Respiratory syncytial virus (RSV) is known to be a frequent cause of lower respiratory tract infection, which can be severe and fatal in haemato‐oncology patients (Dignan et al. [33]). Mortality may be as high as 80% depending upon other haematopoietic progenitor cell transplant complications, the timing of the transplant and degree of immunosuppression. There is a poor prognosis if these infections go untreated, and it is important to diagnose them early and treat promptly (Dignan et al. [33]; see also Chapter c20).

RSV should be suspected and routinely tested for in any coryzal patient undergoing high‐dose chemotherapy treatment. RSV and other influenza pathogens are best detected by a nasopharyngeal aspirate (NPA) sample (Dignan et al. [33]). An NPA should be done at the earliest opportunity following the presentation of respiratory symptoms (see Chapter c13: Diagnostic tests). The detection of viral antigen is performed using indirect immunofluorescence, with specific monoclonal antibodies for RSV, adenovirus, influenza A and B and the parainfluenza group (type 1, 2 and 3). This method is highly sensitive, specific, rapid and low cost (Blaschke et al. [14], Raboni et al. [96], Tunsjo et al. [111]).

Ribavirin is classed as a substance hazardous to health under the statutory requirements of the Control of Substance Hazardous to Health Regulations (COSHH [24]) and the accompanying Approved Code of Practice for Carcinogens. Under the regulations, the risk of exposure to ribavirin must be reduced ‘to as low a level as is reasonably practicable’ where use cannot be eliminated.