Despite measles (Rubella) being completely preventable by vaccination, the World Health Organization (WHO) reports that in 2006, worldwide 242,000 individuals died from the disease - this equates to an average of 26 deaths every hour. Whilst alarming, these figures show a dramatic drop from the 757,000 deaths in 2001, mainly due to the introduction of infant vaccination programmes in the poorer countries of the world. The USA was declared measles free in the year 2000 but 131 cases have been reported in the first 6 months of 2008, 89% in people from other countries and most in those aged < 20 years. In Australia, measles was very common prior to the introduction of an effective live attenuated vaccine in 1968 and those born before that year are almost certain to have had the disease and are consequently considered to be immune. At first, only one dose of vaccine was given but in the 1990’s, a two dose regimen was instituted for pre-school children with 94% of infants aged under 12 months being vaccinated. The measles vaccine used is part of the triple vaccine for Measles-Mumps-Rubella (MMR). Its effectiveness is shown by the fact that between 1993 and 2000 there were 12,815 notifications of measles but in the first half of 2008, there have been only 58 cases reported. These were localised clusters in NSW and Queensland, mainly in non- vaccinated immigrants and travellers returning from overseas. There is no evidence of increased morbidity in Aboriginal and Torres Strait Islander people.
Measles is a highly infectious viral disease and vigilance together with continuing vaccination programmes are needed to prevent the disease again becoming endemic. After exposure to the virus, which is spread by respiratory droplets, there is an incubation period of about 10 days after which appear the prodromal symptoms of a general feeling of lack of energy (malaise), cough, runny nose, sneezing and conjunctivitis. On the second or third day in some cases, small white spots appear on the inside of the cheeks or the soft palate, the so called Koplik spots (Figure 1) but these disappear quite quickly. Then as the fever spikes to about 40oC a small red, non-itchy, non-vesicular rash appears behind the ears, spreads to the face and then all over the body (Figures 2 and 3). There is no specific treatment available apart from bed rest, analgesics and adequate fluid intake with the rash lasting at least three days and then gradually fading. However, complications such as bronchopneumonia, acute encephalitis, ear infections (otis media), conjunctivitis and
sometimes death can occur. Recovery provides continuing and long lasting immunity.
The Australian Immunisation Handbook 9th edition 2008
recommends that all health care workers who are involved
in patient care or the handling of human tissues should be
vaccinated against measles. This is particularly important for those who work with children. Those dental therapists, dental hygienists and dental nurses born in Australia would have received the measles vaccine in childhood unless their parents had not consented to the procedure. Immunity lasts a lifetime and booster doses are not necessary but if only one dose of the vaccine has been received, further vaccination is necessary. Those dental care providers from overseas countries where childhood immunization is not available should be vaccinated unless shown by blood tests to be immune.
Whilst a patient with full blown measles is too sick to go to the dentist, it is possible during isolated outbreaks of the disease that a person in the prodromal stage or with a mild attack could present at a dental surgery. A child or adult who presents with fever, cough and a rash should be referred for medical consultation especially if he/she has:
• Never been vaccinated against measles as a child or adult;
• Only had one dose and not two doses of vaccine; or
• Is under 20 years of age and recently returned from travel to a country where measles is endemic.
A non-immune dental care provider (DCP) who comes in
contact with measles is most likely to contract the disease and should be excluded from duty from the time of exposure to
4 days after the rash appears. The giving of vaccine within
72 hours of exposure may prevent the disease as can human immunoglobulin given more than 72 hours but no more than
7 days after first contact. An immunized DCP is not at risk and can continue working.
Further reading
Communicable Diseases Intelligence Aust Govt. 32. Supplement June 2008.
Measles Update MMWR 57. 494-8. 2008.
About the author
Dr Vincent C Amerena is the infection control editor of Auxiliary and a retired periodontist who now works as an infection control and risk management consultant. He has been instrumental in the drafting of infection control guidelines nationally and lectures extensively to assist dental practices and labs in ongoing compliance.
Friday, 15 November, 2024