Tulsa ranks fourth on the top 10 list of US cities where residents are more at risk of contracting influenza. Oklahoma City is ranked second.
Direct Relief also points out that Oklahoma has the highest number of flu cases in the nation as of this month.
The report is questioned by the Tulsa Health Department.
"It's really hard to determine whether or not the source had all of the relevant information to compile their results," said Kaitlin Snider, spokeswoman for the Tulsa Health Department.
Snider added, "We rely on a surveillance program, across the state of Oklahoma, which helps us determine what type of activity we're seeing across the state, as it relates to the flu."
She said the health department has not seen any confirmed cases of the flu this season, despite the fact that some sporadic cases may be appearing in local doctors' offices.
Dr. Steve Nussbaum, at ERgent Care in south Tulsa, tells 2NEWS that he has treated a handful of patients for the flu. He, along with Snider, are encouraging the public to get vaccinated as soon as possible.
"It's a lot easier to prevent the flu than to treat the flu," said Nussbaum.
The Centers for Disease Control is urging parents to vaccinate their children.
According to the medical journal "Pediatrics," 830 children died between 2004 and 2012 due to the flu. The average age was 7 years old.
The journal reports 43 percent of children who died were otherwise healthy.