BACKGROUND: A multi-phase Canadian study was conducted as part of a large-scale community and academic research partnership focused on understanding and improving the employment experiences of people with intellectual disabilities. METHOD: This multi-method study utilized a sequential approach, using findings from qualitative interviews (n = 28) to inform an online survey (n = 149). Participants were invited to share their experiences with paid employment or with persons with intellectual disabilities. RESULTS: Thematic analysis of data across interview and survey findings resulted in six themes: (1) assumptions and attitudes, (2) knowledge and awareness, (3) accessibility of processes, (4) use of accommodations, (5) workplace relationships, and (6) supports and resources. CONCLUSIONS: A holistic and systemic approach has the potential to improve inclusive employment experiences of people with intellectual disabilities. Action is needed mainly at the policy and employer level to reduce barriers and improve on facilitating measures reinforced by the themes shared in this study.
Disabled Persons , Intellectual Disability , Adult , Humans , Patient Advocacy , Canada , Employment
The introduction of cell-free DNA screening has resulted in increased prenatal identification of sex chromosome aneuploidies (SCAs). This study aimed to evaluate genetic counselor experiences disclosing SCAs positive prenatal screening or testing results and genetic counselor-reported parental questions regarding sex, gender, and sexual orientation. Forty-eight prenatal genetic counselors completed the survey. When asked to quantify their experiences, 97.9% of counselors reported disclosing a SCAs positive screen result within the previous year, and 81.3% disclosed a diagnostic result. Of those counselors, 53.8% reported always or often receiving parental questions about sex, 33% always or often about gender, and 25% always or often regarding sexual orientation. Counselors were asked to share examples of parental questions following a positive screen or diagnostic testing for SCAs. Parental questions were stratified by karyotype and content analysis revealed questions about the fetus' sex, anatomy, reproduction, being cisgender, gender expression, behavior, being transgender, and sexual orientation. The examples of parental questions provided by genetic counselors suggested some parents may have misconceptions about the intersection of SCAs with sex, gender, and sexual orientation following prenatal screening or diagnostic testing. The majority of counselors (83.3%) agreed to some extent that they desired further education on responding to parental questions about SCAs. Findings from this research suggest a need for genetic counseling strategies that accurately and respectfully discuss SCAs in the context of sex, gender, and sexual orientation with prenatal patients.
Opportunities for genetic counselors to work in a variety of practice settings have greatly expanded, particularly in the laboratory. This study aimed to assess attitudes of genetic counselors working both within and outside of the laboratory setting regarding (1) the re-wording and/or expansion of key measures of genetic counselors' competency, including practice-based competencies (PBCs) and board examination, to include laboratory roles, (2) preparation and transferability of competencies developed in master's in genetic counseling (MGC) programs to different roles, (3) need of additional training for genetic counselors to practice in laboratory settings, and (4) preferred methods to obtain that training. An e-blast was sent to ABGC diplomats (N = 5458) with a link to a 29-item survey with 12 demographic questions to compare respondents to 2021 NSGC Professional Status Survey (PSS) respondents. Statistical comparisons were made between respondents working in the laboratory versus other settings. Among 399 responses received, there was an oversampling of respondents working in the laboratory (52% vs. 20% in PSS) and in non-direct patient care positions (47% vs. 25% in PSS). Most respondents agreed the PBCs were transferable to their work yet favored making the PBCs less direct patient care-focused, expanding PBCs to align with laboratory roles, adding laboratory-focused questions to the ABGC exam, and adding laboratory-focused training in MGC programs. Most agreed requiring post-MGC training would limit genetic counselors' ability to change jobs. Genetic counselors working in the laboratory reported being significantly less prepared by their MGC program for some roles (p < 0.001) or how the PBCs applied to non-direct patient care positions (p < 0.001). Only 53% of all respondents agreed that NSGC supports their professional needs and others in their practice area, and genetic counselors working in the laboratory were significantly less likely to agree (p = 0.002). These sentiments should be further explored.
Research related to the practice of genetic counseling has historically been accomplished through student projects, small private grants, or as a part of a larger research study. Yet, recent initiatives supported by the National Society of Genetic Counselors and the National Human Genome Research Institute have recognized and promoted the need for additional genetic counseling research funding and training. In this study, we aimed to characterize awards from the United States' National Institutes of Health (NIH) over the past 10 years that support research related to genetic counseling. A search of the NIH RePORTER database conducted on April 25, 2022, using terms broadly related to genetic counseling, identified 3993 awards from fiscal years 2011 to 2022. After deduplication, 1231 grants were reviewed for screening. The final dataset included 43 awards of various types with the majority being research or R series grants [R01 (n = 17), R21 (n = 7)]. The remaining awards were Cooperative Agreements (U01, n = 6), intramural (Z-grants, n = 5), Center Core (P30, n = 2), Specialized Center (P50, n = 1), Career Development Award (K01, n = 1), Other Transactions (OT2, n = 1), Resource Program (G13, n = 1), and Research Training and Fellowship (T32, n = 1). Most grants were awarded between 2019 and 2022 (n = 24, 55.8%). The majority of awards were categorized as studies that included a comparison of different genetic counseling models (n = 23), outcomes of implementing genetic counseling (n = 11), core resources for genetic counselors (n = 5), and genetic counseling training programs (n = 4). Thirteen of the awards (30.2%) had a specific aim/goal/focus on underserved or underrepresented populations. The topics were predominantly related to cancer (n = 26). Nine awards were led or co-led by a genetic counselor (20.9%). Despite significant growth in genetic counseling research support from US-based funders over the past 3 years, major gaps related to funding exist, including that most award recipients are not genetic counselors.
Rapid advancements in genetics care requires responsive genetic counseling (GC) training capable of integrating new discoveries and practice into their curricula. The utilization of shared or standardized educational resources may address this need. Recognizing the potential of shared resources, the Pharmacogenetics (PGx) Working Group of the NSGC Precision Medicine Special Interest Group (SIG) launched a standardized education module using a flipped-classroom format to provide all GC programs equal access to PGx expertise and alleviate the burden of curriculum development. Following the initial success of the program, we aimed to explore the utilization of shared and standardized education resources more broadly, and better understand the perspectives of GC program faculty regarding their use. Twenty-nine program faculty representing at least 14 programs responded to an online survey. The majority (n = 21) reported sharing educational materials with another GC program, and 90% of those reported the shared materials to be beneficial as they promote collaboration, efficiency, address a gap in content, and provide access to experts. Similar benefits were described when using a standardized curriculum, which was defined as standardized lectures and activities created about a particular topic and made available to all genetic counseling programs; 16 participants indicated they would be very likely or likely to use a standardized curriculum. A secondary aim of the survey was to assess the existing PGx module that utilizes a flipped-classroom format. Overall, the PGx module was well received, indicating that a standardized shared module is well-suited for instruction on emerging and specialty topics. All participants believed the flipped-classroom format to be very or somewhat beneficial. In summary, results indicate that shared educational materials, including standardized education modules, are a potential solution to challenges related to efficiency and access to content experts in GC education, and program leadership is receptive to using them.
Curriculum , Genetic Counseling , Humans , Faculty , Surveys and Questionnaires , Educational Status
Genetic counseling graduate programs provide a rigorous curriculum comprised of coursework encompassing counseling and medical genetics, fieldwork, and research experience. Students face similar emotional and mental demands as practicing genetic counselors while also experiencing stressors commonly associated with graduate study. Increased self-awareness may help combat these stressors. This mixed-methods study surveyed 154 genetic counseling graduate students to determine the types of self-awareness practices they would like to have included in their graduate training and surveyed 11 program faculty regarding the feasibility of implementing these practices. The students' most preferred practices were self-reflection (n = 73, 47.4%), support from peers, colleagues, and/or supervisors (n = 71, 46.1%), and mental health counseling (n = 71, 46.1%). Analysis of responses to open-ended questions capturing students' recommendations for programs yielded six recurrent themes: (1) Consistent, Structured Practice with Accountability, (2) Emphasis on Mental Health, (3) Practical Techniques, (4) Access to Resources, (5) Encouragement and Support, and (6) Barriers to Implementation. Many students suggested that programs should incorporate repetitive exercises that could be implemented on a schedule with an emphasis on consistency (Theme 1). Students also emphasized the importance of providing exposure to multiple examples of self-awareness practices, so they could find an approach that was most beneficial on an individual basis (Theme 3). These findings were shared with program faculty via a presentation at the Association for Genetic Counseling Program Directors annual meeting, and attendees were subsequently surveyed regarding self-awareness practices currently integrated into their curriculum, as well as the feasibility and likelihood of integrating new practices. Program faculty respondents indicated that most of the recommended practices were included in their curriculum already or would be feasible and likely to incorporate. These results provide insight into the attitudes of genetic counseling students toward structured practice in self-awareness and how genetic counseling graduate programs might integrate such practices into the curriculum.
Genetic Counseling , Meditation , Humans , Mental Health , Counseling/education , Students , Curriculum
Opportunities for genetic counselors to work in the laboratory have grown exponentially, yet the professional development needed to serve in these roles had not been previously explored. This study aimed to identify competencies required for entry-level genetic counselors working in the laboratory, explore the perceived level of preparation of these competencies as noted by experts in the laboratories, and assess the perceived value of additional credentialing for genetic counselors practicing in these settings. Twenty genetic counselors working in the laboratory setting and five MD or PhD laboratory managers, identified through purposeful and snowball sampling and with at least 5 years of experience working in a laboratory, were interviewed using a semi-structured protocol. Transcripts were analyzed thematically using deductive and inductive coding. Key findings included the distinction of laboratory and industry roles as involving nondirect patient care and differing from genetic counseling roles in the clinical setting. Genetic counselors working in the laboratory feel well prepared to transition into this setting and provide a unique patient-focused perspective to laboratory roles, including variant interpretation, marketing, and product development. Practice-based competencies (PBCs) were translatable to those used in the laboratory, yet variant interpretation, limitations of genomics-based tests, and the business of health care were noted as important to these roles but not fully addressed in the PBCs. Additional skills were often developed through on-the-job training and interdisciplinary collaboration, but more exposure to diverse roles in genetic counseling programs' didactic and field training was recommended. The majority felt that requiring an additional post-master's credential to work in the laboratory setting may restrict movement into these roles. Several questioned their identity as genetic counselors as they were no longer providing direct patient care and/or had been dissuaded by others from pursuing a laboratory position. Research focused on professional identity among genetic counselors working in nondirect patient care roles is warranted.
Counselors , Humans , Counselors/psychology , Laboratories , Genetic Counseling/methods
Disclosure is the act of sharing a stigmatized identity, and members of the LGBTQ+ community make decisions related to disclosure multiple times throughout their life. Disclosure in medical settings can impact perceptions of care and outcomes for LGBTQ+ patients; however, little is understood about the process of decision-making regarding disclosure in the genetic counseling setting. As such, this study aimed to explore LGBTQ+ experiences in genetic counseling sessions and their disclosure behaviors. Fifty-five LGBTQ+ individuals who attended a genetic counseling session and 91 genetic counselors completed online surveys. The patient survey assessed for disclosure behaviors, experiences of discrimination, and comfort in genetic counseling sessions. The counselor survey evaluated comfort with the LGBTQ+ population in a counseling setting, whether counselors facilitate disclosure in sessions, and whether counseling is tailored for the LGBTQ+ population. Eighty-two percent of genetic counselors "rarely" or "never" ask about sexual orientation, and 69% "rarely" or "never" ask about gender identity. The majority of patients indicated they were not asked about their sexual orientation (87%) or gender identity (80%). Some patients reported experiencing discrimination or homo/transphobia in their genetic counseling sessions, with 6.12% of LGBQ+ patients experiencing discrimination and 24.1% of trans+ patients reporting discrimination. Over half of genetic counselors reported receiving training in LGBTQ+ healthcare and the majority reported comfort with providing care to LGBTQ+ patients. However, discrepancies between patient-reported experiences and genetic counselors' descriptions of their care for the LGBTQ+ population warrant further research and suggest additional training or changes in practice may be necessary.
Counselors , Sexual and Gender Minorities , Humans , Male , Female , Genetic Counseling/psychology , Disclosure , Gender Identity , Counselors/psychology
Advances in technology, decreasing cost of genetic testing, and growing public interest in genetics marked by an increased uptake of genetic testing, particularly direct-to-consumer genetic testing (DTC-GT), have led to an overwhelming demand for genetic counseling services. As such, various alternative service delivery models have been proposed to increase access to genetic counseling. Some service delivery models, such as asynchronous messaging, remain unexplored in the genetic counseling literature. The purpose of this study was to assess communication during genetic counseling for DTC-GT through asynchronous messaging. A thematic analysis was conducted on 34 de-identified chat transcripts between genetic counselors and clients who underwent DTC-GT. Six categories of communication were identified and were grouped based on communication sources from either the client or the genetic counselor. Categories observed in client communication were motivations for seeking DTC testing and/or genetic counseling services, questions posed to the genetic counselor, responses provided during the session, and psychosocial aspects of the session related to the clients' mental, emotional, social, and spiritual needs. Categories of communication that emerged from the genetic counselors' communications were educational aspects of the session and counseling strategies to address concerns that are not related to educational or informational needs. Most clients had specific questions about variants detected or specific conditions. Many clients asked about appropriate subsequent steps related to additional testing or medical management. Genetic counselors discussed the limitations of DTC-GT and recommendations for clinical grade testing in almost all chat transcripts. In several chats, the genetic counselor provided advice to the client related to minimizing time sorting through likely benign results and refraining from altering medical management. Results suggest that genetic counselors are able to provide genetic information to clients and respond to their mental and emotional needs through asynchronous chat following DTC-GT. Findings from this study provide initial insight into a unique genetic counseling delivery model and reveal the informational and counseling needs of clients following DTC-GT.
Counselors , Genetic Counseling , Humans , Genetic Counseling/methods , Genetic Testing , Communication , Counseling
Genetic services are increasingly provided by non-genetics healthcare professionals (NGHPs) with minimal formal training in genetics/genomics. Research demonstrates gaps in knowledge and clinical practices in genetics/genomics among NGHPs, but there is a lack of consensus on the specific knowledge needed by NGHPs to effectively provide genetic services. As clinical genetics professionals, genetic counselors (GCs) have insight into the critical components of genetics/genomics knowledge and practices needed by NGHPs. This study explored GCs' beliefs regarding whether NGHPs should provide genetic services and identified GCs' perceptions of the components of knowledge and clinical practice in genetics/genomics that are most critical for NGHPs providing genetic services. Two hundred and forty GCs completed an online quantitative survey with 17 participating in a follow-up qualitative interview. Descriptive statistics and cross-comparisons were generated for survey data. Interview data were analyzed using an inductive qualitative method for cross-case analysis. Most GCs disagreed with NGHPs providing genetic services, but beliefs varied widely, ranging from disagreement due to perceived gaps in knowledge or clinical skills to acceptance of NGHPs providing genetic services due to limited access to genetics professionals. Across survey and interview data, GCs endorsed the interpretation of genetic test results, understanding implications of results, collaboration with genetics professionals, knowledge of the risks and benefits to testing, and recognizing indications for genetic testing as critical components of knowledge and clinical practice for NGHPs. Several recommendations for improving the provision of genetic services were provided by respondents including educating NGHPs to provide genetic services through case-based continuing medical education and increasing collaboration between NGHPs and genetics professionals. As GCs are healthcare providers with experience and vested interests in educating NGHPs, their perspectives can help inform the creation of continuing medical education to ensure patients' access to high-quality genomic medicine care from providers of varying backgrounds.
Counselors , Education, Medical , Humans , Genomic Medicine , Genomics , Delivery of Health Care , Genetic Counseling
BACKGROUND: Hippocampal place cells play an integral role in generating spatial maps. Impaired spatial memory is a characteristic pathology of Alzheimer's disease (AD), yet it remains unclear how AD influences the properties of hippocampal place cells. OBJECTIVE: To record electrophysiological activity in hippocampal CA1 neurons in freely-moving 18-month-old male TgF344-AD and age-matched wild-type (WT) littermates to examine place cell properties. METHODS: We implanted 32-channel electrode arrays into the CA1 subfield of 18-month-old male WT and TgF344-AD (nâ=â6/group) rats. Ten days after implantation, single unit activity in an open field arena was recorded across days. The spatial information content, in-field firing rate, and stability of each place cell was compared across groups. Pathology was assessed by immunohistochemical staining, and a deep neural network approach was used to count cell profiles. RESULTS: Aged TgF344-AD rats exhibited hippocampal amyloid-ß deposition, and a significant increase in Iba1 immunoreactivity and microglia cell counts. Place cells from WT and TgF344-AD rat showed equivalent spatial information, in-field firing rates, and place field stability when initially exposed to the arena. However, by day 3, the place cells in aged WT rats showed characteristic spatial tuning as evidenced by higher spatial information content, stability, and in-field firing rates, an effect not seen in TgF344-AD rats. CONCLUSION: These findings support the notion that altered electrophysiological properties of place cells may contribute to the learning and memory deficits observed in AD.
Alzheimer Disease , Place Cells , Aged , Alzheimer Disease/pathology , Animals , Disease Models, Animal , Hippocampus/pathology , Humans , Male , Memory Disorders/pathology , Neurons/pathology , Place Cells/pathology , Rats
Stress and anxiety are significant concerns for practicing genetic counselors as well as genetic counseling students and can have downstream effects on patient care. Prior research suggests graduate-level training in self-awareness practices such as self-care, reflection, and mindfulness could have lasting effects for genetic counselors, their patients, and the profession as a whole. This mixed-methods study assessed self-awareness among 154 genetic counseling graduate students using the Self-Reflection and Insight Scale (SRIS), the Mindfulness Attention Awareness Scale (MAAS), and self-described experiences with self-awareness practice. Genetic counseling students had significantly lower mean scores on the MAAS and the Insight subscale of the SRIS compared with other health professionals, indicating that genetic counseling students have lower levels of mindfulness and may lack insight into their thoughts and feelings. After starting genetic counseling graduate programs, students were more likely to reduce participation in active self-awareness practices such as physical activity and mental health counseling. Most students reported having structured practice in self-care (n = 97, 63%), reflection (n = 125, 81.2%), and mindfulness (n = 77, 50%) as a part of their training programs. Second-year genetic counseling students reporting mindfulness practices had significantly higher scores on the Insight subscale of the SRIS than those who did not, indicating that students engaged in mindfulness practice are better able to understand their thoughts, feelings, and behavior. The majority of students reported benefitting from structured practice in self-care (n = 63, 64.9%), reflection (n = 101, 80%), and mindfulness (n = 54, 70.1%). Open-ended responses regarding students' perceived benefits and limitations of structured practice were analyzed for recurrent themes. Students reported improved self-awareness which enhanced their counseling relationships during clinical rotations. However, they also perceived that implementation of self-awareness practices may have been inconsistent. Findings from this study have implications for integrating self-awareness practices into genetic counseling graduate curriculum.
Mindfulness , Anxiety/psychology , Genetic Counseling , Humans , Mindfulness/methods , Self Care , Students
OBJECTIVE: The delivery of pharmacogenetic (PGx) testing has primarily been through clinical and hospital settings. We conducted a study to explore the feasibility of delivering PGx testing through community pharmacies, a less-studied setting. METHODS: We conducted a cluster randomized trial of community pharmacies in North Carolina through two approaches: the provision of PGx testing alone or PGx testing with medication therapy management (MTM). RESULTS: A total of 150 patient participants were enrolled at 17 pharmacies and reported high satisfaction with their testing experience. Participants in the PGx plus MTM arm were more likely to recall a higher number of results (p=0.04) and more likely to clearly understand their choices for prevention or early detection of side effects (p=0.01). A medication or dose change based on the PGx results was made for 8.7% of participants. CONCLUSION: Limited differences were observed in the provision of PGx testing as a standalone test or combined with MTM. A limited number of treatment changes were made based on PGx test results. Patient acceptance of PGx testing offered through the community pharmacy was very high, but the addition of MTM did not impact patient-reported perceptions about PGx testing or medication adherence.
While genetic counselor (GC) utilization of telehealth has increased in recent years, the onset of the COVID-19 pandemic significantly accelerated the adoption of telehealth for many. We investigated GC experiences with telehealth including perceived advantages, disadvantages, and barriers using a one-time online survey of GCs who provided direct patient care in recent years. The survey examined experiences with telehealth before and after the onset of COVID-19. We made broad comparisons to findings from a similar study our research team conducted five years ago. GCs reported an increase in the utilization of telehealth over time, with significant increases from pre-2017 (44%) to pre-COVID-19 (70%) and then to present (87%) (p<.001 and .02, respectively). There was no significant change in the total number of hours worked from pre-COVID-19 to the time of survey completion, nor were there significant changes in the amount of time spent on clinical responsibilities or interfacing with patients. However, the total number of hours worked in telehealth significantly increased (z = 5.05, p<.001) as did the percent of time spent interacting with patients via telehealth [t(72)=3.74, p<.001, d = 0.44]. Participants overwhelmingly preferred video (84%) over telephone; this differs from our previous survey where video was the preferred modality for 59% (p<.001). We utilized open-ended questions to elicit reasons for modality preference. The most-cited barrier to telehealth utilization was billing/reimbursement issues, with 39% noting this obstacle. This is consistent with our previous study where 30% cited billing/reimbursement as the primary barrier. These findings indicate a need for continued efforts to improve billing and reimbursement for genetic counseling offered via telehealth. They also present an opportunity for additional exploration regarding patient preferences for telehealth modality.
COVID-19 , Counselors , Genetic Counseling , Telemedicine , COVID-19/epidemiology , Female , Health Care Surveys , Humans , Male , Pandemics
OBJECTIVE: This study assessed pharmacist experiences with delivering pharmacogenetic (PGx) testing in independent community pharmacies. METHODS: We conducted a cluster randomized trial of independent community pharmacies in North Carolina randomized to provide either PGx testing as a standalone service or integrated into medication therapy management (MTM) services. Surveys and pharmacist data about the delivery of PGx testing were collected. Semi-structured interviews were also conducted. RESULTS: A total of 36 pharmacists participated in the study from 22 pharmacies. Sixteen pharmacists completed the pre-study and post-study surveys, and four pharmacists completed the semi-structured interviews. Thirty-one percent (11/36) of pharmacists had had some education in personalized medicine or PGx prior to the study. The only outcome that differed by study arm was the use of educational resources, with significantly higher utilization in the PGx testing only arm (p=0.007). Overall, compared to the pre-study assessment, pharmacists' knowledge about PGx significantly improved post-study (p=0.018). In the post-study survey, almost all pharmacists indicated that they felt qualified/able to provide PGx testing at their pharmacy. While 75% of pharmacists indicated that they may continue to provide PGx testing at their pharmacy after the study, the major concerns were lack of reimbursement for PGx counseling and consultation given the necessary time required. CONCLUSION: Our findings demonstrated a positive experience with delivering PGx testing in the community pharmacy setting with little difference in pharmacists' experiences in providing PGx testing with or without MTM. Pharmacists were confident in their ability to provide PGx testing and were interested in continuing to offer testing, though sustained delivery may be challenged by lack of prescribing provider engagement and reimbursement.
Relatively few coronavirus disease cases and deaths have been reported from sub-Saharan Africa, although the extent of its spread remains unclear. During August 10-September 11, 2020, we recruited 2,214 participants for a representative household-based cross-sectional serosurvey in Juba, South Sudan. We found 22.3% of participants had severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain IgG titers above prepandemic levels. After accounting for waning antibody levels, age, and sex, we estimated that 38.3% (95% credible interval 31.8%-46.5%) of the population had been infected with SARS-CoV-2. At this rate, for each PCR-confirmed SARS-CoV-2 infection reported by the Ministry of Health, 103 (95% credible interval 86-126) infections would have been unreported, meaning SARS-CoV-2 has likely spread extensively within Juba. We also found differences in background reactivity in Juba compared with Boston, Massachusetts, USA, where the immunoassay was validated. Our findings underscore the need to validate serologic tests in sub-Saharan Africa populations.
COVID-19 , SARS-CoV-2 , Africa South of the Sahara , Antibodies, Viral , Boston , Cross-Sectional Studies , Humans , Immunoglobulin G , Massachusetts , Seroepidemiologic Studies , South Sudan
Dissolution of marine sediment is a key source of dissolved iron (Fe) that regulates the ocean carbon cycle. Currently, our prevailing understanding, encapsulated in ocean models, focuses on low-oxygen reductive supply mechanisms and neglects the emerging evidence from iron isotopes in seawater and sediment porewaters for additional nonreductive dissolution processes. Here, we combine measurements of Fe colloids and dissolved δ56Fe in shallow porewaters spanning the full depth of the South Atlantic Ocean to demonstrate that it is lithogenic colloid production that fuels sedimentary iron supply away from low-oxygen systems. Iron colloids are ubiquitous in these oxic ocean sediment porewaters and account for the lithogenic isotope signature of dissolved Fe (δ56Fe = +0.07 ± 0.07) within and between ocean basins. Isotope model experiments demonstrate that only lithogenic weathering in both oxic and nitrogenous zones, rather than precipitation or ligand complexation of reduced Fe species, can account for the production of these porewater Fe colloids. The broader covariance between colloidal Fe and organic carbon (OC) abundance suggests that sorption of OC may control the nanoscale stability of Fe minerals by inhibiting the loss of Fe(oxyhydr)oxides to more crystalline minerals in the sediment. Oxic ocean sediments can therefore generate a large exchangeable reservoir of organo-mineral Fe colloids at the sediment water interface (a "rusty source") that dominates the benthic supply of dissolved Fe to the ocean interior, alongside reductive supply pathways from shallower continental margins.
BACKGROUND: Relatively few COVID-19 cases and deaths have been reported through much of sub-Saharan Africa, including South Sudan, although the extent of SARS-CoV-2 spread remains unclear due to weak surveillance systems and few population-representative serosurveys. METHODS: We conducted a representative household-based cross-sectional serosurvey in Juba, South Sudan. We quantified IgG antibody responses to SARS-CoV-2 spike protein receptor-binding domain and estimated seroprevalence using a Bayesian regression model accounting for test performance. RESULTS: We recruited 2,214 participants from August 10 to September 11, 2020 and 22.3% had anti-SARS-CoV-2 IgG titers above levels in pre-pandemic samples. After accounting for waning antibody levels, age, and sex, we estimated that 38.5% (32.1 - 46.8) of the population had been infected with SARS-CoV-2. For each RT-PCR confirmed COVID-19 case, 104 (87-126) infections were unreported. Background antibody reactivity was higher in pre-pandemic samples from Juba compared to Boston, where the serological test was validated. The estimated proportion of the population infected ranged from 30.1% to 60.6% depending on assumptions about test performance and prevalence of clinically severe infections. CONCLUSIONS: SARS-CoV-2 has spread extensively within Juba. Validation of serological tests in sub-Saharan African populations is critical to improve our ability to use serosurveillance to understand and mitigate transmission.
We measured plasma and/or serum antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in 343 North American patients infected with SARS-CoV-2 (of which 93% required hospitalization) up to 122 days after symptom onset and compared them to responses in 1548 individuals whose blood samples were obtained prior to the pandemic. After setting seropositivity thresholds for perfect specificity (100%), we estimated sensitivities of 95% for IgG, 90% for IgA, and 81% for IgM for detecting infected individuals between 15 and 28 days after symptom onset. While the median time to seroconversion was nearly 12 days across all three isotypes tested, IgA and IgM antibodies against RBD were short-lived with median times to seroreversion of 71 and 49 days after symptom onset. In contrast, anti-RBD IgG responses decayed slowly through 90 days with only 3 seropositive individuals seroreverting within this time period. IgG antibodies to SARS-CoV-2 RBD were strongly correlated with anti-S neutralizing antibody titers, which demonstrated little to no decrease over 75 days since symptom onset. We observed no cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies with other widely circulating coronaviruses (HKU1, 229 E, OC43, NL63). These data suggest that RBD-targeted antibodies are excellent markers of previous and recent infection, that differential isotype measurements can help distinguish between recent and older infections, and that IgG responses persist over the first few months after infection and are highly correlated with neutralizing antibodies.
Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/epidemiology , Pneumonia, Viral/epidemiology , Protein Domains/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Betacoronavirus/genetics , Biomarkers/blood , COVID-19 , Cohort Studies , Coronavirus Infections/virology , Cross Reactions , Dried Blood Spot Testing , Female , Humans , Immunoglobulin A/blood , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Middle Aged , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry
BACKGROUND: Characterizing the humoral immune response to SARS-CoV-2 and developing accurate serologic assays are needed for diagnostic purposes and estimating population-level seroprevalence. METHODS: We measured the kinetics of early antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in a cohort of 259 symptomatic North American patients infected with SARS-CoV-2 (up to 75 days after symptom onset) compared to antibody levels in 1548 individuals whose blood samples were obtained prior to the pandemic. RESULTS: Between 14-28 days from onset of symptoms, IgG, IgA, or IgM antibody responses to RBD were all accurate in identifying recently infected individuals, with 100% specificity and a sensitivity of 97%, 91%, and 81% respectively. Although the estimated median time to becoming seropositive was similar across isotypes, IgA and IgM antibodies against RBD were short-lived with most individuals estimated to become seronegative again by 51 and 47 days after symptom onset, respectively. IgG antibodies against RBD lasted longer and persisted through 75 days post-symptoms. IgG antibodies to SARS-CoV-2 RBD were highly correlated with neutralizing antibodies targeting the S protein. No cross-reactivity of the SARS-CoV-2 RBD-targeted antibodies was observed with several known circulating coronaviruses, HKU1, OC 229 E, OC43, and NL63. CONCLUSIONS: Among symptomatic SARS-CoV-2 cases, RBD-targeted antibodies can be indicative of previous and recent infection. IgG antibodies are correlated with neutralizing antibodies and are possibly a correlate of protective immunity.
