An investigation of confirmed cases of H1N1 among healthcare workers (HCW) during the 2009-2010 pandemic indicates that 50% were infected within a healthcare setting.
This is one of the findings of “Transmission of Pandemic (H1N1) 2009 Influenza to Healthcare Personnel in the United States,”  an article by CDC researchers appearing in a special supplement on the H1N1 pandemic in the January Clinical Infectious Diseases .
CDC researchers worked closely with state and local health departments to examine the likely routes of H1N1 exposure in likely routes of exposure 70 HCWs covering 22 states.
Here are some highlights of the study:
- More than half of the confirmed HCW H1N1 infections occurred in outpatient settings.
- Of the HCWs infected by patients, only 20% used respiratory protection, such as N95 respirators or surgical masks, for all patient encounters.
- Leading occupations for H1N1 infections were registered nurses (20%), physicians (19%), and nursing assistants (13%).
- The study found more instances of HCW-to-HCW transmission than expected.
- Occupations where HCW-to-HCW transmission occurred were physicians (30%) and nurses (20%). HCW-to-HCW transmission also occurred with a nursing assistants, intake coordinator, medical assistant student, pharmacist, and patient relations staff member.
The study concluded that the likely patient-to-HCW and HCW-to-HCW transmissions in healthcare settings highlighted the need for comprehensive infection control policies which include administering influenza vaccine, appropriate managing ill HCWs, and adherence to infection control precautions such as respiratory protection PPE.