On 25 May 2021, the United Kingdom of Great Britain and Northern Ireland notified the WHO of one laboratory-confirmed case of monkeypox. The patient arrived in the United Kingdom on 8 May 2021. Prior to travel, the patient had lived and worked in Delta State, Nigeria.
On arrival in the United Kingdom, the patient remained in quarantine with family due to COVID-19 restrictions. On 10 May, the patient developed a rash, beginning on the face. The patient remained in self-isolation for a further ten days and sought medical care for the relief of symptoms. The patient was admitted to a referral hospital on 23 May.
Skin lesion samples were received at the Public Health England Rare and Imported Pathogens Laboratory on 24 May. The West African clade of the monkeypox virus was confirmed by polymerase chain reaction (PCR) on 25 May.
On 29 May, a family member with whom the patient quarantined developed lesions clinically compatible with monkeypox and was immediately isolated in an appropriate facility. Monkeypox was confirmed on 31 May. Both patients are stable and recovering.
The health authorities of the United Kingdom activated an incident management team and implemented public health measures, including isolation of the index case and secondary case and contact tracing of all close contacts in the hospital and community.
According to the World Health Organisation (WHO):
Monkeypox is a sylvatic zoonosis with incidental human infections that usually occur sporadically in forested parts of Central and West Africa. It is caused by the monkeypox virus and belongs to the Orthopoxvirus family. Monkeypox can be transmitted by contact and droplet exposure via exhaled large droplets. The incubation period of monkeypox is usually from 6 to 13 days but can range from 5 to 21 days. The disease is often self-limiting with symptoms usually resolving spontaneously within 14-21 days. Symptoms can be mild or severe, and lesions can be very itchy or painful. Milder cases of monkeypox may go unreported and represent a risk of person-to-person transmission. The animal reservoir remains unknown, although is likely to be among rodents. Contact with live and dead animals through hunting and consumption of wild game or bush meat are known risk factors.
There are two clades of monkeypox virus, the West African clade, and the Congo Basin (Central African) clade. Although the West African clade of monkeypox virus infection sometimes leads to severe illness in some individuals, the disease is usually self-limiting. The case-fatality ratio for the West African clade has been documented to be around 1% whereas for the Congo Basin clade it may be as high as 10%.
Currently in the United Kingdom, including these two cases, there have been only six cases of monkeypox reported, including three previously imported cases from Nigeria, two in September 2018 and one in December 2019. Prior to this report, there was also one case of nosocomial transmission in a health worker in England in 2018 due to contact with the contaminated bed linen. In the present case, the first patient was under quarantine with family members due to COVID-19 restrictions for a period of ten days after arrival in the country and an additional two days. Contacts possibly exposed are being monitored. Once monkeypox was suspected, authorities in the United Kingdom promptly initiated appropriate public health measures, including isolation of the case and contact tracing. The second individual was isolated at home until the onset of the rash and in-hospital care thereafter. The risk of potential onward spread in the country is minimized.
In 2017, Nigeria began to experience its first outbreak in 40 years. From the first cases in September 2017 to November 2019, a total of 183 confirmed cases and 9 deaths were recorded in 18 states (Rivers, Bayelsa, Cross River, Imo, Akwa Ibom, Lagos, Delta, Bauchi, Federal Capital Territory (FCT), Abia, Oyo, Enugu, Ekiti, Nasarawa, Benue, Plateau, Edo, Anambra). The outbreak occurred primarily in southern parts of the country including Delta State. Public health measures included enhanced surveillance and health worker training, as well as isolation of cases, contact tracing, and quarantine. Since then, sporadic cases have continued to occur in Nigeria pointing to the endemicity of the disease.
In 2020, there were 14 suspected cases, three confirmed cases, and no deaths. In 2021, a total of 32 suspected cases have been reported from January and May. Of the suspected cases, 7 were confirmed from five states Delta (2), Bayelsa (2), Lagos (1), Edo (1), Rivers (1), and no deaths were recorded.