Pandemic Influenza (H1N1) 2009 Pneumonia: CURB-65 Score for Predicting Severity and Nasopharyngeal Sampling for Diagnosis Are Unreliable

Abstract

BackgroundFrom the first case reports of pandemic influenza (H1N1) 2009 it was clear that a significant proportion of infected individuals suffered a primary viral pneumonia. The objective of this study was twofold; to assess the utility of the CURB-65 community acquired pneumonia (CAP) severity index in predicting pneumonia severity and ICU admission, and to assess the relative sensitivity of nasopharyngeal versus lower respiratory tract sampling for the detection of pandemic influenza (H1N1) CAP.MethodsA retrospective cohort study of 70 patients hospitalised for pandemic influenza (H1N1) 2009 in an adult tertiary referral hospital. Characteristics evaluated included age, pregnancy status, sex, respiratory signs and symptoms, smoking and alcohol history, CURB-65 score, co-morbidities, disabling sequelae, length of stay and in-hospital mortality outcomes. Laboratory features evaluated included lymphocyte count, C-reactive protein (CRP), nasopharyngeal and lower respiratory tract pandemic influenza (H1N1) 2009 PCR results.ResultsPatients with pandemic (H1N1) 2009 influenza CAP differed significantly from those without pneumonia regarding length of stay, need for ICU admission, CRP and the likelihood of disabling sequelae. The CURB-65 score did not predict CAP severity or the need for ICU admission (only 2/11 patients admitted to ICU had CURB-65 scores of 2 or 3). Nasopharyngeal specimens for PCR were only 62.9% sensitive in CAP patients compared to 97.8% sensitivity for lower respiratory tract specimens.ConclusionsThe CURB-65 score does not predict severe pandemic influenza (H1N1) 2009 CAP or need for ICU admission. Lower respiratory tract specimens should be collected when pandemic (H1N1) 2009 influenza CAP is suspected.

Clinical characteristics of 75 pandemic H1N1 influenza patientsfrom Turkey; risk factors for fatality

“…In the literature, there are rare studies evaluating pneumonia severity with CURB-65 scoring in order to predict the severity of pneumonia with H 1 N 1 infection. No correlation was found between CURB-65 scoring and the severity of pneumonia in their study (24). In the current study, we showed that both CURB-65 scores and serum D-dimer levels were correlated with the severity of pneumonia in H 1 N 1 -positive patients.…”

TGF-β Blood Levels Distinguish Between Influenza A (H1N1)pdm09 Virus Sepsis and Sepsis due to Other Forms of Community-Acquired Pneumonia

“…Three of the most common clinical scores-CURB-65, APACHE II, and SOFA-were evaluated, all of which have been used to evaluate the severity of viral and bacterial CAP (15,19,31). Recently, studies demonstrated that CURB-65 is not a good predictor of the severity of pneumonia caused by influenza A (H1N1)pdm09 (29,36). In a previous study, the authors demonstrated that the SOFA score was the best severity predictor in CAP cases, including those patients infected with influenza A (H1N1)pdm09 (32), similar to this study.…”

Current Best Practices for Respiratory Virus Testing

“…The use of nasal or oropharyngeal swab samples is an area of active investigation, but routine use of these specimens is not recommended at present because of concerns about sensitivity for virus detection in some studies (32,38). Lower respiratory tract samples, such as induced sputum, protected brush samples, and bronchial alveolar lavage (BAL) samples, may be necessary, as several studies have demonstrated that in some severe cases of influenza, upper respiratory tract samples are negative while lower respiratory tract samples are positive (29,37,53 (2,8,20,27).…”