Under the previous notification system, the Public Health (Control of Disease) Act 1984 and its associated regulations, emerging conditions such as SARS and influenza H1N1 could not be added in a timely way. Furthermore, non-infectious hazards were not covered. Following a consultation process,1 these issues were addressed in new regulations which came into force in April 2010.^2-5

The new regulations take an all hazards approach, including a catch-all ‘suspected cases of other infections or contamination that present, or could present, significant harm to human health' category, covering outbreaks, diseases which are not normally notifiable,^{2, S3.2} and chemical or radiation hazards.^{2, S3.3} A full list of notifiable diseases can be found on the HPA website (www.hpa.org.uk).

Reporting is now a professional duty, whereas previously failure to report was a crime. Potential sanctions include referral to the GMC, rather than prosecution, or a law suit from a patient whose illness could have been prevented if the clinician had notified appropriately.

Time is often of the essence in terms of public health action, so diagnoses should be notified on suspicion, without waiting for confirmation. There is a simple process for denotification if an alternative diagnosis is confirmed; and awaiting confirmation could result in the illness spreading. For some conditions, such as food poisoning, many reports are received too late for public health action, other than surveillance to monitor trends; and these often duplicate laboratory reports (only being notified once a laboratory report has been received, rather than on suspicion).

In reality, relatively few cases of notifiable diseases are actually notified. Often doctors are unaware of their duty to notify or of the process for doing so. Some doctors notify when they are aware of the need for public health action (e.g. meningococcal disease), or where confirmatory testing depends on the diagnosis being reported (e.g. measles, mumps); however, many are unaware of the urgency.

The new legislation provides guidance on how urgently different conditions should be notified.² Contacts of hepatitis A cases, for example, should be vaccinated as soon as possible - preferably within a few days of exposure. If this is left too late, immunoglobulin may have to be given instead, which is much less pleasant for the patient, and harder to obtain; and some will develop this potentially fatal disease.

Some conditions are notifiable to monitor trends, inform policy decisions or evaluate vaccination programmes. In these cases, notification may be less urgent.

Unfortunately, reporting rates are currently so low that trend analysis is unreliable. Such a small proportion of cases are reported that spurious and misleading changes can arise when, for example, media reports focus on a condition, leading to artefactual changes in reported rates.

The changes to the legislation also permit electronic notification. GP computer systems could be adapted not only to remind clinicians about their duty to notify and explain how to do so; but also to streamline the process, and make it more systematic and reliable. Flagging a diagnosis that is likely to be a notifiable disease could prompt the clinician to complete the requisite data, and automatically send a notification directly to the HPA's computer systems, alerting HPA staff to act promptly.

Prevention of illness rests on prompt and systematic notification by GPs and other clinicians. A basic notification form can be downloaded from the HPA website. These revisions to the public health legislation are a positive step in assisting the Health Protection Agency, with the support of doctors, to carry out its role to protect the public more effectively.