Coronavirus update

Every week brings new developments to understand about coronavirus. Here we go!

1.  How long does someone remain infectious? We have three ways to collect information about this question. 1. How long does a patient feel ill? 2. How long is the viral PCR (polymerase chain reaction) test positive, and 3. What do the antibody tests show? Unfortunately, none of these tests alone or in combination is absolutely definitive of how long someone may remain infectious to others. And like most biological variables, there will be a range with outliers. In other words, 90% of people may be infectious for 10 days after symptoms begin, but some people may be free of virus in 7 days whereas others might remain infectious for 3 weeks. This is important because we have to know when to allow persons back to work or when to remove them from quarantine. We will continue to learn more and refine our knowledge about how long someone remains infectious.
2.  Why do some people get “false negative” results? A false negative result means the person is truly infected with coronavirus but the test is incorrectly reading negative. This can happen for a variety of reasons. First of all, the test may have not been done correctly with the nasal swab. If the swab doesn’t reach the back of the nose, the virus might be missed. Secondly, there can be problems with the reagents, or chemicals, used to transport the sample. Thirdly, the test may be faulty in picking up the viral RNA or viral genetic material. And, finally a clerical error can be made with reporting. If a person has very typical symptoms for coronavirus such as high fever, cough and muscle aches, a negative test should be viewed cautiously, and the person should be re-tested twice. If three tests are negative, that would be very convincing that the person is truly negative for the virus. Given the scarcity of testing, this is not always easy to accomplish, but it is necessary if the consequence includes potentially sending an ill individual back to work where they could infect others.
3.  Why are young people getting strokes? This is a very frightening development. Strokes result from either a blocked blood vessel to the brain or a bleed in the brain. These strokes in people in their 20s and 30s are resulting from clotting that is occurring in the large vessels supplying blood to the brain, such as the carotid arteries. This is highly unusual as carotid strokes almost always occur in people older than 60 with cardiovascular risk factors such as smoking, hypertension and high cholesterol. The coronavirus is causing clotting in blood vessels both large and small. We have also seen patients getting blood clots in their legs as well as in the vessels supplying the kidneys. We know that part of the body’s reaction to overwhelming infection, called sepsis, is a dysregulation of the clotting cascade. In fact, there is a syndrome called DIC or disseminated intravascular coagulation that is a well-known severe complication of sepsis. It is just highly unusual to see the clotting problem begin in the large arteries in the necks of young people.
4.  What are the new symptoms for coronavirus officially added to the list? Though this will not surprise you, the CDC added the symptoms of chills, recurrent chills, muscle pain, sore throat, headache and new loss of taste or smell to the former trinity of fever, cough and shortness of breath.
5.  How far do infected particles travel through the air? The CDC recommends that people stay 6- feet apart. Our natural perception, therefore, is that 6 feet is some kind of magic number. In other words, if we maintain a distance of 6-feet from others we cannot become infected by them. False! The 6-foot suggestion simply means that the risk of getting infected is reduced, but by no means does the risk fall to zero. Why? Because an infected person is breathing out or worse yet coughing out infected aerosolized particles that can remain in the air. A cough spews particles of different sizes. The heavier particles fall to the floor, but the smaller lighter particles remain suspended in the air. MIT researchers demonstrated that coughed particles could travel 16 feet and sneezed particles could travel 26 feet. This is why we strongly encourage people to cough or sneeze into the crook of their arm. It is estimated that an infected person talking for 5 minutes emits as much virus as a person coughing one time. The size of the room and the adequacy of ventilation also has bearing on how transmissible the virus can be. A small room with poor ventilation is the worst scenario. We are all now convinced that wearing masks helps reduce transmission. A mask prevents some of the larger infected droplets from getting out into the air. A mask also prevents the inhalation of some larger particles but does not protect against inhalation of smaller infected particles floating in the air.

 Our best guidance suggests that we become infected primarily in two ways: inhaling the virus or touching the virus to our mouths. Based on our understanding of how other coronaviruses work and how influenza works, the inhaled route is likely the primary one. It is felt that the risk of inhaling the virus while outdoors is vanishingly low.

6.  What is Pepcid and how could it possibly work against the virus? This was one of the stranger headlines I have seen in the last week. Pepcid, also known as famotidine, is in a class of anti-acid drugs called H2 or histamine blockers. This drug, along with its better-known cousin, Zantac, has been around for several decades, and known to be a remarkably safe and effective treatment for excess stomach acid. It is not uncommon that we learn through serendipity that a drug used for one indication actually works for another. But this one is really surprising and may turn out to be completely useless for coronavirus. The story came to light because the observation was made in China that patients who were taking Pepcid seemed to “do better” with coronavirus infection than patients who were not on it. These kinds of observations are important and must be verified in well-controlled studies. Unfortunately, it is natural to run towards the next shiny object and turn hope into expectation. Fortunately, Pepcid is both more available and much safer than hydroxychloroquine – the last shiny object to garner attention. 

7.  Why don’t we do more plasma transfusions? Transfusing a sick coronavirus patient with plasma from a recovered patient is the most promising treatment seen to date. So why don’t we do it more? First of all, it is a little complicated. You need a lab that is capable of drawing off the recovered persons blood, spinning it down, and separating off the plasma from the cells. Then, the plasma can only be given to a patient with a similar blood type – usually A, B or O. In addition, the plasma has to be checked for other viruses such as hepatitis B, C and HIV. The plasma must then be transported to the patient and transfused. The cost for the whole routine is around $1,000. The challenge is more around getting the right lab personnel to organize the procedure than the cost, which is next to nothing compared to the entire cost of a multi-day ICU stay.

8.  What is the endgame? Though I don’t have any inside knowledge about this, I think we know enough from observing the virus here and in other countries to make some pretty good guesses. First of all, widespread testing is required to understand who has the virus with the PCR test and who has already had the virus with IgM and IgG antibody testing. We will need an improvement in the quality and quantity of both tests. Second, we need to ramp up contact tracing ability. This will allow us to more quickly tamp down new flare-ups of the virus. Third, we should definitely consider mandatory quarantine in separate quarters, such as unused hotels, for newly diagnosed persons to help reduce further transmission to family members and others. Fourth, we need to keep up social distancing as much as we can stand in order to stamp out random transmission of the virus. We would also benefit from a nationally coordinated strategy so states don’t end up undermining each other with differing approaches. Finally, we could get lucky and the virus will morph to a less virulent strain; otherwise we will have to wait for a vaccine which will likely take 12 to 18 months.

9. Late breaking news – Remdesivir. Is it any good? Please don’t get too excited. Dr. Fauci stated today the drug looks promising based on one trial. We have not seen those numbers yet. Is it a 30% improvement, 20% or 10% -- we don’t know. Unfortunately, a second trial showed no benefit from Remdesivir. Remdesivir, manufactured by Gilead, has been FDA approved for several years, and must be given intravenously. If it turns out to be helpful, it may only be marginally to somewhat helpful. “One swallow doesn’t make a Spring…”