New measles cases decline in U.S., but the outbreak isn't over yet

U.S. measles cases have been dropping over the past couple of weeks, with 7 cases reported the week ending Sept. 5. Only 2 of those cases were new illnesses, the Centers for Disease Control and Prevention announced Monday.

Why it matters: Most cases are in unvaccinated people, whose infections often originated from travelers from countries where "large measles outbreaks are occurring," CDC said. And while the numbers here have dropped, it only takes one unvaccinated group for the extremely contagious virus to establish a new foothold.

Of note: While it's "too early to say" whether the U.S. will lose "measles elimination status" — which is determined by the World Health Organization and the Pan American Health Organization — the country is facing that prospect if the outbreak that started in New York on Oct. 1 shows a chain of transmission for 12 months, CDC spokesperson Kristen Nordlund tells Axios.

• New York City recently declared its outbreak to be over, but the outbreak continues in the state's Rockland and Wyoming counties.
• As a result, New York has tightened its rules over exemptions, eliminating religious exemptions and causing some people to decide to home school their children this year, per the Wall Street Journal.

The big picture: As of Sept. 5, there were 1,241 confirmed cases in 31 states this year. This is the largest outbreak in the U.S. in 27 years.

• 130 patients have been hospitalized and 65 reported experiencing complications, including pneumonia and encephalitis.
• Some U.S. infections originated in Israel, Ukraine and the Philippines, but the WHO said last month they also are tracking concerning infections in other countries, including the Democratic Republic of the Congo and Madagascar.

Meanwhile, the WHO last week praised Facebook and Instagram's plan to link queries about the MMR vaccine to the WHO's website to help prevent the spread of misinformation. This follows similar efforts by Pinterest.