Prolonged viral shedding in pandemic influenza A(H1N1): clinical significance and viral load analysis in hospitalized patients.
ABSTRACT The clinical significance of prolonged viral shedding (PVS) and viral load (VL) dynamics has not been sufficiently assessed in hospitalized patients with pandemic 2009 influenza A(H1N1). We performed a prospective study of adults with confirmed influenza A(H1N1) virus infection admitted to our hospital from 20 September 2009 to 31 December 2009. Consecutive nasopharyngeal swabs were collected every 2 days during the first week after diagnosis, and then every week or until viral detection was negative. Relative VL was measured on the basis of haemagglutinin and RNaseP gene analysis. PVS was defined as positive detection of influenza A(H1N1) virus by real-time RT-PCR at day 7 after diagnosis. We studied 64 patients: 16 (25%) presented PVS. The factors associated with PVS were admission to the intensive-care unit (69% vs. 33%, p 0.02), purulent expectoration (75% vs. 44%, p 0.04), higher dosage of oseltamivir (62.5% vs. 27%, p 0.016), corticosteroid treatment (50% vs. 21%, p 0.05), mechanical ventilation (MV) (50% vs. 12.5%, p 0.004), and longer stay (34 vs. 7 median days, p 0.003). Multivariate analysis revealed the factors independently associated with PVS to be immunosuppression (OR 5.15; 95% CI 1.2-22.2; p 0.03) and the need for MV (OR 11.7; 95% CI 2.5-54.4; p 0.002). VL at diagnosis correlated negatively with age and septic shock. VL dynamics of patients with acute respiratory distress syndrome and/or mortality were very different from those of other patients. PVS was detected in 25% of hospitalized patients with pandemic 2009 influenza A(H1N1) and was strongly associated with immunosuppression and the need for MV. Diagnostic VL and viral clearance varied with the clinical course.
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ABSTRACT: Even though the pathogenicity and invasiveness of pneumococcus largely depend on capsular types, the impact of serotypes on post-viral pneumococcal pneumonia is unknown. This study was performed to evaluate the impact of capsular serotypes on the development of pneumococcal pneumonia after preceding respiratory viral infections. Patients with a diagnosis of pneumococcal pneumonia were identified. Pneumonia patients were divided into two groups (post-viral pneumococcal pneumonia versus primary pneumococcal pneumonia), and then their pneumococcal serotypes were compared. Nine hundred and nineteen patients with pneumococcal pneumonia were identified during the study period, including 327 (35.6%) cases with post-viral pneumococcal pneumonia and 592 (64.4%) cases with primary pneumococcal pneumonia. Overall, serotypes 3 and 19A were the most prevalent, followed by serotypes 19F, 6A, and 11A/11E. Although relatively uncommon (33 cases, 3.6%), infrequently colonizing invasive serotypes (4, 5, 7F/7A, 8, 9V/9A, 12F, and 18C) were significantly associated with preceding respiratory viral infections (69.7%, P<0.01). Multivariate analysis revealed several statistically significant risk factors for post-viral pneumococcal pneumonia: immunodeficiency (OR 1.66; 95% CI, 1.10-2.53), chronic lung diseases (OR 1.43; 95% CI, 1.09-1.93) and ICI serotypes (OR 4.66; 95% CI, 2.07-10.47). Infrequently colonizing invasive serotypes would be more likely to cause pneumococcal pneumonia after preceding respiratory viral illness, particularly in patients with immunodeficiency or chronic lung diseases.PLoS ONE 01/2014; 9(4):e93477. · 3.73 Impact Factor
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ABSTRACT: Background For lung transplant recipients (LTRs) influenza infections pose a considerable risk for complications. These infections have mainly been described in hospitalized patients. The aim of this study was to describe characteristics of predominantly outpatient-treated influenza infections.Methods We conducted a single-season (2010/2011) retrospective observational study using database information of our cohort. Patients with evidence for respiratory tract infection received empirical oseltamivir and an oral antibiotic, pending results from nasopharyngeal swab analysis. In laboratory-confirmed influenza infection, treatment was continued and serial weekly swabs were performed until virologic results were negative.ResultsWe identified 22 infections in 21 of 173 patients followed up; influenza A virus was diagnosed in 13 and influenza B virus in 9 infections. Leading presenting symptoms were cough and rhinorrhea. Oseltamivir was given within 48 h of symptom onset in 13 infections and within 72 h in 21 infections. Prolonged viral shedding (PVS) for ≥7 days was detected in 15 infections; median shedding duration for influenza A was 21 days. In univariable analysis, viral load (VL) at diagnosis was associated with extended duration of shedding (P = 0.006). Multivariable analysis confirmed this association. Bronchiolitis obliterans syndrome stage increased in 3 patients at 6-month follow-up.Conclusion In this study, PVS of influenza virus was detected in the majority of LTRs and high VL at diagnosis was predictive for prolonged shedding, which occurred despite extended antiviral therapy.Transplant Infectious Disease 05/2014; · 1.98 Impact Factor
- Critical care medicine 02/2014; 42(2):457-9. · 6.37 Impact Factor