Factors promoting the prolonged shedding of the pandemic (H1N1) 2009 influenza virus in patients treated with oseltamivir for 5 days

Abstract

BackgroundThe duration of viral shedding is an important determinant of infectivity and transmissibility and provides vital information for effective infection prevention and control. However, few studies have evaluated viral shedding in patients admitted to hospital with 2009 H1N1 influenza and treated with oseltamivir.ObjectiveTo determine the incidence of prolonged 2009 H1N1 influenza viral shedding in patients treated for 5 days with oseltamivir and to identify factors that promote prolonged viral shedding.MethodsThis was a prospective, observational cohort study of 173 patients infected with 2009 H1N1 influenza (confirmed by RT‐PCR) who were admitted to isolation rooms in the emergency department of our hospital between August 25, 2009 and December 31, 2009. All of the patients were treated according to institutional protocols and received routine follow‐up RT‐PCR testing after 5 days of oseltamivir therapy. Prolonged viral shedding was defined as a positive follow‐up RT‐PCR result.ResultOf the 173 patients in our cohort, 88 (50·8%) showed persistent viral shedding after oseltamivir treatment. Viral shedding was significantly prolonged if antiviral therapy was started ≥2 days after symptom onset (OR 2·74, 95% CI 1·29–5·82), if there were major comorbidities (OR 3·07, 95% CI 1·29–7·32), and/or if respiratory symptoms were still present on the day 5 of antiviral treatment (OR 4·13, 95% CI 2·10–8·11).ConclusionsThe presence of major comorbidities, a delay in initiating antiviral treatment, and continuing respiratory symptoms after 5 days of antiviral treatment are associated with prolonged shedding of the 2009 H1N1 influenza virus.

Initial High Viral Load Is Associated with Prolonged Shedding of Human Rhinovirus in Allogeneic Hematopoietic Cell Transplant Recipients

“…However, data on factors associated with prolonged shedding of respiratory viruses is limited with the exception of influenza virus in mainly immunocompetent populations and coronavirus in HCT recipients. 9, 26, 27 The present study showed initial high viral load was a risk factor for prolonged HRV shedding in HCT recipients, consistent with our previous study of coronavirus. 9…”

“…Viral shedding duration is often used as an endpoint in clinical trials of new antivirals [23] , [24] , [25] , and identifying risk factors for prolonged shedding is thus critical for appropriate stratification of patients in randomized trials. However, data on factors associated with prolonged shedding of respiratory viruses are limited, with the exception of influenza virus in mainly immunocompetent populations and coronavirus in HCT recipients [9] , [26] , [27] . The present study showed initial high viral load was a risk factor for prolonged HRV shedding in HCT recipients, consistent with our previous study of coronavirus [9] .…”

Influenza Viral Shedding in a Prospective Cohort of HIV-Infected and Uninfected Children and Adults in 2 Provinces of South Africa, 2012–2014

“…Quantifying influenza shedding duration, a possible predictor of infectivity and transmissibility, can inform infection prevention and control measures [1]. Several factors, such as age and to a lesser extent human immunodeficiency virus (HIV) status, have been found to impact shedding duration [2, 3].…”

Post-transplant Viral Respiratory Infections in the Older Patient: Epidemiology, Diagnosis, and Management

“…Respiratory virus positivity in respiratory specimens is generally up to 14 days in most series; however, virus can remain positive for several months despite resolution of symptoms [13,23,28]. In one study, corticosteroid dosages greater than 1 mg/kg daily were shown to prolong influenza virus positivity compared to persons treated with lower doses (15 vs 9 days) [17].…”