Finding the first flower from Northwest China

SCIENCE CHINA PRESS

Research News

 

IMAGE: A-B. PART AND COUNTERPART OF HOLOTYPE OF GANSUFRUCTUS SALIGNA GEN. ET SP. NOV. SHOWING LEAFY AXES WITH INFRUCTESCENCES AND LANCEOLATE LEAVES. C-D, PART AND COUNTERPART SHOWING AXES WITH ALTERNATE ARRANGED... view more 

CREDIT: ©SCIENCE CHINA PRESS

"Abominable mystery" -- the early origin and evolution of angiosperms (flowering plants) was such described by Charles Robert Darwin. So far, we still have not completely solved the problem, and do not know how the earth evolved into such a colorful and blooming world.

Recently, a new angiosperm was reported based on numerous exceptionally well-preserved fossils from the Lower Cretaceous of Jiuquan Basin, West Gansu Province, Northwest China. The new discovery is the earliest and unique record of early angiosperms in Northwest China. The study has been accepted for publication in the journal National Science Review and is currently available online at https://doi.org/10.1093/nsr/nwab084.

The new angiosperm was named Gansufructus saligna, and all the fossil specimens were collected from the grayish green mudstone of the upper Zhonggou Formation in Hanxia Section. Remarkably, the plant fossils are almost completely preserved with branched axes, attached leaves and paniculate infructescences, providing valuable materials for the morphological studies of early angiosperms.

Gansufructus saligna is erect and graceful, three to four times branched, with alternate arranged axes and leaves. Leaves are simple and willow-shaped, leaf margin is entire, leaf apex is acute and leaf base is decurrent and estipulate with short petiole. Leaf venation is poorly organized with low-rank venations, primary vein prominent, secondary veins pinnate, and tertiary veins reticulate. The infructescences are loose panicles bearing fruits in different stages of maturity. Each fruit is formed from four basally syncarpous carpels borne in a whorle arrangement. And each carpel subtended by a small and persistent tepal at the base and contains three to five anatropous seeds.

Gansufructus saligna is supposed to be a small, slender plant with flexible stems, delicate leaves and paniculate infructescences, and is suggested to be a terrestrial herbaceous eudicot based on the morphology of both vegetative and reproductive organs. It probably grew along the lakeshores, where the environment is low-lying and humid. Moreover, the current fossil specimens together with other fossil records of early angiosperms from the Jehol biota and other regions, indicate that the presence of diverse early eudicots of low stature colonizing areas during the middle-late Early Cretaceous. This study is of great significance in exploring the origin, evolution, diversity and habitat preferences of early eudicots.

See the article:

An Exceptionally Well-Preserved Herbaceous Eudicot from the Early Cretaceous (late Aptian-early Albian) of Northwest China  https://doi.org/10.1093/nsr/nwab084

CAPTION

A new eudicot, Gansufructus saligna gen. et sp. nov. is reported from the late Early Cretaceous of Gansu, Northwest China, based on numerous exceptionally well-preserved axes with leaves and infructescences. It is the earliest and unique record of early angiosperms in Northwest China. Morphological studies indicated that Gansufructus saligna is a terrestrial herb growing in lowland humid areas. The new discovery is significant for exploring the origin, evolution, diversity, and habitat preferences of early eudicots.

CREDIT

©Science China Press

 Who's in this ocean? Tracking down species on the go using environmental DNA

TOHOKU UNIVERSITY

Research News

 

IMAGE: CASSIOPEA IS AN UPSIDE-DOWN JELLYFISH THAT RESTS ON THE BOTTOM OF THE SEAFLOOR view more 

CREDIT: ANDRE MORANDINI

Sloughed off skin and bodily fluids are things most people would prefer to avoid.

But for marine biologist like Cheryl Lewis Ames, Associate Professor of Applied Marine Biology in the Graduate School of Agricultural Science at Tohoku University (Japan), such remnants of life have become a magical key to detecting the unseen.

Any organism living in the ocean will inevitably leave behind traces containing their DNA - environmental DNA (eDNA) - detectable in water samples collected from the ocean

Only recently has molecular sequencing technology become advanced enough to conduct eDNA analysis in the field to identify species that may be endangered, invasive or dangerous, and could otherwise go unnoticed.

Ames chose sampling sites in the Florida Keys (USA) where species of upside-jellyfish Cassiopea occur to test out their newly developed Fieldable eDNA sequencing kit - called FeDS.

Using eDNA for multiple species identification is a multistep process known as metabarcoding. Since the mixed DNA template must first be amplified using the polymerase chain reaction (PCR), metabarcoding experiments in the field have only recently been possible thanks to battery-operated thermocyclers and other portable devices.

Determining the identity of a species from small bits of DNA filtered from seawater requires the use of a Next Generation Sequencer (NGS), a machine that traditionally takes up the whole desktop counter in a laboratory and requires an electrical outlet. A novelty of the portable technology used in this study - Nanopore MinION -- is that as pieces of DNA pass through a microscopic pore in the device, differences in electrical current determine the unique code of each DNA strand.

Instead of the typically large sequencing machines used to complete such a task, Ames and her team were testing a Nanopore system the size of a cellphone, powered by a laptop computer. A drop of the prepared eDNA mixture added to the portable sequencer reveals on the screen the genetic code of all the DNA passing through it in real-time.

Then, DNA sequences are searched against a huge database of sequences to determined which species are represented by the eDNA collected onsite that day. Upgraded "offline" versions of the necessary software and pre-downloading of the reference database to the laptop meant that the whole metabarcoding process could be conducted beyond the walls of a laboratory, away from internet connection.

Ames and the team detected 53 species of jellyfish including Cassiopea, the upside-down jellyfish, two venomous species of box jellyfish, many species with hydroid forms, and two species of stalked jellyfish which were previously unreported in the Florida Keys, indicating that the process could reveal species that would otherwise go unnoticed.

"My hope is that one day this system is used for sting mitigation, almost like a weather forecast app that also reports 'jellyfish stings risk' at certain beaches," said Ames.

Ames has spent much of her time conducting research in areas where jelly stings are common, and warnings about whether venomous jellies are in the area could prevent countless injuries to swimmers. Besides practical purposes in fisheries and conservation, the fact that a sample of ocean water can reveal the organisms in the vicinity is truly a marvel.

CAPTION

Nanopore sequencing experiment being conducted in a rental car in this study

CREDIT

Cheryl L Ames

CAPTION

Ames carefully fills the sequencer with the eDNA solution with assistance from coauthor Ohdera (Florida Keys, USA). ©Cassiopea Model Group

CREDIT

Cassiopea Model Group

Telling up from down: How marine flatworms learn to sense gravity

Zoologists explore the mechanism and development of gravity-sensing ability in marine acoel flatworms

OKAYAMA UNIVERSITY

Research News

 

IMAGE: SENSORY ORGAN OF THE ACOEL FLATWORM PRAESAGITTIFERA NAIKAIENSIS. SHOWN HERE IS A LIGHT MICROGRAPH OF THE WHOLE BODY (LEFT), AND ITS ENLARGED ANTERIOR REGIONS (RIGHT), INCLUDING THE CILIATED EPIDERMIS WITH... view more 

CREDIT: 2021 OKAYAMA UNIVERSITY

All living organisms are equipped with sensory organs to detect changes in their surrounding environment. It may not immediately strike us as obvious but, similar to how we can sense heat, cold, light, and darkness, we are also extremely adept at sensing gravity. In our case, it is our inner ear that does this job, helping us maintain balance, posture, and orientation in space. But, what about other organisms, for instance invertebrates that lack a backbone?

The gravity sensing organ in some aquatic invertebrates, known as a "statocyst," is, in fact, rather fascinating. The statocyst is essentially a fluid-filled sac with sensory cells lining its inner wall and a small, mineralized mass called "statolith" contained inside. During any body movement, the statolith moves and consequently comes in contact with sensory cells in the inner wall, deflecting them. The deflections, in turn, activate the neurons (nerve cells), which then relay signals to the brain about changes in body orientation.

However, exactly how the sensory cells stimulate the neurons is not particularly clear for acoel flatworms--soft-bodied, marine animals with a simple anatomy, which represent one of the earliest extant life forms with bilateral (left-right) symmetry. What zoologists know so far, based on the finding that juvenile acoel flatworms occasionally fail to sense gravity, is that the ability is acquired sometime after hatching from the eggs.

In a new study published in Zoomorphology, scientists from Okayama University, Japan led by Prof. Motonori Ando have now taken a stab at understanding these curious creatures better. But what exactly is so attractive about acoel flatworms? Prof. Ando explains, "Understanding the stimulus response mechanism of Acoela can uncover a fundamental biological control mechanism that dates back to the origin of bilaterian animals, including humans. These organisms, therefore, are key to unravelling the process of evolution."

For their study, the scientists used an acoel species called Praesagittifera naikaiensis or P. naikaiensis that is endemic to the Seto Island Sea coasts at Okayama. "The mysterious body plan of P. naikaiensis could be key to connecting Okayama and the world's natural environment," says Prof. Ando.

To examine the relationship between the statocyst and nervous system of P. naikaiensis, the scientists had to make them both visible, a task usually accomplished by a "marker" or a "label." However, due to a lack of any suitable label for the statocyst, they adopted a different strategy in which they labeled instead the basal lamina, the layer on which the sensory cells sit. As for the nervous system, they labeled the nerve terminals using a well-known marker. Finally, they studied the specimen using confocal microscopy, a technique in which light is focused on to a defined spot at a specific depth to stimulate only local markers.

The results were illuminating. The scientists found that the acoel flatworm developed a gravity-sensing ability within 0 to 7 days after hatching, with the statolith forming after hatching. The statocyst comprised longitudinal and transverse nerve cords, forming what is called a "commissural brain" and a "statocyst-associated-commissure" (stc) characterized by transverse fibers. They hypothesized that a gravity-sensing ability developed when: 1) the statolith acquired a sufficient concentration of calcium salts, 2) stc functioned as the signal-relaying neurons, and 3) the sensory cells were present outside the sac and stimulated indirectly by the statolith through the basal lamina and stc.

Inspired by these findings, Prof. Ando has envisioned future research directions and even practical applications of their study. "It has been reported that closely related species of this organism inhabit the North Sea coast, the Mediterranean coast, and the east coast of North America. Since there is great interest about the commonality of their habitats, we can extend our research to a more global level, using these animals as a novel bioassay system for the environment they live in, especially in the face of the accelerated pace of climate change and anthropogenic habitat degradation. Furthermore, acoel flatworms could be an excellent biological model for studying diseases caused in humans due to abnormalities of sensory hair cells," says an excited Prof. Ando.

It seems modern science is just warming up to the myriad mysteries of this minute worm!

###

"Scuba-diving" lizards use bubble attached to snout to breathe underwater

BINGHAMTON UNIVERSITY

Research News

 

IMAGE: ANOLIS LIZARD REBREATHES EXHALED AIR UNDERWATER USING A BUBBLE CLINGING TO THEIR SNOUTS. view more 

CREDIT: LINDSEY SWIERK

BINGHAMTON, N.Y. - A team of evolutionary biologists including faculty at Binghamton University, State University of New York have shown that some Anolis lizards, or anoles, have adapted to rebreathe exhaled air underwater using a bubble clinging to their snouts.

Semi-aquatic anoles live along neotropical streams and frequently dive for refuge, remaining underwater for up to 16 minutes. Lindsey Swierk, assistant research professor of biological sciences at Binghamton University, documented this behavior in a Costa Rican anole species in 2019. She had been shocked to see an anole submerge itself for such long periods and used a GoPro underwater to document the behavior.

"It's easy to imagine the advantage that these small, slow anoles gain by hiding from their predators underwater - they're really hard to spot!" says Swierk. "But the real question is how they're managing to stay underwater for so long."

The researchers conducted experiments documenting routine air-based underwater respiration in several distantly related semi-aquatic anole species. They found that semi-aquatic anoles can respire underwater by ''rebreathing'' exhaled air that is trapped between their skin and surrounding water.

"We found that semi-aquatic anoles exhale air into a bubble that clings to their skin," said lead author Chris Boccia, a recent master of science graduate from the University of Toronto. "The lizards then re-inhale the air, a maneuver we've termed 'rebreathing' after the scuba-diving technology."

The researchers believe that hydrophobic skin, which they observed in all sampled anoles, may have been exaptative, facilitating the repeated evolution of specialized rebreathing in species that regularly dive. Their analyses strongly suggest that specialized rebreathing is adaptive for semi-aquatic habitat specialists. Air-based rebreathing may enhance dive performance by incorporating dead space air from the buccal cavity or plastron into the lungs, facilitating clearance of carbon dioxide, or allowing uptake of oxygen from surrounding water (i.e., a ''physical gill'' mechanism.) The team used an oxygen sensor inside the rebreathed bubbles to determine whether anoles were consuming oxygen from the bubble. In true "scuba-tank" fashion, the researchers discovered that the oxygen concentration in an anole's air bubble decreases over the length of the dive, in support of this idea.

"The finding that different species of semi-aquatic anoles have evolutionarily converged to extract oxygen from their rebreathed air bubbles leads to other exciting questions," says Swierk. "For example, the rate of oxygen consumption from the bubble decreases the longer an anole dives, which could possibly be explained a reduction in an anole's metabolic rate with increased dive time." Binghamton graduate student co-author, Alexandra Martin, is currently exploring whether body cooling during dives may help explain this phenomenon.

"Rebreathing had never been considered as a potential natural mechanism for underwater respiration in vertebrates," says Luke Mahler, an assistant professor in EEB at the University of Toronto and Boccia's thesis supervisor. "But our work shows that this is possible and that anoles have deployed this strategy repeatedly in species that use aquatic habitats."

Swierk and Mahler are planning future projects to better understand the evolution of the physiology and behavior related to rebreathing. "Anoles are a remarkable group of lizards, and the number of ways that this taxon has diversified to take advantage of their environments is mind-boggling," said Swierk.

###

The paper, "Repeated evolution of underwater rebreathing in diving Anolis lizards," was published in Current Biology.

OOPS

Pu particles from nuclear testing more complex than previously thought

Plutonium particles from British nuclear testing in outback Australia more complex than previously thought, scientists warn

MONASH UNIVERSITY

Research News

 

More than 100 kg of highly toxic uranium (U) and plutonium (Pu) was dispersed in the form of tiny 'hot' radioactive particles after the British detonated nine atomic bombs in remote areas of South Australia, including Maralinga.

Scientists say that these radioactive particles persist in soils to this day, more than 60 years after the detonations. Previously, we had limited understanding of how Pu was released from these "hot" particles into the environment for uptake by wildlife around Maralinga.

But now, a new study published today in Scientific Reports and led by Monash University researchers warns that the particles are actually more complex and varied than previously thought. This means that the processes which slowly release Pu into the environment are also much more complex and varied.

"The British detonated nine nuclear bombs and conducted hundreds of nuclear tests in outback South Australia between 1953 and 1963," said lead study author Megan Cook, a PhD student from the Monash University School of Earth, Atmosphere and Environment. "The resulting radioactive contamination and cover-up continues to haunt us."

"The results of our study profoundly changes our understanding of the nature of hot particles at Maralinga - despite the fact that those were some of the best studied particles anywhere in the world," said study co-author Associate Professor Vanessa Wong.

The research team used synchrotron radiation at the Diamond Light Source near Oxford, UK to decipher the physical and chemical make-up of the particles.

At Monash University they dissected some of the hot particles using a nano-sized ion beam, and further characterised the complex make-up of these particles down to the nano-size in exquisite details.

The researchers demonstrated that the complexity of the hot particles arose from the cooling of polymetallic melts from thousands of degrees Celsius in the explosion cloud during their formation.

"We found that the particles contained low-valence plutonium-uranium-carbon compounds that are typically highly reactive, yet, had been stabilised in the hot-particle matrix for nearly 60 years," said corresponding author Dr Barbara Etschmann.

Between 1950 and 1988 alone there were more than 230 recorded nuclear weapon accidents, including at least 10 with documented release of radioactive particles into the environment. The risks of such incidents are only increasing as international treaties such as the Intermediate-Range Nuclear Forces Treaty were cancelled.

"Understanding the fate of hot particles in the unique setting of the Australian outback is critical for securing Australia in case of nuclear incidents in the region, and returning all the native land affected by the British tests to the traditional Anangu owners of the Maralinga Tjarutja lands," said study co-author Professor Joël Brugger.

###

Vast under-treatment of diabetes seen in global study

Only 1 in 10 people with diabetes in low- and middle-income countries is getting evidence-based, low-cost comprehensive care

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

Research News

 

Nearly half a billion people on the planet have diabetes, but most of them aren't getting the kind of care that could make their lives healthier, longer and more productive, according to a new global study of data from people with the condition.

Many don't even know they have the condition.

Only 1 in 10 people with diabetes in the 55 low- and middle-income countries studied receive the type of comprehensive care that's been proven to reduce diabetes-related problems, according to the new findings published in Lancet Healthy Longevity.

That comprehensive package of care - low-cost medicines to reduce blood sugar, blood pressure and cholesterol levels; and counseling on diet, exercise and weight - can help lower the health risks of under-treated diabetes. Those risks include future heart attacks, strokes, nerve damage, blindness, amputations and other disabling or fatal conditions.

The new study, led by physicians at the University of Michigan and Brigham and Women's Hospital with a global team of partners, draws on data from standardized household studies, to allow for apples-to-apples comparisons between countries and regions.

The authors analyzed data from surveys, examinations and tests of more than 680,000 people between the ages of 25 and 64 worldwide conducted in recent years. More than 37,000 of them had diabetes; more than half of them hadn't been formally diagnosed yet, but had a key biomarker of elevated blood sugar.

The researchers have provided their findings to the World Health Organization, which is developing efforts to scale up delivery of evidence-based diabetes care globally as part of an initiative known as the Global Diabetes Compact. The forms of diabetes-related care used in the study are all included in the 2020 WHO Package of Essential Noncommunicable Disease Interventions.

"Diabetes continues to explode everywhere, in every country, and 80% of people with it live in these low- and middle-income countries," says David Flood, M.D., M.Sc., lead author and a National Clinician Scholar at the U-M Institute for Healthcare Policy and Innovation. "It confers a high risk of complications such as including heart attacks, blindness, and strokes. We can prevent these complications with comprehensive diabetes treatment, and we need to make sure people around the world can access treatment."

Flood worked with senior author Jennifer Manne-Goehler, M.D., Sc.D., of Brigham and Women's Hospital and the Medical Practice Evaluation Center at Massachusetts General Hospital, to lead the analysis of detailed global data.

Key findings

In addition to the main finding that 90% of the people with diabetes studied weren't getting access to all six components of effective diabetes care, the study also finds major gaps in specific care.

For instance, while about half of all people with diabetes were taking a drug to lower their blood sugar, and 41% were taking a drug to lower their blood pressure, only 6.3% were receiving cholesterol-lowering medications.

These findings show the need to scale-up proven treatment not only to lower glucose but also to address cardiovascular disease risk factors, such as hypertension and high cholesterol, in people with diabetes.

Less than a third had access to counseling on diet and exercise, which can help guide people with diabetes to adopt habits that can control their health risks further.

Even when the authors focused on the people who had already received a formal diagnosis of diabetes, they found that 85% were taking a medicine to lower blood sugar, 57% were taking a blood pressure medication, but only 9% were taking something to control their cholesterol. Nearly 74% had received diet-related counseling, and just under 66% had received exercise and weight counseling.

Taken together, less than one in five people with previously diagnosed diabetes were getting the full package of evidence-based care.

Relationship to national income and personal characteristics

In general, the study finds that people were less likely to get evidence-based diabetes care the lower the average income of the country and region they lived in. That's based on a model that the authors created using economic and demographic data about the countries that were included in the study.

The nations in the Oceania region of the Pacific had the highest prevalence of diabetes - both diagnosed and undiagnosed - but the lowest rates of diabetes-related care.

But there were exceptions where low-income countries had higher-than-expected rates of good diabetes care, says Flood, citing the example of Costa Rica. And in general, the Latin America and Caribbean region was second only to Oceania in diabetes prevalence, but had much higher levels of care.

Focusing on what countries with outsize achievements in diabetes care are doing well could provide valuable insights for improving care elsewhere, the authors say. That even includes informing care in high-income countries like the United States, which does not consistently deliver evidence-based care to people with diabetes.

The study also shines a light on the variation between countries and regions in the percentage of cases of diabetes that have been diagnosed. Improve reliable access to diabetes diagnostic technologies is important in leading more people to obtain preventive care and counseling.

Women, people with higher levels of education and higher personal wealth, and people who are older or had high body mass index were more likely to be receiving evidence-based diabetes care. Diabetes in people with "normal" BMI is not uncommon in low- and middle-income countries, suggesting more need to focus on these individuals, the authors say.

The fact that diabetes-related medications are available at very low cost, and that individuals can reduce their risk through lifestyle changes, mean that cost should not be a major barrier, says Flood. In fact, studies have shown the medications to be cost-effective, meaning that the cost of their early and consistent use is outweighed by the savings on other types of care later.

###

In addition to Flood, who is a clinical lecturer in hospital medicine at Michigan Medicine, U-M's academic medical center, the study team includes two others from U-M: Michele Heisler, M.D., M.P.A., a professor of internal medicine and member of IHPI, and Matthew Dunn, a student at the U-M School of Public Health. The study was funded by the National Clinician Scholars Program at IHPI, and by the National Institute of Diabetes and Digestive and Kidney Diseases, Harvard Catalyst, and the National Center for Advancing Translational Sciences.

Variation in SARS-CoV-2 Infection Risk and Socioeconomic Disadvantage Among a Mayan-Latinx Population in Oakland, California

Erin E. Esaryk, MPH¹; Paul Wesson, PhD¹; Jessica Fields, BA^1,2,3; et alFrancine Rios-Fetchko, BA^2,3,4; Christina Lindan, MD, MS¹; Caryn Bern, MD, MPH¹; Alicia Fernández, MD^2,3,4

Author Affiliations Article Information

JAMA Netw Open. 2021;4(5):e2110789. doi:10.1001/jamanetworkopen.2021.10789

COVID-19 Resource Center

Introduction

US Latinx populations are disproportionally affected by the SARS-CoV-2 pandemic, with higher rates of infection and associated morbidity and mortality.¹ Although often treated as homogeneous, members of Latinx communities vary by national origin, immigration status, and language.² Oakland, California, is home to many Latinx individuals and an estimated 10 000 Mayan individuals, many of whom speak Indigenous languages.³ Early in the pandemic, community-based organizations (CBOs) in Oakland, California, observed a high frequency of infections among Latinx individuals in general and even higher frequency among Mayan individuals.⁴ Local CBOs, the University of California, San Francisco (UCSF), and public health authorities formed a collaborative to offer diagnostic testing in Fruitvale, a diverse neighborhood that has among the highest cumulative infection rates in Alameda County.⁵ Using data from the resulting SARS-CoV-2 testing event, we examined variation in infection risk and socioeconomic disadvantage within the Fruitvale community.

Methods

This cross-sectional study was approved by the UCSF institutional review board and followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline. Free SARS-CoV-2 testing was provided for individuals of all ages on September 26 to 27, 2020. Adults gave verbal consent for themselves and for participating children. Anterior nasal swab samples were obtained for polymerase chain reaction (PCR) testing to detect the virus, and venous blood was collected to detect immunoglobin G antinucleocapsid antibodies. Adults completed a survey on sociodemographic characteristics at the testing event. Interviewers fluent in Spanish, 2 Mayan languages, and more than 4 other languages were available. We analyzed cross-sectional associations between demographic and socioeconomic indicators and SARS CoV-2 infection using χ² tests and logistic regression analyses adjusted for age and sex and accounting for household clustering. Statistical significance was set at P < .05. Data analyses were conducted in Stata version 16 (StataCorp). Additional information regarding the methods appear in the eAppendix in the Supplement.

Results

We tested 1186 individuals (1034 [87.2%] adults; 152 [12.8%] children; 610 [51.4%] female participants; mean [SD] age, 40.0 [18.3] years); 108 (9.1%) were Mayan individuals, 661 (55.7%) non-Mayan Latinx individuals, and 417 (35.2%) non-Latinx individuals. Compared with other Latinx individuals, Mayan individuals were more likely to live in households with 5 or more people (49 [53.3%] vs 152 [32.6%]; P < .005), report food insecurity (53 [62.4%] vs 172 [41.8%]; P = .001), have difficulty finding work due to the pandemic (12 [13.0%] vs 31 [5.4%]; P = .01), lack a regular medical practitioner (55 [64.7%] vs 340 [76.2%]; P = .03), and have no health insurance (35 [38.0%] vs 118 [20.7%]; P < .001) (Table 1). Mayan individuals were also more likely to have limited English proficiency compared with other Latinx participants (49 [58%] vs 187 [46%]; P = .04); 41 (44.6%) spoke a Mayan language at home. Mayan and non-Mayan Latinx participants had significantly greater odds of having a positive PCR test compared with non-Latinx participants (Mayan: adjusted odds ratio [aOR], 16.66; 95% CI, 3.54-78.41; P < .001; non-Mayan Latinx: aOR, 8.48; 95% CI, 1.91-37.67; P = .004). Mayan individuals were significantly more likely to have positive serology results compared with non-Latinx participants (aOR, 5.58; 95% CI, 2.13-14.65; P < .001) (Table 2).

Discussion

We found that Latinx participants were more likely to have current SARS-CoV-2 infection than non-Latinx participants, reflecting state and national trends.¹ Our data highlight heterogeneity within the Latinx community, with Mayan individuals having even higher risk than other Latinx individuals. Findings related to socioeconomic disadvantage, including large household size, low income, and food insecurity, likely reflect the heightened susceptibility of Mayan individuals to the pandemic.⁶ In addition, limited English proficiency and access to health care pose challenges for effective public health messaging.

Limitations that reduce generalizability include that the study analyzed a convenience sample of those seeking testing, and that testing and medical referrals were prioritized over questionnaire completion, resulting in missing data. Unmeasured confounding factors could attenuate results.

This study underscores the need to consider heterogeneity within Latinx communities and to prioritize subgroups with higher risks, such as Mayan individuals, in health policies and outreach. Limited Spanish and English proficiency reduce this population’s access to health information and care. Few CBOs or public health departments have Mayan language speakers to provide information and perform contact tracing. Those that do are underresourced. Understanding differential risks within the heterogenous Latinx population can guide more efficient targeting of services. Failure to engage with communities with higher risks increases the likelihood of ongoing transmission and may hinder SARS CoV-2 vaccine uptake.

Back to top

Article Information

Accepted for Publication: March 26, 2021.

Published: May 21, 2021. doi:10.1001/jamanetworkopen.2021.10789

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Esaryk EE et al. JAMA Network Open.

Corresponding Author: Paul Wesson, PhD, Department of Epidemiology and Biostatistics, University of California, San Francisco, 550 16th St, San Francisco, CA 94158 (paul.wesson@ucsf.edu).

Author Contributions: Drs Bern and Fernández had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Ms Esaryk and Dr Wesson are co–first authors and have contributed equally to the work. Drs Bern and Fernández share senior authorship.

Concept and design: Esaryk, Wesson, Lindan, Bern, Fernandez.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: All authors.

Critical revision of the manuscript for important intellectual content: Esaryk, Wesson, Fields, Lindan, Bern, Fernandez.

Statistical analysis: Esaryk, Wesson, Rios-Fetchko, Lindan, Bern.

Obtained funding: Fernandez.

Administrative, technical, or material support: Fields, Rios-Fetchko.

Supervision: Bern, Fernandez.

Conflict of Interest Disclosures: Dr Wesson reported receiving grants from the National Institute of Allergy and Infectious Diseases during the conduct of the study. No other disclosures were reported.

Funding/Support: The community testing event was funded by the University of California, San Francisco COVID-19 Community Public Health Initiative institutional fund and the Crankstart Foundation.

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Additional Contributions: We thank the members of the Sanando Juntos Resilient Fruitvale Collaborative who contributed to this study, including: Chris Iglesias, BA (The Unity Council), Jane Garcia, MPH (La Clínica de la Raza), Aaron Ortiz, MPA (La Familia Counseling), Itzel Diaz-Romo, BA (The Unity Council), Paul Bayard, MD, MPH (La Clínica de la Raza), Erik Solorio, BSN, RN (La Clínica de la Raza), Teena-Marie Benitez-Gonzalez, BA (La Clínica de la Raza), Gabriela Galicia, BA (Street Level Health), Gerard Jenkins, MD, MA (Native American Health Center), Laura Miller, MD (Community Health Center Network), Giuliana Martinez, BASc (GM Consulting), Christian Martinez, AA-T (community advocate), Areli Porras-Pozos (community advocate), Kimi Watkins-Tartt, BA (Alameda County Public Health Department), Charleton Lightfoot, MPA (Oakland Fire Department), Juan Raul Gutierrez, MD, MPH (University of California, San Francisco), Alice Fishman, MSc (University of California, San Francisco), Andres Aranda-Diaz, PhD (University of California, San Francisco), Cady Smith, BA (University of California, San Francisco), John Balmes, MD (University of California, San Francisco), Jacqueline Torres, PhD, MPH, MA (University of California, San Francisco), Ana De Oliveira Franco, PhD, DVM (University of California, San Francisco), and Erika Meza, MPH (University of California, San Francisco).

References

1.

Chen  Y-H, Glymour  MM, Catalano  R,  et al.  Excess mortality in California during the coronavirus disease 2019 pandemic, March to August 2020.   JAMA Intern Med. 2020. doi:10.1001/jamainternmed.2020.7578
ArticlePubMedGoogle Scholar

2.

Rodriguez-Diaz  CE, Guilamo-Ramos  V, Mena  L,  et al.  Risk for COVID-19 infection and death among Latinos in the United States: examining heterogeneity in transmission dynamics.   Ann Epidemiol. 2020;52:46-53.e2. doi:10.1016/j.annepidem.2020.07.007PubMedGoogle ScholarCrossref

3.

Garofoli  J. “We are invisible”: coronavirus just made census counting harder in Bay Area. San Francisco Chronicle. Published April 16, 2020. Accessed January 28, 2021. https://www.sfchronicle.com/politics/article/We-are-invisible-Coronavirus-just-made-15203827.php

4.

Foo  PK, Perez  B, Gupta  N,  et al.  High rates of COVID-19 infection among Indigenous Maya at a US safety-net health system in California.   Public Health Rep. Published online February 16, 2021. doi:10.1177/0033354921990370Google Scholar

5.

Alameda County Public Health Department. COVID-19 data. Accessed January 5, 2021. https://covid-19.acgov.org/data.page

6.

Cervantes  L, Martin  M, Frank  MG,  et al.  Experiences of Latinx individuals hospitalized for COVID-19: a qualitative study.   JAMA Netw Open. 2021;4(3):e210684. doi:10.1001/jamanetworkopen.2021.0684
ArticlePubMedGoogle Scholar