Epidemiology of COVID-19 scenario in India

There was an outbreak of a new Coronavirus infection in Wuhan, Hubei Province, China in late December 2019, which caused acute respiratory syndrome of unknown etiology. The World Health Organization (WHO) named the viral causal agent as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV2) or COVID-19, and declared this infection as a pandemic on the 11 th of March, 2020. The first case of COVID-19 infection in India was reported on late January, 2020, and since then the numbers of confirmed cases have been increasing; thus the government had announced total lockdown of all activities. Most people infected with the COVID-19 virus experience mild to moderate respiratory illness, and recover without the need for special treatments. The elderly people and those with medical problems such as; cardiovascular disease, diabetes, chronic respiratory disease and cancer; are more likely to develop severe illness. Globally, corona virus cases rose to more than 500,000 for the first time on the 27 th of October, 2020. Within two weeks and since 30 th of October, 2020, COVID-19 cases had risen by almost 25 %, and about 400,000 daily cases were reported worldwide. The United States (US) was leading the global corona virus crisis with 8.9 million recorded infections and nearly 228,000 deaths worldwide. Asia had surpassed 10 million infections of the new corona virus on the 31 of October, 2020, and India reported an average of 48,000 cases daily with a total of 8 million cases. The aim of this review was to explore the epidemiological prevalence of COVID-19 in India along with age and gender stratified prevalence of this viral infection.


Introduction
Reports of the spread of a new viral infection were recorded from Wuhan, China in the late December, 2019; named as coronavirus causing acute respiratory syndrome. According to Balogun, (2020), the World Health Organization (WHO) declared this viral infection as pandemic on 11 th of March, 2020; naming it as Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV2) or COVID-19. In India, the first case of this viral pandemic was reported on the 30 th of January 2020; originating from China (Zhang, 2020).
Coronavirus disease  is an infectious disease that can affects either the upper respiratory tract or the lower respiratory tract depending on the severity of the virus. A recent study conducted by Jin et al., (2020) reported that most people infected with the COVID-19 experience mild to moderate respiratory illness and recover without the need for special treatments. The epidemiological pattern of COVID-19 suggests an incubation period of 5-14 days, which can vary accordingly. Metintas, (2020) revealed that the elderly and those people suffering from medical illness including; diabetes, cardiovascular diseases, chronic respiratory diseases and\ or cancer are more sensitive to severe illness. The objective of this study was to explore the epidemiological prevalence of COVID-19 infection in India.

Risk of COVID-19 infection
The COVID-19 can infect peoples of all ages; though adults are more likely to be infected than the children. According to the study conducted by Laxminarayan et al., (2020), the children were reported to have mild respiratory symptoms and they rarely show mortality from this disease. However, Metintas, (2020) highlighted that the risk of severe infection is several times higher among the older people and those suffering from medical illness.

COVID 19-symptoms
COVID-19 affects people in various ways; however, most infected people develop mild to moderate illness and heal without hospitalization. Recently, Sharma and Sharma, (2020) reported the most common symptoms include; fever; headache, tiredness, dry cough, sore throat, aches and pains, loss of smell and\or taste, diarrhea and skin rashes. Meanwhile, problems during inhalation or shortness of breath, chest pain and loss of smell or taste necessities immediate medical help. Healthy people with mild symptoms should quarantine at home. Laxminarayan et al., (2020) revealed that usually it takes about 5-6 days for someone infected with the virus to show disease symptoms, which may extend to 14 days. According to Balogun, (2020), the most common abnormalities in hospitalized patients diagnosed with pneumonia include; leukocytosis, leucopenia and lymphopenia, in addition to an elevated liver enzymes. Additional abnormalities may include thrombocytopenia; neutrophilia, decreased albumin and hemoglobin, and renal impairment. Furthermore, the pulse oximetry may reveal low oxygen saturation (SpO 2 < 90 %). McIntosh et al., (2020) reported that in chest X rays; unilateral lung infiltrates were found in 25 % and bilateral lung infiltrates were recorded in 75 % of COVID-19 patients.

Worldwide distribution of COVID-19 cases
According to WHO, at the 14 th November, 2020; globally there had been 53,164,803 confirmed cases of COVID-19 including 1,300,576 deaths, and about 220 countries were affected (Pan et al., 2020), as shown in Table ( (Laxminarayan et al., 2020), as presented in Table (2).  The source of these data was: Jin et al., (2020)

COVID-19 in South Asia
The most affected country by COVID-19 in south Asia was India (8,773,479), whereas the least affected
The south-western Indian state of Maharashtra reported the highest number of active coronavirus cases (COVID-19) recording over 84 000 cases as of the 12 th November, 2020, followed by Kerala and Delhi with relatively lower recorded mortality rates (Sharma and Sharma, 2020). The gap was reducing steadily with the United States (US), which is the country with the highest recorded coronavirus cases in the world; compared to the rate with which India was adding numbers. Moreover, it was expected that India will overtake the United States, according to the recent study conducted by Lipsitch et al., (2020).

Gender distribution
Data from the Ministry of health and family welfare (MOHFW), India, revealed higher males predilection over females. Referring to the distribution of gender; India's figure matched up to the international pattern, where 76 % of all cases in India were males and 24 % were females. This was also reflected to the rate of fatalities in which 73 % fatalities were recorded among men, and 27 % among women (Sharma and Sharma, 2020).

Age distribution of COVID-19 positive cases
Recently, Sharma and Sharma, (2020) reported that 47 % of COVID-19 cases were less than 40 years of age; 34 % were between 40-60 years, and 19 % were above 60. It is important to read and analyse these data in light of the India's massive young population and life expectancies of 69 years, as highlighted by Jin et al., (2020).

Age distribution of fatalities
According to Berghiche, (2020), about 7 % of COVID-19 fatality cases were less than 40 years of age, 30 % were in the age group of 40-60 years, and 63 % were above 60.

Age distribution linked to co-morbidities
In terms of fatalities linked to co-morbidities; 86 % of deaths recorded in India had significant comorbidities such as; diabetes, hypertension, chronic kidney and heart diseases. India had a massive crisis of lifestyle linked diseases, and unfortunately also had tag of diabetes and heart diseases capital of the world, as revealed by Jin et al., (2020). Moreover, recent study of Sharma and Sharma, (2020) added that the number of young people suffering from these co-morbidities, which was reflected in the numbers of deaths (37 %); were among people below age of 60 years.

Routes of spread
COVID-19 spreads easily from person to person mainly through the following routes highlighted by Park et al., (2020): • Among people who are in close contact with one another (within 6 feet).
• Through respiratory droplets produced when an infected person coughs; breathes, sneezes, talks or sings.
• Respiratory droplets cause infection when they are inhaled and\or deposited on the mucous membranes, such as those lining the inside of the mouth and the nose.
• People who are infected but do not show symptoms (latent infection) can also spread the virus to each other's.

Washing the hands
Wash your hands carefully with soap and water for at least 20 seconds especially after being in a public place, or after blowing the nose, sneezing or coughing. It's especially important to wash the hands; • Before preparing food or eating; • After blowing the nose, sneezing or coughing; • After using the restroom; • Before touching your face; • After handling the mask; • After leaving a public place; • After touching animals or pets; • After caring for sick somebody If soap and water are not readily available, you must use a hand sanitizer containing at least 60 % alcohol (Adhikari et al., 2020). Avoid touching the nose, the eyes and\ or the mouth with unwashed hands (Lipsitch et al., 2020).

Avoid close contact
Avoid close contact with people who are sick inside the home. You have to maintain 6 feet between the sick person and the other household members. Leave a distance of at least 6 feet between you and the people who are not in your household (Park et al., 2020).

General precautions
-Cover your nose and mouth with a mask when you are among the others.
-Monitor your health daily, through being alert for COVID-19 infection symptoms such as; cough, fever and shortness of breath (Balogun, 2020).

Limitations of this study
1. The data were collected from variable sources, so might not represent the exact figures.
2. As huge populations were affected, so there might be no reported cases such as the asymptomatic cases, who we don't recognize their infection.

Conclusion
The first case of COVID-19 in India was reported on the 30 th of January, 2020 and since then the numbers of confirmed cases had increased significantly. As of 15 th November, 2020, the total number of COVID-19 cases in India was as follows: Active cases: 4,79,216; Cured/discharged: 82,05,728; Migrated: 1; Deaths: 1,29,63; with Maharashtra state recording the highest number of corona virus cases followed by Karnataka and then Tamil Nadu. People with less than 40 years old were more susceptible to contracting this viral disease in India. Corona virus causes more deaths among people of 60 years and above.
Generally, COVID-19 infection is characterized by low prevalence rate; case fatality rate and mortality rate; however, the recovery rate is relatively high, and most fatalities are associated with significant comorbidities.