[Disclaimer: this is a new virus so everything here is based on what I found as of 23/02/2020, and there is so much research being carried out it will quickly be outdated]
- COVID-19 (Coronavirus disease-19) is the name of the disease caused by the virus SARS-CoV-2.
- Spread via respiratory droplets (cough or sneeze) within a range of about 6 feet.
- It has also been found in stool samples, but as yet this transmission isn’t confirmed.
- Incubation generally between 2 and 14 days.
- Good hygiene suggested as the main preventative measure (washing hands, covering mouth when coughing or sneezing)
- Infected individuals may be asymptomatic.
There is no vaccine or antiviral yet developed. Current treatment involves relieving symptoms and providing supportive care.
- Real time reverse transcription-polymerase chain reaction (rRT-PCR) on respiratory or blood samples (this technique measures RNA – basically, it looks for the DNA of the virus)
- Results available within a few hours to days.
Signs, Symptoms, Prognosis
According to WHO, around 80% of patients only have a mild form of the disease, 14% develop more severe disease such as pneumonia, 5% have critical disease, and 2% of cases are fatal.
Among those who died initially, many had preexisting conditions, including hypertension, diabetes, or cardiovascular disease.
Common symptoms are fever, cough or shortness of breath. Diarrhoea or upper respiratory symptoms (e.g. sneezing, runny nose, sore throat) are less frequent. Cases can progress to pneumonia, multi-organ failure, and death. but among healthy individuals this is unlikely.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),formerly a novel coronavirus named 2019-nCoV, is a positive-sense single-stranded RNA virus, with strong genetic similarity to bat coronaviruses, from which it likely originated.
The pathology (mechanisms behind how it harms the body) is currently unknown. However it is part of a family of diseases (coronavirus/SARS) so it will likely be very similar.
The pathology may consist of three phases: viral replication, immune hyperactivity, and pulmonary destruction.
- Diffuse alveolar damage, epithelial cell proliferation, and an increase of macrophages
The cells and tissue of the lung are damaged, meaning it’s harder to carry out its function (breathing)
- Lymphopenia and haemophagocytosis – suggests cytokine deregulation
Destruction/reduction of cells important in immune response (fighting disease) may also suggest the the virus has methods of evading the immune system
Lungs and airways of monkeys with SARS (source)
Other areas of the body:
- Not just pneumonia – SARS patients may also exhibit gastrointestinal symptoms and
white-pulp atrophy of the spleen
- SARS-CoV replicates in enterocytes (simple epithelial cells of the intestines), with minimal disruption of the intestinal architecture.
- This absence of intestinal inflammation may be due to upregulation of transforming growth factor β and an antiapoptotic host cellular response in the intestinal epithelial cells
- May also replicate in peripheral blood mononuclear cells (PBMCs)
COVID-19 may, therefore, be a systemic disease with widespread extrapulmonary dissemination.
Importantly, the real-world implications of this outbreak are similar to that of a new strain of flu. While healthy individuals are unlikely to experience more than a few days of feeling unwell, elderly people or those with existing conditions may develop pneumonia and become critically ill. From what we know so far, ensuring infected individuals stay at home and avoid exposing themselves to vulnerable populations (eg avoid visiting hospitals or care homes) should be enough to prevent anything too horrible.