What Is Known About Covid 19 Coronavirus?
Coronavirus 2019 what we know about it and Covid 19 Clinical Features. Towards the end of 2019, they identified a novel coronavirus in Wuhan China, following a spike in pneumonia cases. The virus spread quickly, initially throughout China and then the world after some dithering and indecision by international organisations. By February 2020 the World Health Organisation (WHO) had designated the virus as Covid-19 which is short for coronavirus disease 2019.
The fundamentals of Covid 19 are not yet fully understood, thus evolving with multiple global and national agencies working collaboratively and independently for solutions to mitigate risk, slow the curve and reduce pressure on health services while a vaccine can be developed or as previous pandemics the virus dies out.
1. What is Coronavirus Virology
What do we know about COVID 19 and Coronavirus Virology? 1. Following full-genome sequencing, the virus was found to be in the same family as a severe acute respiratory syndrome (SARS) a beta coronavirus, along with several bat coronaviruses, however a different monophyletic group. The virus attaches on a cellular level at the same point as SARS the angiotensin-converting enzyme. 2. Phylogenetic analysis that has been undertaken so far has identified two strains, the first being L type roughly accounting for 70 per cent of cases and S type roughly accounting for 30 per cent of cases.
2. COVID 19 and Epidemiology Around The World
The WHO has been providing daily updates in global counts that can be seen HERE along with a map of global distribution HERE. At the time of writing, we are rapidly approaching 2 million cases globally.
Every continent other than Antarctica are infected with this blight, however, some countries have passed their peak and short of a second wave have moved away from the danger zone. One good example of this is China, they peaked between late January and Early February 2020 with a significant decrease in new cases by early March, as of April 13th 2020 China is starting to see some imported cases from overseas and are increasing vigilance for a resurgence.
3. How is Covid 19 Transmitted?
A complete understanding of transmission has not yet been attained. However, at the beginning of the outbreak in China there is an initial association with a live and exotic animal market in Wuhan. The market has been visited by most of the early cases, with patient Zero likely to have emerged from this location. After the market was closed and disinfected person-to-person transmission became apparent and the main means for infection of other people.
Human transmission of Covid 19 is now thought mainly to occur via peer-to-peer contact in the respiratory droplets from an infected individual, not overly dissimilar to how influenza spreads. Respiratory transmission can occur through an infected person’s coughs, sneezes, kissing, talking, or via touch and direct contact with mucus membranes, for example, eyes, mouth or nose. The droplets are likely to have a range of 2 meters and are not thought to linger in the air, however, the aerosol properties of the Coronavirus are not fully understood with the odd study suggesting they could linger in the air for up to 3 hours. Whatever the answer, airborne precautions are recommended when dealing with suspected Covid 19 infected person.
Transmission of Covid-19 from asymptomatic people during their incubation period have been found, however, the full extent of this is yet to fully understood, however, quarantine and social distancing measures enacted early by Australia have likely significantly limited this factor. Other countries such as Singapore have found up to 6.4 have been transmitted by asymptomatic carriers. Only a large scale testing or asymptomatic people would give a true representation of the silent carriers of Covid 19 which as of yet seems to be off the agenda of all major nations.
4. COVID 19 What’s the Risk of Transmission?
We need to talk about Covid 19 risk of transmission. The type and duration of exposure are major factors in the risk or transmission between an infected and non-infected person. Household contacts being the highest risk groups for secondary infects, with environmental viral loading having a significant impact, also health care workers are at significant risk when disposable PPE has not been available or not used, and obviously as we have all heard closed environments such as cruise ships are hotbeds for the infection, again likely due to high viral loading and close proximity.
One tool that has been utilised effectively in Australia is contact tracing with experts from our Centre for Disease Control in the early days of the pandemic working overtime to ensure those who needed isolating got the correct information, and other than the very poor management of the Ruby Princess Australia has managed to so far significantly flatten the curve. The risk of just passing someone on the street with social distancing measure in place has not been well explored, however, is thought to be a very low risk.
5. Can People Form Immunity To Covid 19 (Coronavirus)?
Can people form immunity to Covid 19? While yet to be definitively proven it is thought that protective antibodies can be formed by an infected person, the full immune response and lifespan of these antibodies are not fully understood. To help fully understand this government, agencies are exploring immunoglobulin antibodies and upon confirmation, the antibodies are indeed a protective immune response population immunity and risk of reinfection can be fully understood.
6. What are The Clinical Features of COVID 19
The incubation period for Covid 19 is a hotly debated topic, in Australia, they have adapted the model for returning visitors of a 14 day lockdown period, this is in line with the majority of health advisors. Thus it’s thought the incubation period post-contact that a period of 14 days, however, the majority of cases occur within 4-5 days post-exposure leading to infection. One study of over 1000 patients found the symptomatic COVID-19, the median incubation period was 4 days.
7. Covid 19 Range or Severity of the Illness
Covid 19 has a large range in severity of the illness, and can range from mild, almost unnoticeable symptoms all the way through to servere illness and death. Data from WHO suggests approximately 80 percent of cases will show mild symptoms, 14 percent will suffer severe disease not leading to death and critical disease will afflict 5 percent. The virus has a death rate of between 2 and 3 percent with no deaths in non-critical cases.
- Mild disease–URTI symptoms +/- mild pneumonia.
- Server disease–Hypoxia, reduce lung function by 50 percent.
- Critical disease – respiratory failure, shock, or multiorgan dysfunction.
Most cases involving death are of vulnerable populations such as elderly or with underlying medical comorbidities. The location has also played a role with the level of fatality Italy has been hit particularly high were as South Korea the risk of death significantly mitigated and 7.2 percent and 0.9 percent respectively.
8. Risk Factors for Covid 19 Severity of Illness.
Let us see what the risk factors for Covid 19 mean. Higher mortality has been associated with the number of comorbidities, however critical illness can occur in otherwise healthy individuals, that being said critical illness predominantly occurs in the aged population. The risk of critical illness from Covid 19 has been linked with:
- Coronavirus Chronic kidney disease
- Chronic lung disease
- Diabetes mellitus
- Cardiovascular disease
- Severe obesity
- Liver disease
Other factors also play a role in the risk associated with a critical illness from Covid 19 such as Lymphopenia, Elevated liver enzymes, Elevated creatine phosphokinase, but these are outside the scope of this article.
Age appears to be a major contributor to poor outcomes and luckily symptomatic infection in children appears to be relatively uncommon and upon occurrence is usually mild. (Be aware rare severe cases have been reported globally). Asymptomatic infections have also been described, however, not yet well researched.
9. What are the Clinical Symptoms of Covid 19?
Let us talk about clinical symptoms of Covid 19. Some of the latest studies have linked reactive anemia with the more serve cases of Covid 19, however, Pneumonia appears to be the most common and grave manifestation of the Coronavirus. One area that has significantly challenged health care professionals is the lack of or definitive clinical symptoms, with many clinically common features shared with other respiratory infections.
-Symptoms may include:
- Fever in 99 percent
- Fatigue in 70 percent
- Dry cough in 59 percent
- Reduced appetite in 40 percent
- Muscle ache in 35 percent
- Shortness of breath in 31 percent
- Sputum production in 27 percent
-Less common symptoms have included:
- Sore throat
- Runny Nose
- Abdominal pain
Some patients who start off with clinically insignificant symptoms can progress while they are in quarantine and become critically unwell this has been reported to occur up to 11 days after onset of symptoms. Some patients with severe Covid-19 have laboratory evidence of an exuberant inflammatory response, similar to cytokine release syndrome, with persistent fevers, elevated inflammatory markers, these markers are associated with poor outcomes.
10. Testing for Covid 19 in Australia (Subject to Change)
What we know is that Australia has stepped up several drive-through facilities and managed at a state level. GP’s have for various reasons significantly reduced their community support in terms of face-to-face consultations and moved towards telehealth, leaving nursing for example in the Walk-in Centre’s at Canberra at the front line of testing. Testing is an important tool and Australia has maintained a fluid policy responding to community need with regular updates on its policy and interstate coordination. The criteria for the test has evolved and currently stands at:
-The epidemiological criteria include:
•international travel in the 14 days before illness onset
OR •close or casual contact in the 14 days before illness onset with a confirmed case of Covid-19 (this needs to be interpreted sensibly; we do not have sufficient testing kits to test everyone who attends the same large concert as a person with Covid-19).
-The clinical criteria include:
OR •acute respiratory infection (eg shortness of breath, cough, sore throat) with or without fever.
Please note that if the patient has bilateral severe community-acquired pneumonia and no other cause is identified, with or without recent international travel, they are classified as a suspect case.
If the patient has moderate or severe community-acquired pneumonia (hospitalised) and is a healthcare worker, with or without international travel, they are classified as a suspect case.
11. Management of Covid 19 in Australia
Coronavirus 2019 what we know about it: COVID 19 Clinical Features, can it be managed? People with mild symptoms are appropriate for home management with telephone support and education some examples of mild infection may include fever, cough, body aches, or asymptomatic infection, it’s important the infected individuals are able to adequately isolate in the community setting. The management approach is primarily focused on risk reduction, namely reducing the risk of spreading COVID 19 to others. However, some individuals will require hospitalisation and supportive care, with clear pathways set out and expectations to facilitate a smooth transition to hospital.
12. Prevention of Spread of Covid 19
While in the community setting the risk is low, it does likely exist, thus certain precautions can be taken, however, they must be taken with a full understanding of what you are doing and how to use the protective equipment. One example of this was from 3 days ago I was in the pharmacy to purchase some paracetamol, in a gentleman in front of me used his hands to put the mask around his neck so he could better talk to the pharmacist.
I tried to explain viral loading and that a mask should only be touched twice to put it on and to take it off; he dismissed the advice and said it’s good for the week. So this example of how PPE can in some cases place you at a higher risk rather than a lower risk. Some steps you can take and understand more to help reduce your risk, include:
The following general measures are additionally recommended to reduce transmission of infection:
- Diligent hand washing, particularly after touching surfaces in public.
- Use of hand sanitizer that contains at least 60 percent alcohol.
- Covering your cough and sneezes.
- Social distancing.
- Not shaking hands.
- Avoiding touching the face (in particular eyes, nose, and mouth).
- Cleaning and disinfecting objects and surfaces that are frequently touched.
13. Vaccine for Covid 19
What do we know about the vaccine for Covid 19? At this time a number of vaccines are being developed but maybe years away from public availability, your best defense currently is social distancing and discipline. No agent is known to be effective in preventing infection.
Conclusion: What’s Next for Covid 19
Coronavirus 2019 what we know about it. Covid 19 Clinical Features. Nobody knows what the future holds, yet many people a lot smarter than me are working day and night to find solutions for the coronavirus, each of us has a part to play, to do our bit for society, not because the government tells you to, but because you want to. Australia is a great nation, we stand together for the greater good of our nation.
This virus does not have any boundaries and borders, and potentially affects all people the same, however, it’s up to you to look after yourself and make the most of your situation to reduce the risk to yourself and to other around you. For example, if you live in a 12 million dollar estate with a pool and bar your likely in a better position to social distance than in a Govvie flat in Bankstown, that being said it’s up to us and only us as an individual to do the right thing. Stay well and stay informed.
Main Image Source : Pixabay
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