Measles

measles facts

A Personal Story

  • Maureen shares her story of miserable measles here.
  • Chris as he shares his experience of trying to help fight a measles epidemic with you here.

A summary

NRVS poster measles chart

Facts about measles, the disease and how to prevent it

The disease

  • The first sign of measles is usually a high fever, which begins about 10 to 12 days after exposure to the virus, and lasts four to seven days. During this time you can feel generally unwell (much like having a bad cold), with malaise, loss of appetite, a runny nose, a cough, and red and watery eyes. You can also develop small white spots inside the cheeks opposite the back teeth. These are known as Kopliks spots, and only occur in measles, so if they are there, they can help a doctor confirm the diagnosis.
  • After several days, a rash erupts, usually on the head, face and upper neck. Over about three days, the rash spreads, eventually reaching the hands and feet. The rash lasts for four to six days, and then fades. As it fades the skin may peel off. On average, the rash occurs 14 days after being exposed to the virus.
  • The measles rash;

measles-boy-rash

  • If uncomplicated, measles lasts 7 to 10 days in a healthy, well-nourished person. However, being fit and well prior to getting sick does not prevent you from developing complications from the disease.
  • There is no specific treatment to cure measles once you have caught it.

The complications:

  • Complications of measles most often occur in people aged less than 5 years, or over 20, and about 30% of people with measles have one or more complication.
  • Complications include; commonly, dehydration, diarrhoea, stomatitis (inflammation and ulceration of the lips and mouth), otitis media (inflammation of the middle ear) and much less commonly, hearing loss, visual loss, pneumonia, hepatitis, seizures, encephalitis (inflammation of the brain), subacute sclerosing pan-encephalitis (SSPE), miscarriage, premature labour, and death.
  • Even in the healthiest of populations, 1/4 – 1/3 of people with measles will be so sick they have to be looked after in hospital, and one in 1000 will die.
  • In individuals who are unwell, immuno-compromised, or malnourished the complication, hospitalisation, and death rate are much higher. In developing countries, especially in areas with high rates of vitamin A deficiency, the case fatality rate can be 20-30% (ie 20-30 out of every 100 that catch it will die). In any country, the risk of dying from measles if you also have cancer is up to 70%.
  • Survivors of measles have also been found to have a weakened immune system for up to 3 years after the initial measles infection, and are therefore vulnerable to all sorts of other potentially fatal infections in the subsequent years following recovery.
  • SSPE (sub-acute sclerosing pan-encephalitis) is a particularly brutal complication of measles.
    • This occurs in people who for some reason do not clear the measles virus from their body despite having a seemingly normal immune response to the original infection.
    • Originally thought to occur in about 1 per 100,000 cases, recent data from Germany and California suggest that it is far more common, especially those who contract measles at a very young age (when they are too young to be vaccinated themselves). Rates of 1 in 607 have been found in Californian infants who contracted measles between the years 1998-2015 when they were less than one year old.
    • It presents about 7 years after the original disease, and causes progressive brain damage such as memory loss, seizures, loss of vision and hearing, personality changes, loss of motor function, and, eventually, coma, persistent vegetative state, and death.
    • About 95% of people with SSPE will die within 1 to 3 years of diagnosis. In a small number of people, the disease will progress rapidly, leading to death over a short course within three months of diagnosis. An even smaller number (approximately 5 percent) may experience spontaneous long term improvement and regain some lost function.
    • There is no treatment to prevent the progression of SSPE once it has begun, the only prevention  is by vaccination.
    • The incidence of SSPE has declined by at least 90% in countries that have practiced widespread immunization with the measles vaccine.
    • SSPE has never been seen in a vaccinated person who hasn’t had the disease.

How contagious is measles?

  • Measles is one of the most contagious diseases known.
  • People are at their most contagious 2-4 days BEFORE the rash appears, and they remain contagious until 4 days after the rash appears. That means you can spread the disease to other before you even know you are sick.
  • Immune compromised people may remain highly contagious thoughout the entire course of the illness.
  • It is spread by droplets (such as those produced with coughing and sneezing).
  • You do not have to be touched to catch it, Just walking into a room where someone with measles has just been is enough to catch measles.
  • Rooms can stay contagious for about 2 hours after someone has left.
  • One common route by which it is spread is by infected and contagious people sitting in waiting rooms of hospitals and GPs.
  • In vulnerable populations (ie the unvaccinated, and not previously exposed to the disease), the secondary attack rate is about 90%.
    • This means that out of every 100 unvaccinated people exposed to the virus, about 90 will succumb to measles.

 The vaccination

  • The vaccine is extremely effective.
  • One dose leads to 95% immunity, two doses leads to about 99% immunity.
  • Current recommendations for immunisation in Australia are one dose of the Combined Measles, Mumps and Rubella vaccine (MMR) at 12 months, and a second dose at 18 months of MMRV, which also contains varicella (chickenpox) vaccine.
  • Babies younger than 1 year have a degree of protection inherited from their mum whilst still in the womb. In the event of a measles outbreak, a dose can be given at 9 months of age, but a further two doses will still be required as mum’s antibodies may limit how effective and long-lasting the early vaccination is.
  • In a population vaccinated with 2 doses of measles vaccine, out of every 100 people exposed to the disease, only one person, or less, will catch it.
  • In an unvaccinated population, out of 100 people exposed to the disease, 90 will catch it.
  • The vaccine is very long lasting; with only 5% of people needing a booster after 15 years.
  • The vaccine can be even more effective at preventing disease than just by it’s effect on individual immunity, because of herd immunity.
  • Herd immunity means that within a population, if enough people are vaccinated, the virus cannot find anyone to infect, it cannot be passed on, and the whole community is therefore protected, including those too young or frail to be vaccinated themselves. In simple terms, if you don’t catch it, you can’t pass it on. Please see here for an explanation of herd immunity.
  • In addition, measles does not infect any other animal, and cannot live free in the environment for more than a few hours. This means that if enough of the population is vaccinated, there is a real possibility of eradicating the disease altogether (as happened with smallpox). This paper describes how the principles of herd immunity are being used to eliminate measles in Australia (although there are still cases imported from overseas).
  • The vaccine is a live attenuated measles vaccine. This means that the virus has been weakened to such a state that it cannot cause disease, but is sufficient to cause an immune response, and thus lasting immunity.
  • Adverse events to any vaccination can and do occur. However, these are usually very minor, or extremely rare. A short lived fever and mild rash occurs in 5-15% of people, 5-12 days after the vaccine. As with any cause of fever in children, high temperatures can rarely (<1 in 1,000) lead to febrile convulsions, but in the vast majority of children, these do not lead to long term problems. The risk of lasting neurological damage such as encephalitis and SSPE is far greater if you catch measles.
  • The MMR does NOT cause autism. Please click here for more information on how we can be so sure.
  • If a rash and fever do occur after vaccination, this does NOT mean that you are contagious for measles, you do not have the disease, and you cannot pass it on to anyone (even the immuno-compromised).

Below is a graphic demonstrating just how effective the measles vaccination is at preventing measles.

measles vaccine effectiveness

This is a graph showing how 2 doses of measles vaccination dramatically reduced the number of cases of measles in Australia: measles incidence 1991-2009

References:

Page reviewed April 2017.
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