In summary, a highly conserved neutralizing linear B-cell epitope on the gp90 protein of REV-A was identified in this study. The identified conserved epitope may have potential for development of REV specific diagnostic assays and epitope-based marker vaccines. Identification of an Epitope on REV gp90 Protein PLOS ONE | www.plosone.org Lower Respiratory Tract Infection in a Renal Transplant Recipient: Do not Forget Metapneumovirus Human metapneumovirus (hMPV) is emerging as a cause of a severe respiratory tract infection in immunocompromised patients. hMPV pneumonia has only been seldom reported in nonpulmonary solid organ transplanted patients, such as renal transplant recipients. We report here a case of a 39-year-old patient presenting with fever, cough, and interstitial opacities on CT scan diagnosed as a nonsevere hMPV pneumonia 11 years after a renal transplantation. Infection resolved spontaneously. Differential diagnosis with Pneumocystis pneumonia was discussed. We review the medical literature and discuss clinical presentation and detection methods that can be proposed in solid organ transplant recipients. Respiratory viruses such as respiratory syncytial virus (RSV), influenza, parainfluenza viruses (PIV), and adenovirus are commonly associated with mild to severe symptoms, depending on the immune status. Human Metapneumovirus (hMPV) was the sixth most frequent viral infection in patients hospitalized for respiratory illness [1] . hMPV is a nonsegmented, enveloped, negative single-stranded RNA virus [2] responsible for lower respiratory tract infections (LRI), especially in extreme ages [3, 4] . It has a seasonal distribution and occurs mainly in winter and spring, with an incubation period usually between 4 and 6 days [5] . hMPV is now widely recognized as an opportunistic infection in immunocompromised hosts such as hematopoietic stem cell transplant (HSCT) and pulmonary transplant recipients, leading to a significant respiratory morbidity [6] . Although its detection is not yet routinely performed, hMPV appears to account for 9% of acute pneumonia in patients with haematologic malignancies (including HSCT), in a similar proportion to RSV [7] . This rate is close to that reported in lung transplant recipients, ranging from 6% to 12% of LRI [6, 8] .