What is a communicable disease?
It is an illness caused by an infectious agent, such as bacteria, virus, fungi or parasites and/or toxin. Most of these diseases can be passed from one person to another.
Communicable disease reporting under State law is a basic feature of our societal mechanisms for protection of public health. California law mandates healthcare providers and laboratories to report over 80 diseases or conditions to their local health department. Some examples of the reportable communicable diseases include Hepatitis A, B & C, influenza, measles, and salmonella and other food borne illnesses.
How do these communicable diseases spread?
How these diseases spread depends on the specific disease or infectious agent. Some ways in which communicable diseases spread are by:
- physical contact with an infected person, such as through touch (staphylococcus), sexual intercourse (gonorrhea, HIV), fecal/oral transmission (hepatitis A), or droplets (influenza, TB)
- contact with a contaminated surface or object (Norwalk virus), food (salmonella, E. coli), blood (HIV, hepatitis B), or water (cholera);
- bites from insects or animals capable of transmitting the disease (mosquito: malaria and yellow fever; flea: plague); and
- travel through the air, such as tuberculosis or measles.