As of September 21, the current monkeypox outbreak has infected 62,532 people in 105 countries. Nevertheless, the World Health Organization (WHO) has not yet classified the current number of cases as a pandemic.
But could that change? Given its prevalence, monkey pox become a pandemic?
The answer to this question depends on the definition of “pandemic”. A pandemic is a “worldwide epidemic” in which there are high numbers of cases or outbreaks in many countries, Rachel Roper, professor of microbiology and immunology at East Carolina University in Greenville, North Carolina, told Live Science in an E -Mail.
“I think it’s a matter of opinion how many cases you have to have in how many countries,” Roper said. That Centers for Disease Control and Prevention (opens in new tab) (CDC) defines a pandemic as “a disease event in which there are more than expected cases of a disease, are spread across multiple countries or continents, are usually transmitted from person to person, and affect a large number of people.”
There’s always a chance that something like the genetic code of the virus will change, but several factors reduce the likelihood of monkeypox becoming a pandemic. Even if it does, monkeypox won’t take nearly the toll of the COVID-19 pandemic, experts told Live Science.
Historically, monkeypox has not been particularly contagious and outbreaks have been small
Monkeypox (sometimes abbreviated as MPXV or MPX) “is a lot less contagious than COVID,” Roper said. Typically, monkeypox’s chain of transmission was short — a case of MPXV was transmitted to a maximum of seven people before it became extinct, so past outbreaks have been short-lived, Roper said. Monkeypox was first documented to infect humans in 1970, and outbreaks since, with the exception of the current pandemic, have been “kind of small,” she said. In countries where it is endemic, monkeypox is always present in animal hosts and usually only spreads between humans when they catch it from animals and start spreading it to other humans.
But an analysis of monkeypox genomes from the current epidemic, published June 24 in the journal naturopathy (opens in new tab)suggests that the currently circulating version of the virus has been passed in an unbroken chain of human-to-human transmission since 2017. This suggests the average transmission chain is increasing, Roper said.
Nonetheless, in monkeypox the reproduction number (R0), or the number of people directly infected by the disease from each person, has historically been less than 1, meaning that even without active disease control measures, any epidemic would eventually break out (Im In contrast, the R0 for the currently circulating omicron variants of SARS-CoV-2, the virus that causes COVID-19, is estimated to be between six and 10 The conversation (opens in new tab).) But researchers do not know the R0 for the currently circulating version of monkeypox, according to a June 2022 paper (opens in new tab) in the journal The Lancet Infectious Diseases.
It’s hard to say why monkeypox is now infecting so many people, she added. It may be because mutations have made it more transmissible, or it may be because it has entered new populations that have different overall behaviors or risk factors that increase transmission rates, Roper said.
For example, in African countries where monkeypox is endemic, the virus was not previously known to spread through men who have sex with men, Roper said. However, the current outbreak primarily affects men who have sex with men and is therefore spread through sexual and other close physical contact World Health Organization (opens in new tab) (WHO).
Monkeypox mutates fairly slowly
Monkeypox is a virus from DNS, as opposed to being made up of single-stranded ribonucleic acid (RNA). This is important because DNA replication involves fewer errors than RNA copying, so monkeypox mutates more slowly than counterparts such as SARS-CoV-2 or HIV. This gives monkeypox viruses fewer opportunities to evolve to become more transmissible than RNA viruses, the researchers said American Society for Microbiology (opens in new tab).
However, for a smallpox virus, monkeypox quickly develop mutations, according to June Nature Medicine’s genome analysis. Compared to strains circulating in 2018 and 2019, the currently circulating virus has 50 mutations that were most likely picked up during human circulation, according to the paper. That’s six to 12 times the number of mutations expected based on the typical mutation rate for smallpoxviruses, the study authors found.
No lung virus
The virus that causes COVID-19 is “primarily respiratory,” Roper said. “Its main target organ is the lungs.” SARS-CoV-2 spreads when an infected person sneezes, coughs or even just breathes, Roper said. In contrast, monkeypox is primarily spread through “direct contact with a monkeypox rash, scab, or bodily fluids of a person with monkeypox,” according to the Centers for Disease Control and Prevention (CDC). The virus can also be spread when a person touches objects and surfaces used by someone who has monkeypox.
“Monkeypox spreads so inefficiently,” Rodney Rohde, professor and chair of clinical laboratory science at Texas State University, told Live Science. “You have to be very close, skin-to-skin contact or maybe with infection carriers like bedding or clothing. And it actually takes quite a long time, several hours of contact, before it occurs [for] a nebulized virus, it could be instantaneous – someone sneezes or coughs in a room and you inhale it, and maybe 8, 10, 12 people get it.”
We already have vaccines and treatments for monkeypox
Two vaccines, JYNNEOS and ACAM2000, are approved for use against monkeypox in the United States Live Science previously reported.
While there are no treatments specifically for monkeypox, so are the CDC (opens in new tab)antiviral drugs designed to combat smallpoxsuch as Tecovirimat (TPOXX), may be recommended for people with debilitated immune systems.
Given the existence of vaccines and treatments combined with other factors such as the low mortality rate of the currently circulating strain of monkeypox, it should be possible to slow the rate of infection and limit deaths, Rohde said. The fatality rate for the type of monkeypox circulating in the current epidemic has historically been around 1%, according to the CDC (opens in new tab). But the current outbreak could be a lot less deadly; according to WHO figures from the end of September, the mortality rate is 0.04%. While these numbers are still a rough estimate, they suggest that even if monkeypox becomes a pandemic, the number of monkeypox will likely be much, much lower than that of COVID-19. “It could eventually be considered a pandemic because of the number of countries that have cases and the linear increase in cases that we’re seeing,” Rohde said. “But I don’t think it’s going to be the kind of global mortality crisis that we’ve seen with COVID.”
Originally published on Live Science.