WHAT IS COVID 19:doctkhalil
This is a feeble attempt at rearranging my thoughts on COVID 19 over the past 3 months. I have tried to incorporated all the bits of authentic and relevant information in one piece. I will keep updating this article with time.
PANDEMICS AND CAUSATIVE FACTORS:
Pandemics are caused by 2 types of organisms i.e bacteria and viruses. Viruses are interesting because they can jump from one specie to another. HIV came from chimpanzees, Ebola most likely from Bats, Bird and Swine flu from birds and pigs. When these viruses spill to humans, they become zoonotic viruses which are extremely dangerous and can change their outer protein coatings and transform / mutate rapidly once they get into the human population.
Humans had the flu for centuries and it was self limiting. Birds had their flu for centuries and both viruses could not infect the species of each other. But both of these could infect a pig. So these combined in a pig cell and led to the advent of a zoonotic virus that we know as H1N1 which killed more than 50 million people in the 1918 Flu pandemic.
This concept needs to be understood. Wet markets are particularly common in China. The meats in such markets include that of snake, monkeys, frogs, cats, bats , dogs ,cats and chicken. These are termed as exotic meats. Many animal species are kept stacked one upon the other for days in small cages. Most are killed on the spot and their blood and excreta are constantly mixed with increased chances of such zoonotic hybrids being formed.
The remains of the animals from sewers nearby are mixed with the remaining animal fat by sanitary workers and sold off as edible oil after heating them at high temperatures. These workers themselves are a high risk group of people for transmitting such viruses. Bats have a very high metabolic rate with their mean body temperature at around 39 degrees. Any virus that survives this temperature and gets transmitted to humans is bound to be very resistant and difficult to treat. This is what happened with SARS in 2002 in China (Guangdong) and now in Wuhan a city in the Hubei Province of China.
Because it started appearing in the end of 2019,it was designated as the disease COVID-19, which stands for coronavirus disease 2019. The virus that causes COVID-19 is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
TRANSMISSION AND SYMPTOMATOLOGY:
Person to person transmission via respiratory droplets/ route seems to be the predominant route of transmission. The virus has been isolated in blood and stool specimens but feco oral does not seem to be a major transmission route. So far more than 2 million cases have been reported worldwide with 170,000 deaths till date. WHO declared it as a Pandemic in March 2020.
Any person who presents with fever, respiratory symptoms (including cough, shortness of breath, runny nose, constant sneezing) has a higher likelihood of having COVID 19, in the current scenario. The risk increases if the individual has been in contact with a known COVID 19 patient. High risk groups include healthcare professionals (symptomatic) and patients admitted in hospital.
COVID 19 ADVICE FOR HEALTH CARE STAFF:
Healthcare professionals are at particular risk. The general public is exposed to a very small inoculum as compared to a healthcare professional busy in doing an aerosol generating procedure such as intubation or CPR. The basic idea being that if you get a massive exposure , the immune response as a result could be overboard and result in a response that would cause more harm.
For Healthcare professionals ,whilst doing any procedure , try to keep everything ready in advance and time yourself so that you do not over expose yourself. This is particularly important for the house officers/ interns/ Junior doctors. If you fail to do a procedure e.g ABG, bloods, LP etc , dont just keep on trying for the next 20 minutes. Attempt once or twice then come out and ask your senior for help. the second person attempting should also try to minimize time spent and keep everything ready (ideally not more than 20 minutes) and ask from help from the next senior person available.
GRADED EXPOSURE : A POSSIBLE EXPLANATION:
There is a lot of mystery surrounding the virus and even developing antibodies after exposure is now being questioned as synonymous to immunity or not. This is a hypothesis at best, but if it comes to it, the whole idea should be of a graded exposure for the immune system to have time to respond and to mature. If high titers of virus exposure is undertaken e.g in aerosol producing procedures like Nebulization, intubation , high flow oxygen and suction then the immune system may be overwhelmed and whatever response there is would not be an appropriate one.
APPROACH TO PATIENTS WITH COVID 19:
A patient with typical features of COVID 19 e.g NEW cough, fever or Shortness of breath with typical X ray chest findings, does not need a full General and systemic exam – for diagnosis ; unless the history points you towards it e.g abdominal pain or focal neurology etc. A good approach would be to hear for crackles at the bases, listen to heart sounds and check for pedal edema. This should give you the maximum relevant clinical information you need to decide upon the management plan.
You do not need to look for cerebellar signs in a such a patient, just for the sake of completeness – Pun intended. The old adage that If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck. So do not over complicate things. Keep it simple. This will hopefully minimize the exposure as much as possible.
FUTILITY OF ANTIBODY TESTS:
After exposure to COVID-19 an antibody test can become positive but that gives us very limited information. It could have been a mild infection due to a lower level of exposure. It could also have been a false positive test. Some of the quantitative Ab tests are also available in the market and give us the number of antibodies formed as a response to the infection. However there is no reference range to interpret whether the Ab titre is in the immune range or not. For example we measure the surface antibodies to Hepatitis B to look for the immune response of an individual after vaccination. According to these ranges we can decide whether a person needs further vaccination booster or not i.e we can determine the immune status of a patient from those antibody levels. Unfortunately we do not have the same luxury with corporate 19 as these ranges take several years to develop and this virus is a novel virus about which we are discovering new info on a daily / hourly basis.
Regarding duration of immunity even if one recovers from an infection how long does the immunity last ? we do not have a simple answer for that. The only answer that scientists have tentatively given is based upon the behavior of similar viruses before and most likely if you recover from this illness you will develop lasting immunity or at least immunity for the next 2 to 3 years. But that is not a given, its only a prediction. Currently there are hundreds of Antibody tests in the market while only four of them are approved under EUA (Emergency Use Authorization) by the FDA so there are a lot of poor quality tests that maybe giving questionable results and whose accuracy may be questionable.
The issue of false positive tests is also making things difficult. The best tests available in the market have a false positive percentage of 5% at least. This means that if in a population of hundred people there are five people who have the disease ,and if the same test is applied to the population of hundred people then this test with false positive rate of 5% will end up showing 10 people as having the disease. So the accuracy of this test will be 50% because of a low prevalence. However if the same test is applied to a population where there are 50 patients off COVID-19, Then the test will end up showing 55 people out of 100 as having the disease so the accuracy of the test will be 90% as you can see the accuracy of the test varies according to the prevalence of the disease. Based on the prevalence and case fatality rates of the virus, one can start easing the social restrictions and opening up the economy of those areas. But the take-home message from this discussion is that these tests do not tell you whether you are immune or not and give very limited information about the immune status or disease status of a single individual however they are very helpful at the collective level. Careful interpretation of these tests is needed especially in places where there is low prevalence of Covid 19.
COVID 19 TREATMENT OPTIONS:
As far as treatment options or vaccine is concerned, there are no effective treatment options or vaccination available at present. Treatment is mostly supportive. Hydroxychloroquine, remedesevir and other options are under studies but none have showed any clear effectiveness till now. Remdesevir has recently shown some encouraging results and is currently the only drug shown to be of some benefit. US president Donald Trump and Dr. Oz (Physician and TV star) vastly popularized the Hydroxychloroquine use for COVID 19. This was originally suggested by controversial French Didier Raoult. FDA did an emergency authorization for HCQ. However, European registration authorities refused to authorize the drug as is its effectiveness was largely unsubstantiated. A physician should be a scientist and a researcher. He should follow scientific evidence. Remember that expert opinion of a single physician / professor is the lowest form of evidence and can never be a substitute for a clinical trial. Anecdotal evidence does not equal facts. HCQ does have in vitro effect against SARS COV 2 at higher doses. However, in medicine time and again we see that just based on in vitro effect or ideal mechanism of action, clinical outcomes in patients cant be identical all the time.
HCQ SHOULD NOT BE USED AS A TREATMENT FOR COVID INFECTION:
Let me explain this with the help of digoxin and thalidomide. Digoxin was used as a treatment for heart failure for decades. Its a drug that improves the contractility of the heart and in a failing heart that was unable to pump, it seemed to be the logical drug to go for. Results showed that use of digoxin in patients with heart failure was actually increasing mortality in those patients (basically killing them faster) and its use was stopped based on that evidence. An alternate approach of slowing down the heart with beta blockers was introduced that resulted in lesser ischemic burden on the heart . Thalidomide has a similar story behind it. It was introduced by German pharmaceutical to effectively treat nausea and vomiting for pregnant women based on similar models that did not have any robust clinical evidence. Babies born to mothers taking thalidomide had severe limb abnormalities. Based on the Thalidomide tragedy strict rules were put in place in the USA for the authorization of any medication.
The point being that at higher doses HCQ does have an in vitro effect on SARS COV 2 but at the same high doses , the cardiac effects are also increased. Those downplaying the cardiac effects state that since it has been used for inflammatory arthritis, malaria and lupus, its a safe medication and hence no harm in using it. Well the doses needed in those conditions are relatively lower. HCQ For Malaria , 800 mg then 400 mg at 6, 24 and 48 hours. For Lupus 400 mg OD and RA 600 mg OD. Combining this drug with a drug that is known to prolong QT interval by itself (Azithromycin) increases the risk of ventricular arrhythmia.
The fact of the matter is that one is not stating that HCQ is ineffective. There is no conclusive evidence to suggest that it is effective. A recent study in NIH University of Virginia showed that HCQ was associated with an increased mortality. The use of HCQ should be limited to clinical trials and roughly within the next 2 months we will have more data that would guide its further use or avoidance.
Famotidine use is also becoming a point of interest where studies have shown that those that were already using this medication for GERD/ dyspepsia had better clinical outcomes than those that were not using it, showing protease inhibitor activity that theoretically is thought to retard viral replication. This again is not the point to hoard famotidine but to wait for clinical trials to complete , to show whether it definitely works or not.
DOCTORS WITH HUGE FOLLOWING AND MISINFORMATION:
People blame politicians and world leaders who downplayed and misrepresent the current crisis but there were few well informed doctors who also could not gauge the severity of the current situation. The sad part being that such doctors have a very large following and their advice can lead to a lot of people taking their opinion as proven fact. One such instance is that of Dr. Drew who is a board certified physician in USA. He stated that the Flu is vastly more consequential then the Corona Virus and that Corona virus was way less virulent than the flu. He made these statements in February. In March , he laughed out the possibility of lock downs. These statements were made on television. He was severely criticized on social media particularly twitter. Dr. Drew ultimately issued an apology as he stated that he became ” part of a chorus” that made those claims. It gets very tricky in such situations and as medical professionals its becoming more and more evident that we have to be extremely responsible in what we post as it can come back to haunt us big time if there is no scientific evidence behind what we are stating. Relying on hunches alone wont help.
COVID 19 PREVENTION IS BETTER THAN CURE:
To reduce the risk of transmission basic prevention methods have been repeated a million times. just to repeat once more.
Wash hands diligently for at least 20 seconds while singing your favorite song
Practice respiratory hygiene (eg, cover whilst cough followed by hand washing),
Avoid crowds and close contact with sick individuals and practice social distancing to flatten the curve.
Sanitize your mobile phone… Its the dirtiest piece of equipment we carry.
Wipe your car steering wheel and gear clean before using it.
If you are a smoker, right now is the best time to QUIT. Vaping and e cigarettes are also harmful. Give your lungs a fighting chance – at least.
Make washing your hands a sane ritual.
PSYCHOLOGICAL ISSUES DUE TO COVID 19:
However, some people have taken precautions to an all new level. The psychological effects of the constant fear that is being propagated is also influencing vulnerable people disproportionately. I have come across a friend who is making his family wash their hands every 30 minutes, washing every can or plastic bottle from outside, wearing masks everywhere, ordering hydroxycholoroquine in bulk for prophylaxis, already completed 2 courses of antibiotics (the indication for which was quite dubious). He uses gloves for each and everything and has developed severe anxiety, always glued to the television and keeping a count of death rates and data from various sources.
Prior to COVID , this gentleman was a healthy and normal person with no significant past medical or psychiatric history including OCD (Obsessive compulsive disorder). But the whole situation adversely affected him in such a manner that it lead to this response. I tried to counsel this friend and stressed upon the need to be logical / practical rather than paranoid about it. You cannot completely escape germs / viruses. All you can do is minimize your risk. But paralyzing one’s life thinking about the virus every second of every hour wont help.
COVID 19 MORTALITY AND DEATH RATES
The proportion of severe disease can vary with location. According to uptodate , in Italy, 12 percent of all detected COVID-19 cases and 16 percent of all hospitalized patients were admitted to the intensive care unit; the estimated case fatality rate was 7.2 percent in mid-March. In contrast, the estimated case fatality rate in mid-March in South Korea was 0.9 percent. This may be related to distinct demographics of infection; in Italy, the median age of patients with infection was 64 years, whereas in Korea the median age was in the 40s.
This example is a very good representation of the general pattern that COVID 19 is following at present. Old age, preexisting conditions are a risk factor for severe disease. But at the same time young people with no significant medical history can also end up with severe disease. What exactly is causing that , is a question that remains unanswered yet. Males are affected disproportionately in higher numbers based on the data from China and Italy,
The mortality of COVID 19 is still debatable (1 to 4 %) but its established that 15 to 20 % of the infected individuals will require some form of hospitalization. The health systems in the first world countries have been stretched to their limit and are struggling to cope with these admissions.
COVID 19 AND THE BIGGER PICTURE:
The main cause for this whole crisis needs to be addressed. This is not the 1st pandemic and this certainly wont be the last. As long as we keep invading the sacred spaces that for centuries were reserved for wildlife and we keep disrupting their food chains with rising extinctions , we will keep inviting Zoonotic infections like these more frequently.
Wildlife disruption in combination with modern day connectivity is a recipe for disaster. The solutions , even now are not heroic and acute, in fact they are quite boring. That is why nobody really gets excited.
Quarantine aiming to flatten the curve to avoid all admissions at once is a logical solution.
But this crisis has exposed our priorities. Education and health have been ignored completely and the remnants of these systems are at risk of being overloaded and run over. Our hospitals are virtually collapsed on a good day and struggle to cope with patient flow, let alone a potential crisis.
In such times, people are more sensitized and willing to make changes. Our responsibility is to ask the question why our health sector is so under developed. Why we have to run after ventilators at the very last moment. What good will these ventilators do if there are not enough trained staff to operate them.