Reportable diseases are diseases considered to be of great public health importance. Local, state, and national agencies (for example, the Centers for Disease Control and Prevention) require that such diseases be reported when they are diagnosed by doctors or laboratories.

This permits surveillance (i.e., the collection of statistics on the frequency with which the disease occurs), which in turn allows these agencies to identify trends in disease occurrence, as well as disease outbreaks.

• Mandatory written reporting. Examples are gonorrhea and salmonellosis.
• Mandatory reporting by telephone. Examples are rubeola (measles) and pertussis (whooping cough).
• Report of total number of cases. Examples are chickenpox and influenza.
• Cancer. This is reported to the state Cancer Registry (not all states have cancer registries).

A typical state list may appear as follows:

(Name of state) law requires the following diseases to be reported to the local health department, or the (name of state) Department of Health. Please contact....

Acquired Immunodeficiency Syndrome (AIDS)
Amebiasis
Anthrax *
Botulism *
Brucellosis
Campylobacteriosis
Cancer ***
Chancroid
Chickenpox **
Chlamydial Infections
Cholera *
Coccidioidomycosis
Colorado Tick Fever
Diphtheria *
Echinococcosis
Encephalitis (post-infectious, arthropod-borne, and unspecified)
Food-borne Illness, including food poisoning
Giardiasis
Gonococcal Ophthalmia Neonatorum
Gonorrhea
Granuloma Inguinale
Hemophilus Influenza, Invasive Disease (all serotypes)
Hepatitis A
Hepatitis B, cases and carriers
Hepatitis, other Viral: Type C
Influenza **
Legionellosis
Leprosy
Leptospirosis
Lymphogranuloma Venereum
Malaria
Meningitis, Aseptic and Bacterial
Meningococcemia
Mumps **
Pelvic Inflammatory Disease
Pertussis *
Plague *
Poliomyelitis *
Q-fever
Rabies (Human and Animal) *
Relapsing Fever (tick-borne and louse borne)
Rheumatic Fever
Rocky Mountain Spotted Fever
Rubella
Rubella, Congenital Syndrome
Rubeola *
Salmonellosis
Shigellosis
Staphylococcal Diseases **
Syphilis
Tetanus *
Toxic Shock Syndrome
Trichinosis
Tuberculosis
Tularemia
Typhoid *, cases and carriers
Typhus *
Yellow Fever *

* Telephone reporting required
** Report total cases only
*** Cancer should be reported to (state) Cancer Registry

The State Health Department will attempt to find the source of many of these illnesses, such as food poisoning or amebiasis. In the case of sexually-transmitted diseases the state will attempt to locate sexual contacts to assure they are disease-free or are appropriately treated if they are already infected.

The information obtained by reporting allows the state to make informed decisions and laws concerning activities and the environment such as food handling, water purification, insect control, animal control, STD (sexually-transmitted disease) tracking, and immunization programs.

Please remember that the health care provider is bound by law to report these events. People with any of the diseases listed in the state's reporting schedule should make every effort to cooperate with the state health workers. Cooperation may help locate the source of an infection or prevent the spread of an epidemic.