Detection and Control of a Nosocomial Respiratory Syncytial Virus Outbreak in a Stem Cell Transplantation Unit: The Role of Palivizumab

Respiratory syncytial virus (RSV) is a common community-acquired virus that causes upper and lower respiratory tract infections in children, hematologic malignancy patients, and hematopoietic stem cell transplant (HSCT) recipients. Nosocomial transmission of RSV in immunocompromised patients can significantly affect morbidity, mortality, and duration of hospitalization. Stringent infection control measurements are needed to control further hospital transmission. Prophylactic palivizumab was found to result in a significant reduction in hospitalization rates in high-risk children. In this article, we report a nosocomial outbreak of RSV in an adult HSCT unit (4 pods) from January 16 to February 4, 2004, including the infection control interventions used and the prophylactic administration of palivizumab in high-risk patients. Active surveillance identified 5 cases, a substantial increase from previous seasons (2 or 3 cases per season). All infected patients were isolated to 1 nursing pod and placed on contact isolation. All patients on the HSCT unit underwent rapid RSV antigen screening using nasal washes; this was repeated 1 week later, and 1 additional RSV case was identified. Patients identified to be at increased risk for RSV infection received prophylactic palivizumab. Routine screenings of the staff and visitors were undertaken. All patient and visitor areas were thoroughly cleaned with bleach. We educated health care workers about RSV transmission, highlighting proper hand hygiene and contact precautions. Four of 6 patients with RSV infection developed RSV pneumonia, and 2 of these patients died. Staff and visitors with upper respiratory symptoms were screened, and all were negative for RSV. Prophylactic palivizumab was administered in 16 patients who tested negative for RSV, but were considered to be at increased risk for RSV infection. None of these patients developed RSV infections. An RSV outbreak was controlled using prompt preventive measures, including cohorting patients, with a dedicated health care staff; contact isolation of patients; strict adherence to hand hygiene; and screening of visitors, family members, and health care staff for upper respiratory infection symptoms. Immunoprophylaxis with palivizumab, administered to high-risk patients, complemented strict infection control intervention. Thus, the role of palivizumab in the control of RSV hospital outbreaks merits further investigation.

Key Words: Respiratory Syncytial Virus, Hematopoietic stem cell transplantation, Outbreak