In this Ask the Experts feature, John C. Christenson, MD,
director of the Pediatric Travel Medicine Clinic at Indiana University,
discusses the current concerns that travelers should be aware of when
traveling.
What destinations/diseases are the most concerning right now?
The big issue that affects travelers going to all parts
of the world is an upsurge of measles, especially in Europe. The implication
this has for the US is that non-immune travelers are bringing measles back.
There has been an increased number of cases in the US that will lead to a high
number of cases for 2011. Certain groups in the US may have taken for granted
that for many years, measles was not a serious problem. Recently, the CDC made
a recommendation that anybody traveling abroad should be sure to be up-to-date
in their vaccines against measles (MMR). Children as young as 6 months can
receive a dose of MMR.
John C. Christenson, MD
Pertussis and hepatitis A have been conditions
associated with travel abroad with the intention of adopting young children.
Those travelers have to be protected against pertussis and hepatitis A, not
only for themselves, but to prevent it from spreading it to other people back
home.
What immunizations are recommended for all travelers, according to
region?
When people come to the travel clinic, it is important
to consider not only vaccines against exotic diseases, like Japanese
encephalitis virus, but also routine vaccines to protect against hepatitis A,
measles and pertussis should be updated if needed. This is especially pertinent
in adults. Hepatitis A vaccine is by far the most frequently recommended
vaccine, especially for travelers to the developing world where the quality of
water and food, and sanitation may be substandard. Physicians have to do a risk
assessment for other types of vaccines. The risk depends on a variety of
things: history of transmission, the quality of sanitatary infrastructure, and
the type of activities the traveler is planning. Here are some other
recommendations, according to region:
- Africa — Sub-Saharan Africa has the highest concentration of
malaria transmission in the world. Those traveling to this area should receive
antimalarial prophylaxis. In the same region, there are many countries with
yellow fever; travelers should be vaccinated. Some countries require
vaccination before entry into the country. Many countries in this region fall
in the “meningitis belt”, where travelers are more susceptible to
develop meningococcal infection that may cause sepsis and/or meningitis.
Travelers should receive the quadrivalent meningococcal vaccine, especially
during the dry season (usually December-June). In northern Africa, the risk is
high for hepatitis A and typhoid fever. Several countries in southern Africa
are not endemic with yellow fever and don’t require vaccination. Malaria
transmission is also variable within many countries in these regions.
- South America — Malaria is endemic within the Amazon, including
parts of Brazil and Peru. Yellow fever is also a concern. People traveling to
tropical areas need to receive yellow fever vaccine and antimalarial
prophylaxis. Many countries within South America with higher altitudes are free
of malaria and yellow fever. However in these areas high altitude illness can
be a problem for some travelers. In some cases, a medication such as
acetazolamide may be indicated to prevent the condition.
- Southeast Asia — Malaria and typhoid fever are endemic in this
region. Another big problem in this region is dengue fever, a mosquito-borne
viral infection commonly associated with significant morbidity and frequently
with mortality. There is no vaccine or medication for this condition. Bite
avoidance through the use of appropriate insect repellents, clothing and
bednets are highly recommended. In the rural areas of countries in this region,
individuals may be at risk for Japanese encephalitis virus infection. If risk
is considered to be prolonged or frequent exposures are anticipated, vaccine
should be administrated. Rabies remains a serious concern for travelers to this
region. Vaccination is highly recommended for those planning long stays, or who
are traveling with young children at risk for dog bites.
- South Pacific — In some islands of this region, malaria can be
problem, so malaria prophylaxis would be appropriate. Dengue fever remains a
problem in this region as well.
Most travelers to Europe, Japan, Australia and New
Zealand don’t require any special vaccines. However, their vaccinations
against measles should be current.
Are certain populations more susceptible to the various diseases? Are
there any groups with special considerations?
Based on available studies, the group of travelers at
the highest risk of acquiring a preventable disease are those who are visiting
friends and relatives, which is known in travel medicine as the VFR group. They
eat the local food without restrictions, and they also frequently do not take
bite-avoidance precautions. Only a small percentage of these travelers visit a
travel clinic before their trip to receive vaccines or education on how to
prevent disease. These travelers often travel for longer periods of time and
are more likely to visit rural areas where access to health care may be
lacking; and risk of infection are higher. Other travelers, such as those who
travel “off the beaten path,” are at higher risk for diseases. For
example, the risk for infection is higher for someone who is backpacking
through South America than for a traveler who is going to a more touristy type
of place. We also worry about young children. Depending on what part of the
world they’re going to, it might pose a high risk for them.
Has there been an increase of any infection in the US, resulting from
travelers bringing it back?
Measles has been the big problem this year. Importation
of mumps has been a problem in past years. We always see malaria; it’s
always a prominent infection. There is minimal risk for transmission of malaria
in the United States.
Aside from immunizations, what can travelers do to protect themselves
from diseases that are endemic to where they are traveling?
Depending on the country and type of activity, it can be
basic things like behavioral changes, like type of food they consume. When
possible, they should consume foods that are well cooked. Avoiding tap water to
drink or brush teeth reduces the risk of travelers’ diarrhea. In places
where malaria transmission is high, travelers should wear proper clothing
(long-sleeved shirts, long pants) and use insect repellent. One of the most
common health issues that affect travelers is not even infectious, it’s
injuries. Sprained ankles and broken bones are serious problems among
travelers. Injury prevention is one of the things we try to emphasize. Young
children require supervision at all times. Hotel rooms and family homes need to
be child-proofed. When traveling in motor vehicles, carseats and booster seats
should be used to restrain young infants and children. — by Emily
Shafer
John C. Christenson, MD, is the director of the
Pediatric Travel Medicine Clinic at Indiana University. Disclosure: Dr.
Christenson reports no relevant financial disclosures.