Caused by the Morbillivirus, which is a type of paramyoxovirus
This is a single stranded, enveloped RNA virus
It is a highly contagious infection of the respiratory system, and can be passed on by airborne transmission, via droplets expelled in coughing, sneezing and respiration.
Maternal antibodies tend to provide immunity in the first 6 months of life
In the developing world, the death rate is approx 10%
Disease progression and symptoms
Incubation period is typically 10-14 days, followed by the symptomatic phase, of typically 7-10 days.
Patient is infective for the last 2 days of incubation (i.e. before symptoms are apparent!), and for the first 6 days of the symptomatic phase.
Fever – temperature increases from day 1-5, peaks at day 5, before falling.
Koplik’s spots –these are small white spots on the buccal mucosa. Visible usually from days 2-5. These are diagnostic for measles, but often not seen, and when present are transient.
Cough – usually apparent through the whole symptomatic phase
Conjunctivitis and Coryzal Symptoms – days 1-5.
Rash! – this usually starts off behind the ears, and spreads down the body. Initially a maculopapular rash, it typically expands and becomes indistinct. Usually lasts from about days 3-7, but there is a possibility of desquamation towards the end.
When to exclude from school?
Until at least 5 days after the onset of the rash. Typically, viral shedding stops around day 6, and the rash starts at day 3. This allows 2 days leeway, excluding the child from school until at least day 8.
Encephalitis – occurs in 1 in 5000 cases. Presents 8 days after the onset of symptoms of measles, with lethargy, headache and irritability. Can result in LOC and coma. 15% mortality rate. In up to 40% of cases there will be long-term problems, including; deafness, hemiplegia and learning difficulties.
Subacute sclerosing panencephalitis (SSPE) extremely rare–Presents approx 7 years after measles infection. Will cause progressive dementia (over several years) and eventual death. Occurs in 1 in 100 000 cases of measles. Caused by a measles virus variant gaining access to the CNS. Diagnosis is confirmed by high levels of measles antibody in the blood and CNS. May also cause CNS abnormalities.
Ensure isolation in hospital – to prevent the child coming into contact with immunocompromised patients!
Ensure adequate nutrition – continue breastfeeding, even with diarrhoea, supplement and intubate if necessary.
Vitamin A – involved in the immune response, and may be deficient in some, but rarely in the developed world. Supplements available if you suspect it may be a contributing factor
Ribavirin – antiviral. Should not be used in normal cases, but should be used in immunocompromised patients.
Vaccination in the UK
Began in UK in 1960’s
800,000 cases/year before vaccination programme
Almost 100% of children used to get it at some point!
Number of cases has risen slightly after fall in MMR uptake in late 1990’s
No link between MMR and autism
Live attenuated vaccine used – highly effective, and provides life-long protection. The percentage needed to vaccinate for herd immunity is >80%.
In 10-20% of cases, immunity is not achieved after this first dose, hence the ‘booster’ given to children just before they begin attending school (Age 3 years 4 months)
Side effects can include mild variants of the symptoms of the disease being vaccinated against. For example, they can include; rash, fever, and loss of apetite (measels). swollen lymph nodes (mumps), and rarely stiff, swollen joints (rubella).
Dr Tom Leach currently works as a GP Registrar and an Emergency Department CMO in Australia. He is also a Clinical Associate Lecturer at the Australian National University. After graduating from his medical degree at the University of Manchester in 2011, Tom completed his Foundation Training at Bolton Royal Hospital, before moving to Australia in 2013. He started almostadoctor whilst a third year medical student in 2009.
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