The subcommittee hearing will include testimony from someone at the Pittsburgh VA who is "most knowledgeable and able to answer questions," said U.S. Rep. Mike Doyle, D-Forest Hills, who is not on the subcommittee but requested the hearing along with U.S. Rep. Tim Murphy, R-Upper St. Clair.
Mr. Doyle said subcommittee staff told him the hearing may also include testimony from water treatment experts called in to help the Pittsburgh VA with the outbreak over the last year, as well as Victor Yu and Janet Stout, former Pittsburgh VA researchers.
Dr. Yu and Dr. Stout, both renowned Legionnaires' experts who left in 2006 and 2007, respectively, in a dispute with the Pittsburgh VA's management, believe the outbreak was the result of the VA's poor management and maintenance in recent years of the water treatment system they installed at the hospital in 1993.
Dr. Yu could not be reached Thursday but a spokeswoman for Dr. Stout said she has not been invited to the hearing.
Mr. Murphy said he also hopes to hear at the hearing from officials from the Centers for Disease Control and Prevention -- which assisted the Pittsburgh VA in analyzing the outbreak -- as well as "objective" researchers.
The official witness list was not yet available, but Mr. Doyle, who hopes to be able to attend the hearing to listen, said: "As they say, a hearing is only as good as your witnesses and the questions asked."
Pressure on the Pittsburgh VA has been building ever since Nov. 16, when it announced that four patients had contracted Legionnaires during stays at the hospital in Oakland, which had been trying to get the spread of the Legionella bacteria under control in its water system for nearly a year at that point.
Six days later, Nov. 22, it announced a fifth patient had contracted the pneumonia-like disease in the hospital. A day later, that patient, William Nicklas, 87, of Hampton died.
Two other families later told the Pittsburgh Post-Gazette that men in their families -- John McChesney, 63, of Columbus, Pa., who died Oct. 23, and John Ciarolla, 83, of North Versailles, who died July 18, 2011 -- also died after contracting Legionnaires following stays at the University Drive facility. But it is not yet clear if they contracted it in the hospital or outside.
Mr. Murphy said he hopes the hearing will help to answer questions such as: What are the proper procedures for water purification systems and were they followed at the VA? And do the standards for safe levels of Legionella, the bacterium that causes Legionnaires, present in the water system need to be changed?
U.S. Rep. Mike Coffman, R-Colo., chairman of the subcommittee, said in emailed answers to questions that the hearing will be focused solely on the Pittsburgh VA's outbreak and last about two hours, though it could go longer.
He said he hopes Pittsburgh VA director Terry Gerigk Wolf and officials from the infection control department would speak. He declined to answer questions about other possible witnesses.
Mr. Coffman said that while Mr. Doyle and Mr. Murphy asked for the hearing, the subcommittee has been "engaged" in the outbreak since it was first announced and began its own investigation shortly thereafter in November.