Origin Of Coronavirus disease (COVID-19) outbreak
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Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV).
Coronavirus disease (COVID-19) is a new strain that was discovered in 2019 and has not been previously identified in humans.
Coronaviruses are zoonotic, meaning they are transmitted between animals and people. Detailed investigations found that SARS-CoV was transmitted from civet cats to humans and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans.
Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death.
Standard recommendations to prevent infection spread include regular hand washing, covering mouth and nose when coughing and sneezing, thoroughly cooking meat and eggs. Avoid close contact with anyone showing symptoms of respiratory illness such as coughing and sneezing.
Origin Of Coronavirus disease (COVID-19)
Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
The disease was first identified in 2019 in Wuhan, China, and has since spread globally, resulting in the 2019–20 coronavirus pandemic.Common symptoms include fever, cough and shortness of breath. Muscle pain, sputum production and sore throat are less common.
While the majority of cases result in mild symptoms, some progress to severe pneumonia and multi-organ failure.The rate of deaths per number of diagnosed cases is on average 3.4%, ranging from 0.2% in those less than 20 to approximately 15% in those over 80 years old.
The infection is typically spread from one person to another via respiratory droplets produced during coughing and sneezing.Time from exposure to onset of symptoms is generally between two and 14 days, with an average of five days.
The standard method of diagnosis is by reverse transcription polymerase chain reaction (rRT-PCR) from a nasopharyngeal swab or throat swab. The infection can also be diagnosed from a combination of symptoms, risk factors and a chest CT scan showing features of pneumonia.
Recommended measures to prevent infection include frequent hand washing, maintaining distance from others, and not touching one’s face.The use of masks is recommended for those who suspect they have the virus and their caregivers but not the general public.
There is no vaccine or specific antiviral treatment for COVID-19. Management involves treatment of symptoms, supportive care, isolation, and experimental measures.
The World Health Organization (WHO) declared the 2019–20 coronavirus outbreak a pandemic and a Public Health Emergency of International Concern (PHEIC). Evidence of local transmission of the disease has been found in many countries across all six WHO regions.
Coronavirus disease (COVID-19) Cause
The lungs are the organs most affected by COVID-19 because the virus accesses host cells via the enzyme ACE2, which is most abundant in the type II alveolar cells of the lungs. The virus uses a special surface glycoprotein, called “spike”, to connect to ACE2 and enter the host cell.
The density of ACE2 in each tissue correlates with the severity of the disease in that tissue and some have suggested that decreasing ACE2 activity might be protective,though another view is that increasing ACE2 using Angiotensin II receptor blocker medications could be protective and that these hypotheses need to be tested.
As the alveolar disease progresses, respiratory failure might develop and death may follow. ACE2 might also be the path for the virus to assault the heart causing acute cardiac injury. People with existing cardiovascular conditions have the worst prognosis.
The virus is thought to have an animal origin,through spillover infection.It was first transmitted to humans in Wuhan, China, in November or December 2019, and the primary source of infection became human-to-human transmission by early January 2020.
On 14 March 2020, South China Morning Post reported that a 55-year-old from Hubei province could have been the first person to have contracted the disease on 17 November 2019.As of 14 March 2020, 67,790 cases and 3,075 deaths due to the virus have been reported in Hubei province; a case fatality rate (CFR) of 4.54%.
Coronavirus disease (COVID-19) Signs and symptoms
| Symptom | Percentage |
|---|---|
| Fever | 87.9% |
| Dry cough | 67.7% |
| Fatigue | 38.1% |
| Sputum production | 33.4% |
| Shortness of breath | 18.6% |
| Muscle pain or joint pain | 14.8% |
| Sore throat | 13.9% |
| Headache | 13.6% |
| Chills | 11.4% |
| Nausea or vomiting | 5.0% |
| Nasal congestion | 4.8% |
| Diarrhoea | 3.7% |
| Haemoptysis | 0.9% |
| Conjunctival congestion | 0.8% |
Although those infected with the virus may be asymptomatic, many develop flu-like symptoms including fever, cough, and shortness of breath.Less commonly, upper respiratory symptoms such as sneezing, runny nose, or sore throat may be seen.
Gastorintestinal symptoms such as nausea, vomiting, and diarrhoea are seen in a minority of cases. In some, the disease may progress to pneumonia, multi-organ failure, and death.[10][14]
As is common with infections, there is a delay from when a person is infected with the virus to when they develop symptoms, know as the incubation period. The incubation period for COVID-19 is typically five to six days but may range from two to 14 days.
Mild cases typically recover within two weeks, while those with severe or critical disease may take three to six weeks to recover. Among those who have died, the time from symptom onset to death has ranged from two to eight weeks.
Sources :
- https://en.wikipedia.org/wiki/Coronavirus_disease_2019
2. https://www.who.int/health-topics/coronavirus