Across The Globe

I remembered we were told by our JPA agent to avoid from eating at the stalls beside the road when we first arrived Yogyakarta. The surrounding was not that clean, with its location near the dusty road, we could easily get diarrhea or food poisoning.

If centuries ago, less people travel out of their hometown, but as the modes of transportation nowadays varies, people can go anywhere in this world in just several hours, or even minutes. Travelling across countries has promote globalization around the world.

Generally, globalization can be defined as a process of interaction and integration among the people, companies, and governments of different nations, a process driven by international trade and investment and aided by information technology. In a way, globalization facilitates the spread of disease and increases the number of travelers who will be exposed to a different health environment.Travellers often experience abrupt and dramatic changes in environmental conditions(altitude, temperature and humidity), which may have negative effects on health and well-being.

Travel medicine is the discipline devoted to the maintenance of the health of international travelers through health promotion and disease prevention. Tropical infectious diseases are in a classical sense are limited geographically to areas where specific conditions of tropical climate and ecology must be present as a conditio sine qua non for the transmission and spread of the pathogen responsible (specific diseases of the tropics). Today, the problem of this tropical infectious diseases are not only a problem to the tropical countries, but to all other countries a sweell since any travellers who go to the tropical countries are at risk of getting it.

Figure : Causes of death in developed and developing world in 1997 (WHO, 1998)

In the last two decades infectious diseases have regained considerable significance and interest even in high-income countries. This is due to ;

• changes in modern lifestyles (travel, outdoor activities, drug abuse) have created new risks of acquiring certain infections.
• Emerging and re-emerging infectious diseases as well as emerging resistance against anti-infective drugs have clearly shown their potential global spread.
• Medical advances for the treatment of malignancies and chronic diseases have resulted in a growing population of immunocompromised patients susceptible to opportunistic infections that may limit severely the success of modern therapies ( e.g. transplantation)

Some of the modes of transmission of infectious diseases are as listed below :

1. Food borne and waterborne diseases - Examples of diseases acquired through food and water consumption are traveller's diarrhea, hepatitis A, thyphoid fever and cholera. Taking a hygienic precautions with all food, drink and drinking-water consumed when travelling and by avoiding direct contact with polluted recreational waters.
   
2. Vector-borne diseases - Insects such as mosquitoes and other vectors such as ticks can transmit serious infections. Examples of vector-borne diseases are malaria, dengue, yellow fever and chikungunya.
   
3. Zoonoses - Infections can also be transmitted to humans through animal bites or contact with animals, contaminated body fluids or feces, or by consumption of foods of animal origin, particularly meat and milk products. Rabies, tularaemia, brucellosis amd leptospirosis are some of the diseases of zoonoses.
   
4. Sexually transmitted diseases - STIs (HIV/AIDS, Hepatitis B and syphillis) can be reduced by avoiding casual and unprotected sexual intercourse and by use of condoms.
   
5. Blood borne diseases - Direct contact with infected blood or other fluid can trasmit blood borne diseases such as Hepatitis B and C, HIV/AIDS and malaria. Travellers should avoid direct contact with blood and body fluids, avoid the use of potentially contaminated needles and syringes for injection or any other medical or cosmetic procedures that penetrate the skin and avoid transfusion of unsafe blood.
   
6. Airborne diseases - Droplets nuclei (<5μm)>5μm) as a result of coughing, sneezing or even talking can transmit diseases such as severe acute respiratory syndrome (SARS), pneumonias, pertussis, mumps and meningitis.
   
7. Diseases transmitted via oil - In places where soil-transmitted infections are likely to be present, protect the skin from direct contact with the soil to reduce the risk of infections. Certain intestinal parasitic infections (ascariasis and trichuriasis) are transmitted via soil, and infection may result from consumption of soil-contaminated vegetables. Tetanus and anthrax are examples of bacterial diseases transmitted via soil. Fungal infections may be acquired by inhalation of contaminated soil.
   

Further readings :
1. International Travel and Health WHO 2010 ; Chapter 5 - Infectious Diseases of Potential Risk for Travellers

2. Travel Medicine by J. S. Keystone

3. Principles and Practice of Travel Medicine by Jane N. Zuckerman