Dr. Vijay Gupta says the virus is ` ` merciless '' in the way it spreads . Fifteen of the seventeen patients screened have tested positive for the Type I . But officials say further analysis is necessary to fully understand the outbreak . CNN 's Tim Schwarz , Sara Sidner , Madison Park , Jethro Mullen and Josh Levs contributed to this report . At least 64 people have died mysteriously over the past three months .
Dr. Vijay Gupta says the virus is ` ` merciless '' in the way it spreads . Fifteen of the seventeen patients screened have tested positive for the Type I . But officials say further analysis is necessary to fully understand the outbreak . At least 64 people have died mysteriously over the past three months .