The SARS virus is not responsible for China's mysterious pneumonia outbreak, health officials said Jan. 5, according to CNN.
Four things to know:
1. Health officials also ruled out Middle East respiratory syndrome and bird flu as potential causes of the outbreak.
2. The unknown pneumonia strain has sickened 59 people in Wuhan, China, since Dec. 12. Seven patients are in critical condition, and all are being quarantined. Another 163 people who had close contact with infected patients are under observation.
3. Several of the sickened individuals worked at a local market that sold live animals, spurring concerns that a new pneumonia strain has jumped from animals to humans.
4. At present, health officials have not found any evidence of the strain spreading through human transmission.
5. The CDC on Jan. 6 issued a travel notice over the outbreak, urging any Americans visiting Wuhan, China, to avoid contact with animals, animal markets, and any sick individuals.
Editor's note: This article was updated Jan. 7 at 1:10 p.m.