While COVID-19 is reported to have occurred in China in November or December 2019, the adverse impact of COVID-19 was felt all over the world, with confirmation to have spread to Italy on January 31, 2020, when two Chinese tourists in Rome tested positive for the virus. It was confirmed to have spread to Spain on January 31, 2020, when a German tourist tested positive for COVID-19 in La Gomera.
It was first confirmed to have spread to the United States in January 2020. As of March 31, 2020, the U.S. has the most confirmed active cases in the world and ranked third in the number of total deaths from the virus.
In India, a populous country with high density of population per kilometer area, the virus was reported to have been noticed in late February / early March 2020.
Limited availability of data
Globally, the reliable data on COVID-19 spread is available only for two months (February and March 2020). Obviously the available data for making projections for the future scenario is very limited and inadequate.
While gradually the virus has spread all over the world at various growth rates — and with the reason for the original occurrence of the virus still to be conclusively ascertained and the appropriate drug/vaccine for treating the virus still being debate — the astrologers and speculators are giving various explanations and theories on how long the COVID-19 will persist and are suggesting various ways for ending the spread of horrid virus.
It appears that very few people are taking such estimates seriously but looking at the figures more with curiosity and some with vague belief.
Mathematical model for projections
Projections based on mathematical models are being done based on information technology and computer modeling, for which the basic data are obtained from the past experience.
Several agencies all over the world are now making COVID-19 projections based on mathematical models.
There is no doubt that a mathematical model could be a reasonably acceptable methodology from a technical view point, with the past data being used to project the future data with firm formula.
Is mathematical model for COVID-19 projections reliable?
Many people around the world are looking seriously at the figures relating to the growth rate of virus spread and number of deaths that could occur, projected by experts based on mathematical models.
Based on the analysis of the available data over two months , the analysis based on mathematical model has pointed out that the elderly population could be the most affected by the virus and human to human physical contact is the fundamental reason for it’s spread. Further, a number of agencies have come out with vastly varying projections with regard to number of people who would be infected and number of deaths that would happen.
It appears that the mathematical models for projecting the future scenario for COVID 19 does not consider several factors such as the following:
- While the methodology of mathematical models to project the data need not be questioned, the issue is as to whether the limited data available for the short period of two months are adequate to project the scenario for the next two or three months. While it is true that experts making the mathematical models have only two months data available to them, it needs to be recognized that due to inadequate data, mathematical analysis of the future scenario projection may prove to be extremely misleading
- Several traditional medicines and food habits have been suggested and are also being used by people in the post COVID-19 scenario, which might have been useful in preventing the people from being infected with the virus. No allowance has been given for the success or otherwise of this recently emerging practice. Therefore, the projection that growth would happen similar to the past pattern may not be appropriate.
- Food habit and immunity level of individuals and the climate and seasonal conditions in which people live can have a decisive impact on the spread of the virus. After awareness about COVID 19, several people could have changed food habits, life style. Seasonal conditions could change in the coming months. Therefore, the data of last two months may not be appropriate for the future months. It appears that this aspect has not been considered while making the mathematical model, which would be inaccurate in the absence of taking note of the changing life style and conditions in individual countries.
- The epicenter of the virus certainly was China and the Chinese government has not cared to share the authentic data with the world. In the absence of the data from China which claims to have solved the problem now, can the projection for future be reliable? No experts doing the mathematical model appear to have pointed out this handicap in arriving at the future scenario.
- One more aspect is that while this COVID 19 has come from nowhere, it may suddenly vanish due to any reasons unforeseen or not understood at present by the experts. In this connection, the experience gained during the earlier SARS virus spread which did not last long, should be remembered by the mathematical model experts. This possibility does not appear to have been taken into account while making the projections.
Need for sensitivity analysis under alternate conditions
While it is usual practice to conduct sensitivity study under various alternate conditions while making projections based on mathematical model, there is no indication that such sensitivity studies have been duly conducted and publicized.
If it has been done, only the alarming scenario has been highlighted to the people.
Is the mathematical model for future projection of COVID-19 needed?
The mathematical models based on short term data and set formula is leading to alarming conclusions, creating shivers in the mind of the people all over the world.
It is high time that the limitations of the mathematical models for making projections should be recognized and the fact that the conclusion of the mathematical models could be misleading should be duly kept in mind by the world community.
Let the world continue the battle against COVID 19 by social distancing at present and development of drugs/vaccine in the course of time and as early as possible.
Mathematical models may satisfy the curiosity of the people and the news hungry media but the world community can do without it.