2022 monkeypox outbreak in Brazil

Monkeypox is an infectious viral disease that can occur in humans and some other animals.[2] Symptoms include fever, swollen lymph nodes, and a rash that forms blisters and then crusts over.[2] The time from exposure to onset of symptoms ranges from five to twenty-one days.[3][4] The duration of symptoms is typically two to four weeks.[4] There may be mild symptoms, and it may occur without any symptoms being known.[3][5] The classic presentation of fever and muscle pains, followed by swollen glands, with lesions all at the same stage, has not been found to be common to all outbreaks.[2][6] Cases may be severe, especially in children, pregnant women or people with suppressed immune systems.[7]

The disease is caused by the monkeypox virus, a zoonotic virus in the genus Orthopoxvirus.[8] The variola virus, the causative agent of smallpox, is also in this genus.[9] Of the two types in humans, clade II (formerly West African clade)[10] causes a less severe disease than the Central African (Congo basin) type.[11] It may spread from infected animals by handling infected meat or via bites or scratches.[12] Human-to-human transmission can occur through exposure to infected body fluids or contaminated objects, by small droplets, and possibly through the airborne route.[2][12] People can spread the virus from the onset of symptoms until all the lesions have scabbed and fallen off; with some evidence of spread for more than a week after lesions have crusted.[11] Diagnosis can be confirmed by testing a lesion for the virus's DNA.[13]

There is no known cure.[14] A study in 1988 found that the smallpox vaccine was around 85% protective in preventing infection in close contacts and in lessening the severity of the disease.[15] A newer smallpox and monkeypox vaccine based on modified vaccinia Ankara has been approved, but with limited availability.[3] Other measures include regular hand washing and avoiding sick people and animals.[16] Antiviral drugs, cidofovir and tecovirimat, vaccinia immune globulin and the smallpox vaccine may be used during outbreaks.[17][18] The illness is usually mild and most of those infected will recover within a few weeks without treatment.[18] Estimates of the risk of death vary from 1% to 10%, although few deaths as a consequence of monkeypox have been recorded since 2017.[19]

An ongoing outbreak of monkeypox, a viral disease, was confirmed in May 2022.[20] The initial cluster of cases was found in the United Kingdom,[21] where the first case was detected in London on 6 May 2022[22] in a patient with a recent travel history from Nigeria (where the disease is endemic).[23] On 16 May, the UK Health Security Agency (UKHSA) confirmed 4 new cases with no link to travel to a country where monkeypox is endemic. All four cases appeared to have been infected in London.[24] From 18 May onwards, cases were reported from an increasing number of countries and regions, predominantly in Europe but also in North and South America, in Asia, in Africa, and in Oceania.[31] The outbreak marks the first time monkeypox has spread widely outside Central and West Africa.

On 23 July, the Director-General of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, declared the outbreak a public health emergency of international concern (PHEIC).[32] As of 15 October, there had been a total of 73,087 confirmed cases in over 109 countries.[33][34]