Sunday, 27 March 2016

Colombia posts new data on Zika...

In the latest epidemiological report, which includes data on Zika virus disease (ZVD; week #11), has been produced by the excellent Colombian National Institute for Health team.[1] It's a small one this week - only 94 pages.

We see a new format to the graph which more clearly depicts how many of the ZVD cases are in fact only suspected (grey) of being Zika virus infections. 

Very few ZVD cases are confirmed (red) as being Zika virus infections and it appears as though no new laboratory confirmed cases have occurred in the past 7 reporting weeks. 

I've looked at the numbers used in this graph a little differently by calculating the differences between weekly cumulative reported tallies of laboratory confirmed cases. We can see that new confirmations seem do still be occurring. I presume the weeks with zero confirmations just reflect a delay in getting the lab testing data to the reporters on time.

I'm not sure why they are not plotted in red. Perhaps someone familiar with this report can clue me in?
  • This Report (#11): 2,361 (+6 from previous week)
  • Report #10: 2,355 (+265 from previous week)
  • Report #9: 2,090 (+0 from previous week)
  • Report #8: 2,090 (+478 from previous week)
  • Report #7: 1,612 (+0 from previous week)
  • Report #6: 1,612 (+108 from previous week)
  • Report #5: 1,504 (+173 from previous week)
  • Report #4: 1,331 (+281 from previous week)
  • Report #3: 1,050 (+252 from previous week)
  • Report #2: 798 (+22 from previous week)
  • Report #1:  776
In graph form, those values look like...
So total suspected cases - the bulk of what is being reported by Colombia in relation to ZVD - are still declining, however the number of confirmed ZVD cases are not showing that same consistent downward trend. What does that mean?