1. Portada
  2. Notificación de casos de covid-19 en la Comunidad de Madrid
  3. Notification delays

Notification delays

The efficacy of a public health surveillance mechanism for covid-19 rests on the timely compilation of reliable information on contagion growth so that the competent authority can promptly design and implement fitting responses to confront the current situation. This means that positive covid-19 cases should be notified within 24–48 hours, that is, the final count of positive cases on any given date should be known two days later at the most. In Spain, the government document (in Spanish) titled Estrategia de detección precoz, vigilancia y control de COVID-19 emphasized the importance of early notification. This was particularly relevant during the so-called de-escalation period (between May 4th and Jun 21st, 2020) in which the current epidemiological situation critically determined the suitability of transiting to the next phase (see the government document Plan para la transición hacia una nueva normalidad, in Spanish).

Figure 1 shows a prototypical example of the pace at which CM notifies positive covid-19 cases. This sample figure illustrates the notification of positive cases occurred on May 14th, 2020, when CM was in phase zero of the de-escalation stage (which started on May 4th; marked with a pink arrow along the horizontal axis in Figure 1) and looking forward to transiting to the next phase. The report published by CM on May 15th, 2020 declared 49 positive cases on May 14th. Reports subsequently published along the next few days increased the count on May 14th up to a plateau at around 270 cases by June 21st (the date of expiration of the first state of alarm declared on Mar 14th, which also put an end to de-escalation; marked with a green arrow along the horizontal axis in Figure 1). Since then, subsequent reports published by CM slowly but relentlessly assigned more and more positive cases to May 14th, up to a total of 715 cases declared in the report published on Dec 24th, 2020. Past that date, the count of positive cases assigned to May 14th remained virtually unchanged in subsequent reports.

 

 

Figure 2 shows analogous graphs for each and all days from Mar 1st, 2020 up to the date on which this page was last updated. This series of graphs reveals four distinctly different periods as regards the pace of notification:

  • Between Mar 1st and Apr 10th, 2020. Over this period, the daily count of cases stays virtually invariant since the first report published by CM on May 13th, 2020. Yet, the last few days in this period begin to show signs of a pattern similar to that in Figure 1, which characterizes the second period described next.
  • Between Apr 11th and Dec 24th, 2020. Over this period, the count of cases on any given date as declared for the first time in the report published the next day increases progressively in subsequent reports with the stereotypic pattern illustrated in Figure 1.
  • Between Dec 25th, 2020 and Feb 15th, 2021. Over this period, the count of cases first declared for any given day increases in the 5–10 reports published subsequently, remaining relatively stable afterwards.
  • From Feb 16th, 2021 onward. Over this period, the count of cases also increases and then stabilizes across the next few reports published subsequently, but the counts increase again in the reports published on and after mid-April 2021.

Figure 3 shows the overall pace of delayed notifications since CM began to publish daily reports on May 13th, 2020. The total number of cases on each date is taken for these computations from the most current CM report available on the date in which this page was last updated. For each date, the height of the red bar indicates the percentage of cases that was immediately acknowledged, the height of the yellow bar indicates the percentage acknowledged 7 days later, the height of the blue bar indicates the percentage acknowledged 14 days later, and the height of the gray bar indicates the remaining percentage (up to 100%) that was acknowledged after 14 days had already gone by. Across consecutive updates of Figure 3, the gray area gains ground due to the continuous addition of old cases in each new report published by CM.