The World Health Organization (WHO) has now confirmed nearly 100 cases of monkeypox in over a dozen countries, with the highest number in the UK. While most cases so far have been among gay and bisexual men, health officials emphasize that anyone can contract the virus through close personal contact.
The UK Health Security Agency (UKHSA) on May 7 reported the first case of the current outbreak in a man who recently traveled to Nigeria, where monkeypox is endemic. This was soon followed by two more cases sharing a household and four cases in gay and bisexual men, all of whom appear to have contracted the virus locally. As of May 23, the UKHSA has reported 70 confirmed cases in England and one in Scotland.
The latest WHO update, May 21, lists 92 confirmed and 28 suspected cases. After the UK, most cases were reported in Spain and Portugal, with lower numbers in several other European countries, Canada, the United States and Australia. An informal Global.health tally compiled from various sources lists more than 300 confirmed or suspected cases worldwide as of May 25.
According to the WHO, previous cases have been “mainly, but not exclusively, identified in men who have sex with men”. Among the Global.health cases with known sex and age, all but three are young or middle-aged males. Many of the men involved identify as gay or bisexual, or sought help from sexual health clinics. Several cases are said to be linked to a sauna in Spain and a fetish festival in Belgium. Many of the men reported recent trips abroad.
Monkeypox, which is related to smallpox, is not a new disease. Despite its name, it is most commonly associated with rodents. Although occurring primarily in central and western Africa, isolated cases are occasionally reported in Europe and elsewhere, often involving travellers. The current outbreak is the largest ever seen outside of Africa.
Smallpox vaccination also prevents monkeypox, and cases of monkeypox have risen in recent decades since routine smallpox vaccination was discontinued. In 1980, the WHO declared that smallpox had been eradicated worldwide. This means that only older people have vaccine-induced immunity.
Monkeypox is less severe than smallpox and typically causes flu-like symptoms (eg, fever, fatigue, muscle pain), swollen lymph nodes, and skin rash. The rash can appear on the face, genitals, palms, soles of the feet, and other parts of the body. The sores can be flat, raised, or filled with pus and resemble other conditions, such as herpes, syphilis, or chickenpox. In the current outbreak, several cases initially presented with a genital rash, and some reported no other symptoms. The virus has an incubation period of up to three weeks, and the disease typically lasts two to four weeks.
The monkeypox virus is transmitted through close personal contact, including skin contact and kissing. Close contact can involve household members and medical staff. The virus can also spread through clothing or bedding that has come into contact with wound fluid. Monkeypox can be transmitted via respiratory droplets at close range, health officials said, but the virus doesn’t appear to travel longer distances through the air like the SARS-CoV-2 coronavirus that causes COVID-19.
Monkeypox is not generally considered a sexually transmitted infection, and it is not known if it can be transmitted through semen through sexual intercourse. “Monkeypox is not a sexually transmitted infection in the typical sense, but it can be transmitted through sexual and intimate contact,” said Dr. John Brooks, an epidemiologist with the US Centers for Disease Control and Prevention, during a May 23 news conference.
Experts historically thought monkeypox wasn’t easily transmitted between humans, and it’s unclear why it’s now spreading more widely. Some have suggested that the virus might have evolved to be more easily transmissible, but so far genetic sequencing does not support this hypothesis. It is more likely that the virus got into a social or sexual network by accident and found favorable transmission conditions.
Public health advice
Health authorities are urging anyone with an unusual rash or lesions on any part of their body, especially their genitals, to contact their doctor or a sexual health clinic. People who suspect they may have monkeypox are advised to refrain from close social contact until they are tested. Contacts of known high-risk cases should isolate and self-monitor for symptoms for up to 21 days. People with confirmed monkeypox should isolate themselves, abstain from sexual activity and avoid close physical contact until the rash has completely healed, according to the European Center for Disease Prevention and Control (ECDC).
“If anyone suspects they may have a rash or lesions on any part of their body, particularly if they have recently had a new sexual partner, they should limit their contact with others and contact NHS 111 or their local sexual health service as soon as possible – but please telephone ahead of time before attending in person,” said UKHSA’s Chief Medical Advisor, Dr. Suzanne Hopkins.
People with monkeypox usually recover without treatment. The strain circulating in Europe has a mortality rate of about 1%; No deaths have been reported in the current outbreak. Monkeypox tends to cause serious illness in children, pregnant women, and people with compromised immune systems.
People living with HIV who are on antiretroviral treatment with viral suppression and a CD4 count above 200 “are not particularly at risk of feeling significantly worse,” said Dr. Claire Dewsnap, President of the British Association for Sexual Health and HIV, during a May 23 aidsmapCHAT.
“Currently, there is little data to estimate the impact of HIV on monkeypox-related morbidity and mortality,” according to the European AIDS Clinical Society. “It is likely that individuals with advanced and uncontrolled HIV are at greater risk of serious illness and prolonged viral shedding.”
Monkeypox can be combated by ring vaccination, i.e. targeted smallpox vaccination for close contacts of an infected person. The outbreak has sparked calls for universal smallpox vaccination to be resumed, but experts say it’s not currently necessary to control monkeypox in the general population.
The older live smallpox vaccine (made from a virus called vaccinia) can cause adverse events, particularly in immunocompromised people, but there is a newer, safer, non-replicating smallpox and monkeypox vaccine (brand names Imvanex or jynneos). It was approved by European and US regulators in 2013 and 2019 respectively and is recommended by UK authorities for use in the current outbreak. The UK and other countries are stockpiling and increasing smallpox vaccines in case of bioterrorism.
Smallpox vaccines are now being given to high-risk contacts of known cases and healthcare providers. Because the monkeypox incubation period is so long, vaccination up to two weeks after exposure can reduce the risk of symptomatic infection or serious illness. The new vaccine has been tested and shown to be safe for people living with HIV. For people taking antiretroviral drugs with a high CD4 count, Dewsnap advised, “If you’re offered a smallpox vaccine, you should take it.”
Antiviral drugs used to treat smallpox can also be used for monkeypox, including tecovirimate (TPOXX), which prevents virus exit from cells, and the nucleoside analogues cidofovir (Visit; known to treat cytomegalovirus retinitis) and brincidofovir (Tembexa).
Health officials and researchers are still learning from the ongoing outbreak, but monkeypox doesn’t spread as easily as COVID-19, and most don’t expect a new pandemic of this magnitude. Experts predict that monkeypox cases will increase as new people are exposed on social and sexual networks and previously exposed people go through the incubation period. But they hope contact tracing, isolation and vaccination can bring the outbreak under control.
Based on an ECDC epidemiological assessment, “The probability of spread of monkeypox among individuals with multiple sexual partners in the European Union/European Economic Area is considered to be high”. However, as the disease has so far been mild, the overall risk for this group is considered moderate and for the general population low.
Meanwhile, many in the LGBT community are concerned that a disease that primarily affects gay and bisexual men could lead to the same type of guilt and stigma seen with HIV and AIDS. Recognizing who is most affected is important to targeting education and resources, but stigma might deter sick or exposed people from seeking help, and the label “gay disease” might mislead others into assuming they are are not endangered.
“It’s a virus – it doesn’t choose, it doesn’t judge, it doesn’t have morals,” said Matthew Hodson, executive director of aidsmap. “Fight the disease, don’t fight people who may be at greater risk of contagion.”