A man dressed in protective hazmat clothing leaves after treating the front porch and sidewalk of an apartment where a second person diagnosed with the Ebola virus resides in Dallas, Texas. (Agence France-Presse)
A total of 76 health care workers may have been exposed to the deadly Ebola virus while caring for a Liberian patient in a Dallas hospital, US health authorities said on Tuesday.
The new pool of at-risk people includes anyone who went into the patient's room or handled his blood specimens, said Thomas Frieden, director of the US Centers for Disease Control and Prevention.
"There were 76 people who had some level of contact and therefore are being actively monitored," Frieden told reporters. They will be checked daily for fever, he said.
Nina Pham, a nurse, was infected with Ebola while caring for Thomas Eric Duncan, who was the first person diagnosed with Ebola in the United States and who died last week after a 10-day hospital stay.
Pham has had contact with just one person since she developed symptoms, and that person has been isolated and is being monitored.
Initially, officials identified 48 people who may have had contact with Duncan before he was hospitalized on September 28.
Those 48 have now passed the two-week mark, indicating that their risk of developing Ebola has decreased.
However, the virus has a 21-day incubation period and they will continue to be monitored until then.
"They have now passed through the highest risk period," said Frieden, adding it would be "unusual" for them to get sick now.
Most people who contract Ebola begin to show symptoms such as fever, aches, vomiting and diarrhea within eight to 10 days of exposure.
Ebola is spread through close contact with bodily fluids.
The current outbreak of Ebola has killed more than 4,000 people in West Africa since the start of the year.
Pham issued a statement earlier Tuesday in which she said she was "doing well" and thanked supporters for their prayers and well-wishes.
The CDC said it has not determined how Pham became infected, though Frieden said Sunday a breach of protocol was to blame.
Health care workers must don protective gear including gowns, face masks and gloves in order to guard against infected bodily fluids.
Taking off the gear is complicated and can result in accidental exposure.
To reduce that risk, Emory University Hospital in Atlanta, Georgia, is sending two experienced nurses to consult with Texas Health Presbyterian Hospital Dallas about the use of personal protective equipment and infection control measures.
Emory has successfully treated Ebola patients already this year, including two American missionaries who were sickened with the virus in Liberia.
Frieden said the CDC was also working to ramp up training for health care workers across the country.