|My beautiful bride|
April 23, 2005
Happy anniversary Holly!
In my post last week I touched on measles vaccine effectiveness. I had already decided to write this week's post on measles before the Centers for Disease Control and Prevention (CDC) published its summary of measles in the United States, 2011.
Last year there were 222 cases of measles in the U.S. Ninety percent of those cases were either imported from other countries or linked to imported cases. More than half of the imported measles cases came from Europe, where there were over 30,000 cases of measles last year. The highest incidence of measles in Europe was in infants too young to receive the measles vaccine.
Eighty six percent of measles cases in the U.S. last year were in unvaccinated people or people whose vaccination status was unknown. Most of the unvaccinated cases were eligible to receive measles, mumps, and rubella vaccine (MMR), but 18 of those cases were children too young to receive MMR. Seventy people (32% of measles cases) were hospitalized with measles in the U.S. last year.
Measles is a highly contagious viral disease transmitted by respiratory droplets. The incubation period (time from infection to the beginning of symptoms) is 10 to 12 days. Symptoms begin with a prodrome of fever, cough, coryza (inflammation of the nasal sinuses), and conjunctivitis (red eyes). These symptoms are easily confused with other upper respiratory infections. The prodromal stage is when a person infected with the measles virus is most contagious. Koplik spots are sores on the inside of the mouth that occur during this period and are considered pathognomonic for measles – meaning, if you have Koplik spots, you have the measles.
The prodromal stage lasts 2 to 4 days and ends with the onset of a rash that begins on the head and face, spreads to the trunk, and then the arms, legs, hands, and feet. The rash fades over 3 to 4 days in the same order as it appeared; face, trunk, extremities.
Complications of measles:
In industrialized countries, around 1% to 6% of people with measles with develop pneumonia, 7% to 9% will develop otitis media (ear infection), 8% will develop diarrhea, and 1 person out of 1,000 to 2,000 will develop encephalitis as the result of the infection.
Measles can cause severe disease and death in people with immune deficiencies, including people with HIV/AIDS, people on immune-suppressing drugs (e.g., cancer chemotherapy and drugs to prevent rejection of transplanted organs), and people with inherited immune disorders. Measles vaccine should not be given to people with severe immune disorders, so this is a population that is especially vulnerable to measles.
Before the introduction of measles vaccine, there were around 200,000 to 500,000 cases of measles every year in the U.S. As a result, there were approximately 150,000 cases of pneumonia, 100,000 cases of otitis media, 4,000 cases of encephalitis, and around 500 deaths caused by measles every year in the U.S.
Globally, the number of deaths due to measles has decreased from an estimated 2.6 million in 1980 to 535,000 in 2000 and 139,000 in 2008, most of which were children in developing countries. In addition to the complication listed above, measles commonly causes diarrhea, dehydration, and blindness in children in developing countries.
Subacute Sclerosing Panencephalitis (SSPE) is a rare but fatal complication of measles. It begins years after the initial measles infection with mental and behavioral changes, then progresses to myoclonic jerking, coma, and death. Jaxon's Cure is a website that tells the story of a boy who got the measles when he was too young to receive the vaccine, developed SSPE when he was 5 years old, and died two and a half years later.
As I discussed in my post on pertussis vaccines, antibodies are transported across the placenta from mother to baby. The same is true of measles antibodies, which provides the newborn baby with some protection against measles in the first months of life. Unfortunately, these antibodies also interfere with baby's immune response to measles vaccines, which is why measles, mumps, and rubella vaccine (MMR) is given when babies are 12 to 15 months old - after maternal measles antibodies have cleared from the baby's blood. In countries where the risk of measles is high, measles vaccine is given at 9 months.
Like live attenuated influenza vaccine (LAIV), MMR is a live virus vaccine, so it should not be given to pregnant women because of the theoretical risk of infecting the unborn baby with vaccine virus. Measles infection during pregnancy can cause miscarriage and premature delivery, so women should be up-to-date on their MMR immunization before getting pregnant.
I've reached a point where I realize that there's still a lot to discuss and this post is already longer that I had anticipated. Besides, it's time for me to make an anniversary dinner for my bride.
- CDC's Travelers' Health: Measles Update
- Jaxon's Cure: Measles and Subacute Sclerosing Panencephalitis (SSPE)
Centers for Disease Control and Prevention. (1998). Measles, mumps, and rubella – vaccine use and strategies for elimination of measles, rubella, and congenital rubella syndrome and control of mumps: recommendations of the Advisory Committee on Immunization Practices (ACIP). Morbidity and Mortality Weekly Report, 47(8),1-57. http://www.cdc.gov/mmwr/preview/mmwrhtml/00053391.htm.
Centers for Disease Control and Prevention. (2012). Measles – United States, 2011. Morbidity and Mortality Weekly Report, 61(15), 253-257. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6115a1.htm.
Centers for Disease Control and Prevention. (2012). Progress in global measles control. Morbidity and Mortality Weekly Review, 61(4), 73-78. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6104a3.htm.
European Centre for Disease Prevention and Control. (2012). Surveillance report: European monthly measles monitoring. http://ecdc.europa.eu/en/publications/publications/sur_emmo_european-monthly-measles-monitoring-february-2012.pdf.
Gershon, A. A. (2009). Measles virus (rubeola). In Mandell, G. L., Bennett, J. E., & Dolin, R. (Eds.). Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. (7th Ed.) [Electronic version].
National Institute of Neurological Disorders and Stroke. (2011). NINDS subacute sclerosing panencephalitis information page. http://www.ninds.nih.gov/disorders/subacute_panencephalitis/subacute_panencephalitis.htm.
Strebel, P. M., Papania, M. J., Dayan, G. H., & Halsey, N. A. (2008). Measles vaccine. In S. A. Plotkin, W. A. Orenstein, & P. A. Offit (Eds.) Vaccines (5th Ed.) [Electronic version]
World Health Organization. (2012). Measles. http://www.who.int/topics/measles/en.