Hello, and welcome to my channel Medicine with Dr. Moran. Monkey pox is in the news
as numerous cases have been documented in many countries over the last few weeks.
What do doctors and medical researchers really know about this particular viral illness?
I'm going to talk about the history of Monkey pox, what's happening now with it, the case fatality
rate and infection fatality rates, as well as symptoms, treatments, and more. Many of the cases
so far around the world have been in men who have sex with men and they're typically between the
age of 30 to 55 who've been in close contact. Now sexual transmission has not been described
before and so it's likely that close contact from person to person may be the root of transmission.
This of course needs to be clarified. At least from reports it doesn't sound like anyone has
been seriously ill so far. There have been more than 70 confirmed Monkey pox cases in
Europe at the time of the video. The spread of the virus is beyond the typical areas in Africa
where a low level of cases is noted every year primarily in the Congo basin. Even in these areas
it's still a relatively rare infection. There have been confirmed infections so far in Spain,
England, Portugal, as well as Canada, the U.S. and Australia. There have been more suspected cases.
I think you're going to see a lot more cases over the next weeks and months ahead.
Of note this week geneticists have actually looked at the genome of Monkeypox and this
is no different from the Monkeypox virus that has been circulating in previous years
in the Congo basin. Monkeypox was first detected in 1958 in laboratory monkeys. Transmission has
occurred from wild animals such as rodents to people or from people to people. It's a DNA virus
which is different from the RNA coronavirus that we're dealing with with this pandemic.
Now DNA viruses are much better at detecting and repairing mutations so it's much less likely that
the Monkeypox virus is suddenly mutated to become more adept at human transmission and we certainly
haven't seen that in the genome report this week. The virus was first identified as causing disease
in humans back in 1970. There's usually a few thousand cases a year in central and western
Africa and cases outside of Africa have been small and usually are associated with travel to African
countries or importation of infected animals. There have been outbreaks in the past including
in 2003 in the U.S. where you may remember there were rodents imported from Ghana which spread
the virus to pet prairie dogs in Illinois. There were more than 70 people infected at that time.
Now the number of cases we're seeing currently is more than the total number detected outside of the
continent typically on a year-to-year basis. I make note that this is a completely different
virus from the coronavirus Covid-19. This journal article from February of this year reviews
Monkeypox. There's a link in the description below. Monkeypox itself is similar to the Smallpox
virus in that it presents with similar symptoms. The number of human Monkeypox cases has been on
the rise since 1970s. We see cases of Monkeypox predominantly in the Democratic Republic of Congo.
The median age appears to have increased from 4 to 21 years of age. There are two
distinct genetic clades of the virus one from the central African form from the Congo basin
and the west African clade now the central African clade from central Africa has an
overall case fatality rate of 10.6% with a 95 confidence interval around that of 8.4 to 13.3%
the West African one has a fatality rate of 3.6% by cases with confidence intervals of 1.7 to 6.8%.
This virus is not as transmissible as Covid-19. We don't have a lot of data in regards to the
case fatality rates in different age groups. The virus that's spread around the world
currently is the West African variant which has the lower case fatality rate of the two.
I was unable to find any information on infection fatality rate. There is a difference between
these two things. The case fatality rate is the number of deaths divided by the total number of
cases that present to health care providers. The infection fatality rate is the number of deaths
divided by the total number of infections whether they present to physicians or not.
There can be a significant difference between the two because many infections
don't come to physicians or other health care providers for assessment or testing thus like
any disease the likelihood of dying from an infection is much less than the case fatality rate
which is the odds of dying from the infection if you're a documented case. This of course was
very important with the recent coronavirus pandemic when the media was propagating the
fact that case fatality rates were as high as 10% early in the pandemic in places like Italy
but what they weren't telling you is that they were only counting cases, not infections and
as you know there are many asymptomatic infections with Covid-19 that never come to medical attention
because they're very mild or people are actually asymptomatic and they're not simply recognized.
This was one of the reasons why early on in the pandemic I made videos on my channel talking about
what the infection fatality rate was in different age groups and ultimately we found that the
infection fatality rate was on the order of 0.25 to 0.5% in people without previous infection or
vaccination. Now that number obviously was much higher in older people with comorbidities but it
was also lower in younger healthier people. The one thing to keep in mind with Monkeypox research
of course is that it's difficult to get a complete picture of the number of confirmed probable or
possible cases of this disease as data quantity and quality vary significantly across the regions
in Africa where Monkeypox is actually present. Under reporting is almost certainly to be the
case. Now confirmatory PCR testing for Monkeypox is actually rarely performed. There's also a
lack of data on the age of cases and age-related fatality rates. This makes conclusions difficult.
I think it's reasonable to say that the fatality rates are lower than what I presented on the
slide, but the absolute numbers are not truly known. How is this virus actually transmitted?
Well animal to human transmission which we call zoonotic transmission can occur with direct
contact with the blood, other bodily fluids, or contact with the skin, or mucosal lesions
of infected animals. Monkeypox in Africa is found in many animals like squirrels, rats,
monkeys, and other species. It's felt that the natural reservoir is probably rodents and monkeys.
It's possible but not known that eating inadequately cooked meat or other animal
products of infected animals would be a risk factor in terms of human to human
transmission. This can result from close contact with respiratory secretions if you're coughing.
Skin lesions of an infected person or possibly recently contaminated objects such as bedding
or clothing the spread through droplet respiratory particles usually requires prolonged face-to-face
contact which means that healthcare workers as well as household members are at greater risk.
The longest documented chain of transmission was nine successive person-to-person infections.
Transmission is known to occur via the placenta from mother to baby which leads to what we call
congenital Monkeypox. it's unclear whether the virus can be transmitted through sexual
transmission. Now there have been 16 studies on secondary attack rate. This would be how
frequently someone in close contact such as a household member actually gets infected. From a
meta-analysis nine of the sixteen peer-reviewed studies reported a secondary attack rate of 0%.
Six of sixteen studies demonstrated a secondary attack rate of 0.3 to 10.2%
and in the remaining single article there was a significant outbreak among 16 households with a
secondary attack rate of 50%. If you get Monkeypox what kind of symptoms are you going to have?
Well from the incubation period which is when you get the virus to developing the symptoms
it's usually a week or two later there are two periods of infection. The very first is called the
invasion phase and this this occurs in the first five days. Typically people get fever, headaches,
swollen lymph glands, back pain, muscle aches, and lack of energy. The swollen lymph glands
are actually a distinctive feature of Monkeypox compared to other similar viral illnesses. I make
note that some of the cases that has actually been seen in the last few weeks involves lesions only
in the genital areas. This of course is atypical for the way people usually present with Monkeypox.
Now the next phase is the skin eruption phase. Skin findings which usually begins within
one to two days of fever. The rash that you get is concentrated on the face and extremities rather
than the trunk in 95% of cases it affects the face, 75% the palms of the hands, and the soles
of the feet, as well as mucous membranes such as the mouth. Once the lesions are crusted over
people are not contagious. This is a self-limited disease which means it goes away with the tincture
of time without any specific treatment other than treatment to minimize symptoms and the symptoms in
total usually last two to four weeks. Severe cases occur more frequently among children. Vaccination
against smallpox actually is protective in the past but because smallpox has been eradicated
we're not using the smallpox vaccines any longer so the population could be more susceptible to
the virus. The complications of Monkeypox can include secondary infections like pneumonia
which can lead to sepsis and multi-organ failure. There also can be brain inflammation now how do
we make a diagnosis of Monkeypox? Well we need to consider other diagnostic possibilities which
we call the differential diagnosis. We need to consider other rash illnesses such as chickenpox,
measles, bacterial skin infections, things like scabies, medication induced rashes, and so on. The
swollen lymph glands are a clinical feature that allows us as physicians to distinguish Monkeypox
from chickenpox or smallpox. Now confirming the diagnosis is through PCR on a sample from either
one of the skin lesions either the roof of the lesion or fluid from inside the vesicle or pustule
or even dried crusts a small biopsy could be an option as well. Now what treatments do we have
available? Well treatment is to minimize symptoms and manage complications as I've just mentioned.
It's important to stay hydrated so appropriate fluids as well as food so that your nutritional
status stays up. Secondary bacterial infection should be treated most people recover from
Monkeypox within a few weeks without any kind of treatment. Countries do maintain a supply
of smallpox vaccines and antiviral treatment thought to be highly effective against Monkeypox
and those are things that we've used to gain small pox now Smallpox was eradicated from the human
population about 40 years ago with the last human case in 1977 from the human population but there's
still two labs in the world who have a supply of smallpox that's the CDC in Atlanta in the us
as well as the State Research Center of Virology and Biotechnology in Russia. In terms of treatment
often a technique called ring vaccination is used where one vaccinates close contacts of people
who've been infected with Monkeypox to cut off the roots of transmission. Data from Africa
suggests that the smallpox vaccine is at least 85% effective in preventing Monkeypox. There
are antivirals available but data on treating human cases of Monkeypox are actually absent.
There is an oral antiviral called Tecovirimat which is approved for treating smallpox although
we don't have any data on Monkeypox. Interestingly and coincidentally the FDA two days ago approved
the IV formulation of this medication. It's owned by a company that's ultimately owned by Pfizer.
These drugs do have proven activity in animal studies and in in vitro lab studies but not in
humans. There also is an immunoglobulin that can be administered which are antibodies given
intravenously to fight off the virus but generally it's just considered in an exposed person
with severe immunodeficiency. I hope we don't start to see comments like masking can protect
against Monkeypox so the public at large should start masking without any evidence of benefit.
Actually that's already happened. This is from the New York City Department of Health
and Mental Hygiene. There's obviously no data that public masking is helpful for Monkeypox.
Of course if it were to be helpful we would want to know this
and if this were to be a virus that was going to spread significantly into the population
a proper randomized control trial would need to be done to show that masking is actually
helpful. As I've said in many of my previous Covid-19 videos we really failed to do proper
masking trials to definitively know whether there's a clinical benefit of cloth masks
even with surgical masks only one of two randomized trials suggested benefit
and the one that did was from Bangladesh and only 11% reduction in Covid-19 infection. Now
that's not to say that a highly filtered mask such as a fit tested N95 might be helpful.
It's completely appropriate that if someone like myself were looking after a patient with Monkeypox
for me or anyone else to take those precautions and put on an N95. Proper PPE including face
shield or goggles might be helpful and we would do that. Hand hygiene would also be important for
me. The patient of course should be isolated in a negative pressure room. The patient's exposed
skin lesion should be covered with a sheet or gown with a patient wearing a surgical mask.
There are other additional precautions we would look after in the hospital if a patient
came into the hospital including containment and disposal of contaminated waste such as dressings,
soiled laundry, patient care, equipment, and procedures would need to be in place for cleaning,
and disinfecting all environmental surfaces. Obviously this virus has been circulating in
other countries for a number of weeks and we're not seeing large scale outbreaks which suggests
that human to human transmission is quite limited at this time. I'm hopeful that this
will be contained as previous outbreaks have been. Understanding the characteristics of transmission
is important along with proper well-tested mitigation strategies studies to understand
the appropriateness of vaccination to prevent and control monkey pox are also important. Thanks a
lot for joining me today on Medicine with Dr. Moran. Remember get healthy and stay healthy..
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