Monkeypox: The New Public Health Emergency on the Block

“How bad is Monkeypox?” in 4 minutes.

Photo by Ethan Robertson on Unsplash.

On July 23rd, the World Health Organization (WHO) declared the ongoing monkeypox outbreak a Public Health Emergency of International Concern, following the unprecedented spread of the disease on a global scale.

As of today, over 21 thousand cases of monkeypox have been reported worldwide— according to the Global.health initiative. The vast majority of which occurred outside of the disease’s endemic regions of West and Central Africa, with Europe being the hardest hit region.

Monkeypox outbreaks in non-endemic countries are nothing new since their international debut in the United States back in 2003, however previous outbreaks had been easier to contain. After all, the disease is easily recognized and preventable.

Monkeypox, first identified in humans in the Democratic Republic of the Congo in 1970, can be described as a more aggressive form of chickenpox. Patients typically present with skin eruptions within one to three days following the onset of flu-like symptoms such as fever, headaches and muscle pain — especially back pain. These skin lesions will concentrate on the face, hands, feet and mucosa (such as the mouth); and may be accompanied by swollen lymph nodes — a distinctive feature of monkeypox when compared to similar diseases (e.g., smallpox, chickenpox and measles).

These symptoms often last between two to four weeks before subsiding on their own, with patient care focusing on minimizing symptoms and long-term sequelae such as skin scarring. But, some patients do experience complications, for example secondary infections, which can ultimately lead to death. Here too, monkeypox is different from similar diseases with its case fatality rate between 3 and 6% — significantly lower than its relative smallpox, which had a rate of 30%.

Because symptoms are rather characteristic, health authorities have previously been able to track down transmission chains. And since the virus spreads through close-contact with respiratory droplets or body fluids (e.g., blood) of an infected person, temporary isolation is often enough to prevent further infections.

However, the fact that the ongoing outbreak is concentrated in Europe has changed how the virus behaves — as reported by Shin Jie Yong.

Digitally-colorized electron microscopic image of monkeypox virus particles. Photo from the CDC PHIL.

Since the outbreak’s announcement in May of 2022, health authorities have identified multiple cases without connection to one another or the endemic regions, which hinders their ability to track transmissions. This suggests that — for unknown reasons — the disease has been spreading silently in Europe, either asymptomatically or by presenting with mild symptoms that do not make infected people seek medical care. In fact, the United Kingdom has updated its case definition to include a single genital lesion — especially if people had sex with a new partner.

The virulence of the monkeypox virus is also lower in Europe. There have been only five deaths as a consequence of monkeypox this year — all of which in Africa, making the case fatality rate of the outbreak almost negligible. This is likely because health care systems are more robust in Europe than in Africa and can better prevent complications from arising.

Another reason behind the lower case fatality rate lies on the genetic background of the circulating monkeypox virus strain. Its genome was first sequenced by researchers at the Portuguese National Institute of Health back in May, who discovered that it belongs to the West African clade — the least virulent of the two, as opposed to the Central African clade.

More recently, the same research group led by Doctor João Paulo Gomes also reported that the (previously slow-evolving) virus has accumulated more mutations than expected when compared to the non-endemic outbreaks of 2018–2019, which suggests it is going through an accelerated evolution process.

A third feature of the outbreak in Europe is that cases are concentrated among gay and bisexual men who have sex with other men, especially those who have sexual relationships with multiple partners. This does not mean that the virus discriminates on the basis of sexuality, but rather that sex with multiple partners is a high-risk behavior, since monkeypox spreads through close-contact. As denounced by the United Nations AIDS Agency, these misconceptions may undermine the response to the outbreak as they have done before for the AIDS epidemic.

Fun-fact: The monkeypox virus was first discovered in laboratory monkeys in 1958, hence its name, but the natural reservoir of the virus is most likely African rodents.

In an effort to control the outbreak, multiple countries including Canada, the United Kingdom and the United States have implemented a ring vaccination strategy — as reported by Nature journalist Max Kozlov. That means, they are vaccinating people who have been in contact with monkeypox patients. The vaccine currently used is the Imvanex vaccine produced by Danish biotechnology company Bavarian Nordic. Initially designed as a smallpox vaccine, its approval has been extended in those countries to also cover monkeypox because it reportedly has 85% effectiveness against it— although data on the subject is rather scarce.

Considering how monkeypox is spreading and evolving in unusual ways, the Director General of the WHO, Doctor Tedros Ghebreyesus, has declared the ongoing outbreak a Public Health Emergency of International Concern. In this way, breaking himself the deadlock between the expert committee, which had been unable to reach a consensus. This is the seventh time the WHO has issued such an alarm.

It is the same label given to the COVID-19 pandemic in 2020 and the strongest call to action that the agency can make.

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Gil Pires

Gil Pires

Junior Consultant | MSc in Biotechnology