A notifiable disease is any disease that is required by law to be reported to government authorities. The collation of information allows the authorities to monitor the disease, and provides early warning of possible outbreaks. In the case of livestock diseases, there may also be the legal requirement to destroy the infected livestock upon notification. Many governments have enacted regulations for reporting of both human and animal (generally livestock) diseases. This usually happens during pandemics.
The World Health Organization's International Health Regulations 1969 require disease reporting to the organization in order to help with its global surveillance and advisory role. The current (1969) regulations are rather limited with a focus on reporting of three main diseases: cholera, yellow fever and plague.
The revised International Health Regulations 2005 broadens this scope and is no longer limited to the notification of specific diseases. Whilst it does identify a number of specific diseases, it also defines a limited set of criteria to assist in deciding whether an event is notifiable to WHO.
The OIE (World Organisation for Animal Health) monitors specific animal diseases on a global scale.
The National Notifiable Diseases Surveillance System (NNDSS) was established in 1990. Notifications are made to the States or Territory health authority and computerised, de-identified records are then supplied to the Department of Health and Ageing for collation, analysis and publication. The Australian national notifiable diseases list and case definitions are available online.
Within Australia the Department of Agriculture, Fisheries and Forestry regulates the notification of infectious animal diseases.
Notification is regulated under Brazilian Ministry of Health Ordinance number 1.271 of June 6, 2014.
Notification is regulated under the Health Act 1956, except for tuberculosis which is regulated under the Tuberculosis Act 1948. All diseases
Requirement for the notification of infectious diseases originated near the end of the 19th century. The list started with a few select diseases and has since grown to 31. Currently disease notification for humans in the UK is regulated under the Public Health (Control of Disease) Act 1984 and Public Health (Infectious Diseases) Regulations 1988. The governing body is Public Health England   List of Notifiable Diseases can be found here .
There are also requirements for notification specific to children in the National standards for under 8s day care and childminding that state:
"Office for Standards in Education should be notified of any food poisoning affecting two or more children looked after on the premises, any child having meningitis or the outbreak on the premises of any notifiable disease identified as such in the Public Health (Control of Disease) Act 1984 or because the notification requirement has been applied to them by regulations (the relevant regulations are the Public Health (Infectious Diseases) Regulations 1988).
In the UK notification of diseases in animals is regulated by the Animal Health Act 1981, as well as the Specified Diseases (Notification and Slaughter) Order 1992 (as amended) and Specified Diseases (Notification) Order 1996 (as amended). The act states that a police constable should be notified, however in practice a Defra divisional veterinary manager is notified and Defra will investigate.
In the past, notifiable diseases in the United States varied according to the laws of individual states. The Centers for Disease Control and Prevention and the Council of State and Territorial Epidemiologists (CSTE) also produced a list of nationally notifiable diseases that health officials should report to the CDC's National Notifiable Diseases Surveillance System (NNDSS). A uniform criterion for reporting diseases to the NNDSS was introduced in 1990.
- International Health Regulations Review - background
- WHO | International Health Regulations
- WHO | Frequently asked questions about the International Health Regulations
- Introduction to the National Notifiable Diseases Surveillance System
-  | [General Information]
- HPA | NOIDS | Day Care and Child Minding (National Standards)
- Defra, UK - Disease surveillance and control - Notifiable diseases
- History and Background | NNDSS
- "Centers for Disease Control and Prevention. Case definitions for public health surveillance" (PDF). MMWR. 39(No. RR-13). 1990.