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Healthcare Workers at Risk for H1N1 Infection

By Amesh A. Adalja, MD, June 19, 2009

Some infectious diseases, such as Ebola and SARS, disproportionately affect healthcare workers (HCWs). While this has not been the case to date for the 2009 H1N1 influenza (A) virus, there have been cases among HCWs, as detailed in the June 19, 2009 MMWR.1 It appears that all could have been prevented had standard infection control measures been taken.

Infections Documented in 81 HCWs

Through May 13, 48 probable or confirmed cases of infection with the novel H1N1 influenza virus in HCWs were reported to the CDC. Since May 13, 33 additional cases have accrued.2 Detailed reports were available for 26 (18 confirmed, 8 probable) of these cases, revealing that 13 (50%) contracted the virus in the workplace setting. Patient-to-HCW transmission was suspected in 12 of the cases, and HCW-to-HCW transmission was suspected in 1 case. Of those for whom vaccination status was available, 50% had received the seasonal flu vaccine.1

Infections by role were reported for 25 of the 48 cases:

  • Physicians: 4 (16%)

  • Registered Nurses: 5 (20%)

  • Nursing Assistants: 4 (16%)

  • Other--pharmacy, LPN, PA’s, etc: 12 (25%)

Two HCWs were hospitalized; one of them had underlying health conditions. Neither required ICU admission. 

Personal Protective Equipment (PPE) Use Sporadic Among Infected HCWs

For those actively infected with the virus, CDC’s infection control guidelines3 recommend use of fit-tested N-95 respirators and eye protection along with standard precautions in patient encounters. However, amongst the 11 HCWs infected through patient contact, only 3 reported full-time use of a surgical mask or N-95 respirator. Glove use was reported by 5, while none reported use of eye protection. No infected HCW reported 100% adherence to the CDC’s guidelines. Of the 3 infected HCWs who reported full time use of a surgical mask or N-95 respirator, 1 was never fit tested, 1 did not use eye protection or a gown, and the third use gown or eye protection only some of the time.1

Infection Control Guidelines Should be Followed

To minimize the risk to HCWs, standard infection control measures for droplet +/- airborne isolation should be followed. As is the case with many nosocomial infections, adherence to infection control procedures are suboptimal in HCWs. The donning of gloves, gown, and a mask or respirator are essential to lessen risks to HCWs and prevent nosocomial spread of this virus.

An ably functioning HCW workforce is the key to success in the management of a pandemic. Any burden of illness amongst HCWs will have an adverse effect on healthcare system response.


  1. CDC. Novel Influenza A (H1N1) Virus Infections Among Health-Care Personnel ‑‑‑ United States, April--May 2009. MMWR 2009; 58: 641-645.
    . Accessed June 18, 2009.

  2. CIDRAP News. H1N1 cases in health workers show need for protection. June 18, 2009. Accessed June 19, 2009.

  3. CDC. Interim guidance for infection control for care of patients with confirmed or suspected novel influenza A (H1N1) virus infection in a health-care setting.
    . Accessed June 19, 2009.