Malta’s Covid-19 reproduction number currently stands at 0.58, statistician Vincent Marmara told The Malta Independent on Sunday in his weekly exclusive video blog.
With 18 new cases of the virus being found over the course of last week, Marmara explained that there was a slight decrease over the previous week, when 20 cases were found. He noted that around half of the cases found in the past week were all part of the same cluster – an important factor when calculating the reproduction number of the virus.
The reproduction number of the virus is one of the key figures which countries across the world have been trying to reduce ever since the Covid-19 pandemic began. The aim for countries has been to reduce the ratio to a level of 1 – which would mean that one person would transmit the virus to one other person.
In recent days there have been several concerns that Malta’s reproduction number had crept up above 1, owing to a few days where the number of new cases found had increased.
Marmara said that the crux of the calculation of the reproduction number of on what data is considered. He said that one can take the data for the whole pandemic, or else can take the data from when there was a second spike in cases, which would present a different looking wave when isolated.
He noted that one can technically also calculate it based on recent weeks when there was a slight increase in case, hence considering that as a third wave.
Marmara explained that the technique he uses to calculate the reproduction number is used a lot in epidemiology, and combines an SIER model and a particle filter algorithm specifically design to acquire the most accurate reproduction number.
He said that if one takes the whole pandemic as a data-set, then the reproduction number will always be less than 1 due to the comparatively high number of cases that were found during the first part of the pandemic.
Therefore, for his calculation, Marmara said that he had excluded the first part of the pandemic, and taken data from when cases spiked a second time. However, the recent small increase was not considered as a new wave, as the number of new cases is still low.
He said that it is important to keep in mind that recent weeks saw the development of a cluster. This is a reference to a cluster which is now made up of 19 cases and which was found over the past two weeks.
He said that the relaxation of measures is continuing because the reproduction number remains below 1, and hence the situation is under control.
When taking into account the fact that there was such a big cluster, he said, the number of new cases in the past weeks has remained stable.
The reopening of the airport for tourism will present a new variable for the reproduction number, he said, which needs to continue to be surveyed, however he emphasised that the most important thing remains for the reproduction number to remain under control.