Introduction

Mumps is caused by RNA paramyxovirus and tends to occur in winter and spring.

Epidemiology

  • Incidence: 2.00 cases per 100,000 person-years
  • Peak incidence: 30-40 years
  • Sex ratio: 1:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Pathophysiology

Spread
  • by droplets
  • respiratory tract epithelial cells → parotid glands → other tissues
  • infective 7 days before and 9 days after parotid swelling starts
  • incubation period = 14-21 days

Clinical features

Clinical features
  • fever
  • malaise, muscular pain
  • parotitis ('earache', 'pain on eating'): unilateral initially then becomes bilateral in 70%

Management

Management
  • rest
  • paracetamol for high fever/discomfort
  • notifiable disease

Complications

Complications
  • orchitis - uncommon in pre-pubertal males but occurs in around 25-35% of post-pubertal males. Typically occurs four or five days after the start of parotitis
  • hearing loss - usually unilateral and transient
  • meningoencephalitis
  • acute pancreatitis

Screening and prevention

Prevention
  • MMR vaccine: the efficacy is around 80%