Traveller’s diarrhea is the most predictable travel-related illness. Depending on destination and season of travel incidence can be from 30% to 70%. They are adding up approximately 40 million diarrhea associated cases each year. Food and water precautions are essential to decrease risk and treatment options are available to fight infection and dehydration. Traveller’s Diarrhea (TD) is a generalizes term for diarrhea caused by a bacteria, virus or parasite that is transmitted via contaminated food and water. Bacteria cause most TD infections.
Below is a list of areas that can be classified as low, intermediate or high risk for TD:
Higher risk for TD is associated with the following situations:
In general, bacterial and viral diarrhea is associated with abrupt onset of symptoms in 6-72 hours and ranging from mild cramps and urgent loose stools to severe abdominal pain, fever, vomiting and bloody diarrhea.
Protozoal diarrhea (giardiasis, amebiasis, cryptosporidiosis and cyclosporiasis) usually has a more gradual onset of low-grade symptoms, and symptom onset is usually 1 to 2 but sometimes a few weeks. Untreated bacterial diarrhea usually lasts three to seven days, while viral diarrhea lasts two to three days. Protozoal diarrhea can persist for long periods.
There are several highly effective antibiotics available for the treatment of bacterial TD, which can be taken with you if it occurs. A vaccine- Dukoral, is available to prevent Cholera and Enterotoxigenic Escherichia coli (ETEC), which causes approx. 25% of all TD infection and should be completed 2 weeks before travel.
Insect/Mosquito Bite Prevention
Many severe diseases are caused by bites of mosquitoes, ticks, fleas and flies such as Malaria, Dengue, Zika, Chikungunya, Yellow Fever, African Tick Bite Fever and Lyme Disease. Some may be prevented by vaccines or medication, but for others, the only option is avoidance measures. The risk of insect bite infections varies depending on the country, season and time of day. Consider the following precautions to protect yourself from bites of mosquitoes, ticks, fleas, and flies.
Insect/Mosquito Bite Prevention Strategies:
Use Insect Repellent (From CDC Website)
– Use EPA-registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone. Find an EPA-registered insect repellent that’s right for you.
– The effectiveness of insect repellents not registered with the EPA, including some natural repellents, is not known.
How to Apply Insect Repellent: Always Follow The Product Label Instructions.
– Reapply as directed.
– If you are also using sunscreen, apply sunscreen first, and insect repellent second.
– Do not spray repellent on the skin under clothing.
Application Instructions for Children
– Dress your child in clothing that covers arms and legs.
– Cover strollers and baby carriers with mosquito netting.
– When using insect repellent on your child:
– Always follow label instructions.
– Do not use products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) on children under 3 years old.
– Do not apply insect repellent to a child’s hands, eyes, mouth, cuts, or irritated skin.
– Adults: spray insect repellent onto your hands and then apply to a child’s face.
Permethrin: Treat clothing and gear (such as boots, pants, socks, and tents) with 0.5% permethrin (an insecticide). You can buy pre-treated clothes or treat your own clothes. If handling items yourself, follow instructions carefully. Do NOT use permethrin directly on skin.
Cover Exposed Skin: Wear long-sleeved shirts and long pants. Some bugs, such as tsetse flies, can bite through the thin fabric.
Avoid Bugs Where You Are Staying: Choose hotel rooms or other accommodations that are air-conditioned or have window and door screens with no holes, so bugs can’t get inside. If bugs can get into where you are sleeping, sleep under a permethrin-treated bed net that can be tucked under the mattress.
Get Vaccinated and Preventative Medication If Available:
Malaria is a major international health problem that affects approximately 215 million people a year worldwide and causes almost 500,000 deaths. The number of cases in travellers is increasing due to the increase in international travel and a lack of precautionary measures taken by visitors to endemic areas. The highest risk group is those that are returning to their native country to visit friends and family.
Malaria is a protozoan parasite, Plasmodium that is primarily transmitted by the Anopheles mosquito. Malaria transmission occurs in large areas of Africa, Latin America, parts of the Caribbean, Asia (including the Middle East), Eastern Europe and the South Pacific. Risk of transmission varies depending on several factors:
Symptoms usually develop in 7-14 days and typically start as flu-like symptoms, i.e. fever, chills, muscle pain, malaise. In severe malaria, symptoms can progress to seizures, mental confusion, kidney failure, respiratory distress, coma and death. Various treatment and preventative options are available depending on the type of malaria, destination and drug resistance.
No medication is 100% effective, and insect precaution measures are still necessary. Suspected or confirmed malaria infection is considered a medical emergency.
Travellers who have symptoms of malaria should seek urgent medical attention from someone experienced in tropical medicine and infectious disease.
One should not forgo medication for prevention and rely on treatment options at their destination as medications are often unavailable or subpar.
Zika is a virus that is transmitted primarily by an Aedes mosquito and also via blood product, e.g. transfusions, sexual contact and from mother to fetus. The mosquito is most active during the day, especially at sunrise and sunset. They can also be indoors and in shady areas.
Most infected people have no symptoms. If symptoms occur, they are generally mild. Common symptoms include fever, rash, joint pain, muscle pain, headache and conjunctivitis and arise typically 2 weeks after exposure.
The severe manifestation of Zika is its effect on a fetus as it can cause microcephaly and other brain abnormalities. Pregnant women should not travel to areas with Zika. Women who have gone to a Zika area should not get pregnant for at least 2 months, and men should use contraception for at least 3 months to avoid transmission.
There is no treatment for Zika infection, the only treatment for symptoms, e.g. pain killer for headache. There is no vaccine or medication for prevention, and insect precaution measures should be undertaken.
Dengue is found in most tropical and subtropical places in the world, including Florida, Hawaii and the Texas-Mexico border and especially in South-East Asia, Latin America and Latin America. There are approximately 50-100 million cases per year, including 500,000 cases of severe disease and 24,000 deaths.
Dengue is transmitted via the Aedes mosquito that is active during the day and is found in urban and rural areas. The mosquito tends to bite more early in the morning or late in the afternoon when it is cooler. They typically live indoors and are often found in the dark, cool places such as in closets, under beds, behind curtains and in bathrooms; they can also live in still water sites in outdoor urban areas such as plant pots.
Most cases don’t present with any symptoms; however, approximately 25 % of cases will have symptoms such as fever, nausea, vomiting, rash, aches and pains, abdominal pain and tenderness, persistent vomiting and bleeding mucosa. Severe Dengue, which occurs in about 5% of people, can cause hemorrhaging (bleeding disorder) and organ failure.
There is no medication available for prevention or treatment of Dengue; only supportive measures such as hydration, ASA (aspirin) and anti-inflammatory medications such as Ibuprofen should be avoided as they can make bleeding worse. No vaccine is available in Canada, and mosquito bite prevention measures should be taken.
Chikungunya is a virus transmitted by an infected Aedes mosquito, and often cause large outbreaks. Outbreaks have occurred in Africa, Asia, Europe, the Pacific Islands, as well as in the Caribbean and the Americas.
The risk to a traveller is highest during epidemics with increasing likelihood during the rainy season; however, outbreaks have occurred during droughts, especially in Africa, near open water containers as they act as breeding sites.
Up to 25% of infected people present no symptoms, and typically symptoms occur 3-7 days after being infected. Chikungunya presents with high fever and joint pains, and they may also develop a headache, muscle pain, arthritis, conjunctivitis, nausea, vomiting and or rash. Illness can last up to a week, and joint pain can often be severe, involving multiple joints. Joint pain is usually asymmetrical and bilateral and commonly affects hands and feet. Rash usually starts before fever onset and typically occurs on the trunk, palms, soles and face. Symptoms usually resolve in 7-10 days; however, some people can have persistent joint pain that can last months or years.
Treatment options are supportive and include pain killers and anti-inflammatories. No vaccine or preventative medication is available, so insect precaution measures are recommended.
Rabies is a virus transmitted via the saliva of a rabid animal. The signs and symptoms of rabies in an animal is not always evident as symptoms can vary. The rabies virus access into a person’s nervous system from a nerve synapse at the bite site. It then goes to the salivary glands so that the virus can be again transmitted. It can also be transmitted if rabid animal saliva comes into contact with broken skin. All mammals are susceptible to rabies though dogs and bats are often the culprits. Approximately 16-200 per 100,000 travellers are exposed to rabies annually.
Symptoms usually develop several weeks to months after exposure, once the virus has invaded the nervous system. Initial symptoms may present as pain, numbness, tingling or burning sensation. After that, rabies progresses quickly, resulting in encephalitis (inflammation of the brain). Signs of encephalitis may present as anxiety, muscle weakness, paralysis, spasms of swallowing muscles, delirium, convulsions, followed by coma and death. Rabies is always fatal.
Treatment for rabies is possible by injecting rabies immunoglobulin in the bite site and vaccinating within 24 hours of exposure and again on days 3, 7, and 14 days. Having a prevention strategy is essential. The vaccine is available for prevention as well and involves a series of 3 vaccinations at 0, 7 and 21 to 28 days. Post-exposure vaccination is still necessary even if a pre-exposure vaccine has been given, but it is simplified; only 2 doses are essential on days 1 and 3. Also, if travellers are going to a remote location, they have more time to get to a medical practitioner for treatment. Unless the animal is caught and tested for rabies, a traveller must always seek treatment since this disease is fatal.
Avoiding animal bites is essential:
J.E. is transmitted by the Culex Mosquito and is one of the most severe cases of encephalitis worldwide. Approximately 50,000 cases with 15,000 cases of long-term neuropsychiatric problems and 10,000 deaths yearly.
J.E. is mainly a concern in rural agricultural areas where there is standing water, e.g. rice fields. J.E. risk varies depending on destination, season, duration of travel and activities a traveller may be engaged in. The mosquitoes bite mainly at dusk and dawn and primarily outdoors. J.E. occurs mostly in Asia, especially S.E. Asia.
J.E. takes approximately 5-15 days before symptoms develop; initial symptoms may present as sudden onset fever, headache and vomiting. Neurological symptoms develop after a few days, these include mental status changes, generalized weakness, movement disorders.
Severe symptoms can be paralysis, seizures and Parkinson’s like symptoms (tremor). Death occurs in 20-30% of people, 30-50% of people have long-term neurological, psychiatric or cognitive effects. There is no medication available for the treatment of J.E.
The vaccine is available in Canada for prevention of J.E., 2 doses are required, 28 days apart. The vaccines can be taken 7 days apart if the traveller is leaving sooner. Mosquito bite prevention measures should be considered.
Measles is a virus transmitted from person to person via airborne droplets or from contact with oral or nasal secretions of the infected person. It is highly contagious with a greater than 90% rate of infection non-immune contacts. Globally large outbreaks have been occurring due to declining immunization rates and an increase in international travel. Since it takes 7 to 21 days for the onset of symptoms, a person could be spreading it unknowingly.
Symptoms include fever, rash, conjunctivitis, runny nose and small red spots with white or bluish-white centers in the mouth. A red, blotchy rash appears on the 3rd to 7th day and starts on the face before spreading to the body. Complications of measles are diarrhea, middle ear infection, pneumonia, encephalitis (brain inflammation), which can result in permanent brain damage.
There is no treatment for measles; however, the vaccine is available for prevention.
Leishmaniasis is a parasitic disease transmitted by the bite of a Sandfly typically at night or twilight hours as they are less active in the heat. It is found in many parts of the world, including some parts of the Middle East, Asia, Africa, Southern Europe, as well as Mexico and south and Central America. Cases have reported in the USA. It is more common in rural areas but has been found in urban areas.
Leishmaniasis is characterized by open or closed sores on the skin that can appear weeks to months, sometimes years after exposure. Lesions are usually painless but can get infected and be painful and can travel to lymph nodes, causing inflammation. Some can spread to the nose or mouth, causing deformities. It can be treated with medication, no vaccine or medicine is available for prevention, so avoiding contact with sand flies and preventative measures are recommended.
Meningitis is a bacteria transmitted person-person via respiratory droplets from an infected person. The highest incidence occurs in Sub-Saharan Africa in the “meningitis belt’ and Saudi Arabia during Hajj or Umrah (a religious pilgrimage to Mecca). Saudi Arabia requires proof of vaccination before they will provide a Visa to people making Hajj or Umrah.
The disease starts 1-10 days after exposure and > 50% meningitis. The most common symptoms are headache, fever, stiff neck and sometimes nausea, vomiting, light sensitivity and altered mental status. It is fatal in 10-15% of people.
Antibiotic is available for treatment but must be started early. A vaccine is available for prevention and is part of the childhood immunization protocol.
Hepatitis A is the most common preventable disease vaccine among travellers. It is a virus transmitted by direct person to person contact and via contaminated water, ice, shellfish harvested in sewage-contaminated water or from contaminated raw, inadequately cooked or frozen fruits, vegetables and other food.
The virus is shed in the feces of infected people. People are most infectious 1-2 weeks before symptoms appear. Hepatitis A is common in countries with inadequate sanitation or lack of clean water, such as parts of Africa and Asia. There have been outbreaks I Europe, Australia and North America.
Symptoms tend to emerge 15-50 days after infection and range in symptoms from none to mild to severe lasting several months. The disease is characterized by fever, malaise, anorexia, nausea, abdominal discomfort, followed within a few days by jaundice. Severe liver disease can occur but is uncommon.
No medication is available for treatment, only symptoms. The vaccine is available and highly effective with lifetime immunity for most people. It requires 2 doses at 0 and 6 to 18 months, depending on the vaccine.
Approximately 2 billion people worldwide have been infected with Hepatitis B, and more than 350 million persons have chronic lifelong infections. Hepatitis B is endemic in most countries of the world, especially the Far East, Middle East, Africa, South America, Eastern Europe and Central Asia.
Hepatitis B is a virus transmitted via blood and other body fluids, i.e.:
This virus is resilient and can remain infectious on environmental surfaces for more than seven days at room temperature.
Symptoms of hepatitis B occurs 45 to 160 days, with an average of 120 days after contracting it. In adults and children aged ≥ 5 years old, 30% to 50% develop illness typical after initial exposure to the hepatitis B virus. Symptoms include malaise, anorexia, fatigue, fever, after 1-2 weeks: nausea, vomiting, muscle and joint pain and jaundice. Most adults infected with Hepatitis B recover entirely, but some can progress to chronic hepatitis B infection.
In infants and children under 5 years, 30% to 90% progress to chronic infection while this occurs in less than 5% of adolescents and adults; Chronic infection with Hepatitis B results in chronic liver disease, including liver cirrhosis and liver cancer, severe and sudden onset hepatitis and death may also occur, especially in pregnant women and in infants born to infected mothers.
No treatment available for acute Hepatitis B but there is for Chronic condition. Vaccine is available for prevention and requires 3 doses at 0, 1 and 6 months. All 3 doses should be given before travel for >95% protection. If the traveller is leaving sooner, then they can receive the vaccine in an accelerated protocol of 0, 7, 21-30 days with a booster in 1 year for long term protection. A combination of Hepatitis A and B is available as well.
Yellow Fever is a virus transmitted via the bite of an Aedes or Haemagogus mosquito and occurs in Sub-Saharan Africa and tropical South America. It occurs in 3 transmission cycles:
The signs and symptoms of the disease vary in severity from asymptomatic to fatal and present after a period of three to six days. Symptoms can include Fever, chills, headache, backache, muscle pain, joint pain, nausea, vomiting, light sensitivity, mild jaundice, stomach pain and Faget’s sign (slow, weak pulse, contrasting with high Fever). Most people improve and recover; 15 % of people will improve for a few hours or a day then progress more severe or toxic diseases characterized by jaundice, hemorrhaging, shock and multi-organ failure with a fatality rate of 20-50%.
There are no available treatment measures; the risk of yellow Fever depends on destination, season, activities the traveller plans to partake in. The number of mosquitoes generally increases during and following a “wet season” (July– October in Africa, January–May in South America).
A vaccine is available for prevention of Yellow Fever; only 1 dose is required and provides lifetime immunity. Some countries require proof of immunity if you are arriving from a Yellow Fever endemic country to diminish the risk of bringing the disease to that country. This information changes regularly, so current information should be accessed at the time of departure.
Yellow Fever is a live vaccine that can be given to persons from 9 months of age. It should not be given to individuals with thymus disease altered, immune status such as HIV infection, immunosuppressive therapy, and given with caution in pregnancy, individuals with asymptomatic HIV, children 6-8 months of age and adults 60 years or over. A medical waiver may be provided if travelling to a Yellow Fever area and unable to receive the vaccine; however, travel to these areas should be avoided or postponed. Insect precaution measures are recommended.
Tetanus is transmitted via cut or scratch that is exposed to tetanus bacteria or via skin that is punctured by a contaminated object, e.g. nail, animal claws, glass etc. It can cause muscle rigidity and spasms and can sometimes be fatal.
Vaccine (Td, Tdap, Dtap or Adacel) is available in combination with Diphtheria and/or Pertussis and should be administered every 10 years. If a person has been exposed and it is more than 5 years since the last vaccination, a booster dose should be given.
Diphtheria is typically a respiratory illness transmitted by exposure to respiratory droplets in the air (e.g. from an infected person coughing) or by close contact with an infected person. In tropical countries, Cutaneous Diphtheria is present and causes skin lesions.
It is transmitted by coming into contact with the infected lesion.
Respiratory diphtheria symptoms usually start 2-5 days after exposure and affect mucous membranes of the upper respiratory tract (nose, pharynx, larynx, tonsils and trachea). It starts with mild fever, sore throat, difficulty swallowing, loss of appetite and a hoarse voice. The trademark symptom of diphtheria is a pseudo-membrane that covers the tonsils, pharynx, larynx, nasal passages and possibly the trachea.
Vaccine (Td, Tdap, Dtap or Adacel) is available in combination with Tetanus and/or Pertussis and is recommended every 10 years.
Pertussis (Whooping cough)
Pertussis is transmitted person to person via respiratory droplets in the air on contact with secretions. In developed countries, infants are at the highest risk as they are too young to be vaccinated. Pertussis typically presents as a mild upper respiratory infection with minimal or no fever. Symptoms start 7-10 days after exposure (range: 6-21) and are followed by spasmodic coughing (may sound like a “whoop”), and can often result in vomiting. Infants under 6 months of age may have symptoms of gagging, gasping and shortness of breath.
Vaccination is essential for travellers as immunity wanes, and if exposed to Pertussis, they can become infected. Pregnant women should be vaccinated at 27-36 weeks of pregnancy as antibodies are passed on to the infant.
Vaccine (Tdap, Dtap or Adacel) is available in combination with Tetanus and Diphtheria and is recommended every 10 years and at least once after the age of 19.