Clinical, virological and immunological features from patients infected with re-emergent avian-origin human H7N9 influenza disease of varying severity in Guangdong province

PLoS One. 2015 Feb 27;10(2):e0117846. doi: 10.1371/journal.pone.0117846. eCollection 2015.

Abstract

Background: The second wave of avian influenza H7N9 virus outbreak in humans spread to the Guangdong province of China by August of 2013 and this virus is now endemic in poultry in this region.

Methods: Five patients with H7N9 virus infection admitted to our hospital during August 2013 to February 2014 were intensively investigated. Viral load in the respiratory tract was determined by quantitative polymerase chain reaction (Q-PCR) and cytokine levels were measured by bead-based flow cytometery.

Results: Four patients survived and one died. Viral load in different clinical specimens was correlated with cytokine levels in plasma and broncho-alveolar fluid (BALF), therapeutic modalities used and clinical outcome. Intravenous zanamivir appeared to be better than peramivir as salvage therapy in patients who failed to respond to oseltamivir. Higher and more prolonged viral load was found in the sputum or endotracheal aspirates compared to throat swabs. Upregulation of proinflammatory cytokines IP-10, MCP-1, MIG, MIP-1α/β, IL-1β and IL-8 was found in the plasma and BALF samples. The levels of cytokines in the plasma and viral load were correlated with disease severity. Reactivation of herpes simplex virus type 1(HSV-1) was found in three out of five patients (60%).

Conclusion: Expectorated sputum or endotracheal aspirate specimens are preferable to throat swabs for detecting and monitoring H7N9 virus. Severity of the disease was correlated to the viral load in the respiratory tract as well as the extents of cytokinemia. Reactivation of HSV-1 may contribute to clinical outcome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • China / epidemiology
  • Communicable Diseases, Emerging*
  • Cytokines / blood
  • Disease Outbreaks
  • Female
  • Humans
  • Influenza A Virus, H7N9 Subtype* / classification
  • Influenza A Virus, H7N9 Subtype* / genetics
  • Influenza, Human / diagnosis
  • Influenza, Human / epidemiology*
  • Influenza, Human / virology*
  • Male
  • Middle Aged
  • Serogroup
  • Severity of Illness Index
  • Viral Load

Substances

  • Cytokines

Grants and funding

This study was supported by Municipal Science and Technology Bureau Foundation of Guangzhou (Grant no. 2014Y2-00031), Emergency Response Project of Ministry of Science and Technology of China (Grant no. KJYJ-2013-01-05), National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant no. 2014ZX10004006). CKPM and JSMP were supported by funding by grant AoE/M-12/06 from the University Grants Committee, Hong Kong. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.