The coronavirus pandemic has shown us just how quickly a virus can wreak havoc on society. In just the span of two years, so much has changed as a result of Covid 19 and many people are fearful that we may experience another covid level pandemic in the near future.
Recently there’s been a lot of talk about monkeypox and a potential outbreak but what is monkeypox? how serious is it? and should you be concerned?
What is Monkeypox?
Monkeypox is a disease caused by infection with the monkeypox virus. It belongs to the family of viruses known as orthopoxviruses which also include things like smallpox vaccinia and cowpox.
Monkeypox was first discovered in the late 1950s as a result of two pox-like disease outbreaks among colonies of research monkeys, hence the name monkeypox. The first human case of monkeypox was recorded in Africa in the 1970s and the disease has been endemic, meaning largely contained to certain regions of Africa since then.
There are two main variants of the monkeypox virus, the Congo Basin Clad and the Central Africa Clade. The Congo Basin variant has historically caused more severe disease and is thought to be more transmissible. Regardless, monkeypox is much less transmissible than smallpox and symptoms tend to be much milder.
Much like other viral illnesses, the first one to three days is characterized by fever, chills, fatigue, headache, muscle aches, and swollen lymph nodes after which infected individuals will start developing a rash that progresses from small flat lesions to eventually large fluid-filled blisters. Over the span of the next few weeks, these blisters will drain, scab over, and eventually fall off.
The disease is usually self-limiting, meaning that it usually goes away on its own and generally lasts anywhere from two to four weeks before subsiding. That being said some individuals experience much more severe symptoms and develop more dangerous issues such as secondary infection, sepsis, and pneumonia to name a few. According to the CDC, as many as 1 in 10 people who become infected with monkeypox in Africa die from the disease
Why is This Important Now?
If we’ve known about monkeypox for over 50 years, why are we so concerned about it now?. The reason is that as of May 2022, dozens of cases have begun to appear outside of Africa where the virus has largely been contained for decades.
At the time of writing this post, over 100 cases have been reported in over 16 different countries. The reason that this is concerning is that the primary mode of transmission of monkeypox historically has been animal to humans such as from a dormouse or rat, the individual may go on to infect a close family member or two but historically the disease has fizzled out quickly.
Human-to-human transmission is thought to occur primarily through direct contact, through large respiratory droplets, or contact with body fluids or lesions, as such transmission rates have been relatively low historically, and limiting close contact with infected individuals, has often been sufficient to prevent further spread of the disease.
The reason that this current outbreak is causing such a commotion is that the disease isn’t following its normal pattern of transmission and more people are becoming infected with monkeypox presumably by human-to-human contact.
Should You Be Concerned?
As of the time of writing this post, there have been no deaths reported from this most recent outbreak and most patient symptoms have been relatively mild. According to the WHO, the case-fatality ratio for monkeypox has been estimated to be around three to six percent however there is an important variable to consider with these numbers.
In regions of Africa where monkeypox is more commonly found, there’s often limited access to healthcare. Oftentimes severe complications from viral illnesses such as secondary infection and sepsis can be treated with supportive care including antipyretics, antibiotics, oxygen fluids, and close observation.
Patients essentially just need a little bit of extra help while their body is recovering from the illness. In addition, there are also some medications available that can be used to help treat more severe cases of monkeypox including the antiviral medications, tecovirimat, and brincidofovir.
For these reasons, the estimated three to six percent case fatality ratio may not be representative in countries with greater access to healthcare. In essence, it’s not necessarily the monkeypox virus alone that is proving fatal but rather having monkeypox and not having access to supportive care.
This is one reason why rising numbers of covid cases have been so concerning over the past few years. When hospital systems are inundated with patients and they don’t have a buffer, access to care can be affected negatively leading people to lose their lives that otherwise wouldn’t have.
Even if the case fatality ratio of monkeypox is less than the estimated three to six percent, the case fatality ratio of covid 19 is estimated between 0.5 and 3 depending on the country and we can see how many people have died. So should we still be concerned?
Mode of Transmission
The issue with covid 19 is that it’s very easily transmitted between individuals. When an infected person coughs, sneezes, or even just talks, tiny respiratory droplets carry the virus into the air and anyone around that individual can then breathe those tiny droplets into their lungs and become infected. As a result, coronavirus can spread quickly through a population.
Monkeypox on the other hand does not spread that way. Transmission from animal to human or human to human is largely thought to occur through direct contact with large respiratory droplets or body fluids and lesion material. For instance, a 2007 study found that touching an infected animal, getting scratched by an infected animal, or changing the bedding of an infected animal were all associated with an increased risk of developing monkeypox.
On the other hand, indirect exposures such as having been near an affected animal which is defined as coming within six feet of that animal without touching it were not associated with the development of monkeypox as such monkeypox is not as easily spread as something like covid which can easily spread just by being in close proximity to someone who is infected. Monkeypox historically has needed direct physical contact.
We can see how much of a difference this mode of transmission makes by comparing R0 values of covid and monkeypox. The R0 value refers to the average number of people to whom each infected individual is expected to transmit the disease to. In essence, this number looks at how spreadable an infectious disease is.
The original covid 19 variant was estimated to have an R0 between 2 and 3, the more contagious delta variant is estimated to have an R0 value between 5 and 7 while the more recent omicron variant is estimated to have an R0 as high as 8.
This means that every one individual infected with the omicron variant of coronavirus is estimated to infect around 8 other people and then each of those eight people can be expected to infect another eight people and so on and so forth. This is how coronavirus has been able to spread so quickly.
Most R0 estimates from earlier outbreaks of monkeypox by comparison are less than 1. This means that some individuals infected with monkeypox don’t even infect another person. As a result, the virus isn’t spread efficiently through humans to allow it to sustain itself in the population. This is why the virus has largely remained endemic to Africa and most cases have occurred due to animal-to-human transmission.
Those at risk for human-to-human infection are often close family members or healthcare workers that are treating patients infected with monkeypox and even then much of that risk seems to be largely mitigated with proper contact precautions.
But if it’s not so easy to transmit from person to person, why are we seeing so many cases recently? Possibly a mutation. The biggest concern is that the virus has changed so that it can be transmitted more easily between humans and that’s why we’re seeing an increased number of cases.
According to reports, research is currently being conducted to see if there has been a change to the genome of monkeypox. Preliminary research from the Icahn school of medicine at Mount Sinai has shown no unusual mutations, however, more research still needs to be done.
Given the type of virus that monkeypox is, it is much less likely to mutate than something like covid 19. Orthopox viruses such as monkeypox are DNA viruses that are in contrast to something like flu or coronavirus which are RNA-based. As a reminder from general biology, DNA and RNA are essentially biological instruction manuals. In general, DNA is used as a template to make RNA which is then used as a template to make different proteins which are then used for a variety of functions.
When viruses enter our body they infiltrate healthy cells and take over the machinery that our cells use to create and replicate DNA and RNA and they use that to instead make more copies of themselves. These replication systems however are not perfect. Each time the virus replicates its genome to create a copy of itself there’s a potential for mistakes to be made, we call these mutations.
These mistakes in the genome, although random, can occasionally affect how the virus interacts with other cells. So the concern becomes that sometimes these mutations can actually make it easier for a virus to move from person to person. RNA viruses such as flu and covid have high rates of mutation as the machinery used for RNA replication is not very good at detecting or repairing mistakes.
On the other hand, the machinery used for DNA replication is much better at detecting and fixing mistakes. In fact, it is about 100 times better at detecting and repairing mistakes than RNA. This means that DNA-based viruses are generally much less likely to develop mutations than RNA-based ones.
In addition, even when mutations occur they are random so the likelihood that a mutation has developed that would confer some sort of benefit to the virus is also relatively uncommon. Is it possible? absolutely. Is it very likely? not so much.
As such, the leading theory as of May 2022 is that this current outbreak is likely the result of a couple of large raves in Europe recently that attracted an international audience. A notable proportion of individuals infected with monkeypox have been young men with no history of travel to Africa who are either gay, bisexual, or have sex with men.
Authorities in Portugal and Spain also said their cases were in men who mostly had sex with other men and whose infections were picked up when they sought help for lesions at sexual health clinics. Although monkeypox is not known to be transmitted through sex, the act of intercourse involves close physical contact which is known to be sufficient for transmission of monkeypox.
Regardless, even in the worst-case scenario that there is a mutation in the genome of monkeypox that’s allowing it to be passed from person to person more easily, what would that mean for us? Could it potentially cause another pandemic? While it’s not impossible, again not very likely.
In the U.S this isn’t actually the first time we’ve had an outbreak of monkeypox. In April 2003, there was an outbreak of monkeypox in the Midwest United States. There was a shipment of rodents from Ghana including different varieties of mice, rats and squirrels some of which were infected with monkeypox. Sometime after arriving in the U.S, these rodents were housed near prairie dogs at an animal vendor which were ultimately sold as pets.
Once in close contact with humans, the monkeypox virus spread from the prairie dogs to their owners. All individuals infected with monkeypox at that time had become ill after having contact with infected prairie dogs. No cases were attributed exclusively to person-to-person contact.
So how did we respond?
The CDC and public health departments worked with other government agencies to do extensive lab testing, develop guidelines for patients, healthcare providers, veterinarians, and animal handlers and investigate human cases. In addition, they deployed smallpox vaccines and treatments. Remember how monkeypox belongs to the same family of viruses as smallpox, well the smallpox vaccine has actually been shown to be effective against monkeypox.
Past data from Africa suggests that the smallpox vaccine is at least 85% effective in preventing monkeypox according to the CDC. Up until the 1970s, the smallpox vaccine was given to everyone as infants in the United States. As smallpox became less common and ultimately eradicated we stopped giving it because it just wasn’t necessary.
Most individuals over the age of 50 today who were also born in the U.S likely received the smallpox vaccine as a child and therefore have some sort of protection against monkeypox. However, anyone under the age of 50 likely did not receive the smallpox vaccine.
That being said we still have copious amounts of the vaccine available should the need to use it arise. In fact, researchers have even developed a more effective version of the vaccine since then. Previously the vaccinia virus, another virus of the orthopoxvirus family was used in the smallpox vaccine. Although highly effective, it was a live attenuated virus and there was a small risk that the vaccinia virus would replicate out of control and cause death in individuals that received the vaccine.
In the United States, there were 68 deaths between 1959 and 1968 due to complications however when you consider that everyone was getting the vaccine it’s still a very minuscule amount of the population. Since then researchers have developed a version of the vaccine that has a far lower risk of adverse effects.
Even in the event that the cases of monkeypox continue to rise it’s unlikely that we are going to need to resort to mass vaccinations with the smallpox vaccine as we did with covid 19. Instead just focusing on populations at high risk of transmission will likely be sufficient to control the spread of the virus given its limited transmissibility
Due to these factors, it’s very unlikely that this is going to turn into another pandemic. What’s more likely is that it’s going to just fizzle out in the coming months. It is still important to be aware of monkeypox especially if you’re in a population that has a higher risk of infection or complications or if you live in an area that is experiencing a lot of cases.
Although seeing headlines about monkeypox or other viruses can be scary, you should always try to separate the signal from the noise.
Should you be afraid of monkeypox?
Probably not, unless maybe you’re in the business of selling African rodents in which case might be time for a career change.