Categories
Epidemiology

When It Comes To COVID-19, Are We Testing The Right Thing?

During this COVID-19 outbreak, I have the dual roles of overseeing our hospital’s response to the pandemic and also of rounding in our ICU and taking care of COVID patients first-hand. One of issues that I struggle with in both of these roles is how accurate is our testing? Currently, we have 3 ways that we test for active COVID-19 infection: a nasopharyngeal swab for a rapid molecular test (made by Abbott Corporation), a nasopharyngeal swab for a PCR (polymerase chain reaction) test, and bronchoalveolar lavage fluid for a PCR test. We use the first two a lot and use the last one rarely. But do we have this backward?

The rapid molecular test by Abbott is very quick and our lab can have the results in < 1 hour. The criticism of this test is that it is less sensitive than the PCR tests so you can miss patients who are infected with COVID-19, particularly if they have mild symptoms or are asymptomatic.

The nasopharyngeal PCR test is currently considered the “gold standard” test for COVID-19. It appears to be more sensitive than the Abbott rapid test so it pick up more patients infected with the virus. However, it takes longer – 8-12 hours if your hospital does testing for it in-house and 2-3 days if it has to be sent to an outside lab. We primarily use this test if the Abbott rapid test is negative and we still clinically suspect COVID infection or if a patient without symptoms needs to be cleared of having the infection prior to undergoing an elective surgery.

The bronchoalveolar lavage (BAL) PCR test requires the patient to undergo bronchoscopy, an invasive procedure that requires sedating the patient and can put hospital staff at risk due to aerosolizing infected lung fluids into the air. Doing bronchoscopy on patients with suspected COVID-19 infection is generally discouraged because of the risk to the staff and the risk to the patient of an invasive procedure. Therefore, we don’t do a lot of BAL COVID tests.

Most respiratory viruses affect either the upper respiratory tract alone or both the upper and lower respiratory tract. The upper respiratory tract consists of the nose and throat; the lower respiratory tract consists of the lungs. COVID-19 is unusual among respiratory viruses in that it primarily causes symptoms in the lower respiratory tract resulting in cough, low oxygen, and shortness of breath. COVID generally does not cause much upper respiratory tract symptoms, such as sneezing or a runny nose.

So one has to wonder, if COVID does not affect the upper respiratory tract, how good is testing nasopharyngeal secretions?  Most of us who care for patients with COVID infection have encountered patients who had 1 or more nasopharyngeal Abbott rapid tests or PCR tests that were negative only to have the 2nd or 3rd PCR test end up being positive. We are also now seeing patients who have multiple negative nasopharyngeal PCR tests who then get a bronchoscopy and their BAL COVID PCR test comes back positive.

We spend a lot of energy debating whether the nasopharyngeal Abbott rapid or the PCR test is the best test. But maybe we ought to be asking whether the BAL is really the best test. When asked why he robbed banks, Willie Sutton famously said “Because that’s where the money is”. For those patients who present to the hospital with COVID-like signs & symptoms but have a negative nasopharyngeal PCR test, we may need to start doing more bronchoscopies with BAL COVID testing before pronouncing those patients virus-free.

May 17, 2020

Categories
Epidemiology

Imagining Life After COVID-19

It is mid-April and physicians and hospitals are already planning on how and when to re-institute normal operations, like flowers poking through snow after a cold winter. But it is pretty clear that the normal operations of the future will not be like the normal operations of the past. I’m using this post to speculate on how things may be different.

Hand sanitizer will become the new tabletop condiment

If  you go to a breakfast restaurant, you’ll find pitchers of syrup and honey on the tables. At lunch and dinner, there will be bottles of ketchup, mustard, and hot sauce on the tables. In the future, look for bottles of hand sanitizer on your restaurant tables.

Obstetricians will be busy in January 2021

“Blizzard baby booms” are a debated phenomenon that lie somewhere between urban myth and obstetric reality. I am a member of the baby boom generation, a surge in babies born after soldiers returned to the U.S. after World War II and the Korean War. That baby boom was a reality but whether there is a mini-boom of babies born 9 months after hurricanes and blizzards keep people indoors for a period of time is more uncertain. A blizzard or hurricane keeps people cooped up together for just a few days but COVID-19 keeps couples isolating at home with little to do for weeks. Will the social isolation of March and April result in a lot of babies in December and January?

Infectious disease physicians will be hospital medical directors

In a war, Majors are promoted to Colonels and Colonels are promoted to Generals by demonstrated success in battle. Similarly, hospitals select their medical directors based on administrative success in leading individual hospital programs. Throughout the world, hospitals are having their COVID-19 response led by epidemiologists and infectious disease specialists. Those who successfully steer their hospital through the infection control and financial perils of the pandemic will find themselves in line for promotion to hospital leadership positions.

Surgical masks won’t just be for surgeons any longer

Wearing a surgical mask does help prevent one from becoming infected with respiratory viruses when an infected person coughs or sneezes in your face. But when everyone wears a mask, there are two other important infection control effects. First, if the person wearing the mask is unknowingly infected with a respiratory virus, it helps prevent that masked person from coughing or sneezing on others. Second, when a person is wearing a mask, it reduces the chance that the person will touch their nose, mouth, or eyes with hands that could have picked up respiratory viruses from fomites such as a door handle, shopping cart, or elevator button that harbored viruses. In the future, people may likely feel more safe when those around them are wearing masks and that may be doubly so for their doctors and nurses wearing masks. Look for future masks emblazed with people’s favorite NFL team, alma mater, or beer maker.

A COVID-19 PCR test will become a routine admission order

When most patients get admitted to the hospital through the emergency department, they get “routine admission labs” – generally a CBC and chemistry panel. Look for a COVID-19 test to be added to that list of routine tests. Right now, there is near-paranoia by many physicians that their patients will have asymptomatic and potentially contagious COVID-19 to the point that they will not do procedures unless their asymptomatic patients have a negative COVID-19 PCR test. Even then, many demand that they be allowed to wear an N-95 mask for patients with a negative test because of the theoretic possibility that the test is a false negative.

Public health nurses will have job security

Countries that have been successful in controlling the COVID-19 outbreak have had very strong case isolation and contact identification. This takes manpower – primarily public health nurses that can go out in the community to interview patients and do testing of contacts. Public health departments are often underfunded  and understaffed. There will be increased demand for public health nurses for the foreseeable future.

Don’t expect your hospital to replace the old MRI machine

Although many U.S. hospitals have their ICUs full of COVID-19 patients, their overall medical/surgical census is generally low. That is because elective surgical procedures have all been postponed. Not only are surgeries not being done but neither are non-emergent diagnostic tests such as MRIs, CT scans, cardiac non-invasive tests, and pulmonary function tests. Hospitals don’t make much money off of medical admissions and depend on those surgeries and diagnostic tests to show a positive financial margin at the end of the year. Currently, hospitals are burning through their reserves (“days cash on hand”) with all of these surgeries and procedures not being done. With days cash on hand depleted, hospitals will be postponing large expenditures over the next couple of years.

The handshake will be a custom of the past

When a patient is infected with COVID-19, their hand becomes a fomite that can transmit the virus to everyone that they touch. Overnight, the handshake has changed from a greeting of politeness to a gesture of threat. Look for the handshake to disappear as an American social convention.

Telemedicine will come of age

Until March 2020, telemedicine was relegated to a few specific circumstances and primarily used in rural, sparsely populated areas of the nation. With the federal government relaxing rules for telemedicine, physicians all over the country are realizing that a lot of routine outpatient care can be done by telemedicine. Medical practices are adopting video telemedicine platforms through their electronic medical record or through separate commercial video applications. I have found that video telemedicine works very well for many of my patients, for both new and return visits. For patients who lack transportation or who live long distances from the office, the convenience of a video visit is a game-changer.

Anti-vaccine proponents will finally be quiet

One of the reasons that anti-vaxxers have flourished is that enough other people get vaccines so that devastating diseases such as polio, measles, and hepatitis B are uncommon enough that herd immunity protects the anti-vaxxers. If there were no influenza vaccines, then even influenza could periodically be as threatening as COVID-19. The current pandemic is a reminder of just how deadly infectious diseases can be and how much they can disrupt the economic structure of a community. An effective vaccine against COVID-19 will hopefully silence the anti-vaxxers since COVID-19 is unlikely to otherwise go away – it will just periodically die back and flare up as long as there are immunologically susceptible people for it to affect. The older the anti-vaxxers get, the more likely they are to become critically ill and die should they become infected and this will hopefully motivate them to forget their conspiracy theories and get a COVID shot.

It will be safe to go outside when your doctor has a beard

All of a sudden, most doctors and nurses in the United States became clean-shaven. That was because they needed to get fit-tested for N-95 face masks and a couple of years ago, OSHA made a rule that men with beards could not undergo fit-testing. Because I normally see patients in the hospital in airborne isolation (for example, those who are suspected of having tuberculosis), I have had an annual N-95 fit test for many years. And each year, I always passed my fit test, even though I had a beard. When OSHA came out with their rule, I was no longer permitted to wear an N-95 mask and had to switch to a PAPR hood but with PAPRs in short supply nationwide, men who provide inpatient healthcare had to shave and be fit tested. Just like robins are the first sign of spring, doctors with beards will be the first sign that the hospitals are no longer full of COVID-19 patients.

April 16, 2020

Categories
Epidemiology

Droplets, Fomites, and COVID-19

The disease COVID-19 is caused by the virus SARS-CoV-2. This is a member of the coronavirus family. These are viruses that can infect humans, other mammals, and birds. Most coronaviruses are rather benign respiratory viruses that account for about 5-10% of annual colds and flu-like illnesses. But occasionally, a coronavirus will successfully jump from one species of mammal to humans. When this happens, humans have never encountered that particular strain of coronavirus and so we have no immunity against it. Recent examples of coronaviruses making this zoonotic jump include SARS (from bats) and MERS (from camels). Although we do not know for sure, it is believed that SARS-CoV-2 originated in bats.

Coronavirus are transmitted the same way as other respiratory viruses are transmitted, by droplets of respiratory secretions. There are two ways that droplets can spread the virus. Either an infected person can cough or sneeze in another person’s face with the result that those respiratory droplets land on the second person’s nose, lips, or face. Or, the the infected person can get those respiratory droplets on their hands by coughing into their hand or touching their nose or mouth with their hand; when the infected person’s hand then touches a surface such as a door knob, light switch, keyboard, or television remote control, then those droplets get passed to those surfaces.

Those surfaces now become fomites. A fomite is any surface that that can serve as a intermediary conduit to get a virus or bacteria from an infected person into another person so that the infection spreads. Fomites are coronaviruses best friends. Certain types of surfaces make better fomites than others. For example, copper surfaces kill viruses whereas stainless steel surfaces do not kill viruses. Smooth surfaces, such as metal of glass, make better fomites than porous surfaces, such as upholstery or fabric, because viruses and bacteria tend to get wedged in between the fibers of fabrics making them harder to be picked up by another person’s hands.

Face masks can help prevent spread of viral-laden droplets from an infected person to an non-infected person, both in the hospital and in public. In the hospital, doctors, nurses, and respiratory therapists wear masks when caring for patients with respiratory viruses such as coronaviruses because they often have to get close to infected patients who can cough or sneeze in their faces. So in the hospital, it is the uninfected people who should wear masks.

In public, it is just the opposite; the infected person should wear the mask and not the average uninfected person. As long as you are maintaining social distancing by standing 6 feet from someone who is infected, even if that person coughs, those droplets are going to fall to the ground by gravity before they reach you. By having the infected person wear the mask, when they cough, they cough into the mask, thus substantially reducing the ability of those respiratory droplets to reach someone else. In fact, when healthy people wear masks when they are out in public, those masks get moist from the humidity of breath and most masks tend to get colonized with bacteria and fungus that can then make that previously healthy person sick.

So, it turns out that most respiratory viruses don’t get transmitted through the air, they get transmitted by fomites. And that means that the most important way to prevent spread of those viruses is by washing one’s hands after touching fomites.

If I could only have one thing to reduce the spread of COVID-19, it would not be a surgical mask or a face shield, or an N-95 mask. What I would want instead is soap and water.

March 30, 2020

Categories
Epidemiology Intensive Care Unit

Re-Using N-95 Masks In The Time Of COVID-19

The geniuses at Battelle have done it again. This time, they have invented a process for sterilizing and re-using N-95 masks using vaporized hydrogen peroxide. Battelle Memorial Institute is a non-profit scientific research and development institute here in Columbus, Ohio that is located about 3 blocks from the OSU hospital. Researchers at Battelle were the ones who invented the photocopier (and then launched Xerox Corporation), the cruise control for automobiles, the first nuclear fuel for nuclear-powered submarines, and the reusable insulin pen for injecting insulin for diabetics. In full disclosure, about 25 years ago, I had a grant from Battelle to assist with development of inhaled chemotherapy for lung cancer and that led to my receipt of the endowed Battelle Professorship in Inhalational Therapeutics that I held until assuming my position as the medical director of our hospital.

N-95 refers to a mask that can filter 95% of airborne particles. In medicine, we use N-95 masks when we care for patients with infectious diseases that are transmitted by airborne routes, such as tuberculosis, disseminated varicella, and measles virus. The virus that causes COVID-19 is the SARS-CoV-2 virus and this is believed to be transmitted by droplet spread rather than by airborne spread. Normally, viruses spread by droplets do not require the use of N-95 masks; a simple surgical mask with a plastic face shield will suffice. However, certain medical procedures, such as endotracheal intubation, can result in aerosolization of droplets containing viral particles and that is when the N-95 masks are needed.

For an N-95 mask to work properly, a healthcare worker must be fit tested to determine which specific type of N-95 mask fits tightly against the face. If a type of mask does not pass the fit test, then it will not filter out 95% of airborne particles and is no better than a regular surgical mask. Everyone’s face is shaped a little differently so different people will need different N-95 mask types. All healthcare workers who use these masks are required to get fit tested once a year to ensure that the mask that they are wearing actually does what it is supposed to do. Recently, OSHA declared that men who wear beards should not be fit tested because beards can interfere with a tight fit of the masks. For many years, I always passed my fit test with a specific type of N-95 mask despite my beard but because of OSHA’s rules, I was not able to be fit tested last year. Two weeks ago, our hospital required all men who could be involved in the care of a COVID-19 patient to shave their beards (so that they can be fit tested for N-95 masks) and thus, I shaved for the first time in 37 years!.

N-95 masks have come to the forefront of public consciousness recently because the COVID-19 outbreak is causing many hospitals to run low on N-95 masks. A misconception has arisen that N-95 masks are safer than regular surgical masks plus a face shield. For day-to-day care of patients with COVID-19, this really is not true because unless you are performing a procedure such as endotracheal intubation, an N-95 mask is unnecessary. Overuse of N-95 masks in situations when they are not necessary now will result in inadequate supples of these masks in situations when they are necessary in the future. In addition, the over emphasis on N-95 masks could lead the public to overlook the single most important way to prevent the spread of viruses spread by droplets, namely washing one’s hands after they touch various surfaces that those droplets land on (such as door handles and elevator buttons).

With supplies dwindling, Battelle invented a process for sterilizing N-95 masks so that they can be reused up to 20 times. They built the equipment to process 160,000 masks per day and this would greatly improve the nation’s N-95 mask inventory. However, medical equipment is overseen by the Food and Drug Administration. The FDA would only grant Battelle’s mask sterilization equipment limited approval, meaning that they are only permitted to sterilize 10,000 masks per day and only here in Central Ohio. That’s good news for our hospital because now we can count on a steady supply of masks in the upcoming weeks of the COVID-19 surge. But it is bad news for every other hospital in the United States.

Desperate times call for desperate measures. This may be a time for the FDA to take the desperate measure of cutting through bureaucracy.

March 29, 2020

 

Categories
Epidemiology Outpatient Practice

Setting Up A COVID-19 Testing Station

In the era of COVID-19, there is a surge in demand for outpatient testing for the virus. When doing tests for regular influenza, patients generally come into their physicians offices and get a nasopharyngeal swab for a flu test in the physician’s office. But with COVID, it is necessary to reduce contact of suspected patients with other patients as well as with office staff. Furthermore, testing requires specialized masks, face shields, and disposable gowns that are generally not available in regular physician offices.

To meet the demand for testing while protecting our healthcare workers and community, we developed drive-up “swabbing stations” to do the tests. The goals were to minimize the time that patients were present in the testing area and minimize the staff exposure to the patients.

The challenge is that in order to track, log, and report tests, a patient must first go through a registration process. Furthermore, in a time of shortages of testing materials, testing needs to be limited to only those people who really need to be tested and not asymptomatic people who are anxious about the pandemic.

Our process was to establish a COVID-19 call center. Patients with symptoms contact their physician who then transfers or directs the patient to the call center. Volunteers in the call center ask the patients scripted questions to determine who requires testing and who does not require testing. Patients meeting testing criteria are registered in the electronic medical record and an order is entered for the test. That order is routed to the patient’s physician, or if the person does not have a physician, it gets routed to a designated physician in our health system – as the medical director our hospital, that often means me.

Patients are told to drive to a specific location and look for innocuous colored signs with arrows labeled with non-specific wording so as to not attract people who just show up without being screened and registered over the phone. They pull their car up to the testing station and a nurse with proper personal protective equipment comes to their window, confirms their identity, performs a nasopharyngeal swab, and the patient drives off. Patients who appear ill are directed to go to the emergency department; others return to their homes.

At our hospital, we chose a side entrance with a covered entryway that in past years led to the emergency department entrance but now is used as a drive-up/drop-off area for ambulances to bring hospital transfer patients to our hospital. We set up a second swabbing station in a parking lot on the University campus that was vacated with University classes all being converted to on-line during the outbreak. This second swabbing station was created using a portable enclosed tent with the ability of several cars to pull up simultaneously on either side of the tent.

The process is that once the patient is registered into the electronic medical record and the order is placed by the call center staff, the patients drive into the swabbing station and call the swabbing station phone number. Staff in the interior of the hospital entrance then print up patient labels for the specimens, pre-label the specimen tubes and then pass those tubes out to the nurse wearing personal protective equipment. That nurse goes to the car window and obtains the nasopharyngeal swab. The patient drives away and the nurse comes into the building and deposits the tube containing the swab into a plastic isolation bag held by another hospital staff member wearing PPE. Another staff member then takes the specimen to the lab for the test to be sent out to a commercial lab (we are currently doing tests on inpatients and employees with our internal hospital test and sending out the outpatient tests to a commercial lab).

I called one of the patients who tested positive over the weekend. She and her husband had returned from a trip overseas the week before. Her husband had mild cough and low grade fever that had since resolved. She had a bit more cough and fever to 101. Because the test takes a few days for the commercial lab to run, by the time her test came back, she was already recovering and no longer had fever or cough. She commented on how smooth and efficient the process went and how upbeat and encouraging the swabbing nurses were.

In Central Ohio, we are still early in the outbreak and the virus is not as prevalent as other parts of the world. Thus far, we have performed 3,000 tests, 1,146 of which have which have been completed. Of these completed tests, we have had 50 positive tests meaning that 4% of tests are positive and 96% are negative. We expect this to change in the next 2 weeks.

March 24, 2020

Categories
Epidemiology

Why Hospital Door Handles Should Be Made Of Copper

This morning, when walking in from my car to my office in the hospital, I had to open 6 doors and press 2 elevator buttons. With each door handle and elevator button, I was having contact with someone else’s fomites. Fomites are the small droplets that are formed when a person coughs or sneezes and are the primary way that respiratory viruses get transmitted. Bacteria, such as Staph aureus, are instead usually transmitted by skin contact with infected tissues, for example, by touching body secretions containing bacteria. In both situations, it is the hands that are the primary conveyance mechanism – whether they touch a person infected with Staph or whether a person with the flu blows their nose into a hand-held Kleenex. Anything that those hands touch can spread the viruses or bacteria in those fomites. Those door handles and elevator buttons that I touched this morning contain the fomites of hundreds of patients and hospital staff.

Certain materials are inherently more antimicrobial than others. Most hospital door handles are made of stainless steel or aluminum because steel and aluminum wipes off easily and because it’s shiny appearance looks clean. However, it turns out that steel and aluminum do not have antimicrobial properties so viruses and bacteria can survive on steel knobs, buttons, and handles for hours. Copper, on the other hand, has potent natural antimicrobial properties. This has been known for centuries – for example, copper water vessels were preferentially used in ancient times because water would be of better quality when transported in copper containers as opposed to containers made of other materials.

The medical literature about copper’s antimicrobial properties is extensive and it has been shown to inhibit/inactivate fungi (such as Aspergillus and Candida), viruses (such as influenza and polio), and bacteria (such as E coli, Clostridium difficile, and MRSA).

One of the problems with copper as a building material is that it tarnishes and then looks old and dirty. However, copper can be combined with other metals to form alloys such as brass (copper + zinc) and bronze (copper + tin) which are more commonly used for building fixtures. Although these alloys are better than steel with respect to their antimicrobial properties, then are not quite as effective as pure copper. For example, 99.9% of E. coli are killed within 120 minutes on copper surfaces but similar kill rates take up to 270 minutes on brass surfaces and 270 minutes on bronze surfaces. In contrast, E. coli can survive on stainless steel surfaces for weeks. The antimicrobial properties of copper are temperature dependent. At temperatures of 4 degrees C (40 degrees F), bacterial killing requires 1 hour longer than at 20 degrees C (70 degrees F).

As we renovate our hospitals in the future, we should look back to using copper and brass door handles, cabinetry fixtures, and buttons. Copper may not look as clean and sterile as stainless steel but looks can be deceiving. A $4 door handle may just have as big of an epidemiologic impact as a $20,000 ultraviolet room sterilizer…

March 10, 2020

 

Categories
Epidemiology

Why COVID-19 Mortality Is Higher In China Than The Rest Of The World

Initial reports from China in January 2020 was that the mortality rate of the novel coronavirus, COVID-19, was about 3%. Since then, the World Health Organization has been reporting daily mortality updates on its situation report website and the mortality rate has held at 3.4% in China. As of February 24, 2020, there have been 77,262 confirmed cases of COVID-19 in China with 2,595 deaths. However, outside of China, there have been 2,069 confirmed cases and only 23 deaths or 1.1%. So, why is the mortality rate of COVID-19 three times higher in China than anywhere else? When analyzing the outbreak, I believe that there is more than one reason.

Differences in hospital care

The United States gets a lot of criticism about poor overall national health compared to other economically advantaged countries. However, our nation’s poor health really relates to lifestyle issues (obesity, high numbers of suicide by gun, etc.) and outpatient healthcare (high percentage of uninsured citizens, poor access to primary care, high cost of medications, etc.). American inpatient hospital care is actually among the absolute best in the world. Similarly, Canadien and European nation hospitals provide great inpatient care to the sickest patients. On the other hand, many countries, such as China, lack the same ability to care for critically ill patients in their acute care hospitals and particularly in their intensive care units. The greatest danger of COVID-19 is respiratory failure and to successfully manage a large number of patients with respiratory failure, there has to be a well-trained population of critical care physicians, critical care nurses, and respiratory therapists. In addition, there has to be a sufficient supply of mechanical ventilators, monitoring equipment, and inpatient infection control practices in place. With SARS and Ebola outbreaks, the highest mortality rates were in those countries with the least ability to manage critically ill patients; in more economically advantaged countries, the mortality rates were much lower.

Virus detection rates

To accurately determine the mortality rate of a disease, you have to be able to identify every person who gets that disease. It is becoming clear that many patients with COVID-19 have milder forms of the disease and likely have gone undetected in China. In other countries, there have been efforts to track down and test any contacts of persons with confirmed cases of COVID-19 and as a consequence, milder cases are more likely to be detected in these other countries. When more of these milder cases are diagnosed, the ratio of deaths to confirmed cases falls resulting in a lower mortality rate. It is likely that there have been many more than 77,262 cases of COVID-19 in China and if that true number was known, then the mortality rate would likely be much less than the currently reported 3.4%.

Differences in the number of elderly and debilitated patients

In China, the outbreak of COVID-19 has struck large metropolitan areas, such as Wuhan (a city of 11 million people). Like influenza, the people who are most likely to die from COVID-19 infection are the elderly, the very young, and those people with chronic medical conditions. In cities such as Wuhan, there are large numbers of these vulnerable people living in close proximity to each other with the result that many elderly and debilitated persons become infected. Until this week, most of the cases outside of China have involved persons traveling from China. International travelers tend to be young and middle aged adults. Newborns, the very elderly, and those suffering from chronic disease tend to not do as much international travel. Those infected international travelers are therefore a select population of people who are best able to survive COVID-19 infection. This may be changing soon, with large numbers of domestically-acquired cases of COVID-19 being recently reported in South Korea and Japan.

Differences in quarantine practices

Here in the United States, the Centers for Disease Control has recommended a very high level of quarantine for patients with suspected COVID-19 infection including droplet, airborne, and contact isolation. This means gowns, gloves, negative airflow hospital rooms, and face shields. Many countries do not have the resources to provide this level of patient isolation. Indeed, persons suspected of having the infection are told to just stay home. In crowded, often multi-generational housing (such as exists in many Chinese communities), this quarantine practice can facilitate transmission to the vulnerable elderly, debilitated, and infants. In hospitals, sub-optimal isolation practices can facilitate transmission to other patients in that hospital and these patients with hospital-acquired COVID-19 are a select population of particularly vulnerable people who are more likely to die of the infection.

Lag-time differences

Death from COVID-19 does not occur instantly. There is first an incubation period of up to 14 days. Once a person develops symptoms, it takes several days to develop respiratory failure and die. The outbreak has been present in China for 2 months and so there has been sufficient time for those persons who get infected to develop symptoms and die of the infection. However, in other countries, patients with the infection have been identified and confirmed relatively early in their disease and in many cases, those people have not yet had time to develop respiratory failure and die.

Last year in the United States, an estimated 35 million Americans contracted influenza and 34,000 Americans died from influenza. That works out to about 1 death per every 1,000 people infected with influenza. The COVID-19 virus kills 34 out of every 1,000 people in China and about 11 out of every 1,000 people in countries other than China. If the outbreak spreads to the United States, based on these numbers we can expect COVID-19 to be about 10 to 11 times more lethal than influenza.

February 25, 2020

Categories
Epidemiology

The Novel Coronavirus 2019-nCoV

In December 2019, an outbreak of a new coronavirus began in Wuhan City, China. Within weeks, it had spread throughout China and to a number of other countries. This post will outline the history of the outbreak, what we have learned from other, previous coronavirus outbreaks, and what physicians and hospitals need to know about managing suspected patients in order to control the outbreak.

Coronaviruses are common upper respiratory viruses that generally cause fairly mild infections. They account for about 5-10% of common colds and cause typical cold-like symptoms such as fever, cough, and sore throat. Like other upper respiratory viruses, they are spread by aerosolized droplets and primarily occur in the winter months. The regular coronaviruses are detected with the standard respiratory viral PCR panels that most hospitals use. These panels detect other common viruses such as influenza, rhinovirus, parainfluenza virus, and others. Treatment is supportive and there are no effective vaccines or anti-viral antibiotics. As with all respiratory viral infections, patients admitted to the hospital should be placed on droplet isolation.

Sometimes, Coronaviruses Go Rogue

SARS.

From 2002 – 2004, an outbreak of a coronavirus resulted in SARS (Severe Acute Respiratory Syndrome). Overall, 8,098 people were known to become infected with 774 deaths, a 10% mortality rate. The natural host of the virus was the horseshoe bat and the outbreak was traced to a remote cave in Yunnan Province in China. From the bats in this cave, the SARS virus was spread to a masked palm civet, a cat-like wild animal in China that is often hunted for food. The civet was killed by a hunter and landed in a meat market in Guangdong, China in November 2002 where the virus then jumped to humans. Chinese health authorities were not forthcoming about the spreading Guangdong outbreak and did not report it to the World Health Organization (WHO) for several months, resulting in rapid spread of the infection due to a lack of public and healthcare worker awareness that it even existed. In February 2003, a businessman traveling from China became ill and was admitted to a hospital in Hanoi, Vietnam. An astute Italian physician working at the hospital, Dr. Carlo Urbani, recognized that the man’s infection was something different than regular influenza and notified the WHO. However, several healthcare workers at the hospital became infected; both the businessman and Dr. Urbani ultimately died of SARS. Meanwhile, a doctor from Guangdong unknowingly infected with SARS had traveled to Hong Kong where he stayed at the Metropole Hotel. He transmitted the virus to 16 international guests at the hotel who then traveled to Canada, Singapore, Viet Nam, and Taiwan, carrying the virus with them. On February 23, 2003, an elderly woman returning to Toronto from Hong Kong became ill with SARS and went to her local hospital. Canadien health authorities and healthcare workers did not have adequate infection control protocols in place and were unprepared for SARS and consequently within weeks, 257 people in Toronto were infected. In the United States, there were 27 cases and no deaths.

The incubation period for SARS ranged from 1-14 days but was usually 4-6 days. Like other coronaviruses, it was spread by droplets. With international efforts to stop the spread of the virus, the outbreak was contained and the last known case was in in January 2004. There are several lessons to be learned from SARS:

 

  1. Air travel permits rapid world-wide spread
  2. Don’t cover it up. By not being forthcoming about the emerging outbreak, Chinese authorities permitted the virus to quickly spread
  3. Rapid epidemiologic investigation is essential
  4. Countries must work together for epidemiological control
  5. Have a high clinical suspicion.
  6. Infection control works. Toronto did not have proper infection control practices in place, resulting in the Toronto outbreak
  7. Health personnel are at greatest risk

MERS.

From 2012 – 2015, another coronavirus caused the Middle East Respiratory Syndrome. Overall, 1,227 people became infected with an average mortality rate of 37%. The natural host was the dromedary camel and the virus made the jump to humans in Saudi Arabia. There were two main outbreaks of MERS, the first in Saudi Arabia in 2014 when 402 people became infected. The second outbreak occurred in 2015 when a businessman traveled from the Arabian Peninsula to South Korea, unknowingly infected with the MERS virus. Ultimately, 150 Koreans became infected and the main locations that these people acquired their infections were hospitals and clinics that were not prepared to institute proper isolation precautions and infection control practices. Ultimately, the South Korean outbreak alone cost $8.5 billion. The main symptoms of MERS were cough, shortness of breath, and fever. Chest x-rays showed patchy pneumonia or ARDS patterns. There are several sessions to be learned from MERS:

  1. A single missed infected person can cause a nationwide outbreak
  2. Hospitals and ERs can accelerate spread
  3. Doctors in community hospitals and clinics are the first line of defense
  4. New coronavirus strains can have a very high mortality rate
  5. Outbreaks are expensive

2019-nCoV

Wuhan City is the 7th largest city in China with a population of 11 million. To put that in context, New York City has a population of 8.6 million, Los Angeles 4 million, and Chicago 2.7 million. Wuhan is a traditional manufacturing hub and the political, economic, and commercial center of Central China. Its location on the Yangtze River as well as its location at the intersection of several rail lines and highways makes it one of China’s main transportation hubs. The main rail station sees up to 80,000 people per day and the airport serves 20 million passengers per year with direct flights to Tokyo, Paris, London, San Francisco, and Chicago among other international destinations. In December, 2019, a new coronavirus called the “novel coronavirus” or 2019-nCoV appeared in Wuhan City and is believed to have originated at a Wuhan market where wild and domesticated animal meats are sold.

As with the SARS outbreak, Chinese health authorities were slow to recognize and report the emerging infection. The result was that the virus rapidly spread through Wuhan City and from there, to other towns and cities in China. Within weeks, the virus had spread to many other countries throughout the world, including the United States. Like other coronaviruses, the presenting symptoms are fever, cough, and shortness of breath. The incubation period is 1-14 days. In some people, the infection is rather mild but in others, it can result in severe illness. The mortality rate is about 3%.

When should 2019-nCoV be suspected?

  1. Fever AND symptoms of lower respiratory infection AND either:
    • Travel from Wuhan City, China in the past 14 days
    • Close contact in the past 14 days with a person under investigation for 2019-nCoV
  2. Fever OR symptoms of lower respiratory infection AND:
    • Close contact in the past 14 days with a person with laboratory-confirmed 2019-nC0V

ALL of the following isolation procedures should be used in suspected cases in the emergency department and the hospital:

  1. Contact Isolation:
    • Gown
    • Gloves
    • Hand hygiene with soap and water (alcohol based hand sanitizer if soap & water not available)
  2. Droplet Isolation:
    • Mask
    • Face shield or goggles
  3. Airborne Isolation
    • Negative airflow room
    • N-95 mask or PAPR

What should you do if you have a  suspected case?

  1. Place patient in isolation immediately
    • In the ER or hospital: contact + droplet + airborne islation
    • In an office setting: put patients with a possible history in a private room with a closed door; give the patient, family members, and healthcare workers a regular mask until additional history is obtained to determine if the patient requires transfer to a hospital for full isolation and additional testing
  2. Obtain a full travel history
  3. Communicate with the hospital infection control personnel and the local health department to determine if the patient needs testing
  4. Currently, testing is only done at the CDC and requires prior permission from the CDC

When performing testing, ALL of the following should be submitted:

  1. Sputum or bronchoalveolar lavage or tracheal aspirate
  2. Serum
  3. Nasopharyngeal AND oropharyngeal swab/wash/aspirate

Importantly, the standard respiratory viral panel test used by most hospitals does NOT detect 2019-nCoV. Therefore, a positive coronavirus test on a respiratory viral PCR panel does NOT indicate 2019-nCoV and instead indicates one of the regular coronaviruses that typically cause a common cold.

All testing should be performed with the patient in proper isolation, including airborne precautions; testing should not be performed in regular emergency department rooms or clinic rooms that are not capable of negative airflow. There is no effective anti-viral for 2019-nCoV so treatment is primarily supportive. For those patients who develop respiratory failure and require mechanical ventilation, intubation should be performed in a negative airflow room with all isolation precautions and should be performed by the most experienced physician available (this is not a procedure for trainees). If a person believes that he/she might have 2019-nCoV, then they should call ahead to the emergency department so that their throughput can be expedited and avoid exposing other patients in the waiting area.

The mainstays of response to any epidemiologic threat are preparedness, surveillance, containment, and education. Even though 2019-nCoV is frightening, influenza remains a greater threat to Americans. The CDC estimates that last year, 35 million Americans became infected with influenza and 34,000 died. So, even if 2019-nCoV is not present in your community, always use standard infection precautions:

  • Maintain proper hand hygiene practices
  • Cover your cough
  • Stay home if you are sick
  • Get your Influenza vaccination
  • Use droplet isolation with any admitted patient with a suspected viral respiratory infection
The 2019-nCoV outbreak is a rapidly evolving situation so check the CDC website and the WHO website for updates.
February 1, 2020
Categories
Epidemiology

Predicting The Next Influenza Season

Last month, in August 2019, we have our first influenza case in our hospital. The patient recently returned from an international gathering so it is likely that he acquired the flu from a Southern Hemisphere resident attending the same gathering. The Southern Hemisphere has its influenza season at the opposite time of year as the Northern Hemisphere. A 2019 article in the journal Scientific Reports indicates that the epidemiology of influenza in Australia in any given season predicts the subsequent epidemiology of influenza in the Northern Hemisphere. So, what does the most recent Australian influenza epidemiology indicate?

The Australian Department of Health maintains a robust website with up to date influenza epidemiology information. The 2019 Australian data indicates that influenza started early this season as is depicted in the red line in the graph below.

Normally, influenza starts showing up in late May in Australia and peaks about the first of September. Australia started the onset of the 2019 influenza season in February, about 3 months earlier than usual, and it peaked about the first of July, about 2 months earlier than usual. So, let’s see how the Australian influenza data compares to information from the U.S. Centers for Disease Control influenza website:

In the above graph, we see the last 5 influenza seasons plus the 2009-10 season (the H1N1 epidemic) and the 2011-12 season. In 2009, the U.S. was caught off guard with the early arrival of H1N1 influenza that started in April and peaked in October. That year, 61,000 Americans got influenza and 12,500 Americans died of it (especially young persons). The 2017-18 influenza season (turquoise line in the graph) had the highest percentage of visits for influenza-like illness in the past 5 years. Comparing that curve to the 2017 Australian influenza season (brown line in the previous graph), there is remarkable similarity.

If the upcoming influenza season in the United States resembles the current influenza season in Australia, then it will start earlier than usual, perhaps in October rather than the normal December onset. The good news is that the most recent influenza season in Australia was not terribly severe with fewer hospitalizations and deaths than normal so hopefully this portends good news for U.S. hospitals and ICUs that may see fewer admissions and deaths from influenza.

What about the specific strains of influenza? Last year in the United States, influenza A H1N1 dominated early in the season in December (brown bars in the graph below). Influenza A H3N2 became the dominant strain by early March (red bars in the graph below). Influenza B was uncommon throughout the 2018-19 season until February and then it increased in prevalence when influenza A was decreasing (green bars in the graph below).

 

 

The graph below shows the various strains seen in Australia in the summer of 2019. Once again, influenza A peaked early in the season (red bars in the graph below) whereas influenza B peaked 4 months later (green bars in the graph below). Overall, influenza B accounted for a higher than usual percentage of the overall influenza cases in Australia. Influenza H1N1 all but disappeared shortly after the Australian flu season started and H3N2 was the dominant strain (although most of the Australian influenza A cases went unsubtyped). If the Australian experience predicts the upcoming flu season in the United States, then we should expect to see mostly influenza A H3N2 and also see a higher than normal number of influenza B this winter.

The 2019-20 U.S. standard strength influenza vaccine is quadrivalent and will cover the following 4 strains:

  1. Influenza A/Brisbane/02/2018 (H1N1)pdm09-like virus
  2. Influenza A/Kansas/14/2017 (H3N2)-like virus
  3. Influenza B/Victoria virus
  4. Influenza B/Yamagata virus

The vaccine is available in a standard strength that is indicate for persons over age 6 months and is made by several manufacturer, sold under brand names including Alfuria, Fluzone, Fluarix, and FluLaval. A high strength (Fluzone High Dose) contains about 4 times the amount of antigen and is indicated for persons over age 65. Unlike the quadrivalent standard strength influenza vaccine, the Fluzone High Dose vaccine is trivalent and does not cover the influenza B/Yamagata virus. This could have immunity implications if the U.S. sees an unusually high number of influenza B cases, as was seen in Australia this summer. Also, the Fluzone High Dose vaccine has a higher incidence of side effects such as injection site pain, fever, and myalgia. So the decision of which vaccine to use in persons age > 65 is not clearcut – the CDC does not recommend one vaccine over the other in people over age 65.

The good news for the upcoming influenza season is that we now have a new drug to treat influenza, baloxavir (trade name Xofluza®) that is given as a single one-time dose and will cost about $150. Tamiflu® is now available as generic oseltamivir at a cost of about $50 for a 5-day course.

So, what can physicians in the United States take away from this season’s Australian influenza season? Vaccinate your patients and do it now!

September 28, 2019