Hospital Infection Control in Hematopoietic Stem Cell Transplant Recipients

Centers for Disease Control and prevention, The Infectious Diseases Society of America and the American Society for Blood and Marrow Transplantation sponsored the Guidelines for Preventing Opportu¬nistic Infections among Hematopoietic Stem Cell Transplant (HSCT) Recipients. The term HSCT is preferable to “bone marrow transplant recipients” (Dykewicz, 1999).
Guidelines for Preventing Opportunistic Infections Among Hematopoietic Stem Cell Transplant Recipients contains a section on hospital infection control including evidence-based recommendations regarding ventilation, construction, equipment, plants, play areas and toys, health-care workers, visitors, patient skin and oral care, catheter-related infections, drug-resistant organisms, and specific nosocomial infections. These guidelines are intended to reduce the number and severity of hospital infections in hematopoietic stem cell transplant recipients (Dykewicz, 2001).
Ventilation
All allogeneic HSCT recipients should be placed in rooms with >12 air exchanges per hour (Streifel, 1999) and point-of-use, high-efficiency (>99%) particulate air HEPA filters capable of removing particles >0.3 µm in diameter. This recommendation is particularly important for facilities undergoing construction and renovation. The need for environmental HEPA filtration for autologous HSCT recipients has not been established; however, the use of HEPA filtered rooms should be considered for autologous HSCT recipients who have prolonged neutropenia, the major risk factor for nosocomial aspergillosis (Cornet et al., 1999).
The use of laminar air flow (LAF) rooms for BMT recipients has been controversial. Such rooms contain filtered air that moves in parallel, unidirectional flow; the air enters the room from one wall and exits the room on the opposite wall (Streifel, 1999). Although LAF protects patients from aspergillosis outbreaks during hospital construc¬tion, its routine use may not be valuable for all HSCT recipients (Walter and Bowden, 1995).
However, the survival of aplastic anemia HSCT recipients in the late 1990s exceeds that reported in the early 1980, and no study has yet determined whether survival of HSCT recipients with aplastic anemia improves when they are treated in rooms with LAF. Therefore, such rooms need not be constructed for every HSCT recipient, and use of available rooms is optional. Hospital rooms should have directed airflow so that air enters at one side of the room and is exhausted at the opposite side. Each hospital room should be well sealed (e.g., around windows and electrical outlets) (CDC, 1997). To provide consistent positive pressure in the HSCT recipient’s room, consistent pressure differentials should be maintained between patients’ rooms and the hallways or anterooms at >2.5 Pascals (Streifel, 1999).
In general, air pressure in hospital rooms of HSCT recipients should be higher than in adjoining hallways, toilets, and anterooms. Backup emergency power and redundant systems should be provided to maintain room pressurization and a constant number of air exchanges in HSCT units when the central ventilation system is shut off for maintenance and repair. In addition, protocols should be developed to protect HSCT units from bursts of mold spores when air-handling systems are restarted after routine maintenance (Streifel, 2000).

Construction
Hospital construction and renovation have been associated with increased risk for nosocomial fungal infection, especially aspergillosis, among severely immunocompromised patients. Therefore, people respon¬sible for HSCT unit construction or renovation should consult published recommendations for environmental controls. Planning for construction should include strategies for intensified aspergillosis-control mea¬sures. The planning committee should include engineers, housekeeping staff, infection control personnel, the director of the HSCT unit, and safety officers (Vesley and Streifel, 1999).
Isolation
HSCT units should follow published guidelines for hospital isolation practices, including CDC guidelines for the prevention of nosocomial infections. However, the efficacy of specific isolation in preventing nosocomial infections in HSCT recipients has not been evaluated. HSCT recipients should be placed in private rooms. When indicated, HSCT recipients should also be placed on airborne, droplet, or contact precautions in addition to standard precautions to prevent transmission of infectious agents among HSCT recipients, health-care workers, and visitors (Garner and HICPAC, 1996).
Hand Hygiene
Hand hygiene is the single most effective procedure for preventing nosocomial infection. Everyone, especially health-care workers, should wash hands before entering and after leaving rooms of HSCT recipients or before and after any direct contact with patients, regardless of whether hands were soiled. HSCT recipients should be encouraged to practice good hand hygiene (e.g. washing hands before eating, after using the toilet, before and after touching a wound). Hands should be washed with antimicrobial soap and water (Garner and HICPAC, 1996).
Health-care workers wearing gloves should put them on in the patient’s room after hand washing and then discard them in the same patient’s room before washing hands again on exiting the room. Gloves should always be changed between patients or before touching a clean area if the gloves become soiled. Appropriate gloves should be used by all persons handling potentially contaminated biological materials (Rotter, 1999).
Equipment
HSCT units should monitor opened and unopened wound-dressing supplies such as adhesive bandages and surgical and elastic adhesive tape to detect mold contamination and prevent cutaneous transmission to patients. All bandages and wound dressings should be discarded that are out of date, have damaged packaging, or are visually contaminated by construction debris, moisture (Bryce et al., 1996).
Plants
Exposure to plants and flowers has not been conclusively shown to cause fungal infections in HSCT recipients. However, most experts strongly recommend that plants and dried or fresh flowers not be allowed in the hospital rooms of HSCT recipients because aspergillus have been isolated from the soil of potted ornamental plants, the surface of dried and fresh flowers (CDC,1997).
Play Areas and Toys
Play areas for pediatric HSCT recipients should be cleaned and disinfected weekly and as needed. HSCT units and clinics should follow published recommendations for washing and disinfecting toys (CDC, 1997).
Health-Care Workers
Each hospital should prepare a written comprehensive policy on the immunization of hospital personnel that meets current recommendations of CDC and ACIP. Immunizations are needed to prevent transmis¬sion of vaccine-preventable diseases to HSCT recipients (CDC, 1997).
Visitors
Hospitals should have written policis for potentially infectious conditions. Such screening should be performed by clinically trained health-care personnel. visitors who have communicable infectious disease such as upper respiratory infection or flu like illness, recent exposure to communicable disease, active shingles rash (whether covered or not), varicella zoster –like rash within 6 weeks of receiving chickenpox vaccine, or a history of receiving a chicken pox vaccine, or history of receiving oral polio vaccine within the previous 3-6 weeks should not be allowed to enter the HSCT unit (Dykewicz, 2001).
Skin Care
Skin care during neutropenia should include daily inspection of sites likely to be portals of infection, such as the perineum and intravascular access sites. HSCT recipients should maintain good perineal hygiene to minimize loss of skin integrity and risk for infection. Immunosuppressed HSCT recipients are defined as being <24 months post HSCT, on immunosuppressive therapy, or having graft-versus-host disease. The use of rectal thermometers, enemas, suppositories, and rectal examination are contraindicated for HSCT recipients because of the risk for skin or mucosal breakdown (Dykewicz, 2001).

Oral and Dental Care
Establishing optimal periodontal health before HSCT is one of the most important steps patients can take to avoid oral infections. Maintaining good oral hygiene after the transplant minimizes the severity and facilitates healing of mucositis, especially before engraftment. All HSCT candidates should receive a dental evaluation and relevant treatment before conditioning therapy begins. HSCT recipients with mucositis and HSCT candidates undergoing conditioning therapy should maintain good oral hygiene by rinsing the mouth 4-6 times per day with sterile water, normal saline, or sodium bicarbonate solutions. HSCT recipients should brush their teeth at least twice per day with a soft regular toothbrush (Schubert et al., 1999).