Epidemiology

During the year 2004 there were

• 2200 cases of scarlet fever notified in England and Wales
• 190 cases in Scotland
• 228 cases in Northern Ireland (1)

During the course of the last century the rates of notification as well as mortality due to scarlet fever showed a steep decline:

• the peak incidence of notification occurred in 1914 with 446 notifications per 100,000 populations. This rate declined to 150 notifications per 100,000 populations by 1950
• the mortality rate attributable to scarlet fever also reduced markedly from a high of 14.8 per 100,000 population in 1902 to 5 per 100,000 population from 1916 onwards (2)

Since the introduction of effective antimicrobials and other therapeutic agents, improved living conditions (nutrition and housing) and a decrease in the virulence of the aetiological agent has resulted in a reduction of the incidence and severity of the disease (2)

• the rate has reduced to 4 notifications per 100,000 population (2)
• during a period of 42 weeks between 2008-2009, 3929 unconfirmed notifications of scarlet fever were made in England which is the highest total since 1995/1996 when 4536 notifications were made (3)

When analysing the pattern of incidence and mortality, a clear cyclical pattern can be observed with an upsurge occurring every 4 years on average (This gap in time is likely to reflect the length of time needed for a sufficiently large group of susceptible children to enter into institutional settings such as schools and nurseries) (2).

With the increasing use of nursery and other communal day care facilities, the cases of scarlet fever has been seen more commonly in pre-school aged children during the past two decades (2).

Reference:

• 1. Marshall S. Scarlet fever : the disease in the UK. The pharmaceutical journal 2006;277
• 2. Health Protection Agency (HPA). Analysis of epidemiological patterns during a century of scarlet fever
• 3. Health Protection Agency (HPA) 2009. Health protection report. Group A streptococcal infections: fourth update on seasonal activity, 2008/09