Performance of laboratory diagnostics for the detection of influenza A(H1N1)v virus as correlated with the time after symptom onset and viral load

2010 ◽  
Vol 47 (2) ◽  
pp. 182-185 ◽  
Author(s):  
Peter K.C. Cheng ◽  
Kitty K.Y. Wong ◽  
Gannon C. Mak ◽  
Ann H. Wong ◽  
Anita Y.Y. Ng ◽  
...  
Keyword(s):  
Viral Load ◽  
Symptom Onset ◽  
Influenza A ◽  
Laboratory Diagnostics ◽  
Influenza A H1n1

scholarly journals Hospitalized Adult Patients with 2009 Pandemic Influenza A (H1N1) in Kaunas, Lithuania

Medicina ◽  
2011 ◽  
Vol 47 (1) ◽  
pp. 11-18 ◽  
Author(s):  
◽  
◽  
◽  
◽  
◽  
...  
Keyword(s):  
Risk Factors ◽  
Symptom Onset ◽  
Pandemic Influenza ◽  
Influenza A ◽  
H1n1 Virus ◽  
Clinical Course ◽  
Antiviral Treatment ◽  
Course Of Illness ◽  
Influenza A H1n1 ◽  
Complicated Course

The objective of this study was to identify case characteristics and clinical course of the disease in patients hospitalized with 2009 pandemic influenza A (H1N1) infection during the first wave of the pandemic and to identify risk factors associated with the complicated course of illness. Material and methods. A retrospective study of adult cases of the laboratory-confirmed 2009 pandemic influenza A (H1N1) virus admitted to three hospitals in Kaunas between November 1, 2009, and March 15, 2010, was carried out. The main outcome measures were clinical characteristics, risk factors for complicated disease, treatment, and clinical course of the disease. Results. The study enrolled 121 of the 125 patients hospitalized due to 2009 pandemic influenza A (H1N1) virus infection. The median age was 31 years (range, 18–83); 5% of the patients were aged more than 65 years. Pregnant and postpartum women comprised 26% of all hospitalized cases. Nearly half (49.5%) of those who underwent chest radiography had findings consistent with pneumonia, which was bilateral in one-third of cases. The risk to have pandemic influenza complicated by pneumonia increased significantly with one-day delay from symptom onset to antiviral treatment (OR, 2.241; 95% CI, 1.354–3.710). More than half (57%) of the patients received antiviral treatment. In 45% of the treated patients, antiviral drugs were administered within 48 hours from symptom onset. Intensive care was required in 7.4% of the cases. The overall mortality was 5% (6/121). The median age of the patients who died was 43.5 years (range, 23–62); 4 patients had been previously healthy, 1 patient suffered from chronic lympholeukemia, and 1 patient was a pregnant woman. Conclusion. The 2009 pandemic influenza A (H1N1) caused considerable morbidity in a significant proportion of hospitalized adults. The main risk factor associated with the complicated course of illness was delayed antiviral treatment.

scholarly journals Convalescent Plasma Treatment Reduced Mortality in Patients With Severe Pandemic Influenza A (H1N1) 2009 Virus Infection

2011 ◽  
Vol 52 (4) ◽  
pp. 447-456 ◽  
Author(s):  
Ivan FN Hung ◽  
Kelvin KW To ◽  
Cheuk-Kwong Lee ◽  
Kar-Lung Lee ◽  
Kenny Chan ◽  
...  
Keyword(s):  
Intensive Care ◽  
Viral Load ◽  
Treatment Group ◽  
Respiratory Tract ◽  
Plasma Treatment ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Control Group ◽  
Severity Scores ◽  
Influenza A H1n1

Background. Experience from treating patients with Spanish influenza and influenza A(H5N1) suggested that convalescent plasma therapy might be beneficial. However, its efficacy in patients with severe pandemic influenza A(H1N1) 2009 virus (H1N1 2009) infection remained unknown. Methods. During the period from 1 September 2009 through 30 June 2010, we conducted a prospective cohort study by recruiting patients aged ≥18 years with severe H1N1 2009 infection requiring intensive care. Patients were offered treatment with convalescent plasma with a neutralizing antibody titer of ≥1:160, harvested by apheresis from patients recovering from H1N1 2009 infection. Clinical outcome was compared with that of patients who declined plasma treatment as the untreated controls. Results. Ninety-three patients with severe H1N1 2009 infection requiring intensive care were recruited. Twenty patients (21.5%) received plasma treatment. The treatment and control groups were matched by age, sex, and disease severity scores. Mortality in the treatment group was significantly lower than in the nontreatment group (20.0% vs 54.8%; P =  .01). Multivariate analysis showed that plasma treatment reduced mortality (odds ratio [OR], .20; 95% confidence interval [CI], .06-.69; P =  .011), whereas complication of acute renal failure was independently associated with death (OR, 3.79; 95% CI, 1.15-12.4; P =  .028). Subgroup analysis of 44 patients with serial respiratory tract viral load and cytokine level demonstrated that plasma treatment was associated with significantly lower day 3, 5, and 7 viral load, compared with the control group (P <  .05). The corresponding temporal levels of interleukin 6, interleukin 10, and tumor necrosis factor α (P <  .05) were also lower in the treatment group. Conclusions. Treatment of severe H1N1 2009 infection with convalescent plasma reduced respiratory tract viral load, serum cytokine response, and mortality.

Viral load dynamics in adult patients with A(H1N1)pdm09 influenza

2013 ◽  
Vol 142 (4) ◽  
pp. 753-758 ◽  
Author(s):  
J. Y. NOH ◽  
J. Y. SONG ◽  
S. Y. HWANG ◽  
W. S. CHOI ◽  
J. Y. HEO ◽  
...  
Keyword(s):  
Viral Load ◽  
Symptom Onset ◽  
Influenza A ◽  
Onset Time ◽  
Clinical Findings ◽  
Viral Clearance ◽  
Virus Infections ◽  
Hospital Visit ◽  
Viral Shedding ◽  
Respiratory Specimens

SUMMARYThe dynamics of influenza A viral load in respiratory samples collected from adult A(H1N1)pdm09 influenza patients were investigated. Three respiratory specimens were obtained every 2–4 days and clinical findings were recorded at the time each specimen was collected. A total of 105 serial specimens were collected from 35 patients. Viral clearance was more rapid in patients aged 15–29 years than patients aged 30–49 years (P < 0·01) or ⩾50 years (P < 0·01). Hospitalized patients showed slow viral clearance compared to outpatients (P < 0·01). Resolution of cough and headache was correlated with viral load reduction in respiratory specimens. Viral shedding was found in 17 patients (48·6%) 5 days after symptom onset. Time to hospital visit after symptom onset was significantly correlated with prolonged viral shedding (odds ratio 9·0, 95% confidence interval 1·56–51·87, P = 0·01). These findings will contribute to infection control aspects with respect to managing patients with influenza virus infections.

scholarly journals Development of oseltamivir and zanamivir resistance in influenza A(H1N1)pdm09 virus, Denmark, 2014

2017 ◽  
Vol 22 (3) ◽  
Author(s):  
Ramona Trebbien ◽  
Svend Stenvang Pedersen ◽  
Kristine Vorborg ◽  
Kristina Træholt Franck ◽  
Thea Kølsen Fischer
Keyword(s):  
Symptom Onset ◽  
Influenza A ◽  
Antiviral Treatment ◽  
Influenza Virus Infection ◽  
Resistance Testing ◽  
Antiviral Resistance ◽  
Resistance Mutations ◽  
Pdm09 Virus ◽  
Influenza A H1n1 ◽  
Two Samples

Antiviral treatment of immunocompromised patients with prolonged influenza virus infection can lead to multidrug resistance. This study reveals the selection of antiviral resistance mutations in influenza A(H1N1)pdm09 virus in an immunocompromised patient during a 6-month period. The patient was treated with two courses of oseltamivir (5 days and 2 months, respectively), with the first course starting at symptom onset, and subsequently zanamivir (2 months and 10 days, respectively). Respiratory samples were investigated by Sanger and next generation sequencing (NGS) and, for NGS data, low-frequency-variant-detection analysis was performed. Neuraminidase-inhibition tests were conducted for samples isolated in Madin-Darby canine kidney cells. In a sample collected 15 days after the end of the first treatment with oseltamivir (Day 20 post-symptom onset), oseltamivir resistance was detected (mutation H275Y with 60.3% frequency by NGS). Day 149 when the patient had almost completed the second zanamivir treatment, mixes of the following resistance mutations were detected; H275Y(65.1%), I223R(9.2%), and E119G(89.6%), accompanied by additional mutations, showing a more complex viral population in the long-term treated patient. Two samples obtained on Day 151 from bronchoalveolar lavage (BAL) and nasopharyngeal swab, respectively, showed different mutation profiles, with a higher frequency of antiviral resistance mutations in BAL. The results emphasise the importance of timely antiviral resistance testing both for treatment of individual patients as well as for preventive measures to control the development and transmission of antiviral resistant viruses.

scholarly journals Influenza A(H1N1)pdm09 infection and viral load analysis in patients with different clinical presentations

2020 ◽  
Vol 115 ◽  
Author(s):  
Vitória Rodrigues Guimarães Alves ◽  
Ana Helena Perosa ◽  
Luciano Kleber de Souza Luna ◽  
Jessica Santiago Cruz ◽  
Danielle Dias Conte ◽  
...  
Keyword(s):  
Viral Load ◽  
Influenza A ◽  
Clinical Presentations ◽  
Influenza A H1n1 ◽  
Load Analysis

Viral load and epidemiological profile of patients infected by pandemic influenza a (H1N1) 2009 and seasonal influenza a virus in Southern Brazil

2012 ◽  
Vol 84 (3) ◽  
pp. 371-379 ◽  
Author(s):  
Ana Beatriz Gorini da Veiga ◽  
Nélson Alexandre Kretzmann ◽  
Laura Trevizan Corrêa ◽  
Alessandra Mari Goshiyama ◽  
Tatiana Baccin ◽  
...  
Keyword(s):  
Viral Load ◽  
Influenza A Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Southern Brazil ◽  
Influenza A H1n1 ◽  
Epidemiological Profile

scholarly journals Coinfection of Parvovirus B19 with Influenza A/H1N1 Causes Fulminant Myocarditis and Pneumonia. An Autopsy Case Report

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 958
Author(s):  
Domitille Callon ◽  
Fatma Berri ◽  
Anne-Laure Lebreil ◽  
Paul Fornès ◽  
Laurent Andreoletti
Keyword(s):  
Viral Load ◽  
Influenza A ◽  
Acute Myocarditis ◽  
Parvovirus B19 ◽  
Fatal Outcome ◽  
High Viral Load ◽  
Viral Reactivation ◽  
Fulminant Myocarditis ◽  
Viral Interactions ◽  
Influenza A H1n1

Parvovirus-B19 (PVB19) is a frequent causative agent of myocarditis. For unclear reasons, viral reactivation can cause acute myocarditis, a leading cause of sudden death in the young. Influenza A/H1N1(2009) virus (IAV/H1N1) is known for causing flu/pneumonia, but the heart is rarely involved. Co-infections of cardiotropic viruses are rarely reported and the mechanisms of viral interactions remain unknown. A 5-year old girl had a flu-like syndrome, when she suddenly presented with a respiratory distress and cardiac arrest. At autopsy, the lungs were found haemorrhagic. Lungs’ histology showed severe bronchiolitis, diffuse haemorrhagic necrosis, and mononuclear inflammation. In the heart, a moderate inflammation was found with no necrosis. IAV/H1N1 was detected in nasal and tracheal swabs, lungs, and the heart. The viral load was high in the lungs, but low in the heart. PVB19 was detected in the heart with a high viral load. Viral co-infection increases the risk of severe outcome but the mechanisms of interaction between viruses are poorly understood. In our case, viral loads suggested a reactivated PVB19-induced acute myocarditis during an IAV/H1N1 pneumonia. Viral interactions may involve an IAV/H1N1-induced cytokine storm, with a fulminant fatal outcome. Clinically, our case shows the importance of investigating inflammatory pathways as therapeutic targets.

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