Tropical Diseases - Travellers Beware

Copyright 2006 Anne Wolski

In a world where there is still a huge proportion of people living in conditions which can, at best, be described as absolutely shocking, is it any wonder that tropical diseases are still rampant and on the increase? Despite the valiant efforts of medical teams and governments, these diseases remain a resilient adversary of the human race.

There are still a large number of people dying from these diseases, particularly in developing countries. Even though there has been much progress in medicine and the understanding of disease, the human toll continues to climb. Even when spared death, many victims are blinded, disabled, and disfigured.

1967 saw the beginning of a ten year campaign against smallpox, the success of which made it the only tropical disease totally wiped out by humans. The cost of this campaign was two hundred million dollars.

In developing countries, diseases such as measles and tuberculosis are still a major problem with the death rate from measles running as high as ten percent. Even such diseases as leprosy, now known as Hansen’s disease, are still prevalent. However, when we think of tropical diseases, we usually think of malaria and other parasitic disorders.

The World Health Organization believes that the likelihood of stamping out tropical diseases is very low despite an ongoing campaign to rid the world of polio and leprosy. One of the problems facing them is the lack of research funding. Despite this, there are a number of diseases that have been identified as being in need of particular attention.

These are: 1. Malaria 2. Schistosomiasis 3. Sleeping sickness 4. Hansens’s disease or leprosy 5. Filariasis; and 6. Leishmaniasis

Malaria is still one of the greatest killers and continues to increase, killing around one hundred million people each year. Though there have been many attempts to create an effective vaccine against this disease, there is yet to be success. This disease is caused by the bite from an anopheles mosquito and control therefore, is in the control of this insidious insect. There is a virtually constant attempt to develop new and more effective drugs to treat this disease.

Schistosomiasis, which is also known as Bilharzias, is caused by worms that infest the liver, bladder, and the intestine. It is very unpleasant and can be fatal. The eggs from the worms pass in the urine and faeces. These eggs then hatch, affecting some snails which produce more organisms that penetrate the human skin, passing into the bloodstream. The usual cause of this is contact with contaminated water.

Sleeping sickness is spread by the tsetse fly which passes a parasite that lives in the blood and the brain. There is no vaccine and people should take extra precautions against insect bites when visiting African game parks. This disease and its carrier have made vast areas of Africa uninhabitable.

Hansen’s disease or Leprosy still affects millions of people around the world. There are effective treatments available but, if treatment is not sought, this desease can lead to severe disability such as paralysis, blindness, and deformities of the body. This disease also carries a social stigma due to antiquated fears of infection.

Filariasis is caused by small worms entering the body via the bites of flies and mosquitoes. They can also cause elephantiasis if they block the lymph passages. If the bite is from a blackfly, it can cause African river blindness which is considered as a form of filariasis. This disease in its various forms affects over one hundred and fifty million people.

Leishmaniasis is caused by a parasite that is spread by sandflies. It affects the skin, liver, and spleen and there is much more to be learned about this disease. More research is needed if it is to be effectively treated and controlled.

The World Health Organization is trying to immunize all children in the world against diseases such as measles, diphtheria, polio, tetanus, tuberculosis, and whooping cough which are still responsible for the deaths of five million children in developing countries each year. Because the majority live in remote areas, the effectiveness of the vaccine is often compromised by the tropical heat before it even reaches these children.

There are a number of factors that contribute to the spread of tropical diseases in the developing world. Poverty, poor nutrition, lack of sanitation, overcrowding, poor housing, and lack of access to a safe water supply are but a few.

Obviously, the transmission of tropical diseases has been made much easier by air travel. It is possible for a traveler to acquire a disease from one country and be back in their home country before the symptoms even show. Because some of these diseases show similar symptoms to a nasty case of the flu, the person is often able to spread the disease before they are aware of the fact that it is a tropical disease. This is particularly true of malaria which affects around two and a half people each year in the Western world.

Very few tropical diseases can be prevented specifically by vaccination, so travellers to countries where diseases are prevalent are at an increased risk of picking up a disease against which they have no natural resistance.

Tropical diseases are a long way from being controlled or eradicated so it is imperative that travelers take precautions to protect themselves and others. Many of these diseases are on the increase and more research as well as new vaccines and more effective drugs are needed to fight the onslaught of these diseases.

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