Travelers’ Health, Summer 2019 - Transcript

Moderator: Kellee Waters and Jonathan Lynch
Presenters: Jeff Nemhauser, M.D.
Date/Time: May 22, 2019, 1 p.m. to 2 p.m. Eastern Time

>> KELLEE: Good afternoon.  I’m Kellee Waters, a health communications specialist on the Emergency Partners Information Connection Team.  In CDC’s Center for Preparedness and Response, Division of Emergency Operations, thank you for joining us for today’s EPIC webinar, titled Travelers’ Health, Summer 2019.

Today we will hear from CDC’s Dr. Jeff Nemhauser.  If you do not wish for your participation to be recorded, please exit at this time.

You can earn continuing education by completing this webinar.  Instructions on how to earn continuing education can be found on our website, emergency.CDC.GOV/epic.  The course access code is EPIC0522.  With all the letters capitalized.  To repeat the course access code to receive continuing education units is in all caps EPIC0522.  Today’s webinar is interactive.  To make a comment, click the chat button on your screen and then enter your thoughts.  To ask a question, please use the Q&A button.  The Q&A session will begin after our presenter has finished.  Closed captioning is available for this webinar.  The button to enable this function can be found either at the top or bottom of your screen.

We are fortunate to have Dr. Jeff Nemhauser as our speaker today.  He is a captain in the U.S. public health service and a senior medical officer in the travelers health branch of CDC’s division of global migration and quarantine.  He is also the editor in chief of CDC health information for international travel, nicknamed the yellow book.

He received his medical degree from Hahnemann University School of Medicine in Philadelphia and board certified in emergency medicine.  Thank you for joining us today, Jeff, please begin.

>> JEFF NEMHAUSER: Thanks, Kellee, and welcome to everybody in the audience.  Hello from Atlanta.  I’m going to spend some time today introducing you all to the topic of international travel health or travel medicine and give you some information that you can use and share with others to help make sure that trips begin and end healthy.

If you’ll see the objective slide, you’ll see there are four main areas where I’ll be focusing my time with you, and these areas include giving you some awareness of current travel health concerns or what’s new in travelers health.  I’m going to talk to you about new or newish developments in travel medicine.  I’m going to talk about how to prepare yourself and others for healthy international travel.  And at the end, I’ll be sharing some of the resources that you and others can access as you’re preparing to go overseas.  So let’s begin.

Before we get started, let me introduce the branch where I work.  Who are we?  Well, the Travelers Health Branch is a group of physicians, scientists, and health communicators dedicated to the mission of protecting the health of U.S. residents traveling internationally or who are living abroad.  And what do we do to help achieve that mission?  We study and monitor illnesses and to a much lesser industry, injury, among travelers.  We also work with partners to learn about and then monitor disease outbreaks and other health threats in destinations around the world.

These are health threats that can have serious health implications for travelers and expatriates and we want them to know about them.

We currently do that using our travel health notice mechanism, and I’m going to talk about that later on.

We provide guidance and advice to international travelers and healthcare providers about what vaccines are needed when they’re going to certain areas of the world.  Areas where vaccine preventable diseases such as yellow fever, are endemic.  We also make recommendations about prophylactic medications travelers need to take to prevent diseases such as malaria.

We communicate our guidance and recommendations to a variety of different audience.  Our traditional audience has been the traveler and healthcare provider, we have a larger audience than that, including public health, the travel industry, and others.  Last, we develop and distribute event specific advice regarding the risks of travel during emergencies.

We can do this using the travel health notice mechanism I just mentioned, as well as by posting information on our CDC website.

One of my goals for today’s presentation is to give you all new awareness of topics in travelers health.  It seems like every day there’s something new going on in the area of travelers health.  Just open a newspaper or go online to your preferred news outlet, and you’ll find it.  From vector borne diseases like yellow fever, Zika, dengue, chikungunya, to older, well known, better established diseases we thought we had eradicated like measles.  International travel is a risk factor for exposure and potential infection.

Speaking of measles, there’s been a tremendous resurgence in this disease worldwide.  CDC is tracking about 30 countries right now where outbreaks are occurring and ongoing.  And that includes places like the United Kingdom, France and Japan.  Countries that like the United States had eradicated or nearly eradicated the disease.  In the U.S., there have been at least two large measles outbreaks.  We know most cases of measles in this country come from people who pick up the disease during international travel.  It’s highly contagious and travelers without immunity can be infected easily.  We also know that the best way to prevent illness is to be vaccinated before going overseas.  The measles branch at CDC partnered with the Travelers Health Branch to update the guidance we provide travelers on our county destination pages.

With all the outbreaks of measles in countries around the world, more than ever we really want to make sure that travelers going overseas are properly immunized or demonstrate adequate immunity, so they don’t bring it back to potentially, non-vaccinated communities.

Dengue we’re expecting to impact travelers more heavily this year.  It’s any of four single stranded RNA viruses named dengue virus 1, 2, 3, or 4.  A vector borne disease transmitted by the same mosquito species that carries Zika and other flaviviruses.  It’s endemic throughout the tropics and is a cause of febrile illness for those returning from the Caribbean and Southeast Asia.  Up to 400 million people get infected every year.  Approximately 100 million get sick from infection, and 22,000 die from severe disease.  About 75% of infections are asymptomatic, and even symptomatic dengue is a mild, nonspecific illness.  Those with severe life-threatening disease are the concern.  And left untreated, the risk of death approaches 10% with those with severe dengue.  After someone has recovered from dengue, they have immunity, but not to the other three types of virus.  The risk of severe infection increases if a person is infected a second, third or fourth time.  Unfortunately, Ebola is also back in the news.  This time, it’s in the Democratic republic of Congo.  The second largest Ebola outbreak in history.  Unlike the unprecedented outbreak of the disease in West Africa that began five years ago, this outbreak is occurring in a region of Africa where there’s political instability making it hard for agencies to respond with appropriate public health measures to help control the outbreak.  Things like contact tracing, isolation of cases and immunization of contacts.

And as you can see on the slide, as of the end of April, there were nearly 1500 cases and almost a thousand attributed to the disease.

In terms of drug resistant infections, just as travelers can bring back infections such as measles and dengue, they can also bring infections that are rare or highly unusual to see in the United States.  Asking about a travel history is critical to making the correct diagnosis for the individual, and for identifying a larger public health threat among travelers returning from particular destinations.

In 2014 and 2015, travelers to India, Haiti, the Dominican Republic and other countries returned to the U.S. with shigellosis, resulting in a large outbreak of ciprofloxacin resistant infections.  Among men who have sex with men, there have been outbreaks caused by multidrug resistant shigella.  That includes the United States, Australia parts of Europe, Taiwan and Canada.  People who travel internationally to receive healthcare, called medical tourism, can be at increased risk of infection with drug resistant organisms.  Last year, CDC worked with state and local health departments to identify U.S. residents who traveled to the Dominican Republic to have cosmetic surgery.  Several were identified with surgical wounds infected with non-tuberculous mycobacteria.  More recently, U.S. residents who were referred to a hospital in Mexico for bariatric surgery had a higher than expected rate of wounds inspected with a particularly difficult to treat organism.

And finally, this was reported widely in the news, candida, another particularly difficult to treat organism.  This being a fungal infection has been associated with travelers hospitalized in other countries.  All these drug resistant infections have serious implication for public health in the United States and our healthcare system as a whole.

So what’s new in travel medicine?  As I just discussed we’re expecting to see a peak in dengue cases in 2019.  Earlier this month, the FDA approved the use of a vaccine Dengvaxia, a live attenuated vaccine that protects against all four virus serotypes I mentioned.  Before we get too excited about using this let’s look at the indications and contra indications.  Dengvaxia is for children between 9-16 who are already living in endemic areas and who have laboratory confirmation of a previous dengue infection.  People who haven’t been infected before, the vaccine seems to increase the risk of severe dengue, so that’s not good.  We’re not expecting Dengvaxia to have much applicability for the majority of international travelers, but we’ll have to wait and see.

Yellow fever vaccine isn’t new.  And from time to time, there have been shortages in supply here in the United States.  But in 2018, the manufacturer of the only U.S. licensed FDA approved yellow fever vaccine ran out of stock due to production issues.  The manufacturer anticipated this and worked with the FDA to make an alternative vaccine available, a vaccine called Stamril, equal in efficacy and safety to YF-VAX.

Because of the legal issues surrounding the use of an imported non-FDA approved drug, the number of clinics that now provide yellow fever vaccine has decreased by an order of magnitude and then some.

From around 4,000 locations down to about 260.  So our advice, CDC’s advice has been for international travelers, planning to go to areas where there is risk of yellow fever, to plan far in advance of their travel to get their vaccine.

If they can’t get the vaccine, we’re encouraging them to modify their travel plans.  Yellow fever is a potentially deadly disease.

So Sanofi will have more information about when YF-VAX Will be available later in 2019.  So stand by.

Zika is not exactly a new topic to travel medicine either.  We’ve been dealing with the public health response to this illness for a couple years now since the large outbreak in the Americas.  What is new are the updated recommendations CDC has developed in partnership with the World Health Organization and the European Centers for Disease Control, ECDC.  The changes in our recommendations were predicated on the challenges to doing good Zika surveillance.

One, Zika is frequently mild or asymptomatic, so it’s hard to know clinically if someone has been infected or not.  Two, since the illness is mild or asymptomatic, infected people may not even seek care.  Three, the ability to conduct confirmatory laboratory testing may be limited depending on where a person lives.  And four.  Positive tests may not be reported in a timely way or at all.

So taken together, a lack of reported cases does not mean that there isn’t a risk of infection at a particular location or destination.  So based on these limitations, what do we do?  Well, as I said, the CDC, WHO, and ECDC got together to update the Zika travel recommendations as follows.

Countries that have ever reported Zika and yes, that includes the United States, are now considered to always have some level of potential risk.  The vectors there and the virus may be circulating.  Even at very low or indeterminate levels.  The CDC no longer recommends pregnant women avoid all travel to purple countries you see on the map.  Instead, public health agencies are encouraging pregnant women to speak and a trusted healthcare provider to discuss their level of comfort with the risk of travel and the potential consequences to the pregnancy.

What you don’t see on the slide, but what’s also a part of the recommendations and hasn’t changed is that pregnant women are not to travel to areas where there are ongoing, identified outbreaks of Zika.

In malaria, a new drug was recently approved by the U.S. Food and Drug Administration for the prophylaxis and radical cure of vivax malaria.  Radical your is the name given to the additional dose of medication given to people leaving a pandemic area in an effort to eliminate any protozoans that might be still circulating.  The advantage of this new drug is that it is a long half-life.  Travelers don’t have to take it as often.

The disadvantage is that like another quin-prophylaxis drug, it can cause severe hemolytic anemia in people with G6PD deficiency.  Testing is required before prescribing.  But it is the first new malaria drug to come on the market in many years, and it offers another alternative to people traveling where plasmodium vivax is endemic.

Let’s talk a bit now about planning for healthy international travel.  Pretravel preparation begins at least a month before travel.  We encourage people who are going internationally to get their recommended vaccines, any medications they may need and important advice on healthy travel.  Things like food and water safety, how to protect themselves against insect bites, traffic safety.  Many people, in fact more people that are injured or that are taken ill are injured in traffic accidents every year.  We also encourage people to get information if they fall into a special population.  For example, pregnant women, families with children, or immunocompromised travelers.  It’s also important to plan not only for healthy travel, but safe and secure travel as well.  So in addition to CDC’s resources that we will talk about later, we also encourage people to get in contact with the nearest U.S. embassy or consulate using the Smart Traveler Enrollment Program or STEP, which is available from the U.S. State Department.  And we encourage people to leave copies of their passport, credit cards, et cetera, with someone back home in the event that they run into some sort of difficulty.

It’s important to pack a health kit.  So that means important items to prevent and treat common injuries and illnesses.  Things like Band-Aids or other supplies that you may need on your trip in case you get blisters or other things happen to you while you’re away, and you may not be able to access them depending upon where you are.  We encourage people to take prescription medications with them, because you can’t always be assured, you’re going to get the medicine you take at your destination, or that it’s the actual medication you’re supposed to be taking.  You want to make sure that you take enough with you and that you have extra in case of delays.  We also encourage people to take an extra pair of prescription eyeglasses if they need it.  And as I said, don’t assume that anything that you’re familiar with or comfortable with or able to get here at home, you’re going to be able to get when you’re traveling internationally.  It’s also important to know when to seek medical care while you’re traveling abroad.  If you have diarrhea and a high fever above 102 degrees Fahrenheit, that would be an indication.  Bloody diarrhea, another.  If you’re taking malaria prophylaxis, it could be the early signs of malaria infection, and it’s important to seek medical care.  Anytime you’re bitten or scratched by an animal is another concern.  And of course, trauma of any sort, whether it be a motor vehicle accident, an assault, those are also reasons for seeking appropriate medical attention.  One of the things that the CDC recommends is that people get travel insurance before they go.  And there are a variety of types of travel insurance.

So there’s medical coverage, there’s trip insurance, and then of course, there is medical evacuation insurance.  If you’re going somewhere where you may be involved in rigorous activity or climbing or areas where you may be at greater risk and there may be a chance that you need to be evacuated.  Or if you have a health condition that may put you at additional risk, you may want to consider getting a package that allows you to tap into those resources to get you out of harm’s way or to get you to medical care that you’re more familiar with and more accustomed to in order to help you out.

I’d like to now end up the talk spending a little bit of time talking about some CDC resources and some other ways of being connected with the topic of travel medicine.

As Kellee said at the outset, we have a reference for healthcare providers and others who are advising travelers.  The CDC yellow book or health information for international travel.  It’s available both in hard copy and online.  And you can see the link there on your screen.  Or you can purchase it in hard copy from Oxford University Press.  The 2020 edition is now available for sale or I think they’re taking preorders at a variety of publisher’s — at the publisher’s website and places like  So you can get a copy for your own reference.

Travelers health website is another excellent place to go for information, which we frequently update.  It provides specific topics like food and water safety, insect bite prevention, road safety.  It also addresses, as I said, special groups of travelers.  Children, pregnant women, people with other underlying health conditions, senior citizens, et cetera.  And how they can prepare for healthy international travel.  We address specific groups like business travelers, adventure travelers, students who are traveling abroad, and all of those groups have special unique pages on our travelers health website.

The travel health notices, which I mentioned at the beginning and said I would get to is another way that we have here at the CDC of alerting people to situations that may be going on internationally.  The travel health notices or travel notices for short, are designed to inform people who are living or going abroad, and the people who are responsible for their care, about current health issues related to specific destinations.  And these issues can arise from disease outbreaks, special events or gatherings, natural disasters or other conditions that can affect travelers’ health.  You can see on the screen we have them divided into three different categories.  Level one, or watch, in which we are encouraging people to follow proper precautions.  People should be vaccinated against measles.  If you’re traveling anywhere, you should be vaccinated against measles.  You may want to know there’s an outbreak going on at a particular destination, but you should be protected before you even get on that plane to go there.

Level 2 or an alert would be an example of using enhanced precautions.  In other words, there may be particular groups who are susceptible or may be at risk for something, or they may need to take special precautions before they go.  An example of that would be rubella infection in pregnant travelers.  If a woman has not been vaccinated against rubella and she’s pregnant and travels to a place where a rubella outbreak is going on and gets infected, it can have serious consequences for her pregnancy.  So we want to make sure that we call additional attention to those kinds of situations.  And then finally, we have the warning or level 3, which is shown in red.  Which is to avoid non-essential travel.  An example of that might be the Ebola epidemic or sometimes we’ll actually put up a warning in situations where there’s been severe political unrest or where there’s been a severe natural disaster that has so adversely impacted the ability to provide resources where the hospitals are impacted, where there may not be clean water available.  Where we’ll encourage people really not to travel there, certainly not if they’re going for any reason other to serve in a humanitarian aid or relief capacity.

We also have our destination pages.  And the destination pages are divided into clinician and traveler-oriented materials.  Easy to read.  And we provide information on all the things that we’ve been talking about.  Food and water safety, insect bite precautions, other things like that.  What to pack.  We’ll also put up, if there are travel notices.

And this is where you can go if you want to know the specific — more information about the specific destination where you’re going, you can go directly to that page and get all the information that you need for any country around the globe.

We have print materials for travelers in English and Spanish.  You see the web link there.  Simply go to the web page, select travel health from the program’s drop-down menu, and you can view the different print materials that we have available.  We also have mobile apps on our website.  Can I eat this and CDC Travwell, which are two excellent resources you can take with you on the go and access from your mobile device.  If you’re somewhere and you’re not sure, is this something that I want to eat; is this something I should avoid; what’s the risk to me of eating this, that’s a great thing.  The Travwell also provides a lot of resources in terms of where you’re going, giving you information about risks and what you can do in order to mitigate those risks.  Another excellent resource.  So you can stay in touch with us here at the CDC and the travelers’ health branch through a variety of mechanisms.  We have a newsletter and travel notice alerts, and you see the link there where you can subscribe.  CDC info is another way of being in touch with us.  And every day we field both calls and e-mail messages from the public, from providers, from people who have traveled, from loved ones who want to know more information about a particular destination or the impact of international travel on someone.  And we’re there, available to respond to anything that may be escalated our way.  Those phones are staffed by operators who have trained in providing you with a response.  If they don’t know the answer, they send it to us, and we’ll be able to get back to you with the information.

Finally, our travelers’ health branch has a variety of social media channels.  Facebook, Twitter, and figure 1.  All of those are ways in which our communication team shares information about the work that we’re doing, about disease outbreaks and other information about how to stay healthy during international travel.  So that’s about it for today.  A quick whirlwind perhaps of international traveler health in 2019.  But thank you for tuning in, and I’m happy to entertain any questions.

>> KELLEE: Thank you, Jeff.  We’ll now transition to our Q&A session.  Jonathan, can you read the first question?

>> JONATHAN: Hi, everyone.  Our first question comes from an anonymous attendee who says, please advise when newly developed shingles vaccine, will be available overseas.  Particularly interested in southeast Asia or Thailand.  Also, if vaccinated against measles in infancy, is another that is a booster required when going to a measles endemic zone?

>> JEFF NEMHAUSER: The answer to the first question is I don’t know.  Perhaps we can try and get that information for this caller or for the person who’s asking the question.  I don’t know when drugs will become available internationally.  As far as the second question about a baby being vaccinated in infancy, if a child is — or an infant is vaccinated before the age of 1.  So for example, we do have the recommendation that infants between the ages of 6-12 months, if traveling internationally, they get a shot of measles vaccine.  That’s to protect them during their travel, but it only covers them for a short period of time, and once they turn 1, they need to get the full measles series.  As long as they’ve had both measles shots as prescribed according to the ACIP, that person should be protected for life.  And that is the current recommendations that we’re giving people.

>> JONATHAN: Thank you.  The next question comes from Caroline who apparently is planning a trip both to Bolivia and then to West Africa.  Who asks about taking doxycycline for the trip to Bolivia for malaria, and then taking Malarone when going to West Africa, and can they be taken at the same time?

>> JEFF NEMHAUSER: They can be taken at the same time, but they don’t cover the same organisms.  And so it’s important that she work with her healthcare provider to make sure that she’s taking the right antimalarial for the region of the world and for the likely protozoan that she’ll be exposed to when she’s traveling.  It’s also important to know that doxycycline can predispose people to sun sensitivity.  So it’s also important to be concerned about that.

But it sounds like she may have already spoken to somebody and has the information that she needs to know where to take what drug and when to take it.  So it sounds like she’s in pretty good shape.

>> JONATHAN: OK.  There won’t be problems with overlap if she goes from one location to the other.

>> JEFF NEMHAUSER: No.  She just needs to make sure she starts in the medication in advance of entering an area where she’s going to be at risk, and that she continues to take the medication after she’s left that area for any potential residual infection that she may have.  But her healthcare provider should be able to provide her with the specific dosing and prescribing information.

>> JONATHAN: Great.  Thank you.  The next question comes from Cathy Bridson who asks, can you speak to the need for measles vaccine for someone who is 56 years old and will be traveling internationally if they know that they were vaccinated as a child according to the normal schedule, but do not know their immune status.  Is a booster recommended?

>> JEFF NEMHAUSER: Right now, as I said, the current recommendations, and we can pull those up again.

>> JONATHAN: Stephanie is looking so you don’t have to go back to the slides.

>> JONATHAN: Cathy, I hope you’re looking forward to your trip.  We’ll have the recommendations up shortly.

>> JEFF NEMHAUSER: So as long as someone has had two doses, separated by 28 days, that would be an indication of appropriate immunity.  We also recommend that if someone has only one dose, which was the case, before 1989, that that person get a second dose.  So it all depends on when that shot was given and whether they got those doses before or after that cut-off date.  When the second dose was added to the prescribing regimen.

>> JONATHAN: The next question comes from Gene Collins who asks what about the change for yellow fever.  Now it only requires one dose.

>> JEFF NEMHAUSER: I didn’t understand the question.

>> JONATHAN: What brought about the change for yellow fever for now, only requiring one dose?

>> JEFF NEMHAUSER: That was looked at by both the World Health Organization, as well as the CDC.  And by looking at large numbers of people who had received the yellow fever vaccine, they were able to find evidence that those people were adequately protected or had adequate — evidence of adequate immunity long after the ten years that had previously been recommended.  It used to be recommended that somebody get a yellow fever vaccine every ten years if they were going into a yellow fever endemic area.  As I said, both public health agencies, WHO and CDC, made the determination that was in fact no longer the case.

There is a little bit of a difference between what CDC and WHO recommends, in that with CDC in particular, if you had a shot more than ten years ago and you’re now traveling into an area where there is an outbreak or there is a much greater preponderance of yellow fever infection above baseline than normal, CDC recommends that people consider getting a booster dose.  But that’s a decision that would be made in conjunction with a travel health professional.  In most cases, center people who are traveling internationally — in most cases for people who are traveling international, the one dose is sufficient.

>> JONATHAN: Great, and we also have a couple questions about hepatitis A and B.  One person asks if there are any updates or changes on the hepatitis A and B precautions.  And another comment — this is Caroline again, who asks if it is true that hepatitis A and B vaccines now last for life and don’t need boosters.

>> JEFF NEMHAUSER: I’m going to have to go and look that up.  I would be happy to get back to her on that.  But the last that I’m aware, I don’t recall hearing anything new on that recently.  But if she has specifics, she can reach out to us through CDC info or through whatever links it is that you provide to the people who are tuning into this webinar.  We’d be happy to get back to her on that.

>> JONATHAN: And this is  This happens sometimes where a question may come in that’s just a little bit off of the focus of the webinar.  And we’re happy to follow up and forward those questions on to presenters or other people as appropriate within the organization.  Our next — we have two comments from Annette Dandi, who is traveling soon to Tanzania.  She’s wondering what vaccines would be needed or if that’s harder to recall for every country off the top of your head, just a reminder how to acquire that information.  And Annette is wondering if Ebola is a threat in Tanzania.  Before you answer, I just want to comment, we’re doing a webinar on the Ebola crisis in Democratic Republic of the Congo next month.  That will be the June webinar.

>> JEFF NEMHAUSER: I can answer your question specifically about Tanzania.  But what I’d rather do is instruct you to go to the CDC website.  I think there’s a lot of information there that you can get that I won’t be able to necessarily communicate over the phone or over the line.  And just sort of going around the website and finding information, I think you may get something out of it more than me just sort of listing what vaccines or what medications you might need.  So I would encourage you to take a look at the CDC website or look at the yellow book.  If you have any questions, we’re more than happy to answer them, but I would encourage you to poke around a little bit and see when you can get on that.  As far as Ebola goes, to the best of my knowledge, right now, the outbreak is limited to the Democratic republic of Congo.  We are obviously monitoring all the countries that surround the DRC.  But to the best of my knowledge, Tanzania is not currently impacted by that outbreak.

>> JONATHAN: We have another question.  Are meningitis B vaccines indicated for certain population groups?

>> JEFF NEMHAUSER: We don’t generally recommend meningitis B for travelers.  Meningitis B is — unless there’s a known outbreak of meningitis B in a particular destination, generally we recommend the quadrivalent, which I believe is ACYNW are the serotypes of meningitis vaccine for people that we recommend for people going to meningitis endemic countries or people traveling to the Hajj where it’s a requirement by the Kingdom of Saudi Arabia that people are vaccinated.  But it’s not one we recommend as a routine travelers’ vaccine.

>> JONATHAN: Taking malaria prophylaxis in long term, greater than six months.  Any concerns?

>> JEFF NEMHAUSER: In fact, no.  There are people who are in areas where malaria is endemic, who are going to be spending more than six months in that area.  We want to make sure people are adequately protected.  Our concern is people who stop taking medication too early and they are at risk for infection with a potentially lethal disease.  So none that I can think of.

>> JONATHAN: Sometimes it seems like people who don’t live in malaria affected areas may not oftentimes realize how serious malaria is worldwide.

>> JEFF NEMHAUSER: Even people who live in those areas for whom they believe that they can develop some immunity to the disease, which isn’t true, or they believe that they’re somehow at lesser risk.  In fact, it’s one of the things we encounter in the visiting friends and relatives population, VMR.  There are many people in this country who take the opportunity to travel home to visit family, friends, relatives.  And the family, friends and relatives live in malarious areas, and people will travel.  They won’t take their malaria medication, and they will become infected while they’re there.  It’s hard to get that message out, you’re right.  But it’s important that people take their medications properly and as prescribed, in order to fight off that infection.

>> JONATHAN: Thank you.  Earlier we received a particularly interesting question from John sanders.  He asked what about warning people about feral dogs, especially in India and the Philippines?

>> JEFF NEMHAUSER: It’s a great point.  We know that rabies is a big problem.  It’s a big killer in places around the world, including in Africa and in other countries.  So yes, it’s absolutely important to make sure that people stay away from feral animals.  Many of those countries don’t have adequate vaccination programs for the animals, and as a consequence, rabies can be spread fairly easily.  That includes puppies and kittens as well.  People think you have to be an older dog or cat that can transmit the disease.  That’s not true.  It’s not just from bats.

It can be an animal licking an open wound.  An animal doesn’t necessarily have to display what we would consider to be the classic signs of rabies, with the angry posturing and the foaming at the mouth.  An animal can be completely asymptomatic, or without demonstrating any signs of the illness, and still be capable of transmitting the virus to people.  And rabies is a very serious threat.  It’s one of the things that we encourage people who may be doing wilderness activities or going out into areas where they may have a greater risk of exposure.  Those people may be candidates for pre-exposure prophylaxis for rabies.  And that would be something that again, we would encourage people to go visit with their travel health provider before they leave the country.  Let them know what their planned activities are and what the destination is.  And make appropriate plans to get the vaccine, if they’re going to be at higher risk.  And we know that some people are going to be in that category.  So thanks for the question.  It’s a good one.

>> JONATHAN: Following up on that, Mr. Jakomi asks what is the length or duration of protection for the rabies vaccine.

>> JEFF NEMHAUSER: I don’t remember that one.

>> JONATHAN: That’s OK though.  If you send the question to, we will follow up and get that information back to you.

>> JEFF NEMHAUSER: A little angel just whispered in my ear.  Three shots is good for the lifetime.

>> JONATHAN: Our clinic provides Cipro and azithromycin for travelers’ diarrhea.  You mentioned resistance to antibiotics, should they consider changing this practice?

>> JEFF NEMHAUSER: Our guidance is for mild diarrhea; we don’t recommend that people take antibiotics at all.  That in most cases, mild diarrhea gets taken care of on its own.  The body’s flora will correct whatever problem.  The issue is when somebody develops, as we said, either diarrhea and a high fever or bloody diarrhea.  Those are instance where’s people probably shouldn’t be trying to take care of the problem on their own.  That’s a situation where people probably need to be getting medical attention so proper diagnosis can be made and proper antibiotics can be prescribed.

I think the thinking on treatment and management of travelers’ diarrhea.  Prophylaxis of travelers’ diarrhea, and its ultimate management, that’s an evolving field.  It’s a very interesting one, but right now, I think our current recommendation is for people who have mild travelers’ diarrhea to ride it out as best they can.  It usually resolves within a period of about three days.  And not to prophylaxis against.  I think people giving antibiotics may be contributing to antibiotic resistance, depending on the causative organism.  And that depends on where in the world that person may be.  Yes, I think that looking at the literature and encouraging the people at that clinic to think a little bit more about what their practices are.  I think that would be encouraged and recommended at the time.

>> JONATHAN: For those kind of clinical questions, if you have a more detailed follow-up question, and send that to, I will forward that on to Dr. Nemhauser for more detailed discussion.

Do you recommend that travelers, everyone, receive the twin rex vaccine for hepatitis A and B rather than separate hepatitis A and B series?

>> JEFF NEMHAUSER: Do I have a preference for twinrix versus separate vaccines?  I don’t.  My opinion is people who are traveling internationally should have both vaccines.  And however they get it is how I would recommend that they get it.

>> JONATHAN: OK.  So I’ve been holding onto this question, because I know it might evoke a longer answer.  But the question regards cruise ships and noroviruses.  Can you just comment on that, maybe what travelers should be thinking about?

>> JEFF NEMHAUSER: Well, I think it’s a — let’s put it this way.  It’s a big enough of an issue that CDC has a whole team of people, the vessel sanitation program, who do almost nothing but look at norovirus on cruise ships.  So it’s certainly a big issue.  I think the best thing that people can do is, as we encourage everyone, to practice really scrupulous hand hygiene.  So really washing hands very well with warm water and soap.  When they don’t have a ready source of soap and water, to use hand sanitizers, alcohol based hand sanitizers.  And to be very careful about the things that they eat.  But we know that norovirus is very easily spread.  We know that norovirus can go through ships very easily and can in fact, go through several cycles of cruises.  So I’m not encouraging people not to take cruises.  I think people should go and have a good time.  I think they just need to think carefully about again, making sure that they keep their hands clean, that they keep their hands away from their nose and mouth.  Except for when they’re eating.  And to just be cautious about the food that they eat.  The other thing I want to bring up quickly is some people believe that drinking alcoholic beverages, if there’s — they’ve heard that well, maybe there’s bacteria in the water, in the ice, and somehow that the alcohol in the beverages will kill the infection.  In fact, that’s not true.  So it’s also possible to transmit infections that way as well.  So all of those things are things for people to think about and look out for.

>> JONATHAN: It’s possible that’s an excuse to drink more alcohol.


>> JEFF NEMHAUSER: It’s possible.

>> JONATHAN: A follow-up question from myself about that topic.  When we talk about hygiene practices, I understand that it protects people, say if they get some virus particles on their hands.  Maybe they wash their hands before they touch their food or mouth.  Does it also help protect other people?  Does it interrupt spread of the disease?

>> JEFF NEMHAUSER: Well, if you think of the fact that there are fomites or that there are these particles that are infectious, and if we pick them up on our hands and then we touch someone else, then theoretically that fomite can be spread from one person to another that way.

So I guess, yeah.  That’s another way of thinking of the — helping to protect the public’s health, as well as your own.

>> JONATHAN: OK.  Thank you.  It’s 1:52.  So we can take a couple more.  Do you have any recommendations for altitude sickness?

>> JEFF NEMHAUSER: In fact, there are recommendations for altitude sickness.  Again, I wouldn’t strongly encourage you to look at the CDC — I would strongly encourage you to look at the CDC website.  We have a whole chapter on altitude sickness in the yellow book that will give you a lot of details about that.  And in fact, there are a lot of different ways of treating altitude sickness, depending upon what form of the illness that you’re getting.  Depending on where you are.  What I would encourage you to do, again, is to not only look at that reference that we have on our CDC website, but to talk to a travel professional.  So if you’re going trekking, say to Nepal or going to climb Kilimanjaro.  People often most think of Acetazolamide, but there are others available.  Depending what altitude sickness form you’re prone to or what kind you have.  Whether pulmonary — it’s important to make sure that you not only look at our resources but speak specifically to a clinician who can make sure that you get the right medications for yourself, and that you know how to take them and when to take them.  Of course, the most important thing for altitude sickness, for severe altitude sickness, is to come down from altitude.  So that’s the thing that we always encourage people to do, if the medications aren’t working or if getting additional oxygen supplementation isn’t helpful.  But all of those things are spelled out on our website, or if you have an opportunity, and we strongly encourage you to make the opportunity to meet, before travel, with a travel health medicine specialist.

>> JONATHAN: And it looks like we’re running low on time here.  But I am going to — we had one follow-up on the handwashing.  Which is if you had a preference of soap and water for hand hygiene or using a sanitizer.

>> JEFF NEMHAUSER: That’s a great question.  Our recommendation is to always use soap and water if available.  Clean water and soap is really your best choice.  And then alcohol-based sanitizers is second.  And can be used as a supplemental measure.  But soap and water I think is always number one.

>> JONATHAN: Great.  Looks like we have time for one more and then we’ll close down.  And this is for people who are border dwellers, are there any — I imagine that would apply to borders in many different locations around the world.  Are there any different concerns living next to a different country?  People coming across the border or maybe there’s different practices in different countries.  That kind of thing.

>> JEFF NEMHAUSER: What we tell people is that diseases don’t know borders.  So you can put up a fence or you can put up a barrier, but if the disease is endemic to a region, and the topography, if the environment, if the climate is conducive on both sides of the border, then somebody’s going to be susceptible to those infections or those diseases or whatever conditions may exist on either side of the border.  We’ve certainly seen that in many instances.  So I don’t know that someone who’s living on a border specifically has particular unique concerns, other than to be aware of really what’s going on on both sides of that border.  Because on either side, there may be things going on that could affect their health.

>> JONATHAN: OK.  Looks like we have 3.5 minutes.  My colleagues are asking that we ask a question that came in from the chat section.  A little bit harder to see.  Does the CDC endorse the use of face masks when traveling, especially for air travel?

>> JEFF NEMHAUSER: We don’t, in fact, endorse the use of face masks during travel.  But that is a personal decision that we leave to individuals and to their healthcare providers.  Some people like to use face masks for, say for example, if they’re going to an area where there’s a lot of air pollution, in order to screen the air pollution or the particulates out of the air as they’re breathing.  Or some people may use them to try and filter out viruses or things like that.  Viruses are extremely small, and probably aren’t going to be adequately screened by whatever sort of a face mask that somebody can pick up at the store or at the drugstore.  And the decision about whether to wear a face mask or not, we leave that to the individual.  That’s not something where CDC has a policy or an endorsement one way or the other.

>> JONATHAN: OK.  Thank you.  I’m going to hand it back over to Kellee now.  And thank you, everyone.

>> KELLEE: Thank you, again, everyone, for joining us for today’s webinar.  If you have additional questions, you may e-mail them to  As a reminder, today’s presentation has been recorded.  And you can earn continuing education units for your participation.  Please follow the instructions found on  The access code is EPIC0522, with all letters capitalized.  Thank you again, everyone.  Good-bye.

Page last reviewed: May 1, 2019