H7N9 Cases in China Continue to Increase


On January 24th,  I posted a graph plotting the growth rate of H7N9 cases in China. Based on the trend (link), I estimated that between 30-40 cases of H7N9 would be reported in the coming weeks. Using current data for onset dates (through February 4, 2014), an updated plot indicates a total of 39 H7N9 cases for both Week 4 and Week 5. More than 30 H7N9 cases (without onset dates) have already been reported for Week 6. If the number of cases continues to increase at an exponential rate, more than 100 people a week will be reported as H7N9 cases by Week 7 or Week 8.  If the rate continues at its current pace, China will be experiencing an H7N9 epidemic within the near future.

Current graph of H7N9 cases through Week 5.

Comments

Post a Comment

Popular posts from this blog

The Spread of H7N9 in China

Image
Hong Kong’s Centre for Health Protection weekly Avian Influenza Report published on August 1 is the first weekly report in 2017 with no reported human H7N9 cases from the Republic of China. The last weekly Avian Influenza Report with no reported H7N9 cases was previously published on December 1, 2016. In the intervening 8 months more than 750 human H7N9 cases were reported from China. This is an extremely large number of human infections in a short time period. Human cases of H7N9 were first identified and reported from China late in the 2012-2013 influenza season. Since then, there have been several waves of human H7N9 infections generally corresponding with seasonal influenza outbreaks. Although human cases of H7N9 have been sporadically reported over the past four years, the 750+ cases reported in the last eight months represent about 49% of all reported H7N9 cases. To date, all human infections have occurred in China although some individuals infected in China were identified in...
Read more

What is happening with H7N9 in China?

Image
Based on illness onset dates from January through the end of November 2016, China officially reported about 115 human cases H7N9 infection. Over the course of several days in early January 2017, China notified the World Health Organization of more than 100 additional human cases of H7N9 presumably having been infected in December 2016. It appears that almost as many people were infected in December as all of the preceding months in 2016. The graph below shows the distribution of H7N9 cases by onset date where available and then by reporting date. The graph clearly shows the large increases in the number of infected individual reported recently. Should this increase be a cause for alarm? Increases in human cases of avian influenza always increase the risk for sustained human to human transmission of the disease. Reviewing the minimal data that is available for the 107 recent cases reported by China, some observations can be made. About 36% of these new cases are female and 67% are male...
Read more

The Current Status of the 2016 – 2017 H7N9 Outbreak in China as of March 1, 2017 (Is the Outbreak Just About Over?)

Image
For the purposes of this discussion the current outbreak of H7N9 began November 1, 2016 and is still continuing. More than 460 human cases have been reported from China. Of these cases, 426 have symptom onset dates reported by the World Health Organization (WHO) for cases with onset before February 10, 2017. Graphing the symptom onset dates for these H7N9 cases provides a count of new daily infections of H7N9. Also included in the graph are the remaining 37 cases based on their reporting date rather than symptom onset date which is not available at this time for cases reported after February 11. The graph, an epidemic curve, shows that the greatest number of H7N9 infections occurred on February 1, 2017, based on a five day moving average. Even if The 37 cases for which symptom onset dates are not available are distributed over the 17 days following February 11, they are an insufficient number of new cases to exceed the five-day moving average which peaked above 10 cases per day on Feb...
Read more