Public Health: What's it really about?
Washington, DC, 16 May 2002 (PAHO)-- Despite great progress in science and technology, the challenges of public health continue to be enormous, with the appearance of new epidemics such as AIDS and the persistence of other illnesses associated with poverty, violence and the epidemiological transition.
"What is public health?" Laurie Garrett asks in her book Betrayal of Trust, an impassioned call for greater investment in global public health. "It is not curative medicine," she answers. "CT scans, open heart surgery, hormone treatments, fiber optic visualizations-these are all great boons for medicine, but they are not public health. And, perhaps surprisingly, they have not been responsible for the vast improvements in the public's health." Rather, Garrett writes, public health is "a practical system, or infrastructure, rooted in two fundamental scientific tenets: the germ theory of disease and the understanding that preventing disease in the weakest elements of society ensure[s] protection for the strongest (and richest) in the larger community."
The bacteriological era in medical research identified specific microbiological disease agents, and the science of immunology was developed. As preventive methods became available, progress in engineering and other sciences led to safer drinking water and sanitation services for large segments of the population, which also enjoyed improved housing conditions and workplaces.
It was an English physician of the mid-19th century who made one of the greatest contributions to public health. John Snow (1813-1858), a pioneering anesthesiologist and epidemiologist distinguished himself through his creativity and good use of scientific data. During a cholera outbreak that ravaged London in 1831-32, Snow began to investigate the cause and means of transmission of the disease. In 1849, he published a pamphlet suggesting that cholera was a contagious disease caused by a toxin that reproduces in the human body and which is found in the vomit and feces of those infected. He believed that the principal, though not the only, means of transmission was water polluted with the toxin. At the time, it was believed that diseases were transmitted through inhalation of the "miasma," or bad air, and Snow's hypothesis was not widely accepted.
However, in 1854, Snow would prove his theory during the course of another epidemic in London, when he documented cases of cholera and compared the disease's incidence among the clients of two different companies that supplied the city's water. He showed that cholera was much more frequent among clients of the Southwark and Vauxhall Water Company, which drew its water from the lower Thames, which was contaminated with London sewage. Clients of the Lambeth Waterworks Company, which drew its water upriver, suffered a much lower incidence.
The evidence supported his theory, but an incident that has become legend finally convinced the unbelievers. In the neighborhood surrounding the intersection of Cambridge and Broad streets, a concentration of cholera cases produced 500 deaths in 10 days. Upon investigation, Snow concluded that the problem lay in the Broad Street water pump, and he suggested that officials remove the handle from the pump, so that residents could not consume the polluted water. They did, and the epidemic was halted. The incident went down in history as an example of effective epidemiology and as one of the first applications of public health principles for disease prevention and control. (With public health advances, cholera eventually disappeared from the Americas until 1991, when a new epidemic swept the countries but was controlled relatively quickly through intense public health efforts.)
Gradually, nations came to understand that mass health problems required mass solutions and could not be left to individual initiatives. Countries began to form health boards and health departments. Eventually, international health organizations were created, including the Pan American Health Organization (PAHO) officially established in 1902.
Public health successes such as the eradication of smallpox worldwide, the eradication of polio from the Americas, and the drive to eliminate measles followed, marking some of the greatest achievements of mankind.
Today, PAHO serves as the Regional Office for the Americas of the World Health Organization and is the oldest international health organization in the world. It works with all the countries of the Americas to improve health and quality of life, with the goal of health for all in the Americas.
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