Pathogens Like to Travel
Pathogens more popularly known as "germs" spread, finding
appropriate accommodations in which to settle and multiply. Some travel
by air. Some travel by water or in liquids and foods. And many attach
themselves to clothing and various surfaces posing an ever-present
threat to humans. Pathogens may also be spread by single or multiple
vectors animals such as rats, fleas, ticks, or mosquitoes that carry
the germs or pathogens internally. The warm, moist surfaces of human
hands provide an accommodating place for germs to linger and multiply.
The 1918 Influenza: The Deadly Spread of a Mysterious Disease
In 1918, an unidentified killer disease later identified as a
particularly virulent form of influenza appeared and rapidly became
pandemic, reducing the world's population by 20 to 50 million people by
the time it ran its course. Scientists now know that this mysterious
disease was caused by a well-traveled virus too small to be seen with
microscopes of the time. The close quarters of recruits in American
military camps and the large-scale movement of troops between and within
the United States and Europe during World War I certainly helped spread
the disease. Influenza quickly became the single most deadly American
epidemic of the 20th century. People knew it was contagious, and
suspected that it was airborne, but were incapable of stopping it
despite gauze masks worn for that purpose.
Left: Customer turned away from a San Francisco trolley for lack of a mask, as required
by an emergency city ordinance, 1918.
Upper Right: Dressed for work, 1918.
Lower Right: American soldiers with gauze masks, during World War I, 1918.