All of the above are urgently needed in developing nations. A major barrier to achieving these improvements is the underlying weakness of health systems in resource-poor countries, including a shortage of health workers and a lack of disease surveillance programs.

All of the above are urgently needed in developing nations. A major barrier to achieving these improvements is the underlying weakness of health systems in resource-poor countries, including a shortage of health workers and a lack of disease surveillance programs.

All of the above are urgently needed in developing nations. A major barrier to achieving these improvements is the underlying weakness of health systems in resource-poor countries, including a shortage of health workers and a lack of disease surveillance programs.

Strep throat is a bacterial infection that can be treated with antibiotics. The common cold and influenza are both viral infections, which do not respond to antibiotics. Antivirals may be prescribed instead.

Strep throat is a bacterial infection that can be treated with antibiotics. The common cold and influenza are both viral infections, which do not respond to antibiotics. Antivirals may be prescribed instead.

Strep throat is a bacterial infection that can be treated with antibiotics. The common cold and influenza are both viral infections, which do not respond to antibiotics. Antivirals may be prescribed instead.

About one quarter of all deaths worldwide are caused by infectious disease. More than two-thirds of the deaths in children under the age of five are caused by infectious disease.

About one quarter of all deaths worldwide are caused by infectious disease. More than two-thirds of the deaths in children under the age of five are caused by infectious disease.

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.

Scientists believe that hot weather may speed up both the breeding cycle of mosquitoes and replication of the virus in insects’ guts.

The human papillomavirus (HPV) causes more than 90% of cervical cancer cases.

The human papillomavirus (HPV) causes more than 90% of cervical cancer cases.

The expanded use of cell phones does not have an impact on the spread of infectious disease. Climate change, ecosystem disturbances, war, poverty, migration, and global trade all contribute to the spread of infectious disease.

The expanded use of cell phones does not have an impact on the spread of infectious disease. Climate change, ecosystem disturbances, war, poverty, migration, and global trade all contribute to the spread of infectious disease.

The expanded use of cell phones does not have an impact on the spread of infectious disease. Climate change, ecosystem disturbances, war, poverty, migration, and global trade all contribute to the spread of infectious disease.

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

By identifying pathogens in the animals where they naturally live and monitoring those organisms as they move from animals into people, it may be possible to prevent deadly new infections of animal origin from entering and racing through human populations.