Long lasting viremia in hantavirus pulmonary syndrome cases caused by Andes virus

BELLOMO CARLA; ALONSO DANIEL; IGLESIAS AYELÉN; COELHO ROCIO; PERIOLO NATALIA,; MARTINEZ VALERIA

Leuven,

Congreso; 11TH INTERNATIONAL CONFERENCE ON HANTAVIRUSES; 2019

Introduction: Hantavirus pulmonary syndrome (HPS) is a devastating disease with fatality rates up to 50%; in Argentina, more than 1200 cases were reported up today. The main causative agent of HPS in Argentina is Andes virus (ANDV) that has the particular property of person-to-person transmission.There are not specific treatments or vaccines for HPS. Ribavirin, was tested for efficacy in patients or in animal models, without obtaining positive results for HPS cases, possibly because of therapeutic interventions that target viral replication may not be effective unless given early.Recently, in Argentina, the largest person-to-person transmission outbreak of HPS was reported, involving 34 cases, 11 of which were fatal (32%). Four-link chains of viral transmission were identified, and the followupof the contacts by RT-qPCR allowed us early identification of new cases. Four cases from 34 (11%), who were confirmed around day 0 of onset of disease, wereRibavirin treated.Objective:HPS cases showed high levels of viremia at the onset of pulmonary edema but there were no studies showing how long it is maintained. The objective was to establish a kinetic viral load in HPS cases linkedto an outbreak of person-to-person transmission.Methods:At least one blood sample was obtained daily form 33 of 34 patient involved in the outbreak and 150 samples were analyzed. IgM and IgG titles were quantified by ELISA test. Taq-Man RT-qPCR was performed to quantify a viral S-Segment fragment.Results and Discussion: IgM titers were detectable since day 0 to 4 after onset of fever, while viral genome since onset of disease day.Viral genome was detected until day 34 after onset without clearance and withless than 22% of decrease in viral RNA values, even for patients discharged from the hospital. There were not significant differences in viral load between samples from Ribavirin treated (up to day 19 after onset of symptoms) and untreated patients.Future studies of viral genome in samples such as urine, semen, etc., could be suggest the presence of immunological privilege sites and it would infer the implication of the prolonged viremia for the pathology, viral transmission and evolution.