T3. Studies of the epidemiology of infections in transplant patients and patients with impaired immunity due to underlying disease or immunosuppressive drugs
Janet A. Englund, MD
Seattle Children's Hospital/Univ. of Washington
Disclosure: AstraZeneca: Grant/Research Support
Chimerix: Grant/Research Support
GlaxoSmithKline: Consultant, Grant/Research Support
Meissa Vaccines: Consultant
Merck: Grant/Research Support
Novavax: Grant/Research Support
Sanofi Pasteur: Consultant
Michael Boeckh, MD PhD
Fred Hutchinson Cancer Research Center
Disclosure: Ablynx: Consultant, Grant/Research Support
Ansun Biopharma: Consultant, Grant/Research Support
Astellas: Consultant, Grant/Research Support
Bavarian Nordic: Consultant
Chimerix: Consultant, Grant/Research Support
Gilead: Consultant, Grant/Research Support
Janssen: Consultant, Grant/Research Support
Lophius: Grant/Research Support
Merck: Consultant, Grant/Research Support
Shire: Consultant, Grant/Research Support
Vir Bio: Consultant, Grant/Research Support
Background : Limited data exist regarding the impact of human bocavirus (BoV) in hematopoietic cell transplant (HCT) recipients. We examined incidence and disease spectrum of BoV respiratory tract infection (RTI) in HCT recipients.
Methods : In a longitudinal surveillance study of viral RTIs among allogeneic HCT recipients, pre-HCT and weekly post-HCT nasal washes and symptom surveys were collected through day 100, then every 3 months, and whenever respiratory symptoms occurred through 1 year post-HCT. Samples were tested by multiplex semi-quantitative PCR for RSV, parainfluenza virus 1–4, influenza A/B, adenovirus, human metapneumovirus, rhinovirus, coronavirus and BoV. Plasma samples from BoV+ subjects were analyzed by PCR. In addition, we conducted a retrospective review of HCT recipients with BoV detected in bronchoalveolar lavage or lung biopsy.
Results : Among 469 patients in the prospective cohort, 21 distinct BoV RTIs (3 pre-HCT and 18 post-HCT) were observed by 1 year post-HCT in 19 patients (median 42 years old, range 0-67) without apparent seasonality. BoV was more frequently detected in the latter half of first 100 days post-HCT (Figure 1). The frequencies of respiratory symptoms in patients with BoV detected did not appear to be higher than those without any virus detected, with exception of watery eyes (p<0.01) (Figure 2). Univariable models among patients with BoV RTI post-HCT showed higher peak viral load in nasal samples (p=0.04) and presence of respiratory copathogens (p=0.03) were associated with presence of respiratory symptoms; however, BoV detection in plasma was not (p=0.8). Retrospective review identified 6 allogeneic HCT recipients (range 1-64 years old) with BoV detected in lower respiratory tract specimens [incidence rate of 0.4% (9/2385) per sample tested]. Although all 6 cases presented with hypoxemia, 4 had significant respiratory copathogens or concomitant conditions that contributed to respiratory compromise. No death was attributed mainly to BoV lower RTI.
Conclusion : BoV is infrequently detected in respiratory tract in HCT recipients. Our studies did not demonstrate convincing evidence that BoV is a significant pathogen in either upper or lower respiratory tracts. Watery eyes were associated with BoV detection.