The United States recorded 14 new measles cases between July 3 and July 11, federal health officials said on Monday, signaling a slowdown in the spread of the disease, which has infected 1,123 people this year in the worst U.S. outbreak since 1992.
The Centers for Disease Control and Prevention said the new cases represented a 1.3% increase since the previous week and that it has recorded cases of the highly contagious and sometimes deadly disease in 28 states.
In recent weeks, the CDC has reported smaller increases in the number of measles cases, compared with a surge of more than 100 cases reported in a single week earlier this year.
Disease outbreaks have not been reported in any new states since June 10.
The running tally of cases this year includes active cases and those that have since resolved. No fatalities have been reported.
Health experts say the virus has spread mostly among school-age children whose parents declined to give them the measles-mumps-rubella vaccine, which confers immunity to the disease. A vocal fringe of U.S. parents cites concerns that the vaccine may cause autism, despite scientific studies that have debunked such claims.
Measles was declared eliminated in the United States in 2000, meaning there was no continuous transmission of the disease for a year. Still, cases of the virus occur and spread via travelers coming from countries where measles is common.
CDC officials have warned that the country risks losing its measles elimination status if the ongoing outbreak, which began in October 2018 in New York, continues until October 2019.