Measles, mumps and rubella

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Measles virus is transmitted by aerosols and is exceptionally contagious. Replication in respiratory epithelium and lymphoid tissue produces viraemia, transient immune suppression and a T-cell-mediated rash. The clinical sequence matters: prodromal fever with cough, coryza and conjunctivitis precedes Koplik spots and the cephalocaudal exanthem. Pneumonitis and encephalitis are major acute threats, while subacute sclerosing panencephalitis is a rare delayed consequence.

Mumps virus spreads through respiratory droplets and saliva. Viraemia targets salivary glands, testes, ovaries, pancreas and central nervous system. Parotitis is recognisable but not universal, and aseptic meningitis may occur without obvious gland swelling. Post-pubertal orchitis can be intensely painful; atrophy may follow, although sterility is uncommon after unilateral disease.

Rubella virus spreads by respiratory contact and is frequently mild or subclinical after birth. Its importance is transplacental infection: early fetal infection disrupts organogenesis and can cause miscarriage or congenital rubella syndrome with sensorineural deafness, ocular disease, congenital heart defects and neurodevelopmental injury. A mild maternal rash therefore has consequences disproportionate to maternal illness.

All three infections are preventable by live attenuated MMR-containing vaccines and are notifiable in the UK. Clinical suspicion triggers notification, laboratory coordination and contact management. Routine childhood products changed in England in 2026 to include varicella through MMRV for eligible cohorts, while older catch-up and adult protection continue to use the current age-specific MMR or MMRV pathway.

Key points

Measles causes high fever, cough, coryza and conjunctivitis followed by Koplik spots and a blanching rash that begins on the face or hairline and spreads downwards.
Isolate suspected measles from shared air and notify the health protection team immediately on clinical suspicion; do not wait for oral-fluid confirmation.
MMR-containing vaccine within 72 hours of measles exposure can protect eligible susceptible contacts; selected vulnerable contacts may need human normal immunoglobulin as soon as possible and up to six days.
Mumps usually causes painful unilateral or bilateral parotid swelling, but orchitis, aseptic meningitis, pancreatitis and hearing loss can dominate the presentation.
Rubella is often mild, with low fever, fine rash, posterior auricular or suboccipital lymphadenopathy and adult arthralgia, yet maternal infection can cause congenital rubella syndrome.
MMR and MMRV are live vaccines and are contraindicated during pregnancy and substantial immune suppression; vaccinate susceptible patients after pregnancy when safe.
Children born on or after 1 January 2025 are offered routine MMRV at 12 and 18 months in England; transitional cohorts and catch-up follow their date-of-birth schedule.
There is no routine specific antiviral for uncomplicated measles, mumps or rubella: care is supportive while infection control, complication treatment and prevention remain decisive.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Measles aerosols

Airborne morbillivirus remains suspended after an infectious person coughs or breathes, allowing rapid transmission in poorly ventilated shared spaces.

Mumps droplets

Paramyxovirus in saliva and respiratory secretions spreads through close contact, shared utensils and droplets before and after gland swelling.

Rubella respiratory spread

Rubella virus passes between people through respiratory secretions and can cross the placenta during maternal viraemia.

Immunity gaps

Missed doses, disrupted programmes and incomplete catch-up create susceptible clusters in which imported infection can produce sustained outbreaks.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Measles viraemia
Respiratory replication seeds lymphoid tissue and distant organs, while the antiviral T-cell response produces rash and temporary immune suppression.
2
Mumps gland tropism
Viraemic virus inflames salivary, gonadal and pancreatic tissue and can enter the meninges, creating organ-specific swelling and pain.
3
Rubella placental invasion
Maternal viraemia infects placenta and fetal tissues, disrupting cell division, blood vessels and organogenesis during vulnerable early development.
4
Live-vaccine immunity
Attenuated vaccine viruses produce humoral and cellular memory without wild-type organ invasion, substantially reducing infection, complications and onward transmission.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Measles prodromeRed flag

High fever with cough, coryza, red watery eyes and malaise precedes the rash; tiny white Koplik spots may appear on the buccal mucosa.

Measles exanthemRed flag

A blanching erythematous maculopapular rash begins behind the ears or at the hairline, spreads down the trunk and limbs and may become confluent.

Mumps parotitis

Tender swelling elevates the ear lobe and obscures the mandibular angle, often with fever, headache, malaise and pain when chewing acidic food.

Mumps complicationsRed flag

Testicular pain and swelling, meningism, encephalopathy, upper abdominal pain or hearing loss can occur with or without prominent parotitis.

Acquired rubella

Low-grade fever, fine pink rash, posterior auricular or suboccipital nodes and symmetrical arthralgia are typical, but many infections remain subclinical.

Congenital rubella syndromeRed flag

Sensorineural deafness, cataract or pigmentary retinopathy, patent ductus arteriosus, growth restriction and developmental impairment indicate fetal infection.

Red flags requiring action

Suspected measles in a waiting room, ward or emergency department requires immediate airborne isolation and public-health notification before test confirmation.
Hypoxia, respiratory distress, dehydration, encephalopathy, seizure or focal neurology during measles requires hospital assessment for pneumonitis, bacterial complication or encephalitis.
Mumps with severe headache, neck stiffness, altered consciousness, testicular pain, abdominal pain or hearing change suggests meningitis, orchitis, pancreatitis or sensorineural injury.
Any suspected rubella illness or exposure during pregnancy needs same-day obstetric, virology and health-protection assessment because congenital risk depends on gestation and true maternal infection.
A rash illness in a substantially immunosuppressed person may be atypical, prolonged and severe, so absence of classic morphology does not safely exclude measles or rubella.
An infant, pregnant contact or severely immunosuppressed contact exposed to measles needs urgent health-protection risk assessment while post-exposure prophylaxis remains possible.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Immediate clinical and exposure assessmentFirst step
Why
Identify probable measles and vulnerable contacts before laboratory confirmation.
Interpretation and limitations
Record rash onset, vaccination history, travel, known exposure, pregnancy and immune status; compatible fever-rash illness still requires isolation and notification when vaccination history is incomplete or exposure is plausible.
02
UKHSA oral-fluid test
Why
Confirm suspected measles, mumps or rubella through the health-protection pathway.
Interpretation and limitations
Arrange the supplied oral-fluid kit after notification and add throat swab, urine or other urgent diagnostic samples when the health protection team advises; do not delay control measures while awaiting results.
03
Measles PCR and serology
Why
Provide rapid confirmation in severe, admitted or outbreak-associated suspected measles.
Interpretation and limitations
PCR from appropriate respiratory or urine samples is most useful early; IgM timing, recent vaccination and false-positive rash illnesses require laboratory and epidemiological interpretation.
04
Mumps PCR
Why
Confirm mumps when parotitis or a complication is clinically suspected.
Interpretation and limitations
Buccal or oral-fluid PCR close to symptom onset is preferred; serum amylase is non-specific and a negative late sample does not automatically identify another cause.
05
Rubella serology and PCR
Why
Confirm acquired rubella and establish maternal immunity or recent infection.
Interpretation and limitations
IgG documents immunity, while IgM alone can mislead; suspected infection in pregnancy requires reference-laboratory confirmation, comparison with stored sera, avidity or PCR selected by virology.
06
Complication screen
Why
Measure organ injury in a systemically unwell patient.
Interpretation and limitations
Use oxygen saturation, chest imaging, FBC, renal and liver tests, glucose and targeted CSF, testicular ultrasound or pancreatic tests according to respiratory, neurological, gonadal or abdominal findings.
07
Pregnancy and fetal assessment
Why
Define fetal risk after suspected rubella or measles exposure or illness.
Interpretation and limitations
Confirm gestation and maternal immunity urgently, involve fetal medicine and virology, and individualise serial imaging or diagnostic sampling; neither rash appearance nor one IgM result is sufficiently reliable.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Other viral exanthem

Parvovirus B19, roseola, enterovirus and EBV can cause fever with rash but differ in sequence, distribution, exposure and targeted testing.

Bacterial parotitis

Unilateral toxic swelling, purulent Stensen-duct discharge, dehydration and neutrophilia favour bacterial infection requiring culture and antibacterial treatment.

Medication eruption

A temporally related symmetrical rash may mimic measles or rubella, but does not remove notification duty when fever and epidemiology fit.

Kawasaki disease

Persistent fever with conjunctival injection, oral change, extremity findings and lymphadenopathy requires cardiovascular evaluation rather than isolation alone.

EBV mononucleosis

Exudative pharyngitis, posterior cervical nodes, splenomegaly and atypical lymphocytosis suggest EBV, sometimes with an antibiotic-associated rash.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01MEASLESIsolate and notify firstFirst stepFever with cough, coryza, conjunctivitis or a descending rash creates clinical suspicion of measles.

1Keep the patient out of common waiting space, place them in an appropriate airborne isolation room and use respiratory protective equipment under local infection-control policy.
2Notify the proper officer or health protection team immediately, recording rash onset, vaccination, travel, exposure, pregnancy, immune status and places attended while infectious.
3Obtain oral-fluid and any rapid PCR samples advised by UKHSA without sending the patient through shared clinical areas or delaying treatment of complications.
4Assess oxygenation, hydration and neurology, admit severe disease safely, and treat bacterial superinfection or organ failure while providing supportive measles care.

02CONTACTSUse the prophylaxis windowA susceptible or uncertain contact has had a credible measles exposure.

1Contact the health protection team urgently to define exposure, susceptibility, age, vaccine history, pregnancy, immune suppression and time since first and last contact.
2Offer an age-appropriate MMR-containing vaccine within 72 hours to eligible susceptible contacts; vaccination later may still protect against future exposure or complete catch-up.
3Give human normal immunoglobulin to selected vulnerable susceptible contacts as soon as possible and up to six days, using the current national product and dose pathway.
4Provide symptom monitoring, exclusion and rapid-access instructions for the full incubation window because prophylaxis can modify presentation and does not guarantee prevention.

03MUMPSSupport and detect complicationsParotid swelling or a compatible meningitic, gonadal or pancreatic illness suggests mumps.

1Notify suspected disease, arrange oral-fluid or buccal testing, assess vaccine and exposure history, and avoid unnecessary attendance in shared settings.
2Use oral fluids, paracetamol or appropriate ibuprofen and local comfort measures; support an inflamed testis without relying on antibiotics unless bacterial infection is suspected.
3EscalationEscalate meningism, encephalopathy, dehydration, severe abdominal pain, bilateral orchitis or hearing change for hospital and organ-specific assessment.
4Exclude from school, work or close-contact settings for five days after parotid swelling begins and review household immunisation for future protection.

04RUBELLAProtect pregnancyRubella-like rash, confirmed contact or uncertain immunity occurs during pregnancy.

1Avoid exposing other pregnant people, notify health protection and obtain precise gestation, symptoms, vaccination records and exposure dates.
2Ask virology to test and compare maternal IgG, IgM, avidity, PCR or stored antenatal sera as appropriate; do not diagnose recent rubella from IgM alone.
3Refer confirmed or credible maternal infection to fetal medicine for gestation-specific counselling and specialist diagnostic planning.
4Do not administer live MMR or MMRV during pregnancy; offer indicated MMR after birth and advise avoiding pregnancy for one month after vaccination.

05PREVENTIONComplete two-dose protectionA child, adolescent or adult has an incomplete or uncertain MMR-containing vaccine history without a contraindication.

1Check the current date-of-birth schedule because routine MMRV, transitional MMRV and older MMR catch-up cohorts differ after the 2026 programme change.
2Offer two valid MMR-containing doses at the age-appropriate interval rather than relying on a verbal history of non-specific childhood rash.
3Screen for pregnancy, substantial immune suppression and previous anaphylaxis to a vaccine component; egg allergy alone is not a routine reason to withhold MMR-containing vaccine.
4Record product, batch, route and date, report serious reactions and use the Green Book or health-protection pathway for exposure-specific timing.

Key medicines and prescribing safety4 treatments · regimens, roles and cautions

Provides active protection against measles, mumps, rubella and varicella for eligible childhood routine and transitional cohorts in England.

MMRV vaccine for the routine childhood programme

Paediatric programme dose: give 0.5 mL of the supplied live MMRV vaccine by the authorised subcutaneous or intramuscular route; children born from 1 January 2025 receive routine doses at 12 and 18 months.

Confirm the date-of-birth pathway, product information, live-vaccine contraindications, pregnancy and substantial immunosuppression; programme transitions mean not every child receives the same ages or number of MMRV doses.

Completes measles, mumps and rubella protection outside eligible routine MMRV cohorts and provides active measles post-exposure prophylaxis when given promptly.

MMR vaccine for older catch-up and measles exposure

Give 0.5 mL of an authorised live MMR vaccine by the product-approved route; use two valid doses at least four weeks apart for susceptible older children or adults, and give eligible measles PEP within 72 hours.

Do not give during pregnancy or substantial immune suppression; assess previous severe component allergy, defer when clinically appropriate, and advise avoiding pregnancy for one month after vaccination.

Provides temporary passive protection for selected susceptible vulnerable measles contacts who cannot rely on timely live vaccination.

Human normal immunoglobulin for measles exposure

National PEP dosing includes approximately 3,000 mg intramuscularly for a susceptible pregnant contact and 100 mg/kg up to 1,000 mg for an eligible infant; administer as soon as possible and no later than six days after exposure.

Eligibility and product route are determined urgently with health protection; divide large intramuscular volumes between sites and account for interference with later live-virus vaccination.

Relieves fever, headache, myalgia and painful parotitis while the viral infection resolves and hydration is maintained.

Paracetamol for symptomatic care

Give 500 mg to 1 g orally every four to six hours when required, with a maximum of 4 g in 24 hours for a typical adult; reduce the ceiling in low body weight or hepatic risk.

Check combination products and overdose risk, use weight-based paediatric dosing, and do not let antipyresis delay assessment of hypoxia, meningism, encephalopathy or severe dehydration.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Measles pneumonitis

Primary viral lung injury or secondary bacterial pneumonia causes hypoxia, respiratory failure and death, especially in infancy or immune suppression.

Measles encephalitis

Acute brain inflammation causes seizure and neurological injury, while delayed subacute sclerosing panencephalitis produces progressive fatal neurodegeneration years later.

Mumps organ injury

Orchitis can cause testicular atrophy, while meningitis, encephalitis, pancreatitis, oophoritis and permanent sensorineural deafness occur less often.

Congenital rubella syndrome

Fetal infection causes miscarriage, deafness, cataract, pigmentary retinopathy, congenital heart disease, growth restriction and developmental impairment.

Outbreak transmission

Delayed recognition exposes healthcare settings, schools and households, causing preventable illness among infants, pregnant people and immunosuppressed contacts.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

For measles, monitor oxygen saturation, work of breathing, hydration, neurological state and bacterial complications; deterioration after initial improvement can indicate secondary pneumonia.
Trace the infectious timeline with health protection, documenting settings attended and pregnancy, infancy or immune suppression among contacts before prophylaxis windows close.
During mumps, reassess severe testicular pain, abdominal pain, meningism, hearing change and oral intake rather than assuming all parotitis remains uncomplicated.
After suspected rubella in pregnancy, follow the reference-laboratory and fetal-medicine plan until maternal infection and fetal risk are resolved.
Audit two-dose vaccine completion and schedule the outstanding dose, because one dose or uncertain verbal history leaves avoidable outbreak susceptibility.
After live vaccination, distinguish expected short-lived fever or rash from true wild-type infection using timing, exposure history and health-protection advice.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Notification precedes proof

Measles, mumps and rubella are notified on suspicion, allowing public-health teams to protect contacts while confirmatory samples are still in transit.

Measles suppresses immunity

Transient immune dysfunction contributes to bacterial pneumonia and can erase part of established immune memory, extending morbidity beyond the visible rash.

Mumps lacks parotitis

Aseptic meningitis or orchitis can occur without obvious salivary swelling, so exposure and vaccination history remain relevant in compatible complications.

Rubella can look trivial

Mild maternal symptoms do not imply low fetal risk, particularly early in pregnancy when organogenesis is vulnerable to transplacental virus.

Vaccine products changed

Routine English childhood vaccination now uses MMRV for eligible cohorts, but older people and several catch-up situations still require MMR according to age and history.

11Common pitfallsFrequent interpretation and management errors.

01
Do not leave a suspected measles patient in a communal waiting area while taking a routine history or awaiting permission to isolate.
02
Do not wait for a positive oral-fluid or PCR result before notifying suspected measles, mumps or rubella and starting contact assessment.
03
Do not assume two vaccine names or childhood rash history proves two valid doses; check records and use the current catch-up algorithm.
04
Do not administer MMR or MMRV during pregnancy or substantial immune suppression, and do not confuse postpartum vaccination with treatment of maternal infection.
05
Do not diagnose rubella in pregnancy from rash appearance or isolated IgM because false positives can cause profound avoidable harm.
06
Do not treat painful mumps orchitis with antibiotics unless clinical evidence supports a bacterial epididymo-orchitis alternative.