Definition: A viral infection caused by the Measles Virus.
Epidemiology: Rates have fallen drastically in the developed world since the introduction of the vaccine in the 1960’s rates of Measles have rapidly declined, however it still represents a major cause of morbidity and mortality in the third world.
Measles is a highly infectious virus, and still affects approximately 20,000,000 children worldwide annually. It is spread by Droplets during the viral shedding phase (1-2 days before symptoms arise, and then the first 5-6 days of clinical disease).
Humans represent the only source of disease, with no known animal reservoir.
This, as occurred with Small Pox, represents a great potential to eliminate the disease.
Signs and Symptoms: Fever, Malaise, Cough, Runny Nose, Conjunctivitis, Rash,
Viral Exanthema, Diarrhoea, Vomiting, Otitis Media, etc..
The natural course of the disease occurs over several weeks. Initial exposure to the virus often precedes symptoms by 10 days to two weeks. In the last few days of this period patients become infectious as they enter the viral shedding phase.
The clinical phase of the illness begins with fever which increases over the first five days of illness. This is accompanied by Conjunctivitis and Coryzal symptoms
(4-5 days), and cough (which persists for ~10 days). On Day 2 Koplik spots
(white spots on the buccal mucosa) which are pathognomic of Measles, may be noted. From day three a Maculo-Papular Rash may be noticed, starting behind the ears, the spreading across the head and neck, before covering most of the body, this rash is often itchy and persists for approximately five days.

Complications: Encephalitis occurs in 1 in 5,000 cases usually 7-9 days after the onset of rash (this may be signaled by headache, progressing through convulsions and coma) – Measles Encephalitis has a 1-in-6 mortality rate and may otherwise lead to Hemiplegia, severe learning difficulties and long-term seizures.
Subacute Sclerosing PanEncephalitis (SSPE): A rare (1–in-100,000), but extreme, long-term complication of measles. Manifesting approximately 5-10 years after initial measles infection. Persistence of Measles within the Central
Nervous System leads to progressive loss of Neurological Function leading to
Death.
Giant Cell Pneumonia
Secondary Bacterial Infections Including: Pneumonia, Otitis Media, Tracheitis.
Febrile Convulsions, Diarrhoea, Hepatitis, Appendicitis, Corneal Ulceration,
Myocarditis
DDx: Measles, Mumps, Parvovirus, Roseola, Scarlet Fever, Kawasaki Disease,
Rubella, Rocky Mountain Spotted Fever, Infectious Mononucleosis, Erythema
Infectiosum, etc..
Ix: Measles is often a clinical diagnosis (however IgM response to Measles on blood tests, or isolation of Measles virus from respiratory specimens could also be used to diagnose Measles.
Mx: Management of measles should be symptomatic – Rest, Fluids, Paracetamol,
Isolation, etc.. However, in those with complications, or inability to tolerate fluids, or extremely unwell hospitalization may be required. In immunecompromised patients Ribavirin may be used. Within the third world or in cases of underlying severe malnourishment modest doses of Vitamin A may also be used to help modulate the immune response.
Measles is a Notifiable Disease in many jurisdictions.
Prevention: The Measles Vaccine (often given as part of the MMR – Measles/
Mumps/ Rubella) has greatly decreased rates of disease in the first world, providing both individual and herd immunity. However, increasingly poor rates of uptake pose a major public health concern as rates in Europe and Australia near 20 year highs as returning travellers carry back the infection from Endemic regions such as Vietnam.