Validity of clinical case definitions for influenza surveillance among hospitalized patients: results from a rural community in North India

Influenza and Other Respiratory Viruses

Vivek Gupta⁴  Fatimah S. Dawood¹  Sanjay K. Rai³  Shobha Broor³  Rajan Wigh³  Akhilesh C. Mishra²  Kathryn Lafond¹  Joshua A. Mott¹  Marc-Alain Widdowson¹  Renu B. Lal¹ 

[1] Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA;National Institute of Virology, Pune, India;All India Institute of Medical Sciences, New Delhi, India;AIIMS-INCLEN collaborative influenza projects, The INCLEN Trust International, New Delhi, India

关键词: Case definitions;    epidemiology;    FARI;    ILI;    India;    influenza;    inpatients;    SARI;    surveillance;    validity;   

DOI  :  10.1111/j.1750-2659.2012.00401.x

来源: Wiley

【 摘 要 】

Abstract

Objective:  Clinical case definitions used for influenza surveillance among hospitalized patients vary and need systematic evaluation.

Design, setting and sample:  During July 2009–August 2011, we collected clinical data and specimens (nasal and throat swabs) from rural patients hospitalized for acute medical illnesses. Specimens were tested by rRT-PCR for influenza viruses.

Main outcome measures:  Case definitions evaluated the following: influenza-like illness (ILI: measured fever plus cough or sore throat); severe acute respiratory illness (SARI: ILI with difficulty breathing in ≥5 years, Integrated Management of Childhood Illness–defined pneumonia or severe pneumonia, or physician diagnosed lower respiratory infection in <5 years); acute respiratory infection (ARI: ≥1 of cough, nasal discharge, difficulty breathing or sore throat); febrile acute respiratory illness (FARI: fever plus either cough, sore throat, runny nose, difficulty breathing, or earache). Variants that included “reported fever” and additional sign–symptom combinations were also evaluated.

Results:  We enrolled 1043 hospitalized patients, including 257 children <5 years of age (range 1 day–86 years). Seventy-four patients tested influenza virus positive (including 28 A(H1N1)pdm09). Sensitivity(95% CI) and specificity (95% CI) for influenza infection were 78% (67–87) and 60% (57–63) for ILI (measured/reported fever); 37% (26–49) and 78% (75–80) for SARI (measured/reported fever); 82% (72–90) and 57% (54–60) for FARI (measured/reported fever); 88% (78–94) and 45% (42–49) for ARI; and 74% (63–84) and 61% (58–64) for measured/reported fever plus cough. Case definitions including only measured fever had lower sensitivity.

Conclusion:  ILI and FARI with measured/reported fever provided good balance between sensitivity and specificity among hospitalized patients. The simpler case definition of measured/reported fever plus cough is suited for field surveillance.

【 授权许可】

Unknown   
Published 2012. This article is a US Government work and is in the public domain in the USA.