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Travel Medicine on the Black SeaGary Podolsky MD
Objectives:
Introduction- what is Travel MedicineTravel Medicine, by definition is the prevention and treatment of illnesses associated with travelling, but this may be widely interpreted by a variety of clinics. We will define travel medicine to involve the health of travelers before, during and after their trip. Traditionally clinicians have focused on the prevention of infectious illnesses, mainly through giving advice and immunizations.
In the last several years there has been an increase in the number of choices available for travelers: different anti-malarial medications, different brands of vaccines, and more is known about the nature and distribution of illnesses.
One famous Travel Medicine doctor ruefully observed, "Travellers today may only be able to afford their vaccines but not their trip". We must try to present the appropriate information to patients without becoming to technical so that they may make informed decisions about their own health keeping in mind the benefits, costs, and adverse events.
One must keep abreast of the latest information available and educate all clients so that they may make an informed choice of what they want since cost as well as need must be factored in. It should be emphasized that many very cheap common sense habits and precautions are perhaps even more important than relying on expensive immunizations to keep travellers healthy.
This talk will focus on common situations that occur in a travel clinic. There are many ways of approaching certain problems and examples are taken from our travel clinic but there are many other perspectives as well.
Travel Medicine Practices Travel clinics should be familiar with all of the common immunizations for travel, including yellow fever (even if they themselves do not administer yellow fever onsite they should know enough to be able to inform patients). Phone Advice For Setting Up AppointmentsObviously every person comes in with a different medical history and distinct itinerary so that any advice suggested over the phone is for an itinerary and is not personal medical advice . Individuals needing specific advice must be assessed in person. Some vaccines are very strongly recommended while others are not. Some are even discouraged because we may feel there is not enough time to receive protection from them. It is only when our medical staff reviews a person individually that we can remark on what is either required or recommended in the context of their geographic destinations; activities planned or anticipated; and medical health or allergy profile for each patient. We encourage a discourse during our visits so that we can go over the benefits, limits and price of each vaccine so that our clients may have informed consent for everything they receive. At each visit we give a record of all immunizations administered including time for each booster date if required.
On-Line resources for Travelers who wish to research their itineraryMany travelers may wish to look up their risk of diseases by country themselves and this is now made easy by some very good websites.
Both the Centre for Disease Control (CDC) http://www.cdc.gov/travel/index.htm and World Health organization (WHO) www.who.int are very good places to start as they contain very detailed and frequently updated information and are often quoted as the source of other recommendations. They are the most likely places to find news of new outbreaks and news bulletins. Another well written website for travellers is www.travmed.com which also sells useful traveller supplies. They have an on-line book , International Guide to Traveller's Health , which is completely free from their site.
Health Care for Travelers AbroadWith the onset of the Internet and near universal access to the Internet patients travelling abroad may contact us. Email and Internet are not reliable 100% of the time and we never give advice to people we cannot examine. To keep our active travellers healthy we recommend they contact a reputable local physician recommended through their Canadian (or other country's) Embassy. Alternatively the International Society of Travel Medicine keeps a website of travel clinics at www.istm.org where travellers may find clinics.
We are also a part of IAMAT the International Association for Assistance to Travelers www.iamat.org . This group is fee to join and will help travelers find physicians abroad at standardized rates. Our clinic is similarly available to see travellers coming to Canada who are also seeking medical aid within our Healthcare system.
Travel VisitsWhen the patient is seen it helps them to fill out a standard form of their demographics, and medical history as well as additional information on their previous immunization record (if known) and nature and duration of their travel.
Short term travelers will be at less at risk of significant diseases while long term expatriates will approximate more of the risk of a regular native who lives there. North Americans are of course wealthier, have access to better food and accommodations so that they may be much less at risk of diseases. Some developing countries may also under report disease.
General statements regarding the prevalence of commonly acquired diseases are available (see references) and these have gone into making recommendations for each country. Various authorities do not always agree on the same advice for identical situations, but in modern travel medicine there is usually agreement. WHO and CDC guidelines are accessible by everyone and currently available for everyone. In the early days of Travel medicine this information was more privileged and updated infrequently but is much easier to find today. Physicians with computers can easily practice simple travel medicine by looking up country recommendations and anti-malarial advice. The decision to give specific immunizations is based on the prevalence of the disease and the likelihood of the traveller acquiring it. Many vaccines have become more expensive so that the patient must also agree to pay for them.Traveller's DiarrheaThis is very common in travelers and may approach 50% in some trips. Although not usually serious, cramping, diarrhea, pain and dehydration may occur.
Taking Pepto-Bismol 2 tablets four times daily will significantly decrease symptoms. We do not recommend preventative antibiotics but people may take a strong antibiotic like Ciprofloxacin to treat diarrhea if they get it (500mg twice daily) and Imodium.
There is one vaccine against E.coli but it only works 20% of the time.
Some areas of the world are now resistant against Ciprofloxacin such as Cambodia and Azithromycin is used here instead. Diarrhea in the returned traveller may represent simple traveller's diarrhea or be from a parasite.
Cyclospora a relatively new protozoa, is resistant to cipro but very sensitive to Septra.
Giardia may also be in the differential diagnosis.
Other parasites are possible. Some travelers living long term in endemic countries will periodically deworm themselves by taking mebendazole 100mg twice per day for 3 days. If clinical suspicion part of the work up for post trip diarrhea may include stool analysis for ova and parasites.
Common Immunizations :
Tetanus Diptheria (Td) should be up to date and given every 10 yrs. This is standard within Canada and also applies to travellers.
Recently adult pertussis has been suggested to be added to the Td formulation. In Manitoba an adult pertussis is added to the Td received at age 14 although no recommendations for use in travellers or those with tetanus prone wounds have been made.
Polio (IPV) This may also be combined with Td (Td-polio) or given separately (IPV), and should be given every 10 yrs for travelers travelling outside North America. In 2001 a polio outbreak occurred in the Dominican Republic and Health Canada had recommended that all travelers to the Dominican Republic consider polio boosters. Recently there have been no further cases and at present the Western Hemisphere is considered polio free. Childhood polio series are still completed. Polio is recommended for travelers to India, Africa and other areas that have still had cases. It is hoped that near universal vaccination will decrease the amount of susceptible people available thereby ending wild type polio transmission. Using a model similar to the small pox eradication program polio may be likewise gone. Immunizations for travelers should proceed until eradication is certain.
Figure 5 Distribution of tetanus diptheria and polio Hepatitis A vaccine is also strongly recommended for most of the developing world. Hepatitis A is acquired from contaminated food or water and can make people very sick.
Hepatitis A may infect up 0.3 % of travellers (per month) staying in endemic areas regardless of the type of accommodation. Backpackers and those who go off the beaten path have higher rates. Usually Hepatitis A is self-limited even with jaundice and illness. Some individuals, particularly over 40 years may die from it. The vaccine gives protection for 12 months. A second dose, which must be given no sooner than 6 months, will boost this protection to at least 10-20 yrs and by some research likely lifelong. This is the most cost effective travel vaccine.
Figure 6 Distribution of Hep A an B
Hepatitis B is a different virus also causing hepatitis, although it is acquired through blood and body fluids. It is more common, is easier to catch and kills more people than HIV. Risk factors for Hepatitis B include: contact with blood and other bodily fluids, unclean needles, unprotected sex (although even condoms do not reduce the risk to zero), IV drugs, and blood transfusions. People who will be staying longer than 3 months in countries where Hepatitis B is very high are also recommended to have this vaccine.
Those going for very short periods 1-2 weeks and not exposed to the above risk factors do not need Hepatitis B. They may still wish it for cumulative risks from other sources.
Hepatitis B should be given in 2 full doses one month apart with a booster dose after 6 months. (0,1,and 6 months).
All the different brands of Hepatitis A and B are equally effective. Some people prefer the pre mixed vaccine of Twinrix but if they use this brand they must receive 2 full doses to be adequately protected against both Hep A and B. Twinrix should be given in 2 full doses one month apart with a booster dose after 6 months. (0,1, and 6 months).
Typhoid Typhoid is a bacterial food borne illness and is suggested for travellers going to higher risk countries such as Africa and India. It is not usually recommended for resorts and tourist vaccinations but may be considered for extended or off the beaten path travels.
Two types of vaccines are used: • Injectable Typhoid (Typherix or Typhim Vi), which is good for 3 years. • Oral typhoid (ty21a) is 4-vaccine capsules, which are taken on days 0,2,4, and 6. Antibiotics and alcohol interfere with the vaccine. This vaccine gives 5 years of coverage.
Figure 7 Distribution of Typhoid
Rabies Rabies causes 60,000 deaths worldwide, half of which are in India. Countries completely free of rabies include: Australia, New Zealand, Japan, Honk Kong, Singapore, Great Britain, and some Scandinavian countries. The virus Rhabdoviridae Lyssavirus causes rabies. All mammals are capable of transmitting the disease to other animals or people. 99% of cases are from dogs.
Figure 8 Rabies Distributions in the World
Animal commonly carrying rabies:
Infections with rabies occur when the virus is first inoculated into the victim and then absorbed into a susceptible cell where it multiplies. The virus then enters nerve endings. The virus will migrate to the brain and once the virus has entered the brain, rabies symptoms begin to occur. Rabies is almost universally fatal afterwards. The term rabies refers only to when the person has the fatal condition. The average incubation time before the development of symptoms is 90 days, although is has occurred is as little as 7-10 days up to greater than a year. Rarely, only a few days resulted in rabies and 1 case took over 16 years to emerge. Children tend to develop symptoms faster because bites are closer to the brain (the virus has less distance to travel towards the brain), and is often more severe. Symptoms of rabies in people are divided into 2 types - encephalitic (furious) and paralytic (dumb). Early symptoms may be vague and non-specific (fever, upset stomach). Local symptoms may occur at the bite site (burning, numbness, tingling or itching).
Characteristics of encephalitic (furious) rabies:
After a rabid bite the rabies vaccine is usually given on days 0, 3, 7, 21, and 28. The vaccine is given in the deltoid (or thigh in children). It is not to be given in the gluteal muscle because there is poor absorption of the vaccine when it is given in the gluteal area.
Sometimes a double dose of the vaccine is given on day 0 if the patient is immune deficient or had a very bad bite. If a person who had been previously vaccinated within 5 years is bitten they only require 2 booster doses at days 0 and 3 but do not need rabies immunoglobulin.
Rabies immunoglobulin is given to those people with severe bite(s) who have no prior antibodies. (Antibodies will bind to the virus to prevent it from entering nerve tissue and spreading to the brain.)
This should be given as soon as possible after being bitten since rabies has developed a few days after being bitten. People will begin to produce their own antibodies 7-10 days after being vaccinated. The immunoglobulin should be injected into the wound with a separate syringe from one used for the rabies vaccine. Treatment should not be withheld while waiting tests or quarantined animals.
Intradermal injection of vaccine for post rabies exposure is done in some developing countries, which is much cheaper since less vaccine is given intradermally. The vaccine is given at days 0, 3, and 7 in double doses; and at days 28 and 90 at single doses. Some North American centres will give intradermal injections for pre-exposure since this is likewise cheaper. However when doing the intradermal method, these patients have to be followed closely by lab tests to confirm the effectiveness of this type of immunization with extra injections given if a low immunoglobins titre is found.
Complied by Gary Podolsky June 2001 Reference 1. Pasteur Merieux Connaught monograph 2001 W.H.O- guidelines on rabies.
Japanese Encephalitis Virus This is a mosquito acquired flavivirus infection that occurs in Asia. At least 35,000 cases with 10,000 deaths are reported yearly. The virus is similar to Yellow Fever and other flavivirus.
Most infections are not symptomatic. One in 250 infections cause illness after 5-15 days of incubation. Illness begins with a high fever, changes in mental status, gastrointestinal symptoms, headache followed by disturbances in speech, gait or motor problems. Symptoms progress to stupor and coma. Five-30% of cases are fatal and 1/3 of survivors may have neurological injury. Treatment of Japanese Encephalitis is mostly supportive for affected people.
Japanese Encephalitis Vaccine Japanese Encephalitis Vaccine is used to protect local populations in Asia who are most at risk. Others, such as military personnel or expatriates (people who live as residents during a transmission season) may consider the vaccine. In most Asian countries the peak Japanese Encephalitis season lasts about 5 months and traveler's need only be vaccinated if at high risk during that time.
The Japanese Encephalitis vaccine is given in 3 doses administered at 0,7, and at 14-21 days, with a booster at 3 years. Side effects of vaccination include local redness and soreness at vaccination site, low-grade fever, and muscle aches. Allergic reactions to JEV have occurred up to 20-336 hours after vaccination, which are treatable with corticosteroids and antihistamines.
In conclusion, Japanese Encephalitis is extremely rare in travelers but immunization may be indicated for select people.
Figure 9 World distribution of Japanese encephalitis
Reference: The Textbook of Travel Medicine and Health, Second Edition 2001 Herbert L. Dupont, M.D., Robert Steffen, M.D.
Required Vaccines. Most immunizations are elective and patients may decline if they wish. Only Yellow fever and Meningitis vaccines are still required by some countries for entry. This information may change with epidemiology and governments policy changes.
In the past smallpox and cholera were also required. Small pox is considered eradicated but has recently been discussed as a bioterrorist threat but there is as yet no convincing evidence that this is true.
Cholera has been and is sometimes demanded by Ugandan and Sudanese officials although this is not officially required. The WHO does not recommend cholera vaccine.
Yellow FeverYellow fever is a virus transmitted by daytime biting mosquitoes in Central and South America and Africa. It has a high mortality rate and countries fear its accidental importation by unvaccinated travellers.
Many countries require proof of immunization with the Yellow Fever Vaccine if travelers are arriving from countries that might have yellow fever. Each country has its own list and some include all countries.
Travelers may require proof of Yellow fever vaccination, especially if going through multiple countries, purely for political purposes
Travelers may also be recommended Yellow Fever vaccine due to the actual risk of disease.
Sometimes the recommendations and requirements are different. This can be confusing and people may phone our clinic line for clarification. This information is also available at www.travmed.com or www.who.int .
The Yellow fever vaccine is considered safe for healthy people, but some individuals who were immune compromised, ill or very old have become very sick and a few have died from this vaccine.
The risk of a serious adverse event is recognized as less than one in several hundred thousand or less, and no serious adverse events have occurred in Canada. Despite this, vaccination is still recommended and is still required for entry into some countries. Only registered clinics, as certified by Health Canada are able to give this immunization.
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High risk groups identified include College age Students living on and off campuses Military Recruits Correctional Institutions These are all groups that have young adults clustered together. Some American universities require meningitis immunization prior to admission, although this is not consistent. For these people meningitis vaccines that are conjugated and that protect against meningitis type A are recommended, and give very long protection. |
Two conjugated meningitis vaccines are available in Canada that gives very long protection against the type c disease.
Outside of North America other types of meningitis exist and a different vaccine is needed. Menomune gives protection against types a, c, w-135, and y. This is a polysaccharide-based vaccine and is only effective for about 3 yrs (different countries estimate between 2-5 years).
A new product, conjugated meningitis vaccine is effective against type a, c, w-135, and y has been licensed in the US in 2005 and is expected to arrive in Canada next year will give much longer protection (? lifelong). This immunization is not really needed in North America but will have a huge public Health benefit in the African countries that lie within the "meningitis belt"
Figure 11 Meningitis belt of Africa
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Meningitis Requirements and Recommendations for Travelers |
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Meningitis immunization with Menemune is recommended for travelers with "extended contact" going to: The Sub-Saharan African "meningitis belt" Other countries including Nepal and Outer Mongolia but to a much lesser degree. This list may change so please check with us regarding up to date recommendations. |
Meningitis Vaccination Is Required For All Travelers To Saudi Arabia For Entry |
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Malaria
Malaria affects 500 million people worldwide and kills at least 2 million per year. Over one million Africans die yearly (mostly children). Yearly, 30,000 Europeans and North Americans are affected. Anopheles mosquitoes are responsible. They carry malarial parasites, (plasmodium falciparum, vivax, oval, or malaria), which are four different species.
Anopheles mosquitoes are sometimes identifiable by the way they bite (head downward when biting), compared with Culex mosquitoes that stand parallel. Female mosquitoes of the Anopheles type bite at night or twilight. Urbanization may create areas where mosquitoes may breed close to people (stagnant water).
Mosquitoes don't travel more than two miles from where they are bred. Weird exceptions are airport malaria acquired by passengers being bitten by mosquitoes indoors during stopovers. Wind could also blow mosquitoes further away. Only female mosquitoes drain blood. Males eat nectars and fluids.
Malaria is caused by a parasite transmitted by certain species of mosquito. Once a mosquito bites an infected person the parasite, a gamocyte enters the mosquito and breeds internally creating oocytes and then sporocites, which travel to the salivary glands of the mosquito. These sporocites can penetrate the liver of an infected human within 45 minutes. Within 9-16 days the sporocites differentiate into merozites, which invade red blood and liver cells. Blood cells rupture, releases gametocytes and merozites, which cause the cycle of fevers and chills.
Different malarial species cause different severity of diseases all of which are bad. Sometimes malaria may be easy to recognize, but also sometimes difficult to diagnose. Symptoms of malaria may be very subtle - flu like attack, fever and chills which may lead to multi-organ failure and death. It is important to note that malaria medication will lessen symptoms of malaria but does not guarantee immunity. Malaria chemoprophylaxis helps prevent life threatening malaria that will kill people before they reach medical attention. Any symptoms should be investigated with a thick and thin malarial smear. This can still lead to misdiagnosis, as a smear may not "catch" parasites on microscopic analysis. If malaria is suspected, one normal smear does not rule it out. It is generally assumed that any returning traveller with fever has malaria until proven otherwise. Many other infectious diseases may also manifest with flu like symptoms but malaria is the one diagnosis not to miss.
Many other mosquitoes co-exist with the Anopheles mosquito-Aedes aegypti, Culex, Haemogogus, Sabethes, and Masonia, which cause other diseases like yellow fever, filariasis, viral encephalitis, dengue and other hemorrhagic fevers. Other insects (tse-tse flies, black flies, deerflies, sand flies, lice, ticks and mites) cause a variety of illnesses, many of which have no known vaccine or medication to prevent illness as well as no good treatment. General recommendations are to avoid all insects similarly to malarial mosquitoes.
Prevention is best accomplished by avoiding being bitten. Wear long sleeved shirts and long pants. Use insect repellent, sleep under a mosquito net, use mosquito coils, don't sleep on the ground, and check for ticks and insect bites daily. Travelers should be knowledgeable of the signs and symptoms of the diseases you may likely encounter where you are travelling.
Types of medication to prevent malaria (chemoprophylaxis) include:
Chloroquine: (Aralen ): Cheap, well tolerated but bitter in taste, can cause upset stomach and blurred vision. There are many areas resistant to Chloroquine. Medication is started one week prior to travel, and taken weekly during and for four weeks after trip.
Mefloquine: (Larium): More expensive, but 2-5% of people reported side effects (anxiety, nausea, hair loss, poor sleep, irritation). It is used where Chloroquine resistance. Medication is also weekly, starting one week before, during trip and for four weeks after the trip.
Doxycycline : Daily medication used where there is mefloquine resistance or as an alternative to above. Side effects include stomach irritation and photosensitivity. It is started two days prior to the trip, and continues for four weeks after leaving area.
Chloroquine, mefloquine and doxycycline should be taken for 4 additional weeks after leaving the malarious area because they are only effective for malaria in the blood. Since the parasite may be in the liver for 4 weeks, they must also be taken for that long. Long-term use should be monitored for adverse effects but has been used for years in expatriates.
Malarone: (Atoraquine/Proquinil): Is new, but expensive and can cause nausea and vomiting. This drug may be started 2 days before the trip. It is taken daily and then discontinued 7 days after the trip. It is discontinued sooner because it is effective at killing malaria in the liver. So there is no need to take this medication as long as mefloquine, Chloroquine or doxycycline.
Self-treat malaria kits are available. Many travelers would do self-testing and then treat themselves with strong anti-malarial. Large doses of malaria drugs in a sick person are not without side effects. Self-treatment is not recommended by our clinic since we feel that many travelers will over treat themselves. Instead preventative measures are best and one must seek medical attention immediately if ill. Ninety percent of travelers with malaria do not become ill until after they return home. This illusion of good health may foster urban myths among travelers on laxity of mosquito precautions.
Taking medications to prevent malaria is not a perfect solution but is still the over all best way to prevent malaria. All the malaria medications have some type of side effects but the benefits of them preventing malaria far outweigh these effects.
Other Travel Medicine Issues
Cruise Ship Medicine
Travelers embarking on Cruise vacations should also consider immunizations for the countries visited in port as well as contact with crew and other passengers
Travelers going on cruises may have concerns about seasickness, risk of outbreaks and other concerns, which may be addressed during their immunization visit. This will be discussed in our Cruise ship session.
Scuba Medicine
Scuba concerns are also a frequent issue with travellers
Any diver with an acute problem suggestive of a serious dive accident must attend the nearest emergency centre for immediate treatment. Our clinic is listed as a resource through the divers alert network , and can be consulted on for dive injuries but acute cases must always go through the emergency department.
Divers Alert Network (DAN at www.diversalertnetwork.com ) is an excellent resource for divers with pre existing medical problems as well as those with suspected Dive injuries. They have a good travel insurance plan for divers and also provide phone assistance for divers.
Aviation Medicine
Our clinic sees many people with anxieties and questions about flying. Our session on in flight emergencies will discuss medical concerns that may arise aboard aircrafts.
Jet Lag
Jet Lag is encountered as travelers cross time zones and is typically worse going east. Various treatments and diets have been advocated.
There is benefit to exercise in the morning on arrival and exposure to bright light. Both benadryl and melatonin have been used (melatonin is not licensed for use in Canada). Benzodiazepams and sedatives should be avoided as they generally make sleep worse.
Conclusions
Travel Medicine remains an interesting new discipline. There are many references available to assist family physicians in developing their own travel services for patients. Specialized or exotic travels may require referral to specialized travel clinics.
References:
Travel Medicine and Migrant Health.
International Society Travel Medicine, General Meeting, 2001
Baxter monograph on Tick Borne Encephalitis
International Travel Health Guide 2001 - Twelfth Edition: Stuart Rose, M.D.
Textbook of Travel Medicine and Health- Second Edition: Herbert L. Dupont, M.D., Robert Steffen, M.D.
Canada Communicable Disease Report Volume 27, No.15 - August 1, 2001
Key Travel Health Information Sites for Canadians
World Health Organization http://www.who.int
International Travel and Health: Vaccination Requirements and Health Advice, January 2000 edition www.who.int/it.english.index.htm
Detailed country by country yellow fever vaccination and malaria requirements
Disease Outbreak News - http://www.who.int.emc/outbreak_news/index.html Listings of current outbreaks, along with archives dating back to 1996
International Immunization Profiles - http://www.who.int/gpv-surv/intro.html Listing of international immunization profiles and schedules from the Global Programme for Vaccines and Immunization.
Centers for Disease Control and Prevention http://www.cdc.gov/travel/index.html Includes information on disease outbreaks around the world, geographic health recommendations, and information on specific diseases.
Health Information for International Travel (Yellow Book) - http:/www.cdc.gov/travel/reference.htm complete text of the 19999-2000 editions available electronically at the above URL.
Includes in-depth information on: vaccination and disease prevention; yellow fever vaccine requirements and malaria risk and prophylaxis by country; and information for travelers with special needs
The Blue Sheet - www.cdc.gov/travel.bluesheet.htm
Summary of Health Information for International Travel " Lists cholera, yellow fever, and plague infected countries.
Morbidity and Morality Weekly Report - http://www2.cdc.gov/mmwr/mmwr_wk.html Weekly CDC publication containing information useful for travel health practitioners
International Society of Travel Medicine http://www.istm.org/
Listings of travel clinics in over 50 countries around the world
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