Background: 
There are few data regarding the clinical presentation of respiratory viral infections (RVI) in children undergoing hematopoietic stem cell transplant (HSCT), especially in developing countries. We determine the clinical outcome of RVI in this population.

Methods:
Prospective study in children with cancer and HSCT admitted with fever in the Bone Marrow Unit, Hospital Calvo-Mackenna, Chile (April 2016-January 2018). Children were evaluated by clinical examination, laboratory tests, bacterial cultures and nasopharyngeal multiplex-PCR for 20 respiratory pathogens. Clinical outcome variables were collected; children were followed-up in each episode of fever until discharge.

Results:
A total of 45 fever episodes were enrolled in 28 children, of whom 30 (67%) were RVI-positive. Median age was 9,5 years, 73% were male. Most detected viruses were rhinovirus (47%), followed by coronavirus (20%), parainfluenza (11%), RSV, adenovirus (8%) and influenza(6%). RVI was detected with a median of 145 days after HSCT. 20/30 (67%) episodes had respiratory symptoms at admission, 25/30 episodes were single RVI and 5 were co-infections. 4 out of 5 children had ≥1 episode of fever with the same virus detected (median=79 days). 20/30 (67%) episodes were lower respiratory tract infections(LRTI), 50% required oxygen supplementation and 4 (13%) admission to the PICU. Median days of fever, oxygen and hospitalization were 2, 2 and 12, respectively. No cases of sepsis or mortality were reported. In 9 episodes (30%), antimicrobials were withdrawal after knowing the result of the multiplex-PCR. 

Conclusions:
RVI were frequently detected in fever episodes after HSCT in children. We observed a predominance of LRTI, oxygen requirement and long hospital-stay. Viral persistent-detection was reported in 22% of episodes. RVI detection might help to rationalize the use of antimicrobials in this population (FONDECYT-Grant#1171795).

CLINICAL OUTCOME OF RESPIRATORY VIRAL INFECTIONS IN CHILDREN UNDERGOING HEMATOPOIETIC STEM CELL TRANSPLANT