The World Health Organization said Sunday that a mysterious virus that killed one person and infected 40 others in China has not spread outside its origin city, according to the South China Morning Post.

What’s going on: A virus that spread in the Chinese city of Wuhan remains isolated there, according to SCMP.

  • There was widespread worry that the virus — which some believed to be from the same family as SARS and MERS, which caused epidemics in China — would spread internationally. But the WHO said the outbreak hasn’t gone outside of Wuhan.
  • The WHO said the virus originated in a single seafood market, which has been closed.
  • WHO in a statement (via SCMP): “The evidence is highly suggestive that the outbreak is associated with exposures in one seafood market in Wuhan.”
  • “At this stage, there is no infection among health care workers, and no clear evidence of human to human transmission.”

Some history: Early reports of the virus popped up in December. Many likened the disease to SARS or MERS, though medical professionals were unsure what to make of the illness, according to the Deseret News.

  • Early worries were calmed. Per The New York Times, there was no immediate evidence that the disease could spread between humans.
  • The first person who died of the disease “had previously been diagnosed with abdominal tumors and chronic liver disease, said the city’s health commission,” according to The New York Times.
  • “In recent days, authorities have stationed personnel at airports and train stations across the region to scrutinize people who have visited Wuhan. The market linked to the virus is less than one mile away from a train station. Precautions include checking passengers for fever,” according to The New York Times.