The first cases in which the monkeypox virus was transmitted within a hospital and within a family, outside of Africa, have been recorded by doctors in the UK.
One case occurred in a healthcare worker 18 days after initial exposure to the virus, while two further cases involved household transmission within a family who had travelled to the UK from Nigeria.
The cases are among seven included in a retrospective study of monkeypox patients in the UK between 2018 and 2021, published in The Lancet Infectious Diseases journal.
There have been 131 confirmed monkeypox cases and 106 further suspected cases since the first case was reported on May 7th outside the countries where it usually spreads, the World Health Organisation said on Tuesday.
The Lancet study suggests antivirals may have the potential to shorten symptoms and reduce the amount of time a patient is contagious.
The authors say further research into antivirals as a treatment for monkeypox is urgently needed.
"Our study offers some of the first insights into the use of antivirals for the treatment of monkeypox in humans," said Dr Hugh Adler of the Liverpool University Hospitals NHS Foundation Trust, lead author on the paper. "Although this latest outbreak has affected more patients than we had previously encountered in the UK, historically monkeypox has not transmitted very efficiently between people, and overall the risk to public health is low."
On Tuesday, the Health Protection Surveillance Centre said there are no known monkeypox cases in Ireland at present.
Recent cases of monkeypox have been detected in the UK and other European countries, North America, Israel and Australia.
“The vast majority of these cases do not have a travel link to a country where monkeypox is endemic. Several of the cases were diagnosed in sexual health clinics and self-identify as gay, bisexual or other men who have sex with men,” the HPSC said.
The HSE has set up a multidisciplinary incident management team to prepare for the possible arrival of monkeypox, and infectious diseases experts are on alert for patients with symptoms of the virus.
What is monkeypox?
Monkeypox is spread via animal-to-human transmission, typically from an animal bite or eating improperly cooked meat. In rare cases, the virus can spread via human-to-human transmission. The first human case of monkeypox was reported in 1970 in the Democratic Republic of the Congo and rarely occurs outside central and western African countries.
There are two types of monkeypox: West African monkeypox and Congo Basin monkeypox. The Congo Basin type is more severe, but only the milder, west African type has been spread to countries outside Africa.
Infection can be spread from person-to-person through contact with bodily fluids and skin lesions of a monkeypox case.
Monkeypox is not very infectious, the HPSC says, as it takes close physical contact to spread between people.
“Contact with close family members or sexual contact poses the biggest risks of person-to-person spread. The risk of spread within the community, in general, is very low,” it advises.
Initial symptoms include fever, headache, muscle aches, backache, swollen lymph nodes, chills and exhaustion. The virus causes a rash that starts out on the face before spreading on the body. Raised red spots quickly develop into little blisters, typically within one to three days of fever onset.
The HPSC says monkeypox infection is usually a self-limiting illness and most people recover within weeks, although severe illness can occur in people with very weak immune systems, and in very small babies.