Spreading the Word: The Prevention of Emerging Pandemics

Article excerpt

ON DECEMBER 14, 1994, A US GOVernment interagency working group was established under the jurisdiction of the Committee of International Science, Engineering, and Technology Policy (CISET), under the auspices of of President Clinton's National Science and Technology Council. This working group consists of members from 17 different government agencies and departments, including the National Institutes of Health (NIH), the Centers for Disease Control (CDC), the Department of Defense, and the Department of State.

The group was assembled to assess the global threat of emerging and reemerging infectious diseases. Included in the group's recent report was a map detailing the current outbreaks of infectious diseases worldwide. Only one continent remains unaffected by outbreaks of deadly infectious diseases, and Antarctica offers precious little refuge for the world's populations against the rising threat of widespread epidemics.

Once again humanity faces diseases so deadly and infectious that entire populations could be decimated. What is especially problematic is the rate at which disease can now spread aided by modern transportation. Certain diseases seem to be leapfrogging continents at an alarming rate, and worst of all, the origin and mode of transmission for diseases is becoming increasingly difficult to determine.

Adding to this already grim situation, public health officials are worried that diseases are growing ever more resistant to the drugs we use to treat them, and that not only will there be a surge in epidemics of current diseases, but also that old strains thought long defeated will reappear. To understand why drug resistant disease strains are becoming so troublesome, though, a basic understanding of antibiotics is required.

The action of antibiotics involves several different aspects. First of all, an antibiotic is a chemical that disrupts the life cycle of an infectious agent. Antibiotics are generally used on bacteria or simple unicellular microscopic organisms, with several different effects. An antibiotic can inhibit the growth of the bacterial cell wall, impede the transfer of nutrients in and out of the bacterial cell, interfere with protein synthesis in a bacterial cell, or even disrupt bacterial gene replication. If an antibiotic kills a microorganism outright, it is called bactericidal; if it merely inhibits their growth, it is termed bacteriostatic. Penicillins are the most notable bactericidal antibiotics, and the tetracyclines are known for their bacteriostatic effect.

The discovery and use of antibiotics has occurred within the last century. In the late 19th century Louis Pasteur and Jules Francois Joubert recognized that anthrax bacteria failed to grow if they were contaminated by airborne bacteria. However, it wasn't until 1928 that the first antibiotic was scientifically identified. Alexander Fleming noticed that the bacteria S. aureus was killed by the bread mold Penicillium notatum, and he named the chemical agent that had done the deed penicillin. However, isolating the active agent proved to be difficult, and penicillin remained scarce until 1957, when it was synthesized in the laboratory. Modern antibiotics are thus mostly semisynthetic, or part culture-grown and part synthesized.

With these potent chemicals at the disposal of modern medicine, it is no wonder that widespread epidemics suddenly seemed to be a thing of the past during the last few decades. Why are epidemics still occurring, then, if the modern medicine has such a sensitive and thorough line of defense? Part of the problem stems from the appearance of bacterial diseases resistant to our modern antibiotics.

Resistance to antibiotics among these new diseases is a product of artificial selection. When antibiotics came into widespread use in the 1950s, bacteria were mostly killed off by the penicillins or tetracyclines with which they came in contact. However, there were always a few survivors, which perhaps had a mutation in their genetic code that gave them resistance to the drug and enabled them to survive. …