The spread of COVID–19 to different parts of the world caused a drastic loss of lives and economy. The people living in different geographical locations have faced a wide variety of impacts of the ailment. The geographical location, the meteorological conditions, the immunity of people as a result of the difference in the climatic conditions at different places and the different age groups are some of the major parameters which can be considered to determine the impact level of the pandemic. In this study, we have studied the variation in the number of cases of corona infection with various parameters like temperature, humidity, air quality, number of testings, population, age groups around the globe. The study then focuses on five major countries of the world to compare the variations and determine the possible reasons behind the variations in the number of cases and predict the future aspect of the disease.
The COVID–19 has spread to 210 countries and territories of the world and 2 international conveyances. The given world map shows the number of infected cases reported, the death cases and the recovered cases around the world. As per the record, the total numbers of cases of SARS-CoV–2 infection in the world till 15 April 2020 have reported to be 2,076,502 with the number of infected cases being 1,427,636 and the number of deaths reaching 138,744. The recovery rate of the patients around the world until mid-April was 78.62% with the number counting 522,122. The different regions of the world have faced a wide variety of severeness of the malady. The major reasons for variable degree of impact are the difference in the geographical locations, the meteorological parameters, the immune power of people and the different age groups. These factors are somewhere related to each other. The meteorological parameters particularly, temperature and humidity play a major role in the transmission of the disease.
Initially, the cases of infection were reported majorly from China and continued to rise until the lockdown was announced in the country which gradually reduced the further transmission of the disease by keeping people indoors. The peak of infected cases begins to rise when the infected people from the country migrated to different regions of the world while being unknown about the infection. This mass movement of people accelerated the transmission of the disease to different parts of the world thus further multiplying the number of patients. Some countries of the world acted smart and announced lockdown at an earlier stage to slow down the transmission which flattened their curve of infected cases quite early.
Countries like America which were initially taking SARS-CoV–2 infection very lightly and declared national lockdown very late even after the onset of the disease is now seeing the situation going out of hand. Delay in lockdown promoted the transmission of the disease and inflation in the number of patients to a large extent. In the cradle stage, the number of deaths was quite low. But, as the number of cases increased the death peak begin to rise due to the difficulty in the proper treatment of the people. This is a major reason for the rise in the peak in the last week of March. The age factor also played a major role in increasing the death poll. The people in older years faced difficulty in fighting with the disease due to weak immunity and therefore survival rate is low. The places with high air pollution particularly PM2.5 have reported a higher number of deaths due to damaged respiratory system because it is an airborne disease which further destroys the respiratory tract and lungs(Suresh A etal., 2020) Cold weather and humidity promote the transmission of the pandemic as it increases the life of the virus and due to low-temperature people prefer being close to each other to prevent heat loss.
3.1 Trend of COVID–19 infection in the world with time
The numbers of cases reported were quite low initially in January and were majorly from China. The mass movement of people to and from China gradually increased the number of patients all over the world due to the transmission of the disease. The transmission at the community level multiplied the length of the chain of viral infection which resulted in an increase in the number of cases at a higher rate. The countries with colder climatic conditions have reported a higher number of patients as compared to the countries with warmer climatic conditions. The countries in which lockdown was announced late have reported a drastic increase in the number of cases within a few weeks.
In January, the maximum number of deaths were from China for it being the epicentre of the malady. The number of deaths was very low at the earlier stage as the number of infected cases was low and the patients were able to receive proper treatment. Maximum deaths were reported from the regions with higher air pollution levels which already destroy the respiratory system of humans. The sudden increase in the number of patients from April resulted in a simultaneous increment in the number of deaths due to difficulty in proper treatment. The old age people due to low immunity have low survival rates and thus most of the reported deaths constituted them.
The earlier months of the year have seen a lower recovery rate because the proper treatment for the disease was unknown. With the end of February, the recovery rate started to increase due to the discovery of an alternative treatment for the disease. The countries with warmer climatic conditions have reported a higher number of recovery cases due to strong immunity of people. The month of April has seen the highest number of recovery cases till now due to high temperature which has weakened the impact of the virus. The people in the younger years of age have higher chances of recovery than the old age people.
3.2 Comparison of the infected, death and recovered polls of five major countries.
Lockdown and social distancing have served as major weapons in controlling the severity of the pandemic. The countries which announced earlier lockdown and social distancing were able to control the further spread of the disease (Srivastava, A etal., 2020) The spread of disease in China could only be stopped by the announcement of lockdown in the month of January. The mass movement of people to different parts of the world has led to the transmission of the ailment from China to the world. In Italy, the sudden increase in the cases could be controlled by lockdown only. The colder countries have reported higher number of cases because low temperature and humid conditions promote the spread of the SARS-CoV–2 virus. USA due to very late lockdown has reported tremendous increase in the number of cases. In India, the announcement of national lockdown at the very onset of disease helped to reduce the transmission of malady to a great extent. The earliest lockdown in Morocco helped the country to remain safe in the pandemic.
The announcement of lockdown helped to gradually control the increase in the number of cases which helped in successful treatment of people and thus reducing the number of deaths. India and China were able to reduce the number of deaths. The people living in India due to their strong immunity as a result of warm climatic conditions are able to fight the disease which reduced the number of death cases. The high number of patients in Italy and United States of America due to difficulty in proper treatment have a high death rate. Morocco due to early lockdown has a positive sign of zero deaths.
China has reported a high increase in the number of recovered cases in the month of March due to control over the continuously increasing pandemic in the country. USA reported an increase in the recovery rate in the country after the use of hydroxychloroquine drug. The people of India due to their strong immunity recovered quickly from the disease. The use of hydroxychloroquine drug also increased the recovered rate in Italy. Early lockdown protected Morocco from this malady.
Date
|
Predicted Cases
|
Actual Cases
|
01-05-2020
|
3363800
|
3394153
|
02-05-2020
|
3444300
|
3477488
|
03-05-2020
|
3524800
|
3559748
|
04-05-2020
|
3605290
|
3639330
|
05-05-2020
|
3685783
|
3720577
|
06-05-2020
|
3766272
|
3815902
|
07-05-2020
|
3846762
|
3912156
|
08-05-2020
|
3927252
|
4009284
|
09-05-2020
|
4007741
|
4098097
|
10-05-2020
|
4088231
|
4337436
|
Table 1: Predicted and the Actual number of cases
Fig.8 interprets the prediction of SARS-CoV–2 infection round the globe using machine learning and an additive regression model was used to predict the spread. The study was carried out by using the dataset from Kaggle and we predicted the epidemic spread based on the previous data which is collected until 26th April 2020. Table 1 gives the values of the number of predicted cases and the number of actual cases from 1st May 2020 to 10th May 2020. As per our prediction, the number of confirmed cases till April end is 32,83,334 and will reach to 40,88,231 on 10 May 2020. On correlation of the number of predicted cases with the actual number of cases the Pearson correlation coefficient value comes out to be 0.98 which shows perfectly positive correlation therefore proving the accuracy of data.