This Day Relenting God
This Day Relenting God
Cause of Malaria Identified
By: Ronald Ross
About the Author: Sir Ronald Ross (1857–1932) studied medicine in London before joining the Indian Medical Service in 1881. Throughout his career he focused with a single-minded intensity on the prevention of malaria, and in 1897 discovered the species of mosquito that spreads the disease. His work won him a Nobel Prize in 1902, and he was knighted in 1911. Ross spent the remainder of his life conducting studies in the malarial centers of the world, and forming organizations to combat malaria. He directed the Ross Institute and Hospital for Tropical Diseases, established in his honor in 1926, until his death in 1932. In addition to his medical work, Ross was an acclaimed poet.
Malaria is an ancient killer. It is frequently described in the writings of the Greeks and Romans. The word itself is Latin, from the Roman word for "bad air," after the fine mist once supposed to cause it.
For hundreds of years, no one knew exactly what caused malaria and, therefore, no one could stop it. In 1880, Charles-Louis-Alphonse Laveran, a French military physician serving in Algeria, identified the plasmodium parasite in the blood of a sick artilleryman. Seventeen years later in India, Captain Ronald Ross extracted a cyst from a dissected female Anopheles mosquito and identified malaria as an insect-borne disease.
Malaria is not a single disease in humans. It is a family of four different diseases caused by four different parasites. The parasites are similar in appearance, all belonging to the genus Plasmodia. The fevers caused by these four organisms vary enough in their clinical presentations that different labels evolved for their symptoms, even before microbiologists were able to separate them in 1900.
Plasmodium falciparum causes the most severe form of malaria. The victim suffers from intermittent high fevers, with a severe retro-orbital headache, parched throat, and diffuse body aches. The body can be wracked with abdominal cramping, diarrhea, and vomiting. The liver and spleen become enlarged, and if hepatic malfunction reaches a critical level, jaundice may follow. When the parasite reaches a high enough density in the body, it can cause deadly effects by clogging small arteries in the brain and kidneys. The coma of cerebral malaria often comes just before death. Mortality from falciparum malaria can range from 20 to 40 percent in untreated victims.
Plasmodium vivax causes a more benign disease. It can kill up to 5 percent of its victims, although mortality is usually lower. Like falciparum, it causes a high fever, with skull-splitting headache and icy pains throughout the bones. The body undergoes a change in the thermostat that regulates internal temperature. Sensing incorrectly that the body's temperature is too low, the hypothalamus orders shivering in order to increase the temperature. This creates chills that are so severe that a victim's teeth chatter as the bed shakes.
Both vivax and falciparum can cause chronic illness in which the victim suffers repeated infection with the parasite. Since red blood cells are destroyed in a malaria attack, the person suffering from repeated attacks becomes anemic, weak, and tired. Malaria patients typically lack the energy for a full workload, in school or on the job. During the reduced immune state of pregnancy, malaria may flare and kill the fetus, mother, or both. Ovale and malariae are unpleasant but not as deadly as the other two malarial strains.
This day relenting God
Hath placed within my hand
A wondrous thing; and God
Be praised. At his command,
Seeking his secret deeds
With tears and toiling breath,
I find thy cunning seeds,
O million-murdering Death.
I know this little thing
A myriad men will save,
O Death, where is thy sting?
Thy victory, O Grave?
Malaria has not been eradicated despite Ross's identification of its cause. It is still present in 102 countries and sickens 500 million people per year. In 2005 it was the number-one killer in the world, with HIV/AIDS in second place. Malaria kills three to five million people a year, or about one every 12 seconds, with 90 percent of the deaths occurring in sub-Saharan Africa.
It was once believed that malaria could be eradicated. The draining of marshlands and the use of the pesticide DDT dramatically reduced the six million cases a year that the United States experienced in the first decades of the twentieth century. By 1960, the World Health Organization (WHO) had established antimalarial policies in 100 nations and was confident that the disease could be eradicated.
A number of sociopolitical factors, however, combined to slow the advance of medicine. People became complacent about malaria and public health programs were allowed to falter and lapse. Without outside aid, poor nations did not have the money for malarial control methods. Additionally, countries torn by war focused resources on fighting, not on medical care. Meanwhile, malarial microbes evolved in response to drugs, while the ready availability of air travel brought new strains into areas that lacked immunity to them. Global warming is expected to bring malaria back to northern Europe, and it never completely left southern Europe or the United States. WHO now forecasts a 16 percent growth rate in the disease per year.
Desowitz, Robert S. The Malaria Capers: More Tales of Parasites and People, Research and Reality. New York: W. W. Norton, 1993.
Humphreys, Margaret. Malaria: Poverty, Race, and Public Health in the United States. Baltimore: Johns Hopkins University Press, 2001.