Infectious Disease: Evolving Challenges to Human Health


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The Impact of Public Health

This graph demonstrates the impact of sanitation and safe drinking water on mortality from infectious diseases and average life expectancy in the United States.

With the exception of the influenza pandemic of 1918, the trend demonstrates dramatic improvements through the first half of the century, before the first antibiotics and most vaccines were developed. Chlorination of drinking water kills pathogens. Sanitation infrastructure for wastewater, storm water, and refuse along with treatment of drinking water by filtration and chlorination to kill pathogens dramatically decreased exposure of the population to infectious disease.

Graph of life expectancy and disease mortality on the 20th century US

This graph shows decreasing deaths due to infectious disease in yellow and increasing life expectancy throughout the twentieth century in blue. Significant time points include:

1901 - Tenement House Act
1902 - Nobel Prize awarded for identification that mosquitoes transmit malaria
1906 - 40 states have health departments
1908 - First continuous use of chlorine in water in US
1918 - 1918 Influenza Pandemic
1925 - Last human-to-human transmission of the plague in US
1955 - Salk polio vaccine introduced
1962 - Passage of Vaccination Assistance Act
1981 - First case of HIV recognized

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