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. 2014 Sep;20(9):1535-40.
doi: 10.3201/eid2009.140424.

Asymptomatic, mild, and severe influenza A(H7N9) virus infection in humans, Guangzhou, China

Zongqiu Chen, Hui Liu, Jianyun Lu, Lei Luo, Kuibiao Li, Yufei Liu, Eric H Y Lau, Biao Di, Hui Wang, Zhicong Yang, Xincai Xiao

Asymptomatic, mild, and severe influenza A(H7N9) virus infection in humans, Guangzhou, China

Zongqiu Chen et al. Emerg Infect Dis. 2014 Sep.

Abstract

Targeted surveillance for influenza A(H7N9) identified 24 cases of infection with this virus in Guangzhou, China, during April 1, 2013-March 7, 2014. The spectrum of illness ranged from severe pneumonia to asymptomatic infection. Epidemiologic findings for 2 family clusters of infection highlight the importance of rigorous close contact monitoring.

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Figures

Figure 1
Figure 1
Weekly number of confirmed influenza A(H7N9) cases detected by real-time reverse transcription PCR, percentage of pneumonia patients with pneumonia of unknown etiology (PUE), and percentage of patients with influenza-like illness (ILI) tested for influenza A(H7N9), Guangzhou, China, April 1, 2013–March 7, 2014. For PUE and ILI surveillance in Guangzhou, laboratory testing for influenza A(H7N9) virus using real-time reverse transcription PCR was implemented in week 14 of 2013 (April 1, 2013). ILI surveillance was expanded to 19 sentinel hospitals in week 44 (November 2013), according to the requirements of the public health authority of Guangdong Province after 4 confirmed influenza A(H7N9) cases were reported in Guangdong.
Figure 2
Figure 2
Timeline of illness for 2 family clusters of persons with confirmed influenza A(H7N9) virus infection, Guangzhou, China, 2014. ICU, intensive care unit; rRT-PCR, real-time reverse transcription PCR.
See this image and copyright information in PMC

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