Norovirus (Norwalk Virus) | Transmission, Pathogenesis, Symptoms, Prevention
Summary
TLDRThe video script discusses norovirus, a highly contagious virus causing acute gastroenteritis. Originating from Norwalk, Ohio in 1968, it's prevalent in winter and spreads via the fecal-oral route. Symptoms include abdominal pain, nausea, vomiting, and diarrhea, lasting 48-72 hours. Diagnosed clinically, treatment is supportive focusing on hydration. Prevention involves thorough hand-washing with soap and water and sanitizing with bleach, as norovirus is resistant to alcohol sanitizers.
Takeaways
- 🦠 Norovirus is a highly contagious virus that causes acute viral gastroenteritis and is the most common cause worldwide.
- ❄️ It is more prevalent in winter months, hence the nickname 'winter vomiting disease'.
- 🤒 Transmission occurs mainly through the fecal-oral route, often via contaminated water or food, particularly leafy greens.
- 👐 The virus can be shed in an infected person's stool for up to several weeks, even after symptoms have resolved.
- 🔬 Norovirus is resistant to alcohol sanitizers, requiring bleach for effective environmental decontamination.
- 🤮 Symptoms include sudden onset of abdominal pain, non-bloody vomiting, and non-bloody diarrhea, with vomiting being more common than diarrhea.
- 🏥 Diagnosis is primarily clinical, based on symptoms, though real-time qPCR can be used to confirm in outbreak situations.
- 💊 Treatment is supportive, focusing on hydration and symptom management, as it is a self-limiting infection.
- 🚫 There is no specific diet proven to reduce symptoms or duration, and the BRAT diet is not supported by evidence.
- 🧼 Prevention is key, emphasizing handwashing with soap and water and avoiding alcohol-based sanitizers.
- 🏃♂️ Asymptomatic individuals can still shed the virus, highlighting the importance of hygiene even when feeling well.
Q & A
What is norovirus?
-Norovirus is a highly contagious virus belonging to the Caliciviridae family. It causes acute viral gastroenteritis, which is inflammation of the gastrointestinal system.
How is norovirus transmitted?
-Norovirus is transmitted through the fecal-oral route, which can occur through contaminated hands, objects, water sources, and food supplies, particularly leafy greens.
Why is norovirus more common in winter?
-Norovirus is more likely to occur in winter months due to people being indoors more often, leading to closer contact and easier spread of the virus.
What are the symptoms of norovirus?
-Common symptoms include abdominal pain, nausea, vomiting (which is the most common symptom), watery diarrhea, myalgias, headaches, and fatigue. Fever occurs in approximately 50% of cases.
How long does the norovirus incubation period last?
-The incubation period for norovirus is roughly 24 to 48 hours, after which symptoms begin to appear.
How long do norovirus symptoms typically last?
-Symptoms of norovirus usually last for about 48 to 72 hours, but can last longer in immunocompromised individuals.
Can norovirus be diagnosed using a specific test?
-Diagnosis is primarily clinical, based on symptoms. However, real-time qPCR can be used to detect the virus's genetic material, especially in cases of epidemics.
What is the treatment for norovirus?
-Treatment is supportive, focusing on keeping the patient hydrated. There is no specific cure for norovirus as it is a self-limited infection.
Is there a vaccine for norovirus?
-There is currently no vaccine available for norovirus, although research is ongoing.
How can norovirus be prevented?
-Prevention involves hand washing with soap and water, as norovirus is resistant to alcohol sanitizers. Bleach is required to sanitize contaminated environments.
What is the significance of the term 'BRAT diet' in relation to norovirus?
-The BRAT diet (bananas, rice, applesauce, and toast) is sometimes suggested for patients with norovirus, but there is no strong evidence to support its use in reducing symptoms or the length of infection.
Outlines
🦠 Understanding Norovirus
The first paragraph discusses the norovirus, a common cause of gastrointestinal upset and its high infectiousness. It explains the virus's classification as part of the Caliciviridae family, its seven genogroups, and identical symptoms across them. The paragraph also covers the virus's prevalence, its peak occurrence in winter months, and its transmission through the fecal-oral route. It details how the virus spreads via contaminated hands, objects, water, and food, particularly leafy greens. The norovirus's stability in the environment and its ability to be shed in stool for weeks post-infection are highlighted, emphasizing the risk of prolonged transmission. The paragraph also describes the incubation period and how the virus affects the gastrointestinal system, leading to symptoms like decreased gastric emptying, jejunal lesions, and malabsorption of fats, which result in diarrhea.
🤢 Symptoms and Management of Norovirus
The second paragraph delves into the symptoms of norovirus, which include abdominal pain, nausea, vomiting, and watery diarrhea. It notes that vomiting is more common than diarrhea and that fever occurs in about half of the cases. Other symptoms like muscle aches, headaches, and fatigue are also mentioned. The paragraph addresses the duration of symptoms, typically 48 to 72 hours, with a longer duration in immunocompromised individuals. It also touches on asymptomatic carriers who can still spread the virus. The diagnostic process is briefly mentioned, with a focus on clinical diagnosis and the use of real-time qPCR in epidemic situations. The treatment is supportive, emphasizing hydration and symptom management. The paragraph concludes with prevention strategies, including hand-washing with soap and water, the ineffectiveness of alcohol sanitizers, and the necessity of using bleach to sanitize contaminated environments. It also mentions the absence of a norovirus vaccine and encourages viewers to seek more information on infectious diseases.
Mindmap
Keywords
💡Norovirus
💡Gastroenteritis
💡Fecal-oral route
💡Viral shedding
💡Incubation period
💡Gastric emptying
💡Jejunum
💡BRAT diet
💡Hydration
💡Hand-washing
💡Bleach
Highlights
Norovirus is a common cause of gastrointestinal upset and is highly infectious.
Norovirus belongs to the family Caliciviridae and has seven genogroups.
The name 'norovirus' comes from the first outbreak in Norwalk, Ohio, in 1968.
Norovirus is the most common viral cause of gastroenteritis worldwide.
It is often called the 'winter vomiting disease' due to its prevalence in winter months.
Transmission occurs through the fecal-oral route, often via contaminated surfaces or food.
The virus can be shed in stool for up to four weeks, even after symptoms resolve.
Norovirus is very stable in the environment, requiring special disinfection methods.
Incubation period is typically 24 to 48 hours before symptoms appear.
Symptoms include abdominal pain, nausea, vomiting, and watery diarrhea.
Vomiting is the most common symptom of norovirus.
Symptoms usually last for 48 to 72 hours but can be longer in immunocompromised individuals.
Asymptomatic individuals can still shed the virus and spread infection.
Diagnosis is clinical, based on symptoms, and confirmed with real-time qPCR in some cases.
Treatment is supportive, focusing on hydration and symptom management.
The BRAT diet and probiotics have not been proven effective for norovirus treatment.
Prevention involves handwashing with soap and water, and sanitizing with bleach.
There is no vaccine currently available for norovirus.
Transcripts
norovirus like the neuro fires are very
common causes of gastrointestinal upset
and are very infectious in the system we
talk about how we become infected with
these viruses we're also in chocolate
signs and symptoms how we can diagnose
and how we can treat it and most
importantly proper methods to prevent or
reduce the risk of becoming infected
with this virus in the first place so
the norovirus is a virus in the viral
family khaleesi viridi these are small
non envelope RNA viruses and there are
actually seven Geno groups of the
norovirus but all of them have the same
symptoms
so the norovirus causes an acute viral
gastroenteritis so important is it's
acute it's viral and it's a
gastroenteritis so itís meaning
inflammation so information of the
gastrointestinal system and in fact the
norovirus is so common that it's
actually the most common viral cause of
gastroenteritis worldwide in the name
norovirus actually is derived from the
place of its first outbreak in that
place was actually Norwalk Ohio United
States in the year 1968
so the norovirus is often called the
Norwalk virus because of this reason and
the norovirus is more likely to occur in
the winter months most likely due to
individuals being inside more often in
close contact the virus can spread more
easily so it's also known as the winter
vomiting disease so how is the norovirus
transmitted it's transmitted through the
fecal-oral route so if we see an
individual who has the norovirus you
want to look at their family members you
want to look at family members with
similar illnesses because those same
members can easily pass it along to
others through the fecal-oral route so
how does this happen so what happens is
an infected individual can essentially
become contaminated on their hands that
can touch different objects like full
mites which are objects like furniture
can come from contaminated water sources
so if feces from an infected individual
it's in two water supply it can lead to
contaminated water individuals drinking
that water can become infected and
related to this is also contaminated
food supplies so specifically the leafy
greens so contaminated water is getting
onto leafy greens if those greens aren't
washed properly we can get the virus on
those foods and it's very virulent it
only requires very small amounts of
virus to cause an infection usually less
than 100 viral particles so even a small
amount of virus can lead to an infection
in I alluded to this before but the
norovirus is shed in the stool from
infected individuals that is how it is
transmitted so again it's shed in the
stool and it's picked up in other places
an individual who's perhaps hasn't
washed their hands properly you can
touch objects and contaminate those
objects or can get into water or food
and what's really challenging about the
norovirus is that it can be shed in the
stool of an individual for approximately
four weeks and even months in some
patients especially patients with immuno
compromised so even after individuals
have gotten better they've resolved the
infection they can still be shedding the
virus for weeks but the good news is
that transmission of the norovirus is
more likely to happen if a patient is
symptomatic compared to if they're
asymptomatic but it can still happen if
they're asymptomatic and what's really
challenging about the norovirus is that
it is very very stable in the
environment so because of this we have
special ways to deal with this fires and
we're going to talk about that in a
later slides so once an individual does
become infected the incubation period is
roughly 24 to 48 hours so it takes about
24 to 48 hours after becoming infected
with the norovirus to actually start
showing symptoms so how does the
norovirus actually infect and cause
illness so what the norovirus does is it
affects the gastrointestinal system so
the stomach and intestines so what it
does to the stomach is that it decreases
gastric emptying and it's hypothesized
that this is actually the reason why
norovirus causes nausea and vomiting the
norovirus has also been shown to cause
lesions in the jejunum which is a part
of the small intestine in the norovirus
has also been shown to cause
malabsorption by affecting the intestine
mucosa and what it does is it reduces
the activity of enzymes like trelles and
alkaline phosphatase and it also
inhibits the absorption of fats so this
is how the norovirus is likely causing
diarrhea so again the norovirus is
leading to decreased gastric emptying
jejunal lesions and the
priest enzyme activity of trolleys and
alkaline phosphatase as well as
decreased absorption of fats leading to
diarrhea so after the incubation period
signs and symptoms of the norovirus
occur suddenly there's an abrupt onset
of symptoms and some of those common
symptoms of norovirus include abdominal
pain which is described as cramping in
nature and nausea and vomiting like we
mentioned previously and the National
vomiting is actually the most common
symptom of the norovirus but what we do
see is that the vomiting is non bloody
and non bilious we can also see watery
diarrhea again the diarrhea is non
bloody as well and it's described as
moderate diarrhea it's not excessive
like some other gastrointestinal
conditions but you do see four-day bowel
movements per day but what we do see
with the norovirus and what is key to
the norovirus is that nausea and
vomiting occur more often than diarrhea
so there are other viruses that cause an
acute viral gastroenteritis but if you
see an individual with more vomiting
than they are having diarrhea it's more
likely a norovirus
causing the infection and fever doesn't
always happen it's estimated that it
occurs in approximately 50% of cases
some of the other symptoms of the
norovirus include myalgias so achy
muscles headaches and fatigue so very
tired and what we do see is that
symptoms of the norovirus lasts for
about 48 to 72 hours but what's
important to recognize is that it may
last longer in some individuals
particularly in individuals with immuno
compromised and those individuals have
longer presentations and more severe
presentation so more severe symptoms but
we do also see some patients that become
infected with the norovirus and are
asymptomatic and this seems to occur in
approximately 1 in 10 patients even
though they're a somatic they can still
shed the virus in stool which means that
they can still spread the infection and
even after a patient has resolved the
infection so what we do find is that the
resolution of symptoms comes on very
quickly as well but even after they have
recovered from the infection they can
still have symptoms after the infection
and some of these include Harper and
constipation so some residual issues
with the gastrointestinal system so how
do we diagnose and how do we treat the
norovirus so when we're diagnosing this
infection when we're looking at
laboratory investigations we often see a
normal leukocyte count but in some cases
it can be mildly elevated and this
diagnosis is a clinical one so we see a
patient they're having those symptoms we
talked about before we see that they're
having more vomiting than diarrhea so
it's more likely to be norovirus causing
the gastroenteritis and the symptoms
resolved in 42 72 hours that's a
clinical diagnosis of norovirus in some
cases they may also do a real-time qPCR
specifically in cases where they're
looking for the source of an epidemic of
the norovirus so they want to make sure
that the cases are actually the
norovirus so they actually use the
real-time qpcr and detect the viral
genetics of the norovirus once we make
the diagnosis what is the treatment so
as I mentioned before the norovirus is a
self-limited infection the symptoms
resolve spontaneously so the treatment
is supportive so you want to make sure
that the patient stays hydrated and we
can also try to treat some of their
symptoms like the knowledge by using
anti nausea and there are some questions
as to should be use specific diet when
patients have the norovirus and there's
something called the BRAT diet which
stands for bananas rice applesauce and
toast and there was some question as to
should we use the BRAT diet to kind of
help their symptoms or to maybe reduce
the length of infection but there
doesn't seem to be any evidence to
support this and there's so some
question as to should we use probiotics
when they have this infection should we
use zinc again the evidence here is weak
as I mentioned before the norovirus is
extremely stable in the environment so
we have to use specific methods to
prevent it and those specific methods
are hand washing with soap and water we
have to use soap and water because it's
actually resistant to alcohol sanitizers
so even if we use an alcohol sanitizer
that's not going to cut it the norovirus
is actually resistant to alcohol
sanitizers and we have to use bleach to
sanitize a contaminated environment
other sanitizers don't work
the virus is too stable it's too
resistant so we actually have to use
bleach so again we need to use soap and
water for hand-washing we can't use
alcohol sanitizers with norovirus and we
have to use bleach to sanitize the
contaminated environment and there is no
vaccine currently available so there is
still some work ongoing as to the
development of a norovirus vaccine but
it is currently not available so again
it's a clinical diagnosis of norovirus
we use real-time qpcr in the event of
finding the source of the viral epidemic
treatment is supportive
it's a self-limited infection and
prevention requires hand-washing with
soap and water and no alcohol sanitizers
and we need to use bleach to sanitize a
contaminated environment so if you want
to learn more about other infectious
diseases please check my infectious
disease playlist and if you haven't
already please consider liking
subscribing and clicking the
notification ball to help support the
channel and stay up to date on future
lessons
live laughs and continue to always learn
and I hope to see you next time
you
Voir Plus de Vidéos Connexes
Giardiasis - Giardia Lamblia (Giardia intestinalis, Giardia duodenalis) infection
The Symptoms of Dengue
AMEBÍASE - ENTAMOEBA HISTOLYTICA - PARASITOLOGIA| INFECTOLOGIA
Typhoid Fever: Pathogenesis (vectors, bacteria), Symptoms, Diagnosis, Treatment, Vaccine
Infection Prevention Podcast - Ania Swann
Colorectal carcinoma - causes, symptoms, diagnosis, treatment, pathology
5.0 / 5 (0 votes)