National Infant Immunization Week is April 23-30 this year. This week, the History of Vaccines blog features posts about several diseases that can be prevented by vaccination of infants.
Rubeola, or measles (as it’s more commonly known) is an extremely contagious viral disease. It causes a distinctive rash, fever that can reach 104°F or higher, runny nose, and cough, and has many potential complications including ear infection (in about 10% of cases) and pneumonia (about 5% of cases). In about one in a thousand cases, the patient develops encephalitis, a swelling of the brain. About one out of every thousand patients will die.
The rubeola virus spreads easily and rapidly via coughs and sneezes, and remains active and infectious in the air for up to two hours. As a result, a person can become infected just by breathing the air in a room that was occupied by a measles patient as much as two hours earlier. There is no treatment for the disease, although supportive care may be provided, and efforts may be made to lower the patient’s fever.
Although measles deaths are now uncommon in most developed countries, the disease still kills about 200,000 childen annually worldwide. As recently as 2000, 1.1 million young children died from measles in a single year. Wars and food shortages tend to increase death rates.
Measles can be prevented by vaccination. In the United States, the first dose of the MMR (measles, mumps and rubella, or “German Measles”) series is recommended at 12 months of age. Because of how easily the disease can spread, high vaccination coverage is needed to sustain herd immunity and prevent outbreaks.
Recent measles outbreaks in the United States have brought the disease back into the news. In an ongoing outbreak in Minnesota, 23 cases have been confirmed, with 14 hospitalizations. Of the 23 cases, nine were not old enough to receive the vaccine, seven were old enough but didn’t receive the vaccine, one was vaccinated, one was vaccinated before the recommended age, and five had an unknown vaccination status.
Another recent case illustrates the public health measures required when a potential measles exposure is discovered: in Camden County, New Jersey, a man was exposed to a measles patient who recently traveled from Italy to the United States. He is now experiencing symptoms of measles, and visited seven stores and a restaurant during a period when he was potentially infectious (before he developed symptoms). Health officials are now warning residents of southern New Jersey who may have been exposed to measles. (For more information, see this article.)