THE NINETEENTH CENTURY

The nineteenth century was a time of spectacular leaps forward in the understanding of infectious diseases. For many centuries, rival epidemiologic theories associated disease and epidemics like cholera with poisonous fumes

Painting by Georges-Gaston Mélingue (1894). The first vaccination. Here Dr. Jenner introduces cowpox taken from dairymaid Sarah Nelmes (right) and introduces it into two incisions on the arm of James Phipps, a healthy 8-year-old boy. The boy developed cow-pox, but not smallpox, when Jenner introduced the organism into his arm 48 days later. (Courtesy of the National Library of Medicine)

given off from dung heaps and decaying matter (poisons in the air, exuded from rotting animal and vegetable ma­terial, the soil, and standing water) or with contagion (person-to-person contact).

In 1865, English surgeon Joseph Lister (1827-1912) concluded that microbes caused wound infections. He be­gan to use carbolic acid on wounds to kill microbes and re­duce infection after surgery. However, Lister was not alone in identifying hazards in the immediate environment as detrimental to health. English nurse Florence Nightingale (1820-1910) was a leading proponent of sanitation and hygiene as weapons against disease. It was at the English base at Scutari during the Crimean War (1854-1856) that Nightingale waged her battle. Arriving at the army hospi­tal with a party of 38 nurses, Nightingale found nearly 2000 wounded and sick inhabiting foul, rat-infested wards. The war raged on, deluging the hospital with wounded as Nightingale not only organized the nursing care of the wounded but also provided meals, supplied bedding, and saw to the laundry. Within 6 months, she had brought about a transformation and slashed the death rate from approximately 40% to 2%.³

Florence Nightingale caring for wounded at Scutari, Turkey, during the Crimean War. (Courtesy of the National Library of Medicine)

From the 1860s, the rise of bacteriology, associated es­pecially with chemist and microbiologist Louis Pasteur in France and bacteriologist Robert Koch in Germany, estab­lished the role of microorganismal pathogens. Almost for the first time in medicine, bacteriology led directly to dra­matic new cures.

The technique of pasteurization is named after Louis Pasteur (1822-1895). He introduced the method in 1865 to prevent the souring of wine. Pasteur's studies of fermenta­tion convinced him that it depended on the presence of microscopic forms of life, with each fermenting medium serving as a unique food for a specific microorganism. He developed techniques for culturing microbes in liquid broths. Through his work, he was able to dispel the disease theory that predominated in the mid-nineteenth century, attributing fevers to "miasmas," or fumes, and laid the foundation for the germ theory of disease.

The anthrax bacillus, discovered by Robert Koch (1843-1910), was the first microorganism identified as a cause of illness. Koch's trailblazing work also included identifying the organism responsible for tuberculosis and the discovery of a tuberculosis skin-testing material.

In 1895, German physicist Wilhelm Röntgen (1845-1923) discovered X rays. For the first time without a cata­strophic event, the most hidden parts of a human body were revealed. Even though he understood that it was a significant discovery, Röntgen did not initially recognize the amazing diagnostic potential of the process he had discovered.