H1N1 Influenza Virus and HCT Patients

Special precautions are indicated with respect to the H1N1 influenza virus (“Swine Flu”) and hematopoietic cell therapy (HCT) candidates and recipients, whose immune systems already are compromised. If patients present with upper respiratory infections, evaluation, chemoprophylaxis and isolation precautions – including droplet precautions – should be strongly considered.

The following excerpt is from soon-to-be published Guidelines for Preventing Infectious Complications among Hematopoietic Cell Transplant Recipients – a joint report of ASBMT and the Center for International Blood and Marrow Transplant Research (CIBMTR), the National Marrow Donor Program (NMDP), the European Blood and Marrow Transplant Group (EBMT), the Canadian Blood and Marrow Transplant Group (CBMTG), the Infectious Disease Society of America (IDSA), the Society for Healthcare Epidemiology of America (SHEA), the Association of Medical Microbiology and Infectious Diseases Canada (AMMI), the Centers for Disease Control and Prevention (CDC), and the Health Resources and Services Administration (HRSA).

Recommendations Regarding Community-Acquired Respiratory Viral (CRV) Infections: Influenza, Respiratory Syncytial Virus, Human Metapneumovirus and Parainfluenza Virus

M. Tomblyn, T. Chiller, H. Einsele, R. Gress, K. Sepkowitz, J. Storek, J.R. Wingard, J.-A.H. Young, M.A. Boeckh

Preventing Exposure
Preventing community-acquired respiratory viral (CRV) exposure is critical in preventing CRV disease1,2. Use of PCR testing in donors with respiratory infections remains investigational. Viral cultures of asymptomatic HCT candidates are unlikely to be useful. Whether multiplex PCR testing can identify asymptomatic shedders before HCT is presently being studied. PCR-based routine surveillance of asymptomatic patients after HCT remains investigational.

HCT recipients with symptoms of an upper respiratory infection (URI) or lower respiratory infection (LRI) should be placed under contact precautions to avoid transmitting infection to other HCT candidates and recipients, healthcare workers (HCWs), and visitors until the etiology of illness is identified3. Optimal isolation precautions should be modified as needed after the etiology is identified. HCT recipients and candidates, their family members and visitors, and all HCWs should be informed regarding CRV infection control measures and the potential severity of CRV infections among HCT recipients1-2,4.

Preventing Disease
HCT physicians should determine the etiology of an upper respiratory infection (URI) in an HCT recipient, if possible, because respiratory syncytial virus (RSV), influenza, parainfluenza, and adenovirus URIs can progress to more serious lower respiratory infection (LRI), and certain CRVs can be treated. Appropriate diagnostic samples include nasopharyngeal washes, swabs or aspirates; throat swabs (in combination with nasal samples); and bronchoalveolar lavage (BAL) fluid. HCT candidates with URI symptoms at the time conditioning therapy is scheduled to start should postpone their conditioning regimen until the URIs resolve, if possible, because certain URIs might progress to LRI during immunosuppression2,5-7.

If an outbreak occurs with an influenza strain that is not contained in the available influenza vaccine, all healthy family members, close and household contacts, and HCWs of HCT recipients and candidates should receive influenza chemoprophylaxis with an active agent against the current circulating strain of influenza until the end of the outbreak8. Zanamivir may be given for prevention of influenza A and B, including influenza from strains resistant to oseltamivir. The duration of prophylaxis depends on the type of exposure. Zanamivir can be administered to persons 5 years of age and older for prevention of influenza, and 7 years and older for treatment of influenza. Oseltamivir can be administered to persons »1 year of age and older. Patients with influenza should be placed under droplet and standard precautions to prevent transmission of influenza to HCT recipients. HCWs with influenza should be excused from patient care until they are no longer infectious.


1. Garcia R, Raad I, Abi-Said D, et al. Nosocomial respiratory syncytial virus infections: prevention and control in bone marrow transplant patients. Infect Control Hosp Epidemiol. 1997;18:412-6.

2. Raad I, Abbas J, Whimbey E. Infection control of nosocomial respiratory viral disease in the immunocompromised host. Am J Med. 1997;102:48-52; discussion 53-4.

3. Siegel JD, Rhinehart E, Jackson M, Chiarello L. 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Health Care Settings. Am J Infect Control. 2007;35:S65-164.

4. Sable CA, Hayden FG. Orthomyxoviral and paramyxoviral infections in transplant patients. Infect Dis Clin North Am. 1995;9:987--1003.

5. Whimbey E, Champlin RE, Couch RB, et al. Community respiratory virus infections among hospitalized adult bone marrow transplant recipients. Clin.Infect.Dis.. 1996;22:778-782.

6. Whimbey E, Champlin RE, Englund JA, et al. Combination therapy with aerosolized ribavirin and intravenous immunoglobulin for respiratory syncytial virus disease in adult bone marrow transplant recipients. Bone Marrow Transplant. 1995;16:393-9.

7. Folz RJ, Elkordy MA. Coronavirus pneumonia following autologous bone marrow transplantation for breast cancer. Chest. 1999;115:901-905.

8. Fiore AE, Shay DK, Haber P, et al. Prevention and control of influenza. Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2007. MMWR Recomm Rep. 2007;56:1-54.