Introduction

The United Kingdom is in the grip of a nationwide mumps epidemic with almost 5000 notifications in the first month of 2005 alone.1 Most patients are aged between 19 and 23, and there is now the threat of outbreaks among under-immunised children.

As a result of the measles, mumps, and rubella (MMR) vaccine, which was introduced in 1988, the current generation of practising doctors have little experience of mumps infection. Mumps may have permanent sequelae, and not all cases can be diagnosed clinically. Here we explain the basis of the current epidemic and review the epidemiology, clinical presentation, complications, laboratory confirmation, and treatment of mumps.

Methods

We searched Medline for evidence based information on the internet, using a range of search terms. Other internet based resources included the websites of the Health Protection Agency (HPA), the World Health Organization (WHO), and the US Centers for Disease Control (CDC). We also used various formal texts.

Mumps and its transmission

Mumps is an enveloped, single stranded RNA virus belonging to the family paramyxoviridae, which causes an acute infectious disease mainly in children and young adults.2 Transmission is by droplet spread, and humans are the only known host. Mumps is highly infectious and spreads rapidly in susceptible people living in close proximity. The number of secondary cases of infection expected to result from an index case of mumps in a fully susceptible population (R₀ or basic reproduction number) is 10-12. By comparison, measles—a notoriously infectious virus—has an R₀ of 15-17.3

The incubation period from infection to appearance of the characteristic swelling of the parotid glands is 15-24 days.4 The infectious period starts several days before the onset of parotitis and continues for several days afterwards.4 ^w1Infection control guidance for schools and nurseries advises that children stay away from school for …