When Henry Morton Stanley met Dr David Livingstone in 1871 near Lake Tanganyika, Livingston had been exploring Africa for about 30 years. Livingstone had great inner drive, and pursued his goals against all odds. He fell in love with Africa, its natural beauty and its people, despite frequently falling desperately ill with tropical diseases. Cartographers had now drawn the outlines of the continents and most of the islands, and nautical exploration was coming to an end. Africa was dubbed the “dark continent� because map-makers knew so little of its interior that they filled it in with black ink.

The Royal Geographical Society in London was vital in lobbying for public and private funds to support explorers. According to the book by M. Dugard (2003), Charles Darwin earned his membership to the Society due to his scientific breakthroughs in biology, while Livingstone became a member based mainly on his merits as an extraordinary wanderer.

While Dr Livingstone meticulously described the symptoms of the diseases he endured during his travels, the causes were poorly understood. Tropical medicine was in its infancy. Three years after Dr Livingstone died, his 26-year old son Tom died of bilharzia, a parasitic worm that causes liver damage and kidney failure. Tom contracted this disease during his childhood when the entire family lived in Africa. It is now known that these parasites live in freshwater snails. When swimming in a freshwater lake in Africa, one has more chance of dying from the invisible bilharzia than from being killed by a crocodile. Bilharzia is still the second most important tropical disease, after malaria. Since Dr. Livingstone’s day, science has discovered the ecology of certain diseases and helped people to understand how to prevent them.

When Jeff and I were in Lilongwe last Sunday, we saw a nice example of effectively communicating the ecological principles underlying a good practice. A poster by the Department of National Parks and Wildlife showed a simple drawing of a turtle eating bilharzia-infected snails. The take away message is written in English and Chichewa, the main language of Malawi: “turtles eat bilharzia-carrying snails. Killing turtles leads to bilharzia outbreaks.� In public health, as in agriculture, providing crucial ecological information in a clear style helps people understand why a certain practice is useful. Protect turtles to help keep your family healthy.

Reference cited

Dugard, M. 2003. Into Africa. The Dramatic Retelling of the Stanley-Livingstone Story. Bantam Press, London.