A measles outbreak in Washington state originated from multiple importation events connected to South Carolina. In the second event, four residents with close contact with South Carolina visitors fell ill. While infectious, they visited schools, healthcare facilities, and a church. Nine of their contacts and one person exposed in a public location fell ill, leading to a total cluster of 14 cases that spanned January 15 to February 17.
In the third importation event, two state residents returned from South Carolina and fell ill on January 15 to 16. No additional cases were linked to these residents. Similarly, a fourth importation event occurred when a resident returned from travel. The person adhered to isolation and quarantine recommendations, and no cases were linked to this one.
In the fifth importation event, a Washington state resident returned from out-of-state travel where they had contact with ill contacts and fell ill themselves on January 19. While contagious, they visited a school and a healthcare facility. Six close contacts fell ill. In all, this cluster of seven cases spanned January 19 to January 29.
The genome sequences from five of the cases were nearly identical to those seen in South Carolina. Officials credit basic public health work of quarantines, isolation, and contact tracing with keeping the virus from spreading farther than it did. The study highlights how readily this virus can spread among states amid declining vaccination.
Source: Ars Technica · Summarized by HeadlinesBriefing