In the first four-and-a-half months of 2011, there have been 118 reported cases of measles in 23 US states, says an MMWR report from the CDC (Centers for Disease Control and Prevention) – the highest number since 1996. The authors explained that endemic or sustained measles transmission has not occurred in America since the second half of the 1990s, in spite of infected people coming in from abroad.
Between 2001 and 2008 there were 56 (median – ranging from 37 to 140) reported cases each year. 118 cases in the first 19 weeks of this year is a considerable increase.
89% (105) of the 118 reported cases were linked to importations from abroad – including 34 Americans coming back home and 12 foreign visitors. 40 of the 46 cases come from European and South-East Asian nations. 89% (105) of those infected had never been vaccinated against measles. 47 (40%) of measles cases had to be admitted to hospital, and nine had pneumonia.
The CDC urges people to get vaccinated. The increase in measles importations makes it doubly important to be vaccinated.
Below is a breakdown of reported measles cases according to age:
- 15% (18) – less than twelve months
- 20% (24) – 1 to 4 years
- 19% (23) – 5 to 19 years
- 45% (53) – at least twenty years
Importations came from the following countries:
- Kenya – 1
- Nigeria – 1
- Pakistan – 1
- Jordan – 1
- France – 11
- France/UK – 1*
- France/Italy/Spain/Germany – 1*
- Italy – 1
- Poland – 1
- Romania – 1
- Spain – 1
- United Kingdom – 3
- Dominican Republic – 1 Patient probably caught it from French tourist
- India – 14
- Indonesia – 1
- Philippines – 4
- Philippines/Vietnam/Singapore/Malaysia* – 1
- China – 1
*Infected patient traveled to more than one country and could have become infected in one of those countries.
France has had over 10,000 reported cases of measles so far this year, of which 12 developed encephalitis, 360 severe pneumonia, and six died.
Measles is an extremely infectious disease – up to 90% of exposed susceptible individuals get measles. Susceptible refers to unvaccinated people who have never had measles before. Measles complications can be permanently disabling, and even fatal. Over 100 people died during a 1989-1991 measles resurgence in the USA, out of 55,000 reported cases.
The CDC says that those who do not get vaccinated undermine the herd immunity – they put others in their community at risk. Babies less than 12 months who are not vaccinated yet, plus patients with medical conditions who cannot be vaccinated have a particularly high risk of developing measles complications – they depend on the herd immunity, i.e. if everyone is immunized they are protected.
15% of measles hospitalizations this year occurred with babies aged less than 12 months.
MMWR May 24, 2011 / 60 (Early Release)
Written by Christian Nordqvist