Frequency of human metapneumovirus infection in hematopoietic SCT recipients during 3 consecutive years.

Respiratory viruses can cause significant morbidity in immunocompromised hosts. Human metapneumovirus (hMPV) has been increasingly associated with lower respiratory tract infection in hematopoietic SCT (HSCT) recipients, with mortality rates up to 50%. No data on the occurrence of hMPV infection in HSCT recipients have been reported in the southern hemisphere. We conducted a retrospective study including 228 nasal wash samples from 153 HSCT recipients with respiratory symptoms during 2001, 2002 and 2003. hMPV was detected by real-time PCR with primers complementary to the nucleocapsid region of hMPV genome. Eleven of the 153 patients (7.2%) acquired hMPV infection during the study period (6.4% in 2001, 4.7% in 2002 and 11.1% in 2003). Among the 11 HSCT recipients with hMPV infection, 1 died 8 days after the diagnosis, but the role of hMPV in the patient's death could not be established. In 2001 and 2003, hMPV group A prevailed over group B. In 2002, both groups were detected equally. hMPV infections were diagnosed in late winter and spring. The frequency of hMPV infection in HSCT recipients living in Brazil was similar to those observed in the northern hemisphere. Sensitive techniques to detect hMPV should be included in the diagnostic assessment of HSCT recipients with respiratory symptoms.

Herpes Simplex Virus Shedding in Bone Marrow Transplant Recipients During Low-Dose Oral Acyclovir Prohylaxis.

A 400mg dose twice-a-day oral acyclovir prophylaxis regimen was evaluated in 50 allogeneic transplant recipients. Twenty (40%) patients experienced 24 episodes of herpes simplex virus (HSV) shedding; l7 (70.8%) occurring during prophylaxis. Thirteen of such episodes were asymptomatic and, in three, it was difficult to differentiate severe mucositis from viral lesions. In the remaining one, HSV pneumonia was suspected after a bronchoalveolar lavage (BAL) procedure performed in an attempt to early detection of cytomegalovirus (CMV). All cases responded to acyclovir therapy or dose adjustment suggesting that acyclovir resistance did not account for the occurrence of infection in our patients. These data demonstrated that oral acyclovir prophylaxis, 400mg dose twice-a-day, was inadequate to suppress viral shedding. The bronchoalveolar lavage procedure in a patient with HSV shedding could precipitate HSV spread to the lungs and the occurrence of pneumonia.