Smallpox cannot be found naturally in the wild. Smallpox was officially declared eradicated from the globe in 1980, after an 11-year WHO vaccination campaign—the first human disease to be eliminated as a naturally spread contagion. Today, the virus remains only in laboratory stockpiles.

Smallpox cannot be found naturally in the wild. Smallpox was officially declared eradicated from the globe in 1980, after an 11-year WHO vaccination campaign—the first human disease to be eliminated as a naturally spread contagion. Today, the virus remains only in laboratory stockpiles.

The United States imports more than 80 percent of its fish and seafood. About 20 percent of its fresh vegetables and 50 percent of its fresh fruits are imported. As wealthy nations demand such foods year-round, the increasing reliance on producers abroad means that food may be contaminated during harvesting, storage, processing, and transport—long before it reaches overseas markets.    

The United States imports more than 80 percent of its fish and seafood. About 20 percent of its fresh vegetables and 50 percent of its fresh fruits are imported. As wealthy nations demand such foods year-round, the increasing reliance on producers abroad means that food may be contaminated during harvesting, storage, processing, and transport—long before it reaches overseas markets.    

All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

All are examples of ways that pathogens can spread. Coughing is an example of airborne droplet transmission; eating undercooked pork is an example of common vehicle transmission; a flea bite is an example of vector transmission; and breathing contaminated dust particles is an example of airborne transmission.

Our bodies contain at least 10 times more bacterial cells than human cells. 

Most infectious diseases are impacted by changes in the environment. Malaria, dengue, and viral encephalitis infections, for example, are highly sensitive to environmental changes.

Influenza is not a vector-borne disease, meaning it is not transmitted to humans indirectly via an insect, an arthropod, or another animal. Malaria and yellow fever are transmitted by mosquitoes. Lyme disease is transmitted by deer ticks.

Influenza is not a vector-borne disease, meaning it is not transmitted to humans indirectly via an insect, an arthropod, or another animal. Malaria and yellow fever are transmitted by mosquitoes. Lyme disease is transmitted by deer ticks.

Influenza is not a vector-borne disease, meaning it is not transmitted to humans indirectly via an insect, an arthropod, or another animal. Malaria and yellow fever are transmitted by mosquitoes. Lyme disease is transmitted by deer ticks.

More than half of the known pathogens that infect people have come from animals. Of the 37 new infectious diseases identified in just the past 30 years, two-thirds sprang from animals.

More than half of the known pathogens that infect people have come from animals. Of the 37 new infectious diseases identified in just the past 30 years, two-thirds sprang from animals.

Antibiotics only work on bacterial infections, not viral infections such as influenza and the common cold. In fact, inappropriate use and overuse of antibiotics contributes to the emergence of drug-resistant bacteria. 

All of the above can help prevent infectious disease. Other behaviors, such as exercising caution around wild and unfamiliar domestic animals, avoiding insect bites, practicing safe sex, and being vigilant about disease threats while traveling abroad, can also reduce the risk of infection.

All of the above can help prevent infectious disease. Other behaviors, such as exercising caution around wild and unfamiliar domestic animals, avoiding insect bites, practicing safe sex, and being vigilant about disease threats while traveling abroad, can also reduce the risk of infection.

All of the above can help prevent infectious disease. Other behaviors, such as exercising caution around wild and unfamiliar domestic animals, avoiding insect bites, practicing safe sex, and being vigilant about disease threats while traveling abroad, can also reduce the risk of infection.