Question

Below is a quote from Dr. Badu Sarkodie (Director, Public Health of the Ghana Health Service) in a response to a question of where Ghana is on the curve on the COVID-19 curve, during the ministry of information press briefing on 5th May, 2020 “…The best way to assess this curve is to use the daily case incidence. Thus, everyday how many cases we do record and put them on a chart and then clearly you get the case load being built, reach its peak and get to a decline and finally to zero. The next best proxy data for this should be the date for onset for symptoms. If you do not have that, the next line will be the date the various people reported to the facility (i.e. the date they were seen at the facility). The next to that will be the date the sample was taken. If you look how Ghana started attacking the virus, waiting not to chase the virus but to face it directly, by doing enhance contact tracing, there are a lot of people that we tested without they having symptoms. Therefore, if we were using the daily case incidence with onset of symptoms, then we will have a challenge. So clearly the best data we are using for this bell-shaped curve is the data for the date samples were tested….” (a) State the three occurrences for measuring incidence of illness stated in the quote above. [3 marks] (b) (i) State the measure of occurrences that are being used to measure incidence of COVID-19 in Ghana according to the quote above. [3 marks] (ii) Why is this measure preferred to the other measures of occurrence? [4 marks]

Answer 1

“…The best way to assess this curve is to use the daily case incidence. Thus, everyday how many cases we do record and put them on a chart and then clearly you get the case load being built, reach its peak and get to a decline and finally to zero. The next best proxy data for this should be the date for onset for symptoms. If you do not have that, the next line will be the date the various people reported to the facility (i.e. the date they were seen at the facility). The next to that will be the date the sample was taken. If you look how Ghana started attacking the virus, waiting not to chase the virus but to face it directly, by doing enhance contact tracing, there are a lot of people that we tested without they having symptoms. Therefore, if we were using the daily case incidence with onset of symptoms, then we will have a challenge. So clearly the best data we are using for this bell-shaped curve is the data for the date samples were tested….”

(a) three occurrences for measuring incidence of illness stated in the quote above

1. the date for onset for symptoms,
2. the date the various people reported to the facility,
3. the date the sample was taken and tested.

(b) (i) According to the quote above, data for the dates when samples were tested (this data is more reliable as it is noted by the tesing facility) is used as the measure of occurrences of incidence of COVID-19 in Ghana .

(ii) This measure is preferred to the other measures of occurrence beacuse people who do not have symptoms have also tested positive.

(Reporting to facility does not provide confirmation of case being positive. Only way to say with confirmation that the case is positive is after the test, as symptoms may or may not be seen.)