In the 14th century, when the Black Death threatened the pope’s household in Avignon, his doctor informed him that the conjunction of three planets- Saturn, Jupiter, and Mars –in the sign of Aquarius was the principal cause of the plague.
Some four centuries later, George Washington went to bed with a sore throat. Three eminent doctors treated the infection by draining some two liters of blood from his veins. Within a few hours, the patient was dead. Bloodletting was standard medical practice for 2,500 years –from the time of Hippocrates until the mid-19th century.
Although superstition and tradition delayed medical progress, dedicated doctors work hard to discover the causes of infectious diseases and remedies for them. Below are a few of the significant breakthroughs they made.
SMALLPOX: In 1798, Edward Jenner successfully developed a vaccine for smallpox. During the 20th century, vaccines have proved effective in preventing other diseases, such as polio, yellow fever, measles, and rubella.
TUBERCULOSIS: In 1882, Robert Kohn identified tuberculosis bacteria and developed a test for the disease. Some 60 years later, streptomycin, an effective antibiotic for treating tuberculosis, was discovered. This drug also proved useful for treating bubonic plague.
MALARIA: From the 17th century onward, quinine –obtained from the bark of the cinchona tree –saved the lives of millions of malaria sufferers. In 1897, Ronald Ross identified Anopheles mosquitoes as the carriers of the disease, and mosquito control was later promoted to reduce mortality in tropical countries.
Some doctors fear that despite remarkable progress in fighting disease, the gains of the last few decades may only be temporary. The danger posed by infectious diseases has not gone away –it’s worsening, warns epidemiologist Robert Shope.
Nowadays, the horrific epidemics of plague and smallpox may seem like catastrophes long since consigned to the pages of history. During the 20th century, mankind won many battles in the war against infectious diseases, especially in industrialized countries. Doctors discovered the causes of most diseases, and they also found ways to cure them. New vaccines and antibiotics seemed like magic bullets capable of exterminating even the most stubborn disease.
However, as Dr. Richard Krause, former director of the US National Institute of Allergy and Infectious Diseases, points out, plagues are as certain death and taxes. TB and malaria have not gone away. The reminder that pestilence still stalks the globe.
Infectious diseases remain the world’s leading cause of death; they will remain so for a long time to come.
These statistics are necessarily approximate. They do indicate, however, the extent to which pestilence has stalked humankind since 1914.
SMALLPOX [BETWEEN 300 MILLION AND 500 MILLION] No effective treatment for smallpox was ever developed. A massive international vaccination program finally succeeded in eradicating the disease by 1980.
TUBERCULOSIS [BETWEEN 100 MILLION AND 150 MILLION] Tuberculosis now kills approximately two million people each year, and about 1 out of every 3 people in the world carries the tuberculosis bacillus.
MALARIA [BETWEEN 80 MILLION AND 120 MILLION] For the first half of the 20th century, the death toll from malaria hovered at about two million a year. The greatest mortality is now centered in sub-Sahara Africa, where malaria still kills more than one million people yearly.
SPANISH INFLUENZA [BETWEEN 20 MILLION AND 30 MILLION] Some historians say that the death toll was much higher. This lethal epidemic swept the world in 1918 and 1919, close on the heels of the First World War. Even bubonic plague did not kill so many people so fast.
TYPHUS [ABOUT 20 MILLION] Epidemics of typhus often accompanied war, and the First World War provoked a typhus plague that ravaged countries in Eastern Europe.
AIDS [OVER 20 MILLION] This modern scourge is now killing three million people every year. Current estimates by the United Nations AIDS program indicate that in the absence of drastically expanded prevention and treatment efforts, 68 million people will die before 2020.