A nurse became the first person to contract Ebola within the United States on Sunday. The news increased concern amongst health workers around the world dealing with the Ebola virus and federal officials are trying to solve the mystery as to how she contracted the disease despite wearing protective gear.

Decontamination team treated the Dallas apartment where the nurse who caught Ebola lives

The confirmation of the second Ebola case in Dallas following the death of 42-year-old Thomas Eric Duncan, a Liberian national who arrived with the virus to the United States, has caused the Centers for Disease Control and Prevention (CDC) to recommend that healthcare officials look more closely at the protective gear of their staff members. The nurse had treated Mr. Duncan and there are fears at the hospital that she may have violated safety recommendations.

At the entrance of the nurse’s apartment building

There are discussions that special containment units with more experience in dealing with the disease should be created. The CDC is planning a nationwide training conference on Tuesday to increase the readiness of health staff to treat Ebola.

A possible Ebola patient bought to the Texas Presbyterian Hospital

The Texas Health Presbyterian Hospital that had treated Mr. Duncan had at first sent him home on September 25 as he had been misdiagnosed as having a sinus infection before he was finally diagnosed on September 28. The unnamed nurse had extensive contact with Mr. Duncan on many occasions after his admission to the hospital, according to Dr. Thomas Frieden, director of the CDC, who says that even “a single, inadvertent, innocent slip can result in contamination.”