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.

All states have a "reportable diseases" list. Although it is up to states to decide which diseases are reportable, most of these lists are similar with only a few variations depending on geographical location. The diseases are divided into several groups:

• 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.