autologous blood and marrow transplantation - Blog Science ...

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CRVs are a common cause of acute respiratory disease in both allogeneic and
autologous BMT recipients, occurring in a minimum of one-third of hospitalized
BMT transplant recipients with an acute respiratory illness. 3
Although these
infections may occur at any time during the transplant period, either pre- or postengraftment,
the severity of these infections has in some instances been temporally
related to the time of the transplant.
CRV infections in hospitalized blood and marrow transplant recipients are
frequently complicated by life-threatening pneumonias. Approximately 40% of
CRV infections have remained limited to the upper respiratory tract and have been
characterized by rhinorrhea, nasal and sinus congestion, sore throat, and mild
cough. However, 60% of the infections have been complicated by pneumonia,
either primary viral or secondary bacterial/fungal pneumonias, and the pneumoniaassociated
mortality has been approximately 50%. An important clue to the
diagnosis of CRV-associated pneumonias has been the finding that 85% of these
pneumonias have been preceded by signs and symptoms of a URI, in contrast to
pneumonias due to CMV or Pneumocystis carinii, which are not typically preceded
by a URI. In an era of reasonably effective prophylaxis of CMV disease, CRVassociated
pneumonias have assumed a dominating role in BMT recipients,
occurring four times more frequently than CMV pneumonia and accounting for
four times as many deaths. 4
There has been considerable diversity in the frequency and severity of CRV
infections observed in different transplant centers. This diversity reflects several
factors, including the intensity of the surveillance; the time of year when the
surveillance was performed and the viruses prevalent in the community; the type
and degree of immunosuppression of the patients being evaluated; the type of
infection control and influenza vaccination policies; the inclusion of potential as
well as actual transplant recipients; the inclusion of outpatients as well as
inpatients; the types of viruses routinely assayed for in the laboratory; the
multiplicity of laboratory methods used to identify different viruses (e.g., culture,
rapid Ag assays, PCR, histopathology); and the definition of a case (i.e., confirmed
by culture or by rapid detection assays).
RESPIRATORY SYNCYTIAL VIRUS
RSV is the leading cause of serious lower respiratory tract disease in infants and
children, causing tracheobronchitis, bronchiolitis, and pneumonia. Most persons
are infected during the first years of life. Natural immunity is incomplete, and older
children and adults experience repeated infections, which are usually manifested as
relatively benign upper respiratory illnesses or tracheobronchitis. In the elderly,
RSV infections are not infrequently associated with lower respiratory tract
syndromes similar to influenza.