The first entry is always the pin's source. Overall confidence is a weighted average of how firmly each reference supports the start and end times used above; a reference counts half as much for every 180 days older than the newest.
The source dates the start only to "mid-March 2026", so the pin takes the middle of that month and leaves the end open: the outbreak is ongoing.
The WHO's account of how measles spreads and what coverage stops it, which is what the outbreak's size measures.
Something missing or wrong? Say it in your own words: a link that backs this pin up, a different start or end date and why, or a fact it lacks or gets wrong. The AI checks it against this pin's sources, searches for better ones, and adds any page that backs you up. The pin's own sources still count most.