On 23 July, WHO Director-General Tedros Adhanom Ghebreyesus declared the escalating global monkeypox outbreak a "Public Health Emergency of International Concern" (PHEIC). Currently, the vast majority of reported cases occur in the WHO European Region and the UNITED States. What is the current prevalence of monkeypox? Why did the WHO decide to escalate the monkeypox alert at this point?
Monkeypox virus.
What is the current prevalence?
Dr Boris Pavlin, who is responsible for monkeypox epidemiological research at WHO headquarters, introduced at a media symposium on July 27 that from 1 January 2022 to 22 July 2022 at 5 p.m., laboratories around the world confirmed a total of 16,016 cases of monkeypox, with 5 deaths (3 in Nigeria and 2 in another). Cases have been reported in 75 countries in 6 WHO regions.
"From the data point of view, the number of reported monkeypox cases began to rise around the end of April and the beginning of May, but in fact, when we look back at the past data, we found that in the African region, the previous months had begun to show signs of an increase in the number of cases." Pavlin said.
At present, the global reported cases are mainly concentrated in European and American countries. The countries with the highest number of reports were Spain, the United States, Germany and the United Kingdom and France. As of 20 July, Spain reported 3125 monkey pox cases, while the Four Countries, The United States, The United Kingdom and France reported 2316 cases, 2268 cases, 2137 cases and 1453 cases respectively.
Countries and regions reporting monkeypox cases as of 22 July.
According to data available to the WHO, the hospitalization rate of infected people is about 9%. The more common symptom of monkeypox is a rash and may be accompanied by severe pain. As of 23 July, there have been only five deaths in the global monkeypox outbreak, all in Africa. But within a week of the workshop, brazil, Spain and India outside Africa had already reported several deaths.
98.8% of those infected are men
According to reports, as of July 19, 98.8% of the laboratory-confirmed infected people are men, and the proportion of female infected people is very low. In these cases, some reported their sexual patterns in epidemiological surveys, with 98.1% (3434 people) reporting the presence of male sex, but another reporting no male sex (65). "In fact, if the population is further subdivided, not all male sex men are at high risk of monkeypox virus, but more precisely, people with multiple sex partners who often attend large parties and rallies." Pavlin said it's hard to know who is infected on these occasions.
One reason for the surge in cases in Europe is the large number of rallies such as music festivals across Europe during the summer months. These intensive activities create an "excellent" chance of transmission of the virus, which is mainly transmitted by skin-to-skin contact.
WHO Director-General Tedros Adhanom Ghebreyesus also said, "The current outbreak is concentrated in the population of men who have sex with men, especially those who have multiple sexual partners. "In Africa, however, women make up 40 percent of monkeypox patients.
The proportion of men and women in reported cases worldwide.
The main mode of transmission of the monkeypox virus is skin-to-skin contact. "In the flow, the specific scene of SCF in most cases is sexual activity, and it is understandable that there is of course more skin-to-skin contact during sex." Pavlin said there have also been cases of infections caused by exposure to items at home.
Even so, Pavlin said, "Monkeypox viruses are certainly much less contagious than respiratory-transmitted viruses such as covid-19." ”
Things have changed
Unlike the COVID-19 outbreak in late 2019, monkeypox is not a newly discovered virus. In fact, humans discovered 52 years ago that monkeypox viruses can infect people.
In 1970, scientists first detected human monkeypox in humans in a 9-year-old boy in the Democratic Republic of the Congo, and the region eradicated smallpox in 1968.
In 1970, monkeypox infection in humans was first detected.
The clinical presentation of monkeypox is similar to smallpox. Smallpox vaccination prevents monkeypox with an 85% effective rate, but the smallpox vaccine is no longer available to the general population after the global eradication of smallpox. This means that most people born after 1980 have not been vaccinated against smallpox and therefore lack immunity to the monkeypox virus, except for older people. In the more than 40 years of eliminating smallpox, monkeypox virus has taken advantage of the gradual expansion of human immunity depression after eliminating smallpox, and has gradually invaded the "human world".
"From its first discovery to the present, it took 52 years for the monkeypox virus to become a 'public health emergency of international concern', which in part makes people have to 'awe-inspired'." Says Tieble Traore, technical officer for emergency preparedness and response at the WHO Regional Office for Africa.
But for a long time in the beginning, case reports of monkeypox virus came mainly from rural and rainforest areas in the Congo Basin, especially in the Democratic Republic of the Congo.
Jean Paul Kimenyi, an epidemiologist in the WHO African region, said that in the West African country of the Central African Republic, for example, from 2001 to 2021, there were 40 monkeypox outbreaks in the country, with a total of 99 infected people confirmed and 12 deaths. Most outbreaks occur during the rainy season or when the weather is warmer (June-December). In 16 of the 40 outbreaks, contact with local animals was explicitly traced.
It wasn't until 2003 that the monkeypox virus first came out of Africa. The first monkeypox outbreak outside Of Africa occurred in the United States, which was linked to exposure to infected pet prairie dogs. These pets are kept with Gambian kangaroos and sleeping rats imported from Ghana to the United States. The outbreak has led to more than 70 cases of monkeypox in the United States.
Before 2022, the monkeypox virus last triggered a large outbreak in 2017.
This year, a large-scale outbreak broke out in the African country of Nigeria, where 466 suspected cases were reported from 2017-2021, of which 205 were confirmed.
"As of now, the number of monkeypox infections reported in Nigeria in 2022 has exceeded its peak in 2017." Jean Paul Kimenyi, an epidemiologist in the WHO African region, said.
There is an argument that this wave of global monkeypox outbreaks was caused by the continuation and spread of the epidemic in Nigeria in 2017. The outbreak in Nigeria in 2017 did not receive a global response, and the epidemic did not really control it, but slowly spread among the population.
Dimie Ogoina, a professor of medicine and infectious diseases at the Niger Delta University in Nigeria, said in a recent interview that the larger Nigerian monkeypox outbreak in 2017 has taken on different characteristics than in previous decades: for example, infected people have changed from children to young people between the ages of 20 and 40; And the number of infected people has also expanded significantly, with only a few dozen cases reported in previous outbreaks. In addition, more infected people in the outbreak that began in Nigeria in 2017 did not have direct contact with animals.
Changes in the epidemiology of these outbreaks were also observed in the 2022 outbreak.
Dr Boris Pavlin, who oversees epidemiological research on monkeypox at the World Health Organization headquarters, believes that the monkeypox epidemic in 2022 is indeed a little different from the past.
"Many cases cannot explain where they may have been exposed to the virus, suggesting that the monkeypox virus may have been circulating in the population for some time just months before people became aware of the monkeypox outbreak." Pavlin said.
At the same time, "some analysis of gene sequencing has shown that some variations in the monkeypox virus genome have made monkeypox viruses more likely to spread in humans than before." WHO is currently conducting further investigations into the mutation of the virus. Pavlin said that before this wave of outbreaks, it was thought that the monkeypox virus was mainly transmitted among animals, or mainly from animals to humans; And now in this wave of outbreaks, things have changed, and it may have been originally infected from animals, but the virus has adapted to human-to-human transmission.
Why is the alarm sounded at this point?
Currently, the WHO ranks the risk of global monkeypox virus epidemics as moderate, but in the European Region as high risk. China's western Pacific region is "low moderate."
At present, the number of people infected with monkeypox cases has not reached the level of the new crown virus, and more importantly, the fatality rate of monkeypox is very low. So why did the World Health Organization designate the monkeypox outbreak as a "Public Health Emergency of International Concern" (PHEIC) on 23 July?
The World Health Organization convened the Emergency Committee in late June under the IHR. At that meeting, committee members disagreed, but eventually reached a consensus that the outbreak did not constitute a Public Health Emergency of International Concern (PHEIC).
However, a month later, WHO Director-General Tedros Adhanom Ghebreyesus announced that the monkeypox outbreak would eventually be declared to constitute PHEIC.
"The Emergency Committee, while not reaching a consensus, has decided to underpin the Director General's decision." Tedros said the monkeypox outbreak had been met by the three criteria set out in the IHR for declaring a "Public Health Emergency of International Concern", namely "unusual events, public health risks to other countries posed by the international spread of the disease, and the need for a coordinated international response".
"An important consideration is whether the virus is spreading continuously." Pavlin explains that while current cases are still concentrated in people with male sex (the number of infections in other populations has increased but remains low), the number of infections overall is increasing; The number of countries reporting cases is also increasing.
At the last WHO Emergency Committee meeting, a total of 3 040 cases had been reported from 47 countries around the world, and by 19 July, the number of cases had increased to 13,884 in one month, an increase of 357%, with a total of 71 member states and regions reporting cases. In addition, in Spain, the United States and the United Kingdom, there is a continuous community transmission of monkeypox virus within these countries.
Another question considered by the WHO Emergency Committee is whether the monkeypox virus could spread from the current male sex population to the general population, affecting vulnerable people such as the elderly, children and immunocompromised groups. "In some places, surveillance systems may be over-targeting groups of men who have sex with men, leaving infected people in the general population (such as sex workers) unintended." Pavlin said it's one thing we need to keep an eye on at the moment.
"Currently, the mortality rate of monkeypox cases is very low, but once the monkeypox virus infection gradually expands to the elderly, children and other people with weak resistance, the mortality rate may rise." Pavlin said. At present, human surveillance systems, clinical treatment, diagnostic capacity, and effective vaccines and drugs for monkeypox are limited.
Is monkeypox virus like a global pandemic like COVID-19? "What happens after that is hard to say," Pavlin said, but what we can see at the moment is that the spread of monkeypox has not yet expanded to the general population.
Written by: Nandu reporter Wu Bin from Beijing