Portuguese health authorities on Wednesday confirmed five cases of monkeypox – a rare viral infection related to smallpox – in young men, marking an unusual outbreak in Europe of a disease typically limited to Africa.
Portugal’s General Directorate for Health added it was investigating another 15 suspected cases and that all were identified this month around the capital Lisbon.
All the Portuguese cases involve men, most of them young, authorities said.
They have skin lesions and were reported to be in stable condition. Authorities did not say if the men had a history of travel to Africa or any links with recent cases in Britain or elsewhere.
British health authorities said on Monday they had identified four cases of monkeypox infections in London among gay and bisexual men, bringing the total to seven.
Spain’s Health Ministry said on Wednesday it had also detected eight suspected cases of monkeypox that still needed to be confirmed.
How did this outbreak start?
The UK Health Security Agency (UKHSA) was the first health authority in Europe to publicly report a case of monkeypox on May 7, in a person who had recently flown into the UK from Nigeria.
Since then it has confirmed six more cases and said it was investigating links among four of them, who all appear to have been infected in London and all self-identify as gay, bisexual, or other men who have sex with men.
« We are particularly urgent men who are gay and bisexual to be aware of any unusual rashes or lesions and to contact a sexual health service without delay, » said Dr Susan Hopkins, the agency’s chief medical adviser.
The UKHSA recommended particularly looking out for lesions on genitalia.
Britain previously reported three earlier cases of monkeypox, two involving people who lived in the same household and the third someone who had traveled to Nigeria, where the disease occurs frequently in animals.
What are the symptoms of monkeypox?
Monkeypox is a relative of smallpox, a disease that was eradicated in 1980, but is less transmissible, causes milder symptoms and is less deadly.
The illness typically lasts for two to four weeks and symptoms can appear anywhere from five to 21 days after infection.
Monkeypox symptoms usually begin with a mix of fever, headaches, muscle aches, backache, chills, exhaustion, and swollen lymph nodes.
This latter symptom is typically what helps doctors distinguish monkeypox from chickenpox or smallpox, according to the World Health Organization (WHO).
Once you have a fever, the key feature of monkeypox, a nasty rash, tends to develop one to three days later, often starting on the face and then spreading to other parts of the body.
The number of lesions may range from a few to thousands.
The lesions will go through an ugly ripening process, from macules (flat lesions) to papules (raised lesions), vesicles (fluid-filled lesions), then pustules (pus-filled lesions) and then finally scabs (crusty lesions) before eventually falling off.
Why is it called monkeypox?
Monkeypox virus belongs to the Orthopoxvirus genus in the family Poxviridae. It was first discovered in 1958 when two outbreaks of a pox-like disease occurred in lab monkeys kept for research, hence the name.
But monkeys might not be the ones to blame for outbreaks, and the natural reservoir of monkeypox remains unknown, though the WHO says rodents are the most likely.
“In Africa, evidence of monkeypox virus infection has been found in many animals including rope squirrels, tree squirrels, Gambian poached rats, dormice, different species of monkeys,” says the UN health agency.
Where is monkeypox typically found?
Human monkeypox primarily causes outbreaks in the tropical rainforest regions of Central and West Africa and is not typically seen in Europe.
The Democratic Republic of the Congo (DRC) had the first recorded human case of monkeypox in 1970.
Since then, cases have been reported in 11 African countries: Benin, Cameroon, the Central African Republic, the Democratic Republic of the Congo, Gabon, Ivory Coast, Liberia, Nigeria, the Republic of the Congo, Sierra Leone, and South Sudan.
The first outbreak of monkeypox reported outside of Africa was linked to the importation of infected mammals in 2003 in the United States, according to the US Centers for Disease Control and Prevention (CDC).
More recently, in 2018 and 2019, two travelers from the United Kingdom, one from Israel, and one from Singapore, all with travel history in Nigeria, were diagnosed with monkeypox following a large outbreak there, according to Europe’s own health agency, the European Center for Disease Prevention and Control (ECDC),
How do you catch monkeypox?
You can catch the virus from the bite or scratch of an infected animal, by eating bush meat, being in direct contact with an infected human or touching contaminated bedding or clothing.
The virus enters the body through skin lesions, the respiratory tract, or the mucous membranes (the eyes, nose, or mouth).
Human-to-human transmission is thought to occur primarily through large respiratory droplets, which generally cannot travel more than a few feet, so prolonged face-to-face contact would be needed.
Some British experts commenting on the recent UK outbreak said it was soon to conclude that monkeypox had spread through sexual contact, but that it was a possibility.
« The recent cases suggest a potentially novel means of spread, » said Neil Mabbott, a disease expert at the University of Edinburgh, adding that related viruses were known to spread via sex.
Keith Neal, an infectious diseases expert at the University of Nottingham, said the transmission might not have occurred through sexual activity but just “the close contact associated with sexual intercourse ».
Should I be worried?
Monkeypox “is usually a mild self-limiting illness and most people recover within a few weeks,” the UKHSA said in its statement.
“It is important to emphasize that monkeypox does not spread easily between people and the overall risk to the general public is very low,” said Dr Colin Brown, the agency’s director of clinical and emerging infections.
The patients infected in England contracted the West African clade of the virus, which health officials say is mild compared to the Central African clade and has a case fatality ratio of around 1 per cent.
Although its symptoms are milder than those of smallpox, monkeypox has been shown to cause death in as many as 10 per cent of patients infected with the Congo Basin clade, compared to about 30 per cent for smallpox, according to WHO data.
Mortality is higher among children and young adults, and immunocompromised individuals are especially at risk of severe disease.
Monkeypox during pregnancy may also lead to complications, congenital monkeypox, or stillbirth, the WHO warned on Monday.
« Milder cases of monkeypox may go undetected and represent a risk of person-to-person transmission, » it said in a statement.
Treatment and prevention
There is currently no specific treatment recommended for monkeypox, and it usually goes away on its own.
Vaccination against smallpox is believed to be highly effective in preventing monkeypox, but because smallpox was declared eradicated more than 40 years ago, first-generation smallpox vaccines are no longer available to the general public.
A newer vaccine developed by Bavarian Nordic for the prevention of smallpox and monkeypox has been approved in the European Union, the United States and Canada (under the trade names Imvanex, Jynneos and Imvamune), and antivirals are also under development.