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Measles, Mumps and Rubella (MMR)
Essentials
- The incidence of measles, mumps and rubella has greatly reduced in many Western countries after the introduction of the MMR vaccine. Cases may be mostly found in travellers.
- Both measles and mumps, however, still occur widely in Europe.
- Outbrakes or epidemics of measles, mumps or rubella occur in many European countries mainly because of too low vaccination coverage. See current situation in Europe http://www.ecdc.europa.eu/en/vaccine-preventable-diseases and in the world http://apps.who.int/immunization_monitoring/globalsummary.
- All travellers should be protected againts MMR diseases. See national guidance on immunization (notice especially small children who have not yet been vaccinated).
- If one of these illnesses is suspected, a specialist in infectious diseases should be consulted. The diagnosis must always be confirmed with antibody and PCR assays.
- The MMR diseases are often classified as notifiable (or dangerous communicable) diseases. Find out about their local status and relevant regulations.
- Take into account local regulations concerning dangerous communicable diseases.
Transmission
- Measles is readily transmitted by contact and droplets, as well as by the airborne route. The viruses remain infective in room air and surfaces even up to 2 hours.
- The incubation period is usually 9-11 days (7-21 days) to the appearance of catarrhal symptoms and 14 days to the eruption of a rash
- The contagious period starts just before the catarrhal symptoms appear (4 days before the rash appears) and ends 4 days after the appearance of the rash.
- A person who has acquired one or two doses of MMR vaccine may still catch measles, especially if the exposure is strong and long-lasting.
Signs and symptoms
- The catarrhal symptoms are always typical: rhinitis, cough, conjunctivitis; in addition there is fever
- Light-coloured enanthema spots 1-3 mm in diameter are often visible on the buccal mucous membrane before the eruption of the rash (Koplik's spots).
- The bright red rash is patchy and starts behind the ears. It spreads down to the trunk and extremities and changes into a violet colour before fading away (pictures ). The patches merge to form more extensive areas of rash.
Diagnosis
- Drug rashes and exanthema associated with other viral infections (mononucleosis, adenovirus, enterovirus) should be excluded as they are much more probable at least in the industrialized countries.
- Measles should be suspected if an unvaccinated child has a febrile upper respiratory tract infection and an associated exanthema. The possibility of the child having measles is increased if he/she has been staying in an area where measles cases are known to occur or he/she has had contact with a person in whom measles is susptected.
- If the exposure is exceptionally close and prolonged, even a vaccinated person may catch measles. In such a case the clinical picture is usually mild and not easily recognized.
- In suspicion of measles, a physician responsible for communicable diseases or a specialist in infectious diseases should be consulted, in order to assess the justification of the measles suspicion.
- The diagnosis must always be confirmed with antibody assays and a PCR test of a throat specimen.
- Find out about locally available laboratories performing such tests and about local guidance on diagnostics.
- Otitis media
- Pneumonia
- Encephalitis 1:1 200-1 800
- Subacute sclerosing panencephalitis (SSPE; see Uncommon Infections of the Central Nervous System) is a rare but serious late complication.
- Measles may be serious in immunosuppressed patients.
- In developing countries, vitamin A improves the prognosis.
Rubella
Transmission
- The incubation period is 14-21 days.
- The infectiousness of rubella is at its highest a couple of days before the rash appears and 7 days after the appearance of the rash. The presence of the virus in the nasopharynx, however, has been shown to occur already 7 days before the rash onset and even 14 days after it.
- Having the disease or MMR vaccination (2 doses) produces immunity against rubella.
Signs and symptoms
- Symptoms usually include mild common cold -type symptoms and rash.
- The infection may also be asymptomatic.
- Enlargement of suboccipital and postauricular lymph nodes is common before the appearance of a rash.
- A fine, erythematous macular rash spreads from the face to the trunk and limbs within one day, and it persists for 2-3 days.
- An infection during pregnancy may cause serious foetal damage.
Diagnosis
- The clinical picture is not sufficient for diagnosis. Many viral exanthemas and drug reactions have a similar presentation.
- In suspicion of rubella, a specialist in infectious diseases should be consulted.
- The diagnosis must always be confirmed by antibody and PCR assays. Consult local guidance on diagnostics.
- Take into account local regulations concerning notifiable diseases.
Complications
- An infection during pregnancy may lead to miscarriage, foetal death or congenital malformations (defects in hearing, vision or the heart, psychomotoric developmental disability).
- Articular symptoms are common in adolescents and adults. They are usually transient.
- Thrombocytopenic purpura is rare.
- Encephalitis is rare.
- Administration of gammaglobulin is of no benefit after a person has become infected.
Mumps
Transmission
- The incubation period is 14-21 days.
- Mumps is spread readily by droplet infection. The contagious period starts 1-2 days before symptoms appear and ends about one week after the emergence of symptoms.
- May also occur in vaccinated persons, in which case the symptoms are usually milder and complications rare.
Signs and symptoms
- Prodromal symptoms may resemble those of common cold.
- Fever
- Unilateral or bilateral painful swelling of the salivary glands which extends to above the angle of the mandible and in front of the ear, which will distinguish it from lymph node enlargement.
- Pain on swallowing
- May also be asymptomatic or mildly symptomatic.
Diagnosis
- Bilateral swelling of the cheeks and fever in an unimmunised patient
- The diagnosis is confirmed by determining mumps antibodies and/or by demonstrating the virus with a PCR test. Consult local guidance on diagnostics.
- Take into account local regulations concerning notifiable diseases.
Complications
- The patient may develop meningoencephalitis. The symptoms usually emerge within a few days of disease onset: headache, nausea and vomiting.
- Encephalitis is much rarer and may develop later.
- Orchitis develops in 30-40% of men who contract mumps after puberty.
- Symptoms include scrotal swelling and pain as well as a feeling of warmth.
- Orchitis is bilateral in 20% of patients.
- Bilateral involvement causes sterility in 2% of cases.
- Rarer complications include pancreatitis, thyroiditis, oophoritis, mastitis and hearing loss.
References
- Seppälä E, Zöldi V, Vuorinen S ym. A cluster of measles linked to an imported case, Finland, 2017. Euro Surveill 2017;22(33). [PubMed]