Updated on 16th April 2020
We will continue to update the questions we are being asked both in our clinical practice and in response to our newsletters:
We are told to test and test. How do we do this without burdening yourselves with people overloading the system please?
Our current advice remains that testing for COVID-19 should mostly be undertaken in situations in which it is clinically indicated and the patient should ideally be assessed and the best option for testing discussed with a doctor. This can be by telephone. We have performed over 750 tests and >97% are negative. If you are not a direct COVID contact, have not just arrived from overseas and are not in quarantine then the likelihood of symptoms being due to COVID-19 is very small at present.
However, this is clearly a very important illness. The public health department is likely to continue to expand testing capacity and OT&P will continue to fully support these efforts. We are currently undertaking a study of the prevalence of antibodies in our demographic and will update this and other changes to testing advice by email.
Are there any resources on COVID-19 for children?
This free booklet has been produced by Professor Graham Medley at the London School of Tropical Medicine. It gives a nice child friendly summary in PDF format.
Thank you for your articles on nutrition and COVID-19. Is there any evidence about Vitamin C? I was told that is has been used in the US but can’t find any evidence.
In some ways it is surprising that such a cheap and readily available supplement has not been more extensively investigated. There are some sound scientific reasons to suggest it may be helpful in the immune storm associated with COVID and there are some studies underway. We have reviewed the history of Vitamin C and current evidence here.
I have been told there are online tests for COVID-19. Are they reliable?
There are basically two different tests for COVID-19:
- Tests which look for the virus: These are typically PCR tests and can be performed on different bodily fluids. Typically we are using special nasal swabs or sputum (in hospital) or deep throat saliva tests (at home).
- Antibody tests; These are blood tests which tell whether somebody has had the disease in the past.
In Hong Kong having a positive PCR test result for the SARS-COV-2 virus has public health implications. Anyone with a confirmed positive test is admitted to hospital and their close contacts are quarantined. There is a legal obligation for doctors to report all positive PCR tests to the health department. The approved Government laboratories use tests which must conform to international standards. Both the WHO and FDA have issued warnings about the reliability of online marketing of testing kits1.
We have explained previously the importance of antibody testing. This will give key information in helping us to manage the epidemic and predict how long it is likely to be before things get back to normal. These studies will start being conducted over the next few weeks.
You have referred to a mortality of 1% or less but when I look at the number of deaths and cases it seems to be closer to 4%. Can you explain this discrepancy?
It is quite confusing. Typically, in evolving epidemics we use different terms to express the death rate. The sickest patients go to hospital or at least are more likely to be diagnosed. If we know the number of deaths and the number of cases we can divide the two.
Number of deaths from COVID-19 / Number of cases of COVID-19
This gives us the crude fatality rate (CFR). It is crude because some of the sick people may still die. Equally we may not yet have measured all the cases. It is also possible that some people are dying of other things and being counted as COVID-19 deaths. That is certainly the case in Italy where the CFR is > 10%. The overall CFR looking at WHO data is currently around 4%.
Eventually when we get antibody tests we will be able to measure the number of people in the community who had infection without knowing about it. Once we know this number we will be able to calculate the infection fatality rate (IFR). This is the actual chance of anyone who gets the illness dying from it. A recent study in the Lancet estimated this to be 0.66% in China. Of course, the actual risks depend on age, sex, smoking and presence of other illnesses in addition to viral load. This final number may change once we get more data but the current consensus is it is likely to be <1%.
We wrote this article about the dilemma of predicting mortality early in the epidemic.
Can the Coronavirus spread through air?
Infections like Coronavirus are typically spread when an infected individual coughs an explosive aerosol which contains infected virus. These infections are called droplet borne infections. Imagine the tiny drops of fluid in the picture above. They contain virus particles. An aerosol is just a tiny droplet. Coronavirus infections are not airborne as such. They still need a vehicle travel in. They do seem to be able to travel in small vehicles (tiny droplets) and because some people may spread them without having symptoms it is possible that they can come out with talking as well as coughing.
It is easy to imagine somebody close to this cough either breathing the virus directly in or having it going into their eyes. This is why medical staff and close relatives have a higher risk of infection. It is also easy to imagine how a mask or covering with a hand can prevent this infection from spreading.
In practice most of the virus from the cough above goes onto surfaces or the floor and the greatest risk of infection is to pick the virus up on fingers which then make contact with the nose or eyes. This is why hand washing remains the single most important preventative measure for individuals without symptoms.
What is the recovery time for Coronavirus disease?
Most cases of COVID-19 are likely to have mild or no symptoms. They will recover as would be expected from getting a cold. For some people the illness will be more like a bad flu and may take 1-2 weeks to fully recover. In cases with complications, the hospital stay can be protracted and severe illness can involve weeks in hospital followed by a recovery over months. Some of the more severe cases are associated with fibrosis (scarring) of the lungs. It is too early to know if this will persist but the early evidence suggests that it is not as severe as with SARS and there is some hope that many if not all patients will improve.
The number of reported ‘recovered’ cases in the media is misleading. Recovered cases in Hong Kong and China are based upon negative viral testing at an interval. This is not the same as getting over the illness and “feeling better”. There are many cases that have recovered in a traditional sense and some that never had symptoms. These people are sitting in hospital, feeling perfectly well but waiting for their tests to become negative for discharge. Recovered data in media charts is really of no value.
I have read that Zinc and Vitamin B supplements may be useful. Is this true?
We are really at the beginning of our understanding of the immunology of this new disease. There has been an interesting review paper which proposes a possible role for Vitamin B3. We have written a review of the evidence here. Whilst TB and HIV are very different diseases it is interesting to consider that Vitamin B3 has also been considered as a treatment in combined HIV/TB.
When new diseases first appear, one of the first concepts is to look for things which are already “on the shelf”. Drugs which we already use in different situations. For example, the HIV drugs and the anti-malarial chloroquine which are being studied in COVID.
Equally it is important to remember the potential role of natural and nutritional supplements, both in boosting immunity and possibly in the management of infection. There is some good evidence for Vitamins, Zinc and probiotics in both the prevention and management of viral illness. We have given a more detailed explanation along with references here.
Thank you for your explanation of the epidemic curves. I have been looking for a similar curve for the UK but the CHP seems to have stopped updating them. Can you tell me where I can find this information?
We have been constructing our own epidemic curves using the data from the WHO. We also include the consolidated curve which is updated by the WHO daily. We will add the UK and USA curves and will update all curves daily here.
Do I need to worry about my pet?
No. Veterinary experts in addition to the US CDC have tested thousands of cats, dogs and horses. Their position is that there is no risk to animals nor to humans from animals and that further testing is not necessary.
Thank you for the information on Vitamin B3. I have read that probiotics might also help to prevent coronavirus infections. Is there any evidence?
It is too early to say with certainty whether probiotics may help in prevention of COVID-19. There is however a long history of use and evidence of benefit for probiotics in other forms of upper respiratory viral illness as well as other medical conditions. We have given a summary here.
We understand that these are very stressful and confusing times and if there are any questions or concerns, don't hesitate to email us at firstname.lastname@example.org.
1. Commissioner, O. of the. (n.d.). Coronavirus (COVID-19) Update: FDA Alerts Consumers About Unauthorized Fraudulent COVID-19 Test Kits. Retrieved from https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-alerts-consumers-about-unauthorized-fraudulent-covid-19-test-kits
2. Vierty, R., Okell, L. C., Dorigatti, I., Winskill, P., Whittaker, C., & Imai, N. (2020, March 30). Estimates of the severity of coronavirus disease 2019: a model-based analysis. Retrieved from https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30243-7/fulltext