Research Highlights

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  • Clinical medicine

Published online: 30 January 2008 | doi:10.1038/nchina.2008.19

Influenza surveillance: Seasonal predictors

John Fox

Introduction

© (2008) www.istockphoto.com/Stephen Uber

The World Health Organization (WHO) has issued warnings that there is substantial risk of an influenza pandemic within the next few years. Influenza surveillance can help reduce this risk by giving early detection of influenza epidemics. Because flu symptoms vary and are non-specific, laboratory surveillance, which tests for genetic and antigenic changes in patients, provides the most accurate information about viral activity. However this is expensive and time-consuming. Chit Ming Wong and co-workers at the University of Hong Kong¹ have shown that an increase in the consultation rates for influenza-like illness can be used as a reliable form of clinical surveillance to supplement laboratory surveillance.

The researchers used wavelet analysis, a complex statistical technique, to determine a possible association between the seasonality of influenza virus activity determined through laboratory surveillance and consultation rates for influenza-like illness. They found that on average, peaks in the incidence of influenza-like illness reported at general practitioners and general out-patient clinics occurred approximately four and two weeks, respectively, before isolation of influenza virus through laboratory surveillance.

Clinical surveillance of influenza-like illness using wavelet analysis may therefore prove to be a reliable indicator of changes in influenza virus activity and give insight into mechanisms of seasonal occurrence of the virus.

The authors of this work are from:
Department of Community Medicine and Department of Microbiology, University of Hong Kong, Hong Kong, China.

Reference

1. Yang, L. et al. Synchrony of clinical and laboratory surveillance for influenza in Hong Kong. PLoS ONE 3, e1399 (2008). | Article | PubMed |