Infectious Disease Control and Prevention

Infectious disease control and prevention involves stopping the occurrence and reducing the spread, or transmission, of infectious diseases, which are conditions caused by pathogenic organisms, like viruses, bacteria, fungi, and parasites.

Now, infectious diseases are transmitted in a number of different ways. When an infection is transmitted from a parent to an offspring, via sperm, placenta, breast milk, or contact with the vaginal canal during delivery, that’s called vertical transmission. This is seen in syphilis, which is transmitted through the placenta; and HIV, that is transmitted through the placenta, during delivery, or through breastfeeding.

Infectious diseases can also be transmitted from person-to-person, called horizontal transmission, through several routes.

For example, diseases can spread through direct contact with an infected person, like with sexually transmitted infections, or STIs, that are spread during sexual intercourse; and diseases like ringworm and scabies, that spread through skin-to-skin contact.

Other times, a disease can be spread through indirect contact, which involves a vehicle of transmission outside the infected person. This commonly occurs during contact with contaminated objects, called fomites, like doorknobs, countertops, or bedding.

When contaminated medical equipment is involved, health care associated infections, or HAIs, can result, which is when a pathogen is transmitted to a patient within a health care setting while they’re receiving treatment for another condition.

Patients can develop health care associated infections when infection control measures are inadequate, like during or after diagnostic or surgical procedures, or when pathogens are introduced through invasive devices like central lines, urinary catheters, and ventilators.

Health care associated infections can also occur through the common vehicle route, which is when an infectious agent is spread to multiple people through a contaminated source, like food, water, saliva, or blood products. So, in the health care setting, diseases like HIV, hepatitis B, and hepatitis C can be transmitted through contaminated blood products.

In other settings, common vehicle transmission can occur through foodborne diseases, like norovirus, salmonella, and E. coli, that are transmitted due to poor hand hygiene, or improper food preparation, storage, or handling.

On top of that, there’s waterborne diseases, like giardiasis and cholera, that occur when water becomes contaminated, typically by human or animal waste, and illness occurs after drinking, cooking with, or engaging in activities in contaminated water.

Lastly, diseases like tuberculosis are transmitted through contaminated droplets in the air.