On 23 July 2022, the World Health Organization (WHO) declared the outbreak a Public Health Emergency of International Concern (PHEIC) with more than 53,000 reported cases in 75 countries and territories. Signs and symptoms
It is possible for a person to be infected with monkeypox without showing any symptoms. Monkeypox symptoms tend to begin 5 to 21 days after infection, with early symptoms including headache, muscle pains, fever and fatigue, initially resembling influenza. Within a few days of the fever, lesions characteristically appear on the face before appearing on the trunk then elsewhere such as palms of the hands and soles of the feet. The disease can resemble chickenpox, measles and smallpox but is distinguished by the presence of swollen glands which may appear behind the ear, below the jaw, in the neck or in the groin, before the onset of the rash. Many cases in the 2022 monkeypox outbreak presented with genital and peri-anal lesions, fever, swollen lymph nodes, and pain when swallowing, with  some patients manifesting only single sores from the disease.Three-quarters of affected people have lesions on the palms and soles, more than two-thirds in the mouth, a third on the genitals and one in five have lesions in the eyes. They begin as small flat spots, before becoming small bumps which then fill with at first clear fluid and then yellow fluid, which subsequently burst and scab over, persisting for around ten days. There may be a few lesions or several thousand, sometimes merging to produce large lesions.
2017–2019 Nigeria outbreak
According to the Nigeria Centre for Disease Control (NCDC), between 1971 and 1978, only 10 human monkeypox infections were reported in the country.In September 2017, human monkeypox re-emerged in Nigeria, 39 years since it had been last reported. The subsequent 2017–18 Nigerian human monkeypox outbreak was, at that time, the largest ever outbreak of clade II of the virus, with 118 confirmed cases. Unlike previous outbreaks of this clade, infection was predominantly among young male adults and human-to-human transmission appears to have readily occurred. Seven deaths (5 male, 2 female, case fatality rate of 6%) were reported, including a baby and four HIV/AIDS patients. Additionally, a pregnant woman in her second trimester had a spontaneous miscarriage due to monkeypox infection.The Niger Delta University Teaching Hospital reported that a substantial number of its young adult cases had concomitant genital ulcers, syphilis and HIV infection. Monkeypox spread around southeast and south Nigeria with some states and the federal government of Nigeria seeking ways to contain it. By December 2017 it spread to Akwa Ibom, Abia, Bayelsa, Benue, Cross River, Delta, Edo, Ekiti, Enugu, Imo, Lagos, Nasarawa, Oyo, Plateau, Rivers and Federal Capital Territory. The outbreak started in September 2017 and remained ongoing across multiple states as of May 2019. The Centers for Disease Control and Prevention reported cases of American travelers contracting Monkeypox upon return from Lagos and Ibadan.