Ram Sewak Singh Mahila College, BRABU Muzaffarpur, Bihar (INDIA)
This review paper is an attempt to understand and recapitulate the published scientific articles/research papers about the deadly pandemic Coronavirus. In this review paper, we tried to provide an insight regarding early findings on the symptoms, causes, clinical diagnosis, spread, as well as prevention and control of COVID-19. This review is based on the information collected via various research publications on different websites. It can be helpful to get vital information for researchers, scientists, and anyone curious to know about this deadly disease. We hope this paper will support government, agencies or companies to build-up the strategies against control and prevention of this deadly disease during this time of health emergency.
Before the world could be fully recovered from the loss caused by the last H1N1 swine flu pandemic of 2009-2010 which killed about 575,400 people across the globe, the deadly Coronavirus pandemic came up. The Coronavirus Disease 2019 (COVID-19) is caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first case of this virus was reported in Wuhan, China, on December 31, 2019. About a month later, on January 30, 2020, this outbreak was declared as a Public Health Emergency of International Concern. Since it has been spreading to every continent with alarming speed, on March 11, the World Health Organization (WHO) officially declared the outbreak of COVID-19 a pandemic. Never before this has the WHO has declared a pandemic over a coronavirus.
Many public health groups across the world, including the US Centers for Disease Control and Prevention (CDC), WHO and government of countries are monitoring the pandemic and posting updates regularly on their websites. Scientists and researchers started to research the source of the new coronavirus immediately after the outbreak. The first genome of COVID-19 was published by the research team led by Prof. Yong-Zhen Zhang, on January 10 2020 (Virological.org., 2020). As of now no treatment for the disease has been identified, but labs are working on various types of treatments, including a vaccine.
The full breadth of symptoms of COVID-19 is still being studied. Signs and symptoms of COVID-19 may appear two to 14 days after exposure, and so far, as per the CDC, the most evident symptoms of the disease are rise in body temperature, dry coughing and shortness of breath. These may also be accompanied by the headache, sore throat, abdominal pain and diarrhoea, have been reported, but are less common. COVID-19 can also cause respiratory issues that lead to severe problems, such as pneumonia and loss of smell. The disease is caused mostly in old age people, but there are cases in young people also. Furthermore, it seems to become more sensitive and prone with age. As per the study done by the JAMA, the 30- to 79-year-old age bracket predominates the cases identified in Wuhan City as of now, where the outbreak began. Children comparatively seen to be at less risk of suffering noticeable symptoms of the disease. However, a recent study of 2,000 children confirmed or suspected to have COVID-19 found that 6% developed severe or critical illness (Dong et al., 2020).
The novel coronavirus is very contagious and appears to be reasonably quickly spread. However, it is not among the most transmissible diseases out there. The primary reproduction number, also called the R-nought value, is the expected number of individuals who can catch the virus from a single infected person. This value for the novel coronavirus is estimated to be between 2 and 2.5, at the moment (Liu et al. 2020). According to WHO, there are four levels of COVID-19 transmission. These are countries or local areas with: 1. No cases reported. 2. Sporadic cases. 3. Clusters of cases (grouped in place and time), or 4. Community transmission (WHO COVID-19 situation report). If we talk about the route for its transmission, Chinese health authorities (NHC 2020, NHC and CDC, 2020) described three main transmission routes for the COVID-19: 1) droplets transmission, 2) contact transmission, and 3) aerosol transmission.
This disease spreads mostly through person-to-person contact within about a 6-foot (1.8 meters) radius. People with COVID-19, spread viral particles through coughing and sneezing. The particles can land in the mouths or noses of those nearby. It might also be possible to catch SARS-CoV-2 by touching a surface where the virus has recently landed and then touching one’s mouth, nose or eyes, but CDC officials believe this method of transmission is less common. Some coronaviruses can live on surfaces for days, but not much is known about the new coronavirus’ ability to survive on surfaces. There is limited evidence that the new coronavirus can spread through faeces as well.
It is still unknown as to how long can the new coronavirus linger on surfaces. A new analysis found that the virus can remain viable in the air for up to 3 hours, on copper for up to 4 hours, on cardboard up to 24 hours and on plastic and stainless steel up to 72 hours (The New England Journal of Medicine). In The Journal of Hospital Infection, it is reported that the new coronavirus resembles other human coronaviruses, such as its “cousins” that cause SARS and MERS, it can stay on surfaces such as metal, glass or plastic for as long as nine days (In comparison, flu viruses can last on surfaces for only about 48 hours). However, some of them do not remain active for as long at temperatures higher than 86 degrees Fahrenheit (30 degrees Celsius).
PREVENTION AND CONTROL
General precautionary measures recommended by the CDC include washing hands often with soap and water for at least 20 seconds; avoiding touching eyes, nose and mouth with unwashed hands; avoiding close contact with sick people; staying home and cleaning and disinfecting touched objects and surfaces frequently. The common disinfectant used against coronavirus is diluted household bleach solutions, alcohol solutions containing at least 70% alcohol. The bleach solution can be prepared by mixing five tablespoons (one-third cup) of bleach per gallon of water or four teaspoons of bleach per quart of water, the CDC wrote in a set of recommendations.
The public health and social measures are measures helpful to reduce transmission of COVID-19. These include individual and environmental measures, detecting and isolating cases, contact-tracing and quarantine, social and physical distancing measures and vaccines and treatments. Since till now vaccines and specific medications are not yet available, other public health and social measures can play an essential role in reducing the number of infections and saving lives (WHO coronavirus report, April 1, 2020).
As there is no cure for this coronavirus disease until now, the treatments given are basically supportive care for influenza (seasonal flu) and other severe respiratory illnesses. These treatments primarily treat the symptoms such as fever, cough and shortness of breath. In mild cases, this might simply mean rest and fever-reducing medications such as acetaminophen (Tylenol) for comfort.
In hospitals, patients are sometimes treated with the antiviral drug oseltamivir, or Tamiflu, which seems to suppress the virus’ reproduction. The doctors are testing an array of other antivirals initially designed to treat Ebola and HIV, Nature Biotechnology reported. In cases in which pneumonia inhibits breathing, treatment involves ventilation with oxygen. Ventilators blow air into the lungs through a mask or a tube inserted directly into the windpipe.
Researchers around the world are developing more than 165 vaccines against the coronavirus, and 31 vaccines are in human trials. Vaccines typically require years of research and testing before reaching the clinic, but scientists are racing to produce a safe and effective vaccine by next year.\
IMPACT ON ANIMALS
The origin of this virus is unknown, though it is found that coronaviruses (which also include SARS and MERS) are passed between animals and humans. Research comparing the genetic sequence of SARS-CoV-2 with a viral database suggests it originated in bats. Since no bats were sold at the seafood market in Wuhan, it is suggested that an intermediate animal, possibly the pangolin (an endangered mammal) is responsible for the transmission to humans.
The COVID-19 pandemic has been spread mainly by human-to-human transmission, but there are a handful of reports of the infection in animals, which raises new questions about human-to-animal transmission. In February 2020, the first known case of an animal infected with COVID-19 was a dog in Hong Kong. A second German Shepherd pet dog in Hong Kong was reported to be positive for COVID-19 virus on March 20. Later in April, a four-year-old female Malayan tiger, named Nadia from the Bronx Zoo in New York City was reported to be coronavirus positive by the National Veterinary Services Laboratory in Iowa. As per World Organisation for Animal Health and the WHO, no evidence has been found that pet dogs and cats can pass on the coronavirus. Nevertheless, it is suggested that anyone who has become sick should limit contact with pets as the studies are going on to study the issue more.
STATISTICS TILL DATE
As on August 12, 2020, the COVID-19 has led to more than 20,162,474 illnesses and more than 7,37,417 deaths worldwide. Below is the table of the situation in numbers as reported by WHO situation report-205. (Available in PDF)
REPORT OF INDIA
On January 30 2020, the first laboratory-confirmed case of 2019-nCoV was reported in Kerala, a student returning from Wuhan. Gradually, the number of corona positive patients started to increase so, Prime Minister Narendra Modi, in the exercise of the powers under section 6(2)(i) of the Disaster Management Act, 2005, issued an order for complete lockdown in the country for a period of 21 days with effect from March 25, 2020, in order to break the chain of transmission of COVID-19.
WHO Country Office for India is working closely with Ministry of Health and Family Welfare (MoHFW) to strengthen surveillance, build the capacity of the health system and optimize ‘window of opportunity’ created by mandatory physical distancing in India. All transport facilities like flights, trains and buses have been suspended and as of March 25 (through an order), extension of suspension has been made till May 31st 2020. Passenger movement has been strictly restricted including inter-state travel, all efforts to ensure availability of essential commodities through its uninterrupted freight services in place. Ministry of Home Affairs (MHA) issued new guidelines to fight COVID-19 and for Unlock 1 – phased re-opening of areas outside the Containment Zones into effect from June 1, 2020 and would be effective till June 30, 2020. According to Government of India report, till 13 August, 2020, there are 6,53,622 active cases of this disease and 47,033 deaths. There has been significant improvement in the recovery rate amongst COVID-19 patients with present rate of about 60.70%.
HOW IS COVID-19 DIFFERENT FROM SEASONAL FLU?
COVID-19 causes the highest percentage of deaths in people ages 65 and older, in a similar way as that most strains of flu viruses, including those that cause seasonal flu. There is typically some herd immunity to seasonal flu; thus, many people are immune to the infection, because of vaccines or because their immune system has already fought the infection. Similarly, there might be some groups of people who have immunity to the 2019-CoV-2 virus, too, but that is an area that’s still being researched. So far, COVID-19 is most deadly for people over 60 and also those who have underlying health conditions.
The difference between seasonal flu and COVID-19 is that flu viruses are spread in respiratory droplets and airborne particles, while 2019-CoV-2 is primarily spread through respiratory droplets, and in some instances may be shed in faeces. It is not yet know how vital the oral-faecal route of infection is, but it is another reason to wash your hands regularly with soap and water or use sanitizers.
Till now, the mystery about the new coronavirus disease still unsolved and very little is known about the cause, transmission and vaccine. Scientists are working day and night in order to find out more about COVID-19, and our understanding of the virus that causes it and the threat it poses may change as new information becomes available. The disadvantage of living in the social media era is that misinformation about the disease has spread faster than the virus. However, this technological development is helping in improving the speed at which research and vaccine development can occur. Potential treatment and the first trial of a candidate vaccine are already underway, which is impressive and encouraging. It will take time for a vaccine and treatments to be studied, scaled up and reach masses. So, in the meantime, all that we can do is stay home and be safe.
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