2019, Measles OutbreakMeasles is a highly contagious infectious disease caused by the measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than 40 °C (104 °F), cough, runny nose, and inflamed eyes. Small white spots known as Koplik's spots may form inside the mouth two or three days after the start of symptoms. A red, flat rash which usually starts on the face and then spreads to the rest of the body typically begins three to five days after the start of symptoms. Common complications include diarrhea (in 8% of cases), middle ear infection (7%), and pneumonia (6%). These occur in part due to measles-induced immunosuppression.[6] Less commonly seizures, blindness, or inflammation of the brain may occur.
Before the vaccine was available in the 1960s between three and four million cases occurred each year. With consistent widespread childhood vaccination, this figure fell to 13 cases per million by the 1980s, and to about 1 case per million by the year 2000, at which time the U.S. was declared free of circulating measles. A resurgence of measles occurred in the U.S. in 2018 & 2019 with the most recent numbers of confirmed cases reaching 1,282 individuals in 31 states. In the Congo, an outbreak caused nearly 5,000 deaths and 250,000 infected individuals, with most deaths occurring among children under five years of age.