Measles: Reliance on Herd Immunity is not Enough!

In Australia  and generally within our health care system  there is a sense of confidence   that all is under control  in  regard to  most communicable diseases as there is  reliance on Herd immunity. Herd immunity (or community immunity) is  a type of immunity that occurs when the vaccination of a portion of the population (or herd) provides protection to unprotected individuals. Herd immunity theory proposes that, in diseases passed from individual to individual, it is more difficult to maintain a chain of infection when large numbers of a population are immune. The higher the proportion of individuals who are immune, the lower the likelihood that a susceptible person will come into contact with an infectious individual.

On 25 August 2010  Queensland Health put out a media release titled Have you been vaccinated for measles?
The media release and related advice re confirms that we must remain vigilant in our infection control practices and the commitment to eradicating communicable diseases.

Queensland Health is urging all Queensland residents to ensure they have been vaccinated for measles, after cases were confirmed in Tweed Heads, Gympie and Moranbah. The current cases  were identified as  all being highly infectious while out and about in various communities.

Measles is one of the most infectious of all communicable diseases, and can be acquired in public places such as shopping centres or on public transport if infectious people are present.
 Queensland Health Communicable Diseases Branch Senior Director Dr Christine  Selvey recommends anyone born during or since 1966, who has not had two documented doses of Measles, Mumps, Rubella (MMR) vaccine or had proven measles, to visit their local GP for a free extra vaccination.

 Dr Selvey has identified  that  all Queenslanders  should  check if they need to be vaccinated against measles.

 

Basic Facts re  Measles ( Rubeola )

• Measles is extremely infectious and is spread by tiny droplets through coughing and sneezing or through direct contact with secretions from the nose or mouth.. The virus can last for several hours in the environment.
•  Measles can cause serious complications such as pneumonia (lung infection), encephalitis (inflammation of the brain) or otitis media (middle ear infection). Complications are more common and more severe in people with a chronic illness and very young children. Deaths occur mainly in children under five years of age, primarily from pneumonia, and occasionally from encephalitis. Measles should not be regarded as a simple childhood disease.

Symptoms:

 Measles begins with symptoms such as fever, tiredness, cough, runny nose and/or red inflamed eyes. These symptoms usually become more severe over three days. The cough is often worse at night and the affected person may wish to avoid light because of sore eyes. At this stage there may be small white spots on a red base in the mouth on the inside of the cheek (Koplik’s spots).

This is then followed by a blotchy, dark red rash usually beginning at the hairline. Over the next 24 to 48 hours the rash spreads over the entire body, during which time the person generally feels very unwell. Typically with measles, the fever is present and the person feels most unwell during the first couple of days after the rash appears. The rash usually disappears after six days.

 The time from contact with the virus until onset of symptoms is about 10 days but may be from 7 to 18 days.

 A person may be infectious from about five days before the onset of the rash until about four days after the rash appears.

Treatment
There is no specific treatment for measles. The symptoms of measles are usually treated with rest, plenty of fluids, and paracetamol to lessen pain or fever. Do not use aspirin for treating fever in children.
Control
People with measles should be excluded from work, school or childcare centres for at least four days after the appearance of the rash.
People who have not been vaccinated against measles and those who have any condition that compromises their immune system and have been in contact with a person with measles, should be excluded from school and childcare for 14 days from the day the rash appeared in the person diagnosed with measles.

 If unvaccinated contacts are vaccinated with the measles mumps rubella (MMR) vaccine within 72 hours of their first contact with the original person with measles, they may return to childcare, school or work.

Prevention

Vaccination with the MMR vaccine is the most effective way to prevent measles. Two doses are necessary to provide high levels of protection.
The MMR vaccine is recommended for:

•  all children at 12 months of age; and at 4 years of age.
• Vaccination is also recommended for:all children who have not previously received MMR vaccine
• children over 4 years of age who have only received one dose of MMR vaccine
• adults born during or since 1966 who have not received 2 doses of MMR vaccine
• susceptible women should be identified during antenatal counselling and vaccinated with MMR vaccine at least 28 days before pregnancy or immediately after delivery.

For further information contact your local doctor, community health centre, nearest population health unit or the13HEALTH information line (13 432584). Check out Queensland Health  and Government Immunise Australia

 References

  Heymann, D., ed. 2004. Control of Communicable Diseases Manual, 18th edition. Washington, DC: American Public Health Association.

 National Health and Medical Research Council, 2003. The Australian Immunisation Handbook (9th Ed.) Canberra: National Capital Printing.