The United States was declared free of circulating measles in 2000, with 911 cases from 2001 to 2011. In 2014 the CDC said endemic measles, rubella, and congenital rubella syndrome had not returned to the United States. Occasional measles outbreaks persist, however, because of cases imported from abroad, of which more than half are the result of unvaccinated U.S. residents who are infected abroad and infect others upon return to the United States. The CDC continues to recommend measles vaccination throughout the population to prevent outbreaks like these.In 2014, an outbreak was initiated in Ohio when two unvaccinated Amish men harboring asymptomatic measles returned to the United States from missionary work in the Philippines. Their return to a community with low vaccination rates led to an outbreak that rose to include a total of 383 cases across nine counties. Of the 383 cases, 340 (89%) occurred in unvaccinated individuals.From 4 January, to 2 April 2015, there were 159 cases of measles reported to the CDC. Of those 159 cases, 111 (70%) were determined to have come from an earlier exposure in late December 2014. This outbreak was believed to have originated from the Disneyland theme park in California. The Disneyland outbreak was held responsible for the infection of 147 people in seven U.S. states as well as Mexico and Canada, the majority of which were either unvaccinated or had unknown vaccination status. Of the cases 48% were unvaccinated and 38% were unsure of their vaccination status.
In 1980, 2.6 million people died from measles, and in 1990, 545,000 died due to the disease; by 2014, global vaccination programs had reduced the number of deaths from measles to 73,000. Despite these trends, rates of disease and deaths increased from 2017 to 2019 due to a decrease in immunization. Signs and symptoms
Symptoms typically begin 10–14 days after exposure. The classic symptoms include a four-day fever (the 4 Ds) and the three Cs—cough, coryza (head cold, fever, sneezing), and conjunctivitis (red eyes)—along with a maculopapular rash. Fever is common and typically lasts for about one week; the fever seen with measles is often as high as  40 °C (104 °F).Kopliks spots seen inside the mouth are diagnostic for measles, but are temporary and therefore rarely seen. Koplik spots are small white spots that are commonly seen on the inside of the cheeks opposite the molars. They appear as "grains of salt on a reddish background." Recognizing these spots before a person reaches their maximum infectiousness can help reduce the spread of the disease.The characteristic measles rash is classically described as a generalized red maculopapular rash that begins several days after the fever starts. It starts on the back of the ears and, after a few hours, spreads to the head and neck before spreading to cover most of the body, often causing itching. The measles rash appears two to four days after the initial symptoms and lasts for up to eight days.