An opinion piece by UM lecturer, Dr Vincent Marmara within the Faculty of Economics, Management & Accountancy 

The reproduction rate of any infectious disease is very volatile during the first stages. 

In fact, in my PhD study, 'Prediction of infectious disease outbreaks based on limited information' (2016) I showed that the reproduction rate might vary substantially during the first stages, following which it will settle down after a couple of days/weeks. Covid-19 is an extraordinary case where countries are taking a number of drastic measures during the first weeks of the pandemic. Hence, the reproduction rate is changing continuously for different countries. If no measures had to be taken in China, the number of infected people would have run into millions and even the number of deaths. 

However, since drastic measures were taken (in China) the reproduction rate was lowered substantially; hence the internal transmission is now close to zero. Italy is a different case. Decisions were taken late; hence the reproduction rate was already substantially high when the decisions were taken. Hence, when the decision of lockdown was enforced, already substantial number of people were infected. In Malta, taking into account the progression of the disease, decisions were taken before those taken in Italy. 

Thus, Malta's reproduction rate is lower than in Italy. This most probably will produce a lower number of infected individuals in Malta, taking into account the size and ratios of both countries. All this information is pivotal when applying the mathematical modelling techniques, as the models such as the 'SEIR models' and other techniques are dependent on the reproduction rate of the disease. Hence, if models in Malta had to be applied at the beginning of the epidemic thousands of people could have been infected. 

However, measures were taken, and thus the reproduction ratio decreased and substantially a lower number of people will be infected. Furthermore if more measures are taken, the reproduction ratio needs to be re-calculated and hence the new number of predicted infected cases and the number of deaths need to be re-calculated once again. 

If people do not follow authorities instructions, and measures are not enforced, this would result in a higher reproduction rate and hence hundreds of more people will get infected. This would result in a substantial number of deaths as well.

Disclaimer: Opinions and thoughts expressed within this article do not necessarily reflect those of the University of Malta.