- Canada is among the countries affected by recent unique outbreaks of monkeypox
- Doctors in the U.S., Portugal and Italy have reported their preliminary observations
- Most observed cases are among men who have sex with men
Infection with monkeypox virus can cause an illness called monkeypox. An outbreak of monkeypox was first recognized in the UK in mid-May and shortly thereafter in Western Europe. Cases subsequently appeared in North America and on other continents. The current outbreak has at least two unique characteristics:
- So far it has appeared mostly in gay, bisexual and other men who have sex with men (MSM).
- The vast majority of current cases have no history of travel to regions that traditionally have had outbreaks of monkeypox in the past 50 years.
For background on monkeypox virus, please see this previous CATIE News bulletin.
We now present preliminary findings from reports in several countries. Researchers have rushed to get information about the current outbreak into publication in order to help clinicians and researchers who may be treating people with monkeypox or conducting research on this condition. However, due to the sudden appearance of monkeypox in high-income countries and the rush to disseminate research findings, some of the initial reports have missing or incomplete data. This is typical in the first several months of any rapidly developing outbreak with a germ that was previously uncommon.
In this CATIE News bulletin we review findings from the United States, Portugal and Italy.
In the U.S. – the first recognized cases
The U.S. Centers for Disease Control and Prevention (CDC) has presented limited information on the first 17 people diagnosed with monkeypox in that country during the current outbreak. Here is a summary:
- 16 of the 17 people were MSM
- 14 of the 17 people disclosed international travel in the 21 days prior to their development of symptoms
- all were adults with an average age of 40 years (ranging between 28 and 61 years)
- all had a rash that developed between May 1 and 27, 2022
- three people had weakened immune systems (the cause of immunological weakness was not disclosed)
Prior to developing a rash, 12 people reported one or more of the following symptoms:
- fatigue
- fever
- headache
In addition to a rash, people reported all or some of the following symptoms:
- chills – 12 people
- tiredness and feeling unwell – 11 people
- swollen lymph nodes – nine people
- fever – seven people
In eight men, their rashes began in the genital area or around the anus. According to the researchers, “all but one patient developed a disseminated rash, occurring on the arms, trunk, legs and face.”
All people entered isolation and are being monitored at the time of the report. They are all doing well.
Although most cases of monkeypox reported in the outbreak in Europe and North America are in men, most of whom are men who have sex with men, the U.S researchers made an important point:
Noting past research on outbreaks of monkeypox in places where monkeypox is endemic, the researchers stated that in those outbreaks “close contact with infected persons or fomites (e.g., shared linens) is the most significant risk factor for monkeypox virus infection in human monkeypox outbreaks. Monkeypox virus is spread through close, often sustained skin-to-skin contact, but the initial appearance or occurrence of lesions in the anogenital area [area around the anus and genitals] observed in the current outbreak differs from the typical appearance or occurrence beginning on the face, oral mucosa, and hands and feet, then spreading to other parts of the body in a centrifugal distribution [moving outwards from affected areas].”
The researchers also made the following important statement about the distribution of monkeypox cases:
Outbreaks of infectious diseases “are often not confined to certain geographies or population groups; because close physical contact with infected persons can spread monkeypox, any person, irrespective of gender or sexual orientation, can acquire and spread monkeypox.”
Further research is ongoing as additional cases appear in the U.S. and more detailed reports will be published in the future.
In Portugal
Researchers in Portugal provided details on information analysed from some people who were diagnosed with monkeypox in May, 2022. Looking back on the data, the researchers realized that symptoms first appeared in one person in late April, 2022. What is interesting about the preliminary report from Portugal is that researchers stated that “most cases were neither part of identified transmission chains nor linked to travel or had contact with [people or animals with obvious symptoms of monkeypox], suggesting the possibility of previously undetected spread of monkeypox.”
The first recognized cases
The Portuguese researchers reported that on May 3, 2022, five men with unusual skin lesions sought care at a hospital or STI clinic in Lisbon. Most of the lesions were around the anus, on the scrotum and on the penis.
At first, doctors considered a long list of potential sexually transmitted infections as causes but were gradually able to rule them out. Then, on May 16, 2022, the European Centres for Disease Prevention and Control (ECDC) alerted doctors to two cases of monkeypox in the UK. These cases were in MSM who also had genital lesions. Subsequently, three of these men in Portugal were confirmed with polymerase chain reaction (PCR) testing to have monkeypox virus. Around this time, more cases began to appear with similar symptoms and more cases of monkeypox have been diagnosed (and continue to be diagnosed) in Portugal and other countries.
Some data from additional cases
The Portuguese researchers then presented some information collected from additional cases, as follows
- all were men
- the average age was 33 (the men ranged in age from 22 to 51)
- 18 out of 19 men disclosed that they were MSM; the remaining man stated that he had sex only with women
- 14 of the men had HIV infection (details about viral and immunological test results or their use of HIV treatment were not available)
Note: As mentioned earlier, initial reports of outbreaks of emerging infectious diseases are often bedeviled by incomplete or inconsistently collected information, as is the case in this situation.
According to the researchers, in the 21 days prior to the appearance of symptoms, most men with available data (14 out of 16) disclosed sex with multiple partners.
The most common symptoms were as follows:
- rash
- swollen lymph nodes in the groin
- genital ulcers
The men reported that lesions first appeared in the groin. This is an interesting development, because in prior monkeypox outbreaks lesions usually first appeared on the face.
Three of the men required hospitalization and two were subsequently released. Data on the third man was not available.
So far none of the men have died.
Lab tests
Laboratory testing of samples from the men is ongoing. All of the men in these additional cases tested positive for monkeypox DNA by PCR. Genetic analysis of the virus suggests that it is closely related to virus that is associated with outbreaks of monkeypox in West Africa in the past several years.
For the future
The Portuguese researchers advanced the idea that it is plausible that until recently monkeypox may have been circulating at very low levels in parts of Europe. More research is needed to investigate this theory.
In Italy – the first recognized cases
Researchers in Rome reported some details from investigations into four young men who developed monkeypox. They did not require antiviral drugs and are now in good health.
Travel
The men travelled during the first two weeks of May, 2022. Three went to the Canary Islands for a festival and one went to an undisclosed location for sex work. During this time, they had condomless sex with multiple partners.
Patient 1 – This was a man in his 30s. During his travels he developed skin lesions and was treated with the following drugs, which suggests that doctors suspected STIs such as gonorrhea, syphilis and herpes:
- the antibiotics ciprofloxacin and benzyl penicillin
- the antiviral drug acyclovir
By the time he sought care in Italy, the rash had spread and he had deep lesions in his genital area and swollen lymph nodes. He had previously been diagnosed with HIV and was taking treatment with an undetectable HIV viral load.
Patient 2 – This was a male in his 30s who was HIV negative and taking HIV pre-exposure prophylaxis (PrEP). In mid-May, he sought care in Italy because of fever and general weakness. Three days after hospitalization he developed raised lesions around his anus. He also developed painful, swollen lymph nodes in his groin. Subsequently, new lesions appeared near the anus and in other places (on the back, legs and sole of one foot). He was the only patient in this series who was prescribed anti-inflammatory drugs for painful anal lesions and antihistamines for itchy skin in the rest of his body.
Patient 3 – This man was in his 30s and had HIV that was suppressed with treatment. He sought care in Italy because of a two-day history of fever followed by the appearance of lesions around his anus, head, chest, legs, arms, hand and penis.
Patient 4 – This man was in his 30s and was taking PrEP. After having unexpected muscle pain for two days, he developed genital lesions. Six days later he developed lesions on his chest and additional genital lesions.
Lab tests
According to the researchers, swabs or fluids from the following places tested positive for monkeypox DNA (using PCR):
- skin, genitals and anal lesions
- blood
- seminal fluid
- feces
- nasal and throat swabs
All patients subsequently recovered without the use of drugs with potential antiviral activity against monkeypox virus.
Bear in mind
It is not yet clear exactly how the men were infected. It is possible that they could have been infected by the close contact that occurs prior to and during intercourse, including sexual contact.
The presence of the genetic material of monkeypox virus in seminal fluid is interesting. However, by itself, positive PCR results from analysis of semen do not prove that monkeypox virus was spread by semen as a result of condomless intercourse.
The samples used for PCR testing in future investigations of monkeypox need to be paired with viral co-culture (where scientists attempt to grow virus in infected cells) to find out if infectious virus was present in semen (or other fluids).
The Italian scientists stated that “further studies are needed to assess [the] presence, persistence and contagiousness of monkeypox virus in different body fluids.”
—Sean R. Hosein
Resources
An outbreak of monkeypox in Canada and other countries – CATIE News
Montreal’s response to an international outbreak of monkeypox virus: First steps towards action – CATIE blog
Monkeypox: symptoms and management – Public Health Agency of Canada
What you need to know about monkeypox in Montréal – Santé Montréal
Monkeypox – Centers for Disease Control and Prevention
Monkeypox – European Centre for Disease Prevention and Control
REFERENCES:
- Minhaj FS, Ogale YP, Whitehill F, et al. Monkeypox Outbreak – Nine States, May 2022. MMWR. Morbidity and Mortality Weekly Report. 2022; in press.
- Perez Duque M, Ribeiro S, Martins JV, et al. Ongoing monkeypox virus outbreak, Portugal, 29 April to 23 May 2022. Eurosurveillance. 2022 Jun;27(22).
- Antinori A, Mazzotta V, Vita S, et al. Epidemiological, clinical and virological characteristics of four cases of monkeypox support transmission through sexual contact, Italy, May 2022. Eurosurveillance. 2022 Jun;27(22).
- Heskin J, Belfield A, Milne C, et al. Transmission of monkeypox virus through sexual contact – a novel route of infection. Journal of Infection. 2022; in press.