A strange pneumonia-like infection that first popped up in the Chinese city of Wuhan just days ago is beginning to spread, with the total number of infected individuals climbing from 27 to at least 44. Another 121 people are under medical supervision as doctors try to confirm whether or not they have the same illness.

The sickness, which is being compared to bird flu and SARS, appears to have originated in or near the Huanan seafood market, and some of the original infections were traced to workers who operate stalls there. Now, health workers and government officials say that two female patients from Hong Kong are also exhibiting symptoms, and that the pair had visited Wuhan just two weeks prior.

As the South China Morning Post reports, health officials still don’t know exactly where this viral pneumonia came from, though they have ruled out multiple possibilities. Despite the fact that additional infections have been confirmed, it’s still believed that the virus doesn’t pass from person to person, as no medical staff or relatives of those who are infected have been diagnosed with the same illness.

It’s still possible that the illness is related to SARS, or Severe Acute Respiratory Syndrome, according to Dr. Gauden Galea of the World Health Organization. “There are many potential causes of this type of illness and further laboratory tests are ongoing to determine the cause of the disease,” Galea said in a statement. “At this point, Severe Acute Respiratory Syndrome (Sars) coronavirus is not yet confirmed or excluded as the cause of the outbreak.”

It’s important to note that no deaths have been attributed to this new, unknown pneumonia virus and that Chinese officials seem to be doing their best to isolate anyone who might be infected in order to separate them from the general population. Hopefully, this will be enough to put a lid on an increasingly scary situation.