Enhanced Diagnosis of Pandemic (H1N1) 2009 Influenza Infection Using Molecular and Serological Testing in Intensive Care Unit Patients with Suspected Influenza

Abstract

During the 2009 outbreak of pandemic (H1N1) 2009 influenza (pH1N1) in Australia, acute and convalescent serum specimens were collected from 33 patients with severe respiratory disease admitted to intensive care units. Using hemagglutination inhibition of pH1N1, 29 paired serum samples showed significant increases in specific antibody titers. Of these 29 patients, 18 had pH1N1 RNA detected by routine nucleic acid testing. These results indicate that up to one-third of pH1N1 cases may not have laboratory confirmation of infection unless serological testing is included for suspected cases.

The Accuracy of Influenza Diagnosis

“…During the outbreak of pandemic H1N1 influenza in 2009, serological test results confirmed influenza infection in 29 of 33 adult patients who had an illness consistent with influenza in intensive care units, whereas sensitive nucleic acid test results were positive in only 18 of 33 patients. 3 Our findings support those presented by Talbot et al 1 of a high sensitivity (80.8%) of clinical diagnosis. However, we suggest that, to increase the sensitivity of laboratory diagnosis and derive an accurate measure of the specificity of clinical diagnosis, serological testing must be included in any algorithm used for the diagnosis of influenza.…”

Infections with the 2009 H1N1 influenza virus among hematopoietic SCT recipients: a single center experience

“…Similarly, the number of HSCT recipients diagnosed to have the 2009 H1N1 influenza may have been under estimated as the RT-PCR test might not detect all patients with influenza and serology might not be useful in HSCT patients. 31 In addition, optimization of antiviral dosing and duration was not possible in our study because of the unavailability of quantitative virology. Likewise, the exact number of patients who had lower airway disease could not be accurately estimated as not all patients had chest radiographs performed at the time of diagnosis.…”

Use of Multiple Imputation to Estimate the Proportion of Respiratory Virus Detections Among Patients Hospitalized With Community-Acquired Pneumonia

“…Bacterial and viral pathogens can cause pneumonia and can be detected using a broad range of diagnostic tests. However, there is no true “gold standard” for etiology determination, because currently available diagnostic tests for respiratory pathogens have well known limitations [3–5]. Real-time polymerase chain reaction (PCR) assays are most commonly performed on respiratory specimens in etiology studies, because they have improved sensitivity and turnaround time for respiratory virus detection relative to culture [6–10].…”

“…Real-time polymerase chain reaction (PCR) assays are most commonly performed on respiratory specimens in etiology studies, because they have improved sensitivity and turnaround time for respiratory virus detection relative to culture [6–10]. Although not timely, serology may capture infections even if a virus is not sufficiently present to be detected by PCR in respiratory specimens; thus, acute and convalescent (paired sera) serology results can increase the diagnostic yield for respiratory viruses in CAP studies [3, 4, 11–13]. However, even in the research setting, paired sera are not always available from each patient, particularly because convalescent serology requires specimen collection posthospital discharge or death.…”