Whether you've traveled before or not, living and working overseas can be challenging. Learn how best to prepare and make the most of your time internationally. This course will prepare you to work and live overseas. It explores the epidemiology of common morbidity and mortality among travelers and examines key prevention, safety, and travel medicine principles and services to contextualize risks and maintain wellness. The course reviews applicable interventions, appropriate vaccines, and personal protection methods to prepare you to respond to expected and unexpected situations and will challenge you to examine travel health and safety priorities through case studies and discussions. The Honors Lesson will assist you with personal preparations for travel through the creation of a country-specific profile.
Food and Waterborne Diseases
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Do curso por Johns Hopkins University
International Travel Preparation, Safety, & Wellness
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Travel Health & Prevention
It's easier to stay healthy if you know how to anticipate potential challenges, minimize your risk, and access the care that you need.
Conheça os instrutores
Anna KalbarczykResearch Associate
International Health
Hi. My name is Summer Rosenstock and
I'm one of your co-instructors for
the international travel preparation safety and wellness class.
Picture this.
You arrive in a new country, ready and eager to start working, exploring and
learning all about this new country you just landed in.
You hit the ground running.
You're experiencing and trying new things, and then you feel that gurgling,
bloating, cramping in your stomach that stops you in your tracks.
You're not alone.
Living and working overseas in developing countries puts you in contact with lots of
opportunities to also experience diarrhea.
You will find that for the first time,
talking about bowel movements at a dinner party is normal and common conversation.
In this section, we will be talking about diarrheal diseases.
What causes them, how to avoid them, and
what to do when you inevitably get one while living and working abroad.
All right, so let's start out by talking about what causes diarrhea.
There are quite a few causes.
80% of all traveler's diarrhea is caused by bacterial enteropathogens.
So these are things like E coli,
Shigella, things that we often see in the United States as well.
We also see a variety of viral enteric pathogens.
These might be things like norovirus, rotavirus.
And then there are parasitic enteric pathogens.
These might include things like amoebic dysentery, Giardia.
And then there's also just the plain old stomach upset because
you're eating new things and your body's not used to it.
Upset stomach that you might experience.
I'm sure at this point in your studies you know how diarrhea is transmitted.
But for review, this is a fecal, oral route.
So basically, this is ingestion of fecally contaminated food or water.
This may seem easy to control, right, just don't eat contaminated food.
In many countries though, where toilets enclosed sewage systems are not available,
fecal contamination happens very easily.
The fecal count on money or in the sand alone can be really high.
Let's talk about incubation period.
There are a variety of different incubation periods,
depending on the kind of diarrheal disease you might be experiencing.
So for a bacterial pathogen, those happen much more rapidly.
So maybe 6 to 72 hours between exposure and symptoms.
But parasitic pathogens, it can happen any time between a few days to a few months,
but often it's one to four weeks after exposure.
So let's say you're in country for a few months, and then you're home, and
a few weeks later you suddenly feel sick.
It's still good then to make sure that it's not something parasitic.
So what are some of the symptoms that you could experience
when you encounter diarrhea?
Usually, it includes abdominal discomfort, cramping.
Often comes with bloating, but always comes with loose or
watery, and sometimes explosive stools.
It can often be sudden onset, so all of a sudden you're feeling okay one minute,
and then the next minute you're suddenly feeling very sick.
And this also falls hand in hand with an increased urgency to go.
So again, one minute you're fine, and the next minute, you're suddenly rushing for
the bathroom.
It also comes with increased volume and number of bowel movements.
So you might be having four or
five bowel movements per day that are watery or loose.
It can include fevers, chills.
It can also include sweats.
Sometimes you might experience vomiting in addition to the diarrhea, and
then there are cases of dysentery which means that it includes blood or mucus.
So, this especially happens with things like amoebic dysentery, and
there are variety of others that include mucus or blood.
One of the things to be aware of is that it can be intermittent.
And what that means is you might have a few days of feeling really awful, and
then you're good for a little while.
And then all of a sudden you have a few more days of feeling really awful.
And this actually happened to me.
We were living in Togo, and I pretty much had Giardia and amoebic dysentery for
about two years straight.
We came back the United States, I was still
having some problems with diarrheal episodes, and I was told that
it was probably just because the lining of my intestines was still healing from
my previous exposure to the variety of parasites I'd been carrying with me.
And then after a few months, I started having severe cases of diarrhea again.
So I went back into the doctor, and she said, I think you still have Giardia.
And I said, no, no.
That's impossible.
My intestines are still healing, but it seems like it's a long time for
my intestines to be healing still.
So, she then tested me, gave me some medication, and
48 hours later I was feeling much, much better.
So I'd been carrying Giardia around with me for
a solid nine months after I returned to the United States.
So, it's just good to be aware that it can be intermittent.
So, of course, location can really change your level of risk.
There are some countries where encountering
diarrheal pathogens are going to be fairly low, places like the United States,
Canada, Western Europe, you're usually pretty safe and
normal exposure that you would expect to find here in the United States.
There are countries that are especially high risk.
And these include places like most countries in Asia,
the Middle East, Africa, Mexico, Central and South America.
And then there are obviously countries in between.
So, my husband and I, when we were living in Togo,
we would often see people with Gatorade or oral rehydration solution on their desk,
and that's how you knew who was suffering at the moment.
And at any given time, 20,
30% of the office had something like that sitting on their desk.
When we lived in Indonesia, it was a totally different story.
Even though it's a fairly high risk country still,
people weren't consistently suffering from diarrheal diseases.
So really, it depends on where you are and what you're being exposed to.
So what can you do to minimize your risk while you're living abroad, and
having these great experiences, and building your resume, and
really learning the trade of public health?
Well, first and foremost, let's talk about water.
A good rule of thumb is to always drink bottled water, or
water that's been boiled and treated with iodine or chlorine.
I find that drinking bottled water is definitely safer than treating it, but
there are options for treating.
One of the things that people forget about a lot is that adding ice to that bottled
water is really detrimental to the safety of that bottled water.
Normally, ice is made with tap water, which of course,
carries a really high risk for contamination.
The other thing that people don't think about or
consider sometimes is things like tooth brushing, contact lens cleaning.
You're going to want to think about using bottled water for these tasks as well.
Not everybody does, but I certainly suffered from less diarrheal episodes than
my husband did and I used bottled water for my tooth brushing and he did not.
So, just food for thought.
A warning about bottled water.
So over the years of living and working overseas,
my husband and I found some really interesting things going on.
We would go to buy bottled water, and we would find that the water seemed like it
was in a good bottle, labeled, it looked sealed, but if you looked really closely,
some of the children who were selling these bottles of water had taken a match
to the seal and had melted it back together in key places so
that it appeared sealed and it was just refilled with tap water.
So, that's sort of something that you really want to make sure that it's
actually really sealed, and it's not opened or hasn't been resealed.
And we encountered that in multiple countries, so just to put it out there.
Other beverages that you're going to want to think about,
you're going to want to avoid unpasteurized dairy products, so
milk directly from the farm so to speak.
You also want to avoid fresh fruit juices.
These can carry high risk.
Some things that you can feel pretty good about though are bottled sodas, hot tea,
coffee, beer, wine.
All of these things are usually pretty safe.
When you do, though, open a bottle or
can of something that you feel like should be pretty safe to drink,
do remember to clean off the outside of the bottle or the can before drinking it.
Because all of that dirt and possible fecal contamination could be waiting for
you to ingest on the outside of that can or bottle.
When we talk about food, the rule of thumb is sort of boil it, cook it, peel it, or
forget it.
So you'll see that on all sorts of websites all over the place talking to
travelers about how to stay safe when ingesting food overseas.
But more specifically, some things you might want to be thinking about
are avoiding eating from street vendors.
And I have certainly lived by this rule and not lived by this rule, depending on
where I was and how adventurous I was feeling, and I've certainly suffered more
and less based on my vigilance in eating or not eating from street vendors.
You definitely want to avoid raw and
undercooked meat or seafood, and I think that's probably true worldwide.
Again, you want to avoid those unpasteurized dairy products.
When you're eating raw fruits and vegetables,
you want to make sure it's stuff that you've personally peeled.
So, if somebody has peeled all the bananas for you and is handing them to you,
the potential for their hands not to have been properly cleaned and
then passing on fecal contamination on to you is pretty high.
So the longer you live and work in a particular country, the more likely you
are to become adventurous enough to go to the market yourself, pick out your own
vegetables and fruits, and bring them home and decide you're going to cook a meal.
And just remember that things that you can't peel, like bananas or
oranges or other fruits and vegetables that are peelable,
have a high potential for having some sort of fecal contamination.
Especially high risk foods include things like lettuce,
where the water is actually being pulled up into the food itself.
And there aren't really great ways of cleaning vegetables like that.
However, there are ways to sort of disinfect
vegetables like red peppers and cucumbers, and things like that.
And so you should definitely make sure that you find out what the most
appropriate disinfection methods are for the country that you are living in.
And in general, just eat well-cooked food.
So we're in the school of public health, and
washing your hands seems really obvious, in fact, there are entire behavioral
campaigns around it in the school, outside of the school, and developing countries,
in the United States, you see these campaigns everywhere.
When you can use soap and water, that's great.
I find personally that I get my hands cleaner using soap and water,
especially if there's actual physical dirt on them.
If that's not possible, having some hand sanitizer with you is a great option.
But remember, hand sanitizer doesn't kill everything.
The rubbing part of using hand sanitizer and the rubbing part of using soap and
water is potentially one of the best parts of hand washing and
most effective parts of hand washing.
And so, hand sanitizer rule of thumb is you continue to rub all parts of
your hands, fronts, backs, in between, until it's completely dry.
With soap and water, as I tell my seven year old,
you want to make sure you're singing your ABCs a couple of times and not too fast.
But it is really important that you're getting in between the fingers,
under the finger nails, you really want to make sure those hands are clean.
So almost everyone gets diarrhea at some point while living abroad.
The key is keeping hydrated, and knowing when to seek additional treatment.
Let's talk about diagnosis.
There's symptomatic diagnosis, which is basically if you're having three or
more loose watery stools per day, there's probably something going on.
And it could be something that's simply going to pass on it's own,
or it could be something that's going to require more treatment.
If it requires more treatment, probably lab diagnosis is going to be necessary,
and that's going to require stool samples that are collected and
tested for bacterial or parasitic infection.
And usually you're doing this when you have persistent or really severe diarrhea,
and you really feel like you need some additional treatment.
These stool samples have to be collected in very specific containers that usually
a health provider will give you,
so that they are preserved properly and usable for testing.
So lab diagnosis is not 100% correct though.
I've certainly had parasites and gone in for a lab testing, and
everything came out totally fine, and
I knew with 100% certainty that everything was not totally fine.
And the people who are in the lab will tell you that you don't shed bacteria, or
you don't shed cysts, or whatever they're looking for
consistently in every stool sample.
So sometimes it's going to take several times of testing to really find it.
You'll find sometimes doctors will give treatment on the assumption that you
are correct, that things are not right, and you get better,
and if you don't, then they continue testing.
And certainly, the treatments for bacterial and
parasitic infections are different and so that lab diagnosis is important.
What about treatment?
Oral rehydration solution, which I'm sure you all have heard about at
some point during your education here, is really the best choice for rehydration.
And again,
one of the key components of getting through diarrhea is staying well hydrated.
That's what really gets you in trouble, is if you get very dehydrated.
Oral rehydration solution is going to be your best choice for rehydration.
It has just the right balance of exactly what you need.
You can often find, in developing countries, pre-packaged packets of this
sold at a pharmacy or some other kind of convenience shop.
And those are great packets to use.
Sports drinks are going to be a second choice for rehydration, but
they're still fairly effective.
Gatorade has been my friend many times and has kept me very well hydrated.
Beyond sort of the symptomatic treatment of keeping hydrated, and of course,
symptomatic treatment would also be, if we go to the bottom of this list,
things like Pepto-Bismol or antimotility agents.
Just a word of warning that antimotility agents,
even though they help control the diarrhea, are not always recommended.
Especially for those with bloody diarrhea, those with a fever with diarrhea.
But actual treatment is going to include an antibiotic when you've got something
bacterial or parasitic.
If you've got a fever with diarrhea,
you've probably got something going on that's going to need treatment.
Obviously, if you have bloody diarrhea, again, probably something that's going to
need some sort of treatment for some sort of parasitic infection.
Just a word of wisdom from experience,
consumption of alcohol makes diarrhea really significantly worse.
And you may think to yourself, why in the world would I be drinking alcohol if I am
having consistent horrible bouts of diarrhea?
When you live overseas for
a long period of time, and everybody just sort of consistently has diarrhea,
it becomes [LAUGH] just sort of part of life sometimes.
And you go to work and people don't take days off for it,
and it's just sort of the way things are.
And so if you go out, you have a beer or a glass of wine, and
all of a sudden you come home and you have no idea why you are so crazy sick.
And it's because for certain kinds of diarrhea,
alcohol sort of works as a catalyst to really stir things up.
Or that's been my experience anyway.
So, if you are having intestinal issues,
it's really good to stay away from alcohol.
Some of these parasites can be hard on your liver.
Some of the treatments can be hard on your liver.
And it just is a bad combination.
It's inevitably going to happen that you're going to expose
yourself to something at some point that's going to make your stomach upset, and
whether it's a small upset, or it's something that really requires treatment,
you will get through it with keeping some key things in mind and
making sure you're staying hydrated and getting proper treatment.
They key while you're overseas is to explore, have fun,
try new things, experience the culture, experience the food, and the country.
Just take some small precautions and eat smart.
>> Thanks Summer.
This is Anna jumping in to round out this section to talk about a few food and
water borne diseases that you may encounter while you're traveling.
The first one I want to discuss is typhoid.
And typhoid is transmitted by the consumption of contaminated food or water.
This can include fecal-oral transmission, shellfish from polluted areas, and
contaminated milk products.
Areas of high endemicity for typhoid include North and West Africa, South Asia,
parts of Indonesia, and parts of Peru.
All travelers to endemic areas are at potential risk,
though the risk is a bit lower in tourist areas and in business areas.
The good news is that there is a vaccine for typhoid.
In fact there are two.
There's an oral vaccine and an injectable vaccine.
So it just depends on what your comfort level is with injectables.
The oral vaccine requires reactivation after every one to two years.
And you should have your vaccine administered
before you start taking malaria prophylactics.
So this again is just a timing consideration for when you're planning to
travel and when you start thinking about your travel health and wellness.
The injectable vaccine needs reactivation every three years.
Please remember that neither vaccine offers 100% protection.
In fact, it's not even close.
And so food and water safety, as Dr.
Rosenstock had talked about earlier, is really key to preventing typhoid.
Hepatitis A is among the most common vaccine preventable infections
that is acquired during travel.
And you can see on this map that hepatitis A,
you're really at risk almost anywhere you go in the world.
Hepatitis A is common in areas with inadequate sanitation, and
limited access to clean water.
Higher endemic areas include parts of Africa and Asia, though again, if you're
looking at the map, you can see that many countries across the world are at risk.
Prevalence of hepatitis A also varies greatly within a country by region.
The most frequently identified risk factor for hepatitis A is international travel.
And this is among travelers leaving the United States.
So that's not necessarily all travelers from different parts of the world, and
the risk is highest for those who are visiting rural areas,
those who are trekking or backpacking, or frequently eating and
drinking in settings with poor sanitation.
So maybe those of you who might be up for a little bit more risk and like to
have street food, your risk is probably a little bit higher for getting hepatitis A.
All travelers to countries with intermediate or
high hepatitis A endemicity should be vaccinated.
And this is regardless of the purpose of your travel, the frequency of your travel,
or how long you're going to go.
And the vaccine should really be administered as soon as travel is
considered.
So this is an easy one.
As soon as you're starting to think about it,
make sure you get that hepatitis A vaccine to prevent this food borne disease.
And I want to take a moment to wrap up and talk about recreational water.
And in a different section, we talked about schistosomiasis, and
the issues around getting schistosomiasis from recreational water,
from fresh water, but there are a number of other illnesses that you can get.
And even just looking at this photo here,
you can see that we've got a child playing, you've got livestock,
there's likely contamination of the water from feces from both children and animals.
So, take a look around as you decide to go swimming,
decide to go rafting, and look at your surroundings, and
really see what is going on in an area and what you need to consider,
and maybe what you need to talk to your travel doctor about once you get home.
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