GINA FERAZZI / LOS ANGELES TIMES Riverside County medical personnel administer a coronavirus test to a motorist at a drive-thru testing facility at Diamond Stadium in Lake Elsinore, California, on March 21. Those tested have symptoms or have had a risk of exposure.
SAN JOSE, Calif. Monica and Adrian Arima both were infected by COVID-19 at the same time on the same Nile River cruise, probably during a shared dinner buffet between the Egyptian cities of Aswan and Luxor. As they traveled home to Palo Alto, California, the couples early symptoms body aches and low-grade fever were identical.
But then, mysteriously, their experiences suddenly diverged. Monica spent 13 days at Stanford Hospital; Adrian was there for just three days. She needed extra oxygen and an experimental drug; he didnt.
Now, weeks later, she still has a cough. He is fully recovered, healthy enough to go food shopping and do other errands. Meanwhile, two of their traveling companions in their 70s and 80s tested positive but never suffered symptoms.
Their experience illustrates one of the many puzzling questions raised by the lethal new disease: Why is COVID-19 so inexplicably and dreadfully selective? The difference between life and death can depend on the patients health and age but not always.
To understand, scientists are scrutinizing patients medical histories, genomes and recoveries for any clues to explain this mystery.
Why are some people completely asymptomatic, some have mild disease, others have severe disease but recover and others have fatal disease? We are still trying to figure this out, said Dr. Brian Schwartz, vice chief for clinical affairs in UC San Franciscos Division of Infectious Diseases.
For most, not severe
It is a small subset of people that will go on to develop serious disease. Most will not, he said. We want to learn how to prevent people from developing serious disease and if they do, figure out how to treat it the right way.
Its well-known that death rates are higher among older people. Only 0.2% of people younger than 19 die. But for people between the ages of 60 and 69, the death rate is 3.6%. It jumps to 8% to 12.5% for those between ages 70 and 79, and 14.8% to 20% for those older than 80.
But theres more to it than that. Monica Arima is age 64; her husband, Adrian, is 70. But she has asthma and diabetes, while his underlying health is good.
Emerging U.S. data confirms trends seen in China and Italy: Rates of serious COVID-related symptoms are higher in those with other medical problems and risk factors, such as diabetes, hypertension, chronic obstructive pulmonary disease, coronary artery disease, cerebrovascular disease, chronic renal disease and smoking. In a U.S. Centers for Disease Control report released Tuesday, higher percentages of patients with underlying conditions were admitted to the hospital and to an ICU than patients without other health issues.
There may also be a genetic influence.
One of the things that weve learned from human genetics is that there are extremes at the human phenotype distribution, and pathogen susceptibility is no different, Stanford geneticist Carlos Bustamante told the journal Science. Stanford is part of a COVID-19 Host Genetics Initiative, a Finnish effort to link genetic variants associated with COVID-19 susceptibility and severity.
There are going to be people who are particularly susceptible, and there are going to be those who are particularly resistant, he said.
At the cellular level
Biologically, whats going on?
One leading theory is focused on the doors of a cell that permit the virus to enter. We know that the virus enters the body through epithelial cells in the respiratory tract. To get inside the cell, the virus uses a door a receptor called ACE-2 (angiotensin converting enzyme 2) on the cells surface.
Individual variations in this receptor could make it harder or easier for the virus to enter, cause infection and burrow deep into the lungs. In some of us, the cell door may open easily; in others, it may stay closed.
Or perhaps some people simply have more of these receptors on their cells. With more doors, the virus may enter more readily, so patients suffer worse infection and more serious disease, said Schwartz.
Theres an abundance of this ACE-2 receptor in cells in the lower lung, which may explain the high incidence of pneumonia and bronchitis in those with severe COVID-19 infection.
Once someone is infected, their immune systems response to that infection is likely the next big decider of their fate.
Doctors are discovering that nine or 10 days into the illness, theres a fork in the road. In most people, the immune system launches a carefully calibrated and effective response, so they recover. But in others, the immune response is too aggressive, triggering massive inflammation in whats called a cytokine storm. Immune cells are overproduced and flood into the lungs, making it hard to breathe and leading to often fatal acute respiratory distress syndrome. Those people develop sepsis, then acute kidney and heart damage. By day 20, they may be dead.
Why does the immune system misbehave? One reason may be age. As we get older, our immune response grows less accurate. It doesnt respond as effectively, and it is not as well-regulated. Genetics may also play a role.
Finally, other preexisting illnesses seem to elevate our risk, although the precise mechanisms arent known.
There may be something about these illnesses that causes them to have an abundance of ACE-2 open doors on the cell surface, Schwartz speculated.
Or perhaps the viral infection worsens the underlying diseases.
Not just the lungs
While typically considered a threat to the lungs, the virus also presents a significant threat to heart health, according to recently published research.
Cardiovascular disease, for example, is an inflammatory condition; so is COVID-19, said cardiologist Dr. Michelle A. Albert of UC San Francisco and president of the Bay Area American Heart Associations board of directors.
New research shows that the inflammatory response of a cytokine storm can lead to heart failure.
The circulating cytokines released during a severe systemic inflammatory stress can lead to atherosclerotic plaque instability and rupture. And infections can trigger an increase in myocardial demand.
Against the backdrop of existing inflammation, it could set off a cascade that results in a worsened underlying biological system, she said.
Some cancer treatments including chemotherapy, targeted therapies, immunotherapy and radiation can weaken the immune system, making a patient more vulnerable.
And if the airways of the lungs already are impaired by illnesses such as cystic fibrosis, asthma, emphysema or surgery, that person is much more susceptible to a pathogen that enters and infects the injured tissue.
People living with cystic fibrosis particularly need to be cautious because they already have compromised lung function and are susceptible to chronic infections, said Ashley Mahoney of the Cystic Fibrosis Foundation.
That likely explains the different courses of illness experienced by singer songwriter John Prine and his wife, Fiona, both infected during a recent tour in Europe. Fiona has recovered. But Prine, a survivor of lung cancer surgery, is hospitalized and critically ill.
Also at risk is anyone who must take medication to suppress their immune systems, such as organ transplant recipients.
Viral infections are always hard on people with diabetes, according to the American Diabetes Association. Thats because infection can cause the body to produce higher levels of certain hormones, such as adrenaline or cortisol, which counter the effects of insulin. Patients may develop a dangerous condition called diabetic ketoacidosis.
Patients come in all different kinds, said Monica Arima.
Some, like my husband, recover at home, without much help, she said. But I got knocked down.
- Human genetics - Wikipedia - June 22nd, 2020
- human genetics | Description, Chromosomes, & Inheritance ... - June 22nd, 2020
- Human Genetics - David Geffen School of Medicine at UCLA - June 22nd, 2020
- Genetic Mutations as a Tool To Predict Lifespan and Fertility - Technology Networks - June 22nd, 2020
- Human Genetics Market Analysis with Key Players, Applications, Trends and Forecasts to 2026 - Farmers Ledger - June 22nd, 2020
- China Is Collecting DNA From Tens of Millions of Men and Boys, Using U.S. Equipment - The New York Times - June 22nd, 2020
- Researchers identify environmental components that affect gene expression in cardiovascular disease - The South End - June 22nd, 2020
- China collects DNA from millions of men and boys - BioNews - June 22nd, 2020
- Exposure and engagement with tobacco-related social media and associations with subsequent tobacco use among young adults: A longitudinal analysis. -... - June 22nd, 2020
- COVID-19 Test Samples: Why Do We Swab Instead of Spit? - The Wire - June 22nd, 2020
- Coronavirus news and updates: Does Florida's spike in cases make it a new 'epicenter'?; mask rules on airplanes from the FAA - USA TODAY - June 22nd, 2020
- The beauty of flaws - NCC Linked - June 22nd, 2020
- Study finds genetic factors that make some more susceptible to Covid-19 - Health24 - June 22nd, 2020
- Assessment of COVID-19's Effect on Precision Medicine Software Market 2020-2024 | Benefits of Precision Medicine to Augment Growth | Technavio -... - June 22nd, 2020
- Wellness Experts Discuss The Importance Of Individualizing Your Approach To Health - Forbes - June 22nd, 2020
- 1.4 million for genetics research on how obesity in pregnancy affects mother and baby - Mirage News - June 9th, 2020
- Aerpio Hosting Key Opinion Leader Call on a Novel Mechanism for the Treatment of Glaucoma - GlobeNewswire - June 9th, 2020
- Amgen To Present At The Goldman Sachs 41st Annual Global Healthcare Conference - Monterey County Weekly - June 9th, 2020
- COVID-19 Pandemic: Global Risks of More Complex Character and the Visions of the Future World - Valdai Discussion Club - May 19th, 2020
- Rothamsted turn to harvesting coronavirus data - Lab News - May 19th, 2020
- Complement genes add to sex-based vulnerability in lupus and schizophrenia - UAB News - May 19th, 2020
- DU to set up School of Public Health - The Indian Express - May 19th, 2020
- Covid-19 research: 45 Bengaluru startups working on medicine, testing methods and vaccine - Economic Times - May 19th, 2020
- Immortalized Cell Line Market Development, Trends, Key Driven Factors, Segmentation And Forecast to 2020-2026 - Cole of Duty - May 19th, 2020
- Worlds Shortest Population Reveal the Largest Genetic Contributor to Height - Technology Networks - May 15th, 2020
- Group of Genes Have Altered Expression in Autism - Technology Networks - May 15th, 2020
- Why can two young and healthy individuals be affected so differently by coronavirus? - Health24 - May 15th, 2020
- Amgen To Present At The Bank Of America Merrill Lynch Virtual Global Healthcare Conference - BioSpace - May 15th, 2020
- Viewpoint: Darwin's 'Descent of Man' is both deeply disturbing and more relevant than ever - Genetic Literacy Project - May 15th, 2020
- Study Finds Low Proportion of Individuals With Autism Receive Recommended Genetic Tests - Technology Networks - May 15th, 2020
- Cats can catch Covid-19 from other cats. The question is: Can we? - STAT - May 15th, 2020
- Deficient Expression of DGCR8 in Human Testis is Related to Spermatoge | IJGM - Dove Medical Press - May 15th, 2020
- Prevail Therapeutics Reports First Quarter 2020 Financial Results and Business Highlights - GlobeNewswire - May 15th, 2020
- Fulcrum Therapeutics, Inc. (FULC) Q1 2020 Earnings Call Transcript - The Motley Fool - May 15th, 2020
- Scientists concerned that coronavirus is adapting to humans - The Guardian - May 11th, 2020
- Coronavirus quickly spread around the world starting late last year, new genetic analysis shows - CNN - May 11th, 2020
- Your genes could determine whether the coronavirus puts you in the hospital and we're starting to unravel which ones matter - The Conversation US - May 11th, 2020
- Yes, COVID-19 is mutating, here's what you need to know - ABC News - May 11th, 2020
- Conservatives Are Not the Only Ones Who Ignore Facts and the Science - Merion West - May 11th, 2020
- Coronavirus in Scotland: Charity warns Covid will cause a spike in ME cases - as it calls for 'harmful' exercise treatment to be banned -... - May 11th, 2020
- Dr. Misaki Wayengera: The Man Behind Uganda's Covid 19 Test Kits - New Vision - May 11th, 2020
- Its In The Genes? Scientists Think Coronavirus Exploits Silent Hidden Mutations In The Body - International Business Times - May 11th, 2020
- From blood clots to 'Covid toe': Experts confounded by series of medical mysteries - The Straits Times - May 11th, 2020
- MET 2020 Slot booking to commence on July 15, Examination dates available at manipal.edu - Jagran Josh - May 11th, 2020
- Vitagene Launches The First FDA Authorized Saliva based Zero Contact COVID-19 At Home Test - Business Wire - May 10th, 2020
- Genetics in focus after coronavirus deaths of siblings and twins - The Guardian - May 10th, 2020
- 'An anvil on my chest': What it's like to have COVID-19 - LancasterOnline - May 10th, 2020
- Coronavirus may have spread to humans as early as October 2019 - study - The Jerusalem Post - May 10th, 2020
- Team reveals genomic history of ancient civilizations in the Andes - UC Santa Cruz - May 10th, 2020
- Regeneron Reports First Quarter 2020 Financial and Operating Results - BioSpace - May 10th, 2020
- Scientists at Ben-Gurion University of the Negev Develop Anti-Coronavirus Surface Coating Based on Nanomate... - The Auto Channel - May 10th, 2020
- COVID-19 and food security - Fitzwilliam College, University of Cambridge - May 10th, 2020
- Val Sheffield elected to the American Academy of Arts and Sciences - Iowa Now - May 1st, 2020
- DNA gives clues into risk of developing Alzheimer's disease and other dementias - Alabama NewsCenter - May 1st, 2020
- Rare Gene Discovered That Nearly Doubles Risk of Developing a Neurodegenerative Disease - Clinical OMICs News - May 1st, 2020
- Progress in understanding the genetic basis of mental health - SFARI News - May 1st, 2020
- Coronavirus was widespread in UK at very start of pandemic, says genetics expert - Sky News - May 1st, 2020
- This is how you do the genetics heritage filter on Instagram that everyone's doing - The Tab - May 1st, 2020
- COVID-19 vaccine in Ireland could take a year and a half - IrishCentral - May 1st, 2020
- MRC scientists elected Fellows of the Royal Society - Cambridge Network - May 1st, 2020
- Parkinson's discovery implicates "second brain" in the gut - New Atlas - May 1st, 2020
- Humans: are we the most effective vector of disease? - BugBitten - BMC Blogs Network - May 1st, 2020
- Could genetics explain why some COVID-19 patients fare worse than others? - Live Science - April 27th, 2020
- Human Genetics Market Overview, Top Companies, Region, Application and Global Forecast by 2026 - Latest Herald - April 27th, 2020
- American Academy of Arts & Sciences Elects UVM's Wallace to Its Membership - UVM News - April 27th, 2020
- The PBS documentary The Gene showcases genetics promise and pitfalls - Science News - April 9th, 2020
- Few clinical trials are done in Africa: COVID-19 shows why this urgently needs to change - The Conversation Africa - April 9th, 2020
- UCLA web app will enlist publics help in slowing the spread of COVID-19 - Newswise - April 9th, 2020
- COVID-19: Few Clinical Trials are Done in Africa. This Needs to Change ASAP. - The Wire - April 9th, 2020
- 'Behavioral suppression' needed to decrease coronavirus infections in Japan: experts - The Mainichi - April 9th, 2020
- The secret call of the wild: how animals teach each other to survive - The Guardian - April 9th, 2020
- Yann Joly on the fight against genetic discrimination - McGill Reporter - April 2nd, 2020
- Science to the rescue? How modern genetics could help save the world from coronavirus - Genetic Literacy Project - April 2nd, 2020
- Oldest human genetic data gleaned from 1.8-million-year-old tooth Haaretz - News Collective - April 2nd, 2020
- Science to the rescue? How modern genetics could help save the world from coronavirus - Alliance for Science - Alliance for Science - April 2nd, 2020
- BHU department claims to have discovered new technology to test COVID-19 - Jagran Josh - April 2nd, 2020
- Stealth BioTherapeutics Reports Fiscal Year 2019 Financial Results And Recent Business Highlights - BioSpace - April 2nd, 2020
- Researchers at U of T developing antibodies to 'neutralize' novel coronavirus before it invades cells - News@UofT - April 2nd, 2020
- What is coronavirus and Covid-19? An explainer - KTVZ - April 2nd, 2020
- Plasmid Market was Valued at US$ 89.52 million in 2018 and is Estimated to Reach US$ 447.68 Million by 2027, growing at a CAGR of 19.5% over the... - April 2nd, 2020