Queens Zoo and the Bronx Zoo, prompting head pathologist Dr. Tracey McNamara to begin investigating what was going on. At the same time, Dr. Deborah Asnis, an infectious disease specialist at Flushing Hospital Medical Center in Queens, noticed two male patients who were suffering from similar, unusual symptoms. The two patients, aged 60 and 75 respectively, were exhibiting sudden paralysis in their arms and legs, as well as disorientation and high fevers. Lab testing also showed elevated numbers of white blood cells within the spinal fluid of both males. Neither of the patients were responding to antiviral drugs. Possible early hypothesizes included botulism, viral encephalitis, Guillain–Barré syndrome, or meningitis, but none of these illnesses exactly matched the symptoms. Asnis decided to pursue a more concrete diagnosis by contacting authorities and other colleagues. Dr. Asnis contacted Dr. Marcelle Layton, the New York City Department of Health's chief epidemiologist, on Monday, August 23, 1999, to report her patients' symptoms. Layton advised Asnis to send samples of the patients' blood and spinal fluid to the New York State Department of Health in Albany for further analysis. Around the same time, Dr. McNamara identified a potential viral encephalitis in brain tissue from the dead crows and sent samples off for further testing. Meanwhile, by Friday, August 27, just four days after Asnis had contacted Layton, two additional patients had been identified in Queens. The number rose to eight by Sunday, August 29, at Flushing Hospital Medical Center and other hospitals in Queens. All of the early patients resided within a few miles of one another. They were also frequent gardeners in the evenings. The Centers for Disease Control and Prevention (C.D.C.) initially identified the mystery illness as St. Louis encephalitis on September 3, 1999. The city of New York began widespread spraying for mosquitos later that same day. However, laboratory testing continued to determine a definitive cause of the symptoms. On September 9th, Dr. McNamara contacted the C.D.C. with concerns that the epidemiologic pattern of this outbreak were not consistent with St. Louis encephalitis, which does not cause bird die-offs. Additionally, she reported that other known avian viral diseases would have resulted in the deaths of other bird species in the zoos (avian influenza and Newcastle disease would have killed chickens in the petting zoo and eastern equine encephalitis would have killed emus on exhibit). Since only corvids appeared to be dying, she suggested