rodents. However efforts to find the virus in rodents and
other animals have only rarely found the virus. It is possible there is another yet to be identified reservoir that is the primary reservoir, but the reservoir is not believed to be people.