Information on Travelers’ Diseases and Tests for Them

The term “travelers’ diseases” is an inclusive category for any sort of infection or illness that one might acquire while traveling, particularly when going from a well-developed region into a less-developed one. There are specific health risks associated with any given travel destination. Whenever you plan a trip to a different country or region, take the time to learn about potential health issues related to the places you’ll be visiting.

You may want to meet with your healthcare provider to discuss any or all the following topics: 

  • Any diseases that are known to pose a threat at your destination(s) 
  • The length of time you plan to stay at your destination(s) 
  • The activities you plan on engaging in during your trip 

Most travelers’ diseases can be prevented with proper preparation and planning. Common precautions include: 

  • Taking appropriate precautions in areas with known disease-carrying insects or animals 
  • Verifying the safety of food and water 
  • Avoiding risky behaviors that may result in infections 
  • Getting vaccines and/or taking preventative treatments as recommended 

Various travelers’ diseases are found in every part of the world. Travelers’ diseases can, in some instances, cause permanent health problems. Childhood illnesses are especially troublesome without appropriate vaccinations. There are many nationwide vaccination programs designed to reduce the risk of contracting diseases like measles, mumps, polio, and rubella (German measles). These conditions may be greater threats in nations or regions where high vaccination rates have not been achieved. Without adequate local vaccination, such disease can be endemic or break out into epidemics. Such infections pose a serious threat to travelers who lack the appropriate vaccinations, children who have not completed their immunizations, and people with compromised immune systems. 

What Are the Common Causes of Travelers’ Diseases? 

The travelers’ diseases that are caused by infectious microbes (viruses, bacteria, and parasites) may become problems in many ways. Contact with contaminated food or water, soil, or animal droppings may transmit the microbes. Bites and stings from infected animals and insects can cause infection. Even animal hides may pose a risk. Insects that commonly carry travelers’ diseases include mosquitoes, ticks, fleas, and flies. Some travelers’ diseases are water-borne, posing a risk to individuals who swim in contaminated water or walk barefoot. There are also travelers’ diseases that can pass directly from person to person through blood or body fluid contact. 

Signs and Symptoms 

Some travelers’ diseases cause relatively mild symptoms that may resolve without treatment. In some cases, no symptoms may develop until after a traveler returns home, after which they may grow worse, linger, resolve themselves, or disappear and reappear. A few travelers’ diseases can cause serious, permanent complications without treatment, including organ failure, blindness, coma, and even death. Check yourself as thoroughly as possible for the development of new signs and symptoms during and after your trip.

You should speak to a healthcare practitioner if you experience any of the following symptoms: 

  • Fever or flu-like symptoms. If you develop a fever or flu-like symptoms within six months of traveling to a region with malaria, it is especially important to seek medical attention. 
  • Persistent (lasting two weeks or more) diarrhea or recurring diarrhea 
  • Persistent fatigue 
  • Inexplicable weight loss 
  • A yellow coloration on the skin or in the whites of your eyes (may indicate jaundice)  
  • Inexplicable rashes or sores on the skin 

World Health Organization (WHO) recommendations suggest that travelers should get a medical exam if they experience any symptoms within a few weeks of returning home. An exam is particularly important if a traveler has a fever after visiting a region where malaria is present. 

Travelers who have been abroad for more than three months, those that know they were exposed to an infectious disease, and those with chronic medical conditions should all have a medical exam after returning home, whether or not they experience any unusual symptoms. 

Testing for Travelers’ Diseases 

Identifying the cause of travelers’ diseases is very important both to treat the infected individual and to prevent transmission of the specific disease involved. Identifying the disease is also part of documenting the disease’s presence in both the traveler’s home country and the countries they visited. 

The specific tests used to diagnose travelers’ diseases will depend on the signs and symptoms the sufferer displays. Returning travelers who experience symptoms should consult with their regular healthcare provider; their case may be referred to or consulted on by a specialist in infectious and/or tropical diseases. 

Tests – Digestive Tract Symptoms 

Infections that commonly cause symptoms in the digestive tract (such as travelers’ diarrhea) may be tested for with (among others) the tests described below: 

  • Molecular Tests 

These tests seek out foreign genetic material (DNA & RNA) in the digestive tract to diagnose the presence of specific microbes. Molecular testing is growing more common, but it is not available everywhere. 

  • GI Pathogens Panel 

This battery of tests analyzes a stool sample for the presence of multiple disease-causing microbes. A pathogen panel can identify microbes that might be overlooked in less-comprehensive testing. A GI pathogen panel is also useful for identifying co-infections where a patient is infected with more than one microbe. 

  • Stool Culture 

This is a traditional test that is used less often but may still be helpful. It can identify bacterial infections causing diarrhea. 

  • O&P (Ova and Parasite) Stool Test 

This test identifies disease-causing parasites by finding the parasites or their eggs in a stool sample. Samples for an O&P test can be either fresh or preserved. 

There are disease-specific antigen tests available for some digestive parasites. These identify proteins associated with a given strain of the parasite. Examples include Cryptosporidium, Giardia intestinalis (lamblia), and Entamoeba histolytica. 

In cases where diarrhea is caused by a viral infection, identifying the virus responsible can be complicated. Identification is rarely undertaken except in situations where large numbers of people are infected by the same viral strain, such as a norovirus outbreak on a cruise ship. 

Tests for Insect-Born Infections 

  • Malaria 

Malaria is carried by the red blood cells in infected animals and humans. A blood sample can be prepared specifically for examination under a microscope where the responsible parasite can be seen. There is also a rapid antigen assay test that can detect malaria parasites without the need for microscopic examination. 

Testing for specific insect-borne viruses is performed based on where an individual has traveled. Viruses that may be checked for include: 

Tests for Respiratory Illness 

Testing for respiratory infection will be based on symptoms, travel history, and an individual’s vaccination history. Common examples include: 

A basic TB screening test can determine whether you were exposed to the disease. If an infection is suspected, further testing (AFB testing) will be done. 

Several infections are normally prevented by vaccination. If you present the appropriate signs and symptoms, and your immunity is in doubt, your healthcare provider may want to test for: