Weekly Report

Week 05 2016

Article source: Date time:2016-02-22 
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Font: Small Medium Large [print] Release: 2016-02-22 09:03:03 Submitter: YangLei hits:23


Chinese Influenza Weekly Report

(All data are preliminary and may change as more reports are received)

 

Outbreak Surveillance

During week 5(February 1-7, 2016), there were 5 outbreaks reported nationwide, 1 of them was A(H1N1)pdm09, 1 of them was B , 3 of them were mixed .

Surveillance of outpatient or emergency visits for Influenza-like Illness (ILI)

During week 5, the percentage of outpatient or emergency visits for ILI (ILI %) at national sentinel hospitals in south China was 3.0% , lower than last week and the same week of 2014 and 20153.1%4.2% and 3.1%.(Figure 1)

 


Figure 1. Percentage of Visits for ILI at Sentinel Hospitals in South China 
(2011-2016)

During week 5, ILI% at national sentinel hospitals in north China was 4.2%, higher than last week and the same week of 20154.0% and 3.0%),lower than the same week of 20145.0%. (Figure 2)

 


Figure 2. Percentage of Visits for ILI at Sentinel Hospitals in North China (2011-2016)

Virologic Surveillance

During week 5, influenza network laboratories tested 7520 specimens, of which 209227.8% were positive for influenza, influenza A and influenza B virus were 119357.0% and 89943.0%),respectively(Table 1). During week 5, the percentage of specimens that were tested positive for influenza in south China was 21.1%, which was higher than the previous week 19.4%)(Figure 3).During week 5, the percentage of specimens that were tested positive for influenza in north China was 33.3%, which was higher than the previous week 31.5%)(Figure 4).

 


Figure 3. Influenza Positive Tests Reported by Southern Network Laboratories (Week 14, 2014–Week 5, 2016)

Note: Analysis in this part was based on the test results of network laboratories. If it were not consistent with the results of CNIC confirmation, the results of CNIC confirmation were used.


Figure 4. Influenza Positive Tests Reported by Northern Network Laboratories (Week 14, 2014–Week 5, 2016)

Note: Analysis in this part was based on the result of network laboratories. If it were not consistent with the results of CNIC confirmation, the results of CNIC confirmation were used.

 

Antigenic Characterization

Since October 1nd, 2015, 106(96.4%) of the 110 (100%)A(H1N1)pdm09 viruses tested were characterized as A/California/7/2009-like; 29(34.9%) of the 83 A(H3N2) influenza viruses tested were characterized as A/Switzerland/9715293/2013 (H3N2)(EGG)-like, all of the 83(100%) A(H3N2) influenza viruses tested were characterized as A/Switzerland/9715293/2013 (H3N2)(CELL)-like; 170(98.3%) of the 173 influenza B/Yamagata lineage viruses tested were characterized as B/Phuket/3073/2013-like; 43(54.4%) of the 79 influenza B/Victoria lineage viruses tested have been characterized as B/Brisbane/60/2008-like.

Antiviral Resistance

Since October 1nd, 2015, among the influenza viruses tested by CNIC for antiviral resistance, all influenza A(H1N1)pdm09 and all influenza A(H3N2) viruses were resistant to adamantine ; all influenza A(H1N1) pdm09 A(H3N2) and B viruses were sensitive to neuraminidase inhibitors.