Killer diseases such as E. coli infection are back in the news. John Maddox looks at life from a bugs' perspectiveby John Maddox / January 20, 1997 / Leave a comment
Aids day this year fell in the middle of the outbreak of bacterial meningitis in Cardiff and other university campuses, and coincided with the outbreak of the E. coli infection in Lanarkshire. What is going on? Why are we being assaulted by apparently novel infections against which familiar remedies are ineffectual? It is a shock that ten people have already died in Scotland from a variant of a bug that leads an otherwise benign existence in everybody’s intestines. It happened in Japan in July, when the same strain of E. coli killed ten children and hospitalised more than 100 of them. Super-hygienic Japan reacted with shame and shock.
The past quarter of a century has been replete with previously unknown infections. Remember Legionnaires’ disease, which surfaced in the US in July 1976 and was eventually linked to a bacterium adapted to life in water-cooled air-conditioning systems? Aids followed soon after.
Since then, infectious disease has hardly been far from the news. Edwina Currie’s career in British politics was cut short by it, and BSE is an infection, after all. Malaria is resurgent in India and the World Health Organisation is alarmed at the appearance of virulent, drug-resistant strains of the tuberculosis bacillus. There are also repeated alarms about the epidemic infections of Africa, caused by viruses named after the places where they were identified-Lassa, Marburg and Ebola. (Marburg is in Germany, not Africa; its connection goes back to 1967, when a shipment of green monkeys from Uganda infected 30 German laboratory workers and killed 7 of them.) Fears that the Ebola virus may spread to the urban centres of South Africa keeps many people awake at nights.
What is going on? From the point of view of the micro-organisms, the bacteria and the viruses, the name of the game is simply to produce as many of their kind as possible. Often (as in the human gut) they compete for scarce resources-undigested food, in that case-with other micro-organisms. Over many decades, the micro-organisms’ world has become more dangerous, but there are more opportunities for it to flourish than there used to be, too.
What are the dangers for the bugs? Hygiene is one. The disappearance of disease carriers-mosquitoes which carry malarial parasites, tsetse flies which carry sleeping sickness and rats which carry plague-infested fleas-is another. Vaccines, which induce the invaded body of an animal to kill off bacteria and viruses,…