In the September issue of Cancer Research, Hannah Knochelmann, a student in the Medical Scientist Training Program at the Medical University of South Carolina (MUSC) and researcher in Chrystal Paulos’ laboratory, teamed up with investigators at three different NCI-designated cancer centers — MUSC Hollings Cancer Center, Emory Winship and the James at The Ohio State University — to report a new approach to generate T-cells faster for patients in the near future.

The human immune system contains two main types of T-cells: CD4 and CD8. This team cut down the time needed to manufacture T-cells from several months to less than one week by using a remarkably potent CD4 T-cell subset, called Th17 cells.

“In fact,” Knochelmann explained, “very few Th17 cells were needed to eradicate multiple different types of tumors effectively. This new milestone could widen inclusion criteria to promote access to T-cell therapy for more patients with metastatic disease.”

Adoptive T-cell transfer therapy, which is the transfer of therapeutic T-cells into a patient, is used in only a handful of institutions around the world. This makes a potent therapy inaccessible for the general population. These protocols often use billions of CD8 T-cells, which have cytotoxic properties that allow them to kill cancerous cells. However, it takes weeks of growth in cell culture to grow enough CD8 T-cells to be used in a single treatment. Paulos, who is Knochelmann’s mentor and director of Translational Research for Cutaneous Malignancies at Emory University, said, “What is most remarkable about this finding is that we can build on this platform to bring T-cells to patients all over the world.”

The best effector Th17 cells are grown in cell culture for only four days before being infused into the host. Any shorter or any longer in culture reduced the efficacy of the treatment. While the team could generate more Th17 cells over several weeks, more cells were actually equally or less effective compared with fewer Th17 cells expanded only four days. This finding highlights the potential that T-cell therapy can be administered to patients sooner, a discovery that has immediate clinical implications.

Another limitation of conventional T-cell therapy is that patients can relapse — cancer can return even after seemingly successful treatment. Therefore, Knochelmann and the team sought to develop a therapy that was long-lived while understanding factors that can prevent relapse. They found that day-four Th17 cell therapy provides a long-lasting response. Interestingly, IL-6 was a key cytokine in fueling these T-cells to prevent relapse after treatment. This cytokine destabilized the regulatory T-cells, the brakes of the immune system, which empowered the Th17 cells to kill cancer cells.

Paulos said the researchers want this data to inspire physicians with a new way of thinking about immunotherapy. “This treatment has the potential to be very versatile. If the tumor can be targeted, meaning that a unique identifier for the tumor is known, this treatment can be effective. Thus, this therapy can be used to treat patients with either liquid or solid tumors.”

Knochelmann said the core facilities and research environment at MUSC were a critical piece for the success of this work. “Many colleagues gave me key advice on this discovery. In fact, this work is a great example of what can be accomplished when different minds come together. It has been inspiring and rewarding to work on improving medicine for the future.”

This work was funded by the National Institutes of Health and the Melanoma Research Foundation, as independent grants were awarded to both Knochelmann and Paulos. The research team is now collaborating with surgeons and medical oncologists to develop their findings into applicable treatments for patients. “Our vision is that T-cell products will be generated for patients within a few days,” Knochelmann said, “so these therapies can help all patients in need, especially those needing treatment quickly.”

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Materials provided by Medical University of South Carolina. Original written by Caroline Wallace. Note: Content may be edited for style and length.

The cutting-edge research at Manam volcano in Papua New Guinea is improving scientists’ understanding of how volcanoes contribute to the global carbon cycle, key to sustaining life on Earth.

The team’s findings, published in Science Advances, show for the first time how it is possible to combine measurements from the air, earth and space to learn more about the most inaccessible, highly active volcanoes on the planet.

The ABOVE project involved specialists from the UK, USA, Canada, Italy, Sweden, Germany, Costa Rica, New Zealand and Papua New Guinea, spanning volcanology and aerospace engineering.

They co-created solutions to the challenges of measuring gas emissions from active volcanoes, through using modified long-range drones.

By combining in situ aerial measurements with results from satellites and ground-based remote sensors, researchers can gather a much richer data set than previously possible. This enables them to monitor active volcanoes remotely, improving understanding of how much carbon dioxide (CO₂) is being released by volcanoes globally and, importantly, where this carbon is coming from.

With a diameter of 10km, Manam volcano is located on an island 13km off the northeast coast of the mainland, at 1,800m above sea level.

Previous studies have shown it is among the world’s biggest emitters of sulphur dioxide, but nothing was known of its CO₂ output.

Volcanic CO₂ emissions are challenging to measure due to high concentrations in the background atmosphere. Measurements need to be collected very close to active vents and, at hazardous volcanoes like Manam, drones are the only way to obtain samples safely. Yet beyond-line-of-sight drone flights have rarely been attempted in volcanic environments.

Adding miniaturised gas sensors, spectrometers and sampling devices that are automatically triggered to open and close, the team was able to fly the drone 2km high and 6km away to reach Manam’s summit, where they captured gas samples to be analysed within hours.

Calculating the ratio between sulphur and carbon dioxide levels in a volcano’s emissions is critical to determining how likely an eruption is to take place, as it helps volcanologists establish the location of its magma.

Manam’s last major eruptions between 2004 and 2006 devastated large parts of the island and displaced the population of some 4,000 people to the mainland; their crops destroyed and water supplies contaminated.

Project lead Dr Emma Liu (UCL Earth Sciences) said: “Manam hasn’t been studied in detail but we could see from satellite data that it was producing strong emissions. The resources of the in-country volcano monitoring institute are small and the team has an incredible workload, but they really helped us make the links with the community living on Manam island.”

Following the fieldwork, the researchers raised funds to buy computers, solar panels and other technology to enable the local community — who have since put together a disaster preparedness group — to communicate via satellite from the island, and to provide drone operations training to Rabaul Volcanological Observatory staff to assist in their monitoring efforts.

ABOVE was part of the Deep Carbon Observatory (DCO), a global community of scientists on a ten-year quest to understand more about carbon in Earth.

Volcanic emissions are a critical stage of the Earth’s carbon cycle — the movement of carbon between land, atmosphere, and ocean — but CO₂ measurements have so far been limited to a relatively small number of the world’s estimated 500 degassing volcanoes.

Understanding the factors that control volcanic carbon emissions in the present day will reveal how the climate has changed in the past and therefore how it may respond in the future to current human impacts.

Co-author Professor Alessandro Aiuppa (University of Palermo) described the findings as ‘a real advance in our field’, adding: “Ten years ago you could have only stared and guessed what Manam’s CO₂ emissions were.

“If you take into account all the carbon released by global volcanism, it’s less than a per cent of the total emission budget, which is dominated by human activity. In a few centuries, humans are acting like thousands of volcanoes. If we continue to pump carbon into the atmosphere, it will make monitoring and forecasting eruptions using aerial gas observations even harder.”

Co-author Professor Tobias Fischer (University of New Mexico), added: “In order to understand the drivers of climate change you need to understand the carbon cycle in the earth.

“We wanted to quantify the carbon emission from this very large carbon dioxide emitter. We had very few data in terms of carbon isotope composition, which would identify the source of the carbon and whether it is the mantle, crust or sediment. We wanted to know where that carbon comes from.”

Vast amounts of debris, soot, and aerosols shot into the atmosphere when an asteroid slammed into Earth 66 million years ago, plunging the planet into darkness, cooling the climate, and acidifying the oceans. Along with the dinosaurs on the land and giant reptiles in the ocean, the dominant species of marine algae were instantly wiped out — except for one rare type.

A team of scientists, including researchers at UC Riverside, wanted to understand how these algae managed to thrive while the mass extinction rippled throughout the rest of the global food chain.

“This event came closest to wiping out all multicellular life on this planet, at least in the ocean,” said UCR geologist and study co-author Andrew Ridgwell. “If you remove algae, which form the base of the food chain, everything else should die. We wanted to know how Earth’s oceans avoided that fate, and how our modern marine ecosystem re-evolved after such a catastrophe.”

To answer their questions, the team examined well-preserved fossils of the surviving algae and created detailed computer models to simulate the likely evolution of the algae’s feeding habits over time. Their findings are now published in the journal Science Advances.

According to Ridgwell, scientists were a bit lucky to find the nano-sized fossils in the first place. They were located in fast accumulating and high-clay-content sediments, which helped preserved them in the same way the La Brea tar pits provide a special environment to help preserve mammoths.

Most of the fossils had shields made of calcium carbonate, as well as holes in their shields. The holes indicate the presence of flagella — thin, tail-like structures that allow tiny organisms to swim.

“The only reason you need to move is to get your prey,” Ridgwell explained.

Modern relatives of the ancient algae also have chloroplasts, which enable them to use sunlight to make food from carbon dioxide and water. This ability to survive both by feeding on other organisms and through photosynthesis is called mixotrophy. Examples of the few land plants with this ability include Venus flytraps and sundews.

Researchers found that once the post-asteroid darkness cleared, these mixotrophic algae expanded from coastal shelf areas into the open ocean where they became a dominant life form for the next million years, helping to quickly rebuild the food chain. It also helped that larger creatures who would normally feed on these algae were initially absent in the post-extinction oceans.

“The results illustrate both the extreme adaptability of ocean plankton and their capacity to rapidly evolve, yet also, for plants with a generation time of just a single day, that you are always only a year of darkness away from extinction,” Ridgwell said.

Only much later did the algae evolve, losing the ability to eat other creatures and re-establishing themselves to become one of the dominant species of algae in today’s ocean.

“Mixotrophy was both the means of initial survival and then an advantage after the post-asteroid darkness lifted because of the abundant small pretty cells, likely survivor cyanobacteria,” Ridgwell said. “It is the ultimate Halloween story — when the lights go out, everyone starts eating each other.”

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Materials provided by University of California – Riverside. Original written by Jules Bernstein. Note: Content may be edited for style and length.

Several years ago, a pair of dark meteorites were discovered in the Sahara Desert. They were dubbed NWA 7034 and NWA 7533, where NWA stands for North West Africa and the number is the order in which meteorites are officially approved by the Meteoritical Society, an international planetary science organization. Analysis showed these meteorites are new types of Martian meteorites and are mixtures of different rock fragments.

The earliest fragments formed on Mars 4.4 billion years ago, making them the oldest known Martian meteorites. Rocks like this are rare and can fetch up to $10,000 per gram. But recently 50 grams of NWA 7533 was acquired for analysis by the international team in which Professor Takashi Mikouchi at the University of Tokyo was participating.

“I study minerals in Martian meteorites to understand how Mars formed and its crust and mantle evolved. This is the first time I have investigated this particular meteorite, nicknamed Black Beauty for its dark color,” said Mikouchi. “Our samples of NWA 7533 were subjected to four different kinds of spectroscopic analysis, ways of detecting chemical fingerprints. The results led our team to draw some exciting conclusions.”

It’s well known to planetary scientists that there has been water on Mars for at least 3.7 billion years. But from the mineral composition of the meteorite, Mikouchi and his team deduced it’s likely there was water present much earlier, at around 4.4 billion years ago.

“Igneous clasts, or fragmented rock, in the meteorite are formed from magma and are commonly caused by impacts and oxidation,” said Mikouchi. “This oxidation could have occurred if there was water present on or in the Martian crust 4.4 billion years ago during an impact that melted part of the crust. Our analysis also suggests such an impact would have released a lot of hydrogen, which would have contributed to planetary warming at a time when Mars already had a thick insulating atmosphere of carbon dioxide.”

If there was water on Mars earlier than thought, that suggests water is possibly a natural byproduct of some process early on in planet formation. This finding could help researchers answer the question of where water comes from, which in turn could impact theories on the origins of life and the exploration for life beyond Earth.

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Using plastic waste generation data from 2016 — the latest available global numbers — scientists from Sea Education Association, DSM Environmental Services, University of Georgia, and Ocean Conservancy calculated that more than half of all plastics collected for recycling (1.99 million metric tons of 3.91 million metric tons collected) in the United States were shipped abroad. Of this, 88% of exports went to countries struggling to effectively manage, recycle, or dispose of plastics; and between 15-25% was low-value or contaminated, meaning it was effectively unrecyclable. Taking these factors into account, the researchers estimated that up to 1 million metric tons of U.S.-generated plastic waste ended up polluting the environment beyond its own borders.

“For years, so much of the plastic we have put into the blue bin has been exported for recycling to countries that struggle to manage their own waste, let alone the vast amounts delivered from the United States,” said lead author Dr. Kara Lavender Law, research professor of oceanography at Sea Education Association. “And when you consider how much of our plastic waste isn’t actually recyclable because it is low-value, contaminated or difficult to process, it’s not surprising that a lot of it ends up polluting the environment.”

Using 2016 data, the paper also estimated that 2-3% of all plastic waste generated in the U.S. — between 0.91 and 1.25 million metric tons — was either littered or illegally dumped into the environment domestically. Combined with waste exports, this means the United States contributed up to 2.25 million metric tons of plastics into the environment. Of this, up to 1.5 million metric tons of plastics ended up in coastal environments (within 50 km of a coastline), where proximity to the shore increases the likelihood of plastics entering the ocean by wind or through waterways. This ranks the United States as high as third globally in contributing to coastal plastic pollution.

“The United States generates the most plastic waste of any other country in the world, but rather than looking the problem in the eye, we have outsourced it to developing countries and become a top contributor to the ocean plastics crisis,” said Nick Mallos, senior director of Ocean Conservancy’s Trash Free Seas® program and a co-author of the study. “The solution has to start at home. We need to create less, by cutting out unnecessary single-use plastics; we need to create better, by developing innovative new ways to package and deliver goods; and where plastics are inevitable, we need to drastically improve our recycling rates.”

The study noted that although the United States accounted for just 4% of the global population in 2016, it generated 17% of all plastic waste. On average, Americans generated nearly twice as much plastic waste per capita as residents of the EU.

“Previous research has provided global values for plastic input into the environment and coastal areas, but detailed analyses like this one are important for individual countries to further assess their contributions,” said Dr. Jenna Jambeck, Distinguished Professor at the University of Georgia’s College of Engineering and a co-author of the study. “In the case of the United States, it is critically important that we examine our own backyard and take responsibility for our global plastic footprint.”

“For some time, it has been cheaper for the United States to ship its recyclables abroad rather than handle them here at home, but that has come at great cost to our environment,” said Natalie Starr, principal at DSM Environmental Services and a co-author of the study. “We need to change the math by investing in recycling technologies and collection programs, as well as accelerating research and development to improve the performance and drive down the costs of more sustainable plastics and packaging alternatives to address the current challenge.”

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The paper shows “the virus is mutating due to a combination of neutral drift — which just means random genetic changes that don’t help or hurt the virus — and pressure from our immune systems,” said Ilya Finkelstein, associate professor of molecular biosciences at The University of Texas at Austin and co-author of the study. The study was carried out by scientists at Houston Methodist Hospital, UT Austin and elsewhere.

During the initial wave of the pandemic, 71% of the novel coronaviruses identified in patients in Houston had this mutation. When the second wave of the outbreak hit Houston during the summer, this variant had leaped to 99.9% prevalence. This mirrors a trend observed around the world. A study published in July based on more than 28,000 genome sequences found that variants carrying the D614G mutation became the globally dominant form of SARS-CoV-2 in about a month. SARS-CoV-2 is the coronavirus that causes COVID-19.

So why did strains containing this mutation outcompete those that didn’t have it?

Perhaps they’re more contagious. A study of more than 25,000 genome sequences in the U.K. found that viruses with the mutation tended to transmit slightly faster than those without it and caused larger clusters of infections. Natural selection would favor strains of the virus that transmit more easily. But not all scientists are convinced. Some have suggested another explanation, called “founder’s effects.” In that scenario, the D614G mutation might have been more common in the first viruses to arrive in Europe and North America, essentially giving them a head start on other strains.

The spike protein is also continuing to accumulate additional mutations of unknown significance. The Houston Methodist-UT Austin team also showed in lab experiments that at least one such mutation allows spike to evade a neutralizing antibody that humans naturally produce to fight SARS-CoV-2 infections. This may allow that variant of the virus to more easily slip past our immune systems. Although it is not clear yet whether that translates into it also being more easily transmitted between individuals.

The good news is that this mutation is rare and does not appear to make the disease more severe for infected patients. According to Finkelstein, the group did not see viruses that have learned to evade first-generation vaccines and therapeutic antibody formulations.

“The virus continues to mutate as it rips through the world,” Finkelstein said. “Real-time surveillance efforts like our study will ensure that global vaccines and therapeutics are always one step ahead.”

The scientists noted a total of 285 mutations across thousands of infections, although most don’t appear to have a significant effect on how severe the disease is. Ongoing studies are continuing to surveil the third wave of COVID-19 patients and to characterize how the virus is adapting to neutralizing antibodies that are produced by our immune systems. Each new infection is a roll of the dice, an additional chance to develop more dangerous mutations.

“We have given this virus a lot of chances,” lead author James Musser of Houston Methodist told The Washington Post. “There is a huge population size out there right now.”

Several other UT Austin authors contributed to the work: visiting scholar Jimmy Gollihar, associate professor of molecular biosciences Jason S. McLellan and graduate students Chia-Wei Chou, Kamyab Javanmardi and Hung-Che Kuo.

The UT Austin team tested different genetic variants of the virus’s spike protein, the part that allows it to infect host cells, to measure the protein’s stability and to see how well it binds to a receptor on host cells and to neutralizing antibodies. Earlier in the year, McLellan and his team at UT Austin, in collaboration with researchers at the National Institutes of Health, developed the first 3D map of the coronavirus spike protein for an innovation that now factors into several leading vaccine candidates’ designs.

The researchers found that SARS-CoV-2 was introduced to the Houston area many times, independently, from diverse geographic regions, with virus strains from Europe, Asia, South America and elsewhere in the United States. There was widespread community dissemination soon after COVID-19 cases were reported in Houston.

This study was supported by the Fondren Foundation, Houston Methodist Hospital and Research Institute, the National Institutes of Health, the National Institute of Allergy and Infectious Diseases, the Welch Foundation, the National Science Foundation and the Defense Advanced Research Projects Agency. Ilya Finkelstein is a CPRIT scholar in cancer research, funded by the Cancer Prevention and Research Institute of Texas.

An earlier version of the paper was posted last month to the preprint server medRxiv.

The study, published in the journal Nature, provides a new benchmark for understanding the evolution of asteroids, offers insights into a poorly understood population of space debris hazardous to spacecraft, and enhances scientists’ understanding of the solar system.

The researchers used images and laser-based measurements taken during a two-year surveying phase in which the van-sized OSIRIS-REx spacecraft orbited Bennu and broke the record as the smallest spacecraft to orbit a small body.

Presented at the opening day of the American Astronomical Society’s Division of Planetary Science meeting on Oct. 26, the paper details the first observations and measurements of impact craters on individual boulders on an airless planetary surface since the Apollo missions to the moon 50 years ago, according to the authors.

The publication comes just a few days after a major milestone for NASA’s University of Arizona-led OSIRIS-REx mission. On Oct. 20, the spacecraft successfully descended to asteroid Bennu to grab a sample from its boulder-scattered surface — a first for NASA. The sample has now been successfully stowed and will be returned to Earth for study in 2023, where it could give scientists insight into the earliest stages of the formation of our solar system.

Impact Craters on Rocks Tell a Story

Although Earth is being pelted with more than 100 tons of space debris each day, it is virtually impossible to find a rockface pitted by impacts from small objects at high velocities. Courtesy of our atmosphere, we get to enjoy any object smaller than a few meters as a shooting star rather than having to fear being struck by what essentially amounts to a bullet from outer space.

Planetary bodies lacking such a protective layer, however, bear the full brunt of a perpetual cosmic barrage, and they have the scars to show for it. High-resolution images taken by the OSIRIS-REx spacecraft during its two-year survey campaign allowed researchers to study even tiny craters, with diameters ranging from a centimeter to a meter, on Bennu’s boulders.

On average, the team found boulders of 1 meter (3 feet) or larger to be scarred by anywhere from one to 60 pits — impacted by space debris ranging in size from a few millimeters to tens of centimeters.

“I was surprised to see these features on the surface of Bennu,” said the paper’s lead author, Ronald Ballouz, a postdoctoral researcher in the UArizona Lunar and Planetary Laboratory and a scientist with the OSIRIS-REx regolith development working group. “The rocks tell their history through the craters they accumulated over time. We haven’t observed anything like this since astronauts walked on the moon.”

For Ballouz, who grew up during the 1990s in post-civil war Beirut, Lebanon, the image of a rock surface pitted with small impact craters evoked childhood memories of building walls riddled with bullet holes in his war-torn home country.

“Where I grew up, the buildings have bullet holes all over, and I never thought about it,” he said. “It was just a fact of life. So, when I looked at the images from the asteroid, I was very curious, and I immediately thought these must be impact features.”

The observations made by Ballouz and his team bridge a gap between previous studies of space debris larger than a few centimeters, based on impacts on the moon, and studies of objects smaller than a few millimeters, based on observations of meteors entering Earth’s atmosphere and impacts on spacecraft.

“The objects that formed the craters on Bennu’s boulders fall within this gap that we don’t really know much about,” Ballouz said, adding that rocks in that size range are an important field of study, mainly because they represent hazards for spacecraft in orbit around Earth. “An impact from one of these millimeter to centimeter-size objects at speeds of 45,000 miles per hour can be dangerous.”

Ballouz and his team developed a technique to quantify the strength of solid objects using remote observations of craters on the surfaces of boulders — a mathematical formula that allows researchers to calculate the maximum impact energy that a boulder of a given size and strength could endure before being smashed. In other words, the crater distribution found on Bennu today keeps a historical record of the frequency, size and velocity of impact events the asteroid has experienced throughout its history.

“The idea is actually pretty simple,” Ballouz said, using a building exposed to artillery fire as an analogy to boulders on an asteroid. “We ask, ‘What is the largest crater you can make on that wall before the wall disintegrates?’ Based on observations of multiple walls of the same size, but with different sized craters, you can get some idea of the strength of that wall.”

The same holds true for a boulder on an asteroid or other airless body, said Ballouz, who added that the approach could be used on any other asteroid or airless body that astronauts or spacecraft may visit in the future.

“If a boulder gets hit by something larger than an object that would leave a certain size cater, it would just disappear,” he explained. In other words, the size distribution of boulders that have persisted on Bennu serve as silent witnesses to its geologic past.

A Newcomer to Earth’s Neighborhood

Applying the technique to boulders ranging in size from pebbles to parking garages, the researchers were able to make inferences about the sizes and type of impactors to which the boulders were exposed, and for how long.

The authors conclude that the largest craters on Bennu’s boulders were created while Bennu resided in the asteroid belt, where impact speeds are lower than in the near-Earth environment, but are more frequent and often near the limit of what the boulders could withstand. Smaller craters, on the other hand, were acquired more recently, during Bennu’s time in near-Earth space, where impact speeds are higher but potentially disruptive impactors are much less common.

Based on these calculations, the authors determine that Bennu is a relative newcomer to Earth’s neighborhood. Although it is thought to have formed in the main asteroid belt more than 100 million years ago, it is estimated that it was kicked out of the asteroid belt and migrated to its current territory only 1.75 million years ago. Extending the results to other near-Earth objects, or NEOs, the researchers also suggest that these objects likely come from parent bodies that fall in the category of asteroids, which are mostly rocky with little or no ice, rather than comets, which have more ice than rock.

While theoretical models suggest that the asteroid belt is the reservoir for NEOs, no observational evidence of their provenance was available other than meteorites that fell to Earth and were collected, Ballouz said. With these data, researchers can validate their models of where NEOs come from, according to Ballouz, and get an idea of how strong and solid these objects are — crucial information for any potential missions targeting asteroids in the future for research, resource extraction or protecting Earth from impact.

In forests, the most common species can be essential to ecosystem structure and function, which crumble with the decline of these pivotal trees, known collectively as foundation species.

In an effort to identify forest foundation species and elevate their conservation status before they disappear, a unique research collaboration between Chinese and American scientists has synthesized long-term biodiversity data from 12 immense forest study plots spanning 1,500 miles, from China’s far north to its southern tropics.

Their results, published today in the journal Ecology, point to maple trees — long appreciated for their autumn foliage and the syrup that graces our tables — as potential foundation species in both China and North America.

The study comes on the heels of the latest “Red List” published by Botanic Gardens Conservation International, which showed that 36 out of the 158 maples species worldwide — nearly a quarter of all maples — are at high risk of extinction in the near future in the wild. Fourteen of those high-risk species exist only in China.

“Foundation species are the species upon which ecosystems are built and supported, just like the foundation of your house,” explains Aaron Ellison, Senior Research Fellow at the Harvard Forest and a co-author of the study. “But they can be so common that they hide in plain sight, overlooked because they lack the cachet and appeal of rarities.”

The study was led by Xiujuan Qiao, an Associate Professor at the Wuhan Botanical Garden of the Chinese Academy of Sciences, who spent all of 2019 in residence at the Harvard Forest facilitating this global collaboration. She adds, “We should pay more attention to foundation species, identifying and protecting them before their inevitable decline.”

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The study, led by Carlos G. Grijalva, MD, MPH, associate professor of Health Policy, and H. Keipp Talbot, MD, MPH, associate professor of Medicine, found that 51% of others living in the home with someone who was positive for COVID-19 also became infected.

“We observed that, after a first household member became sick, several infections were rapidly detected in the household,” Grijalva said. “Those infections occurred fast, whether the first sick household member was a child or an adult.”

The study found that at least 75% of the secondary household infections occurred within five days of the first person in the household experiencing symptoms.

“This preliminary research is the first to closely follow U.S. households through systematic daily assessments and study the transmission of coronavirus among groups living together under one roof,” Talbot said. “Other similar studies have mostly been conducted abroad, and others have made estimates of household transmission using contact tracing data.”

Similar studies in the U.S., Europe and Asia have reported that 30%, or less, of household members also became infected.

The preliminary findings from this ongoing study were collected from households in Nashville, Tennessee, and Marshfield, Wisconsin.

Also among the study’s findings is that less than half of household members experienced symptoms when they first tested positive, and many reported no symptoms throughout the 7-day daily follow-up period.

The study results underscore the potential for transmission from symptomatic or asymptomatic contact with household members and the importance of quarantine, Grijlava said. Persons aware of recent close contact with an infected person, such as household members, should quarantine at home and monitor for development of symptoms.

As winter approaches, and people start spending more time indoors, it will be important to prepare for potential infections at home.

“In the absence of an efficient approach for identification of infections without regard to symptoms, these findings suggest that prompt adoption of isolation measures as soon as a person feels ill might reduce the probability of household transmission,” the authors concluded.

The study is a collaborative research effort involving investigators VUMC, The Marshfield Clinic Research Institute and the CDC. Other VUMC researchers include Natasha Halasa, MD, and Yuwei Zhu, MD, Ahra Kim, Judy King, Dayna Wyatt, Robert Lyons, Carleigh Frazier, Emily Jookar, Karen Malone, Olivia Doak, Sarah Davis, Jorge Celedonio, Rendie McHenry and Claudia Guevara.