Autoantibodies against chemokines post-SARS-CoV-2 infection correlate with disease course.

Infection with severe acute respiratory syndrome coronavirus 2 associates with diverse symptoms, which can persist for months. While antiviral antibodies are protective, those targeting interferons and other immune factors are associated with adverse coronavirus disease 2019 (COVID-19) outcomes. Here we discovered that antibodies against specific chemokines were omnipresent post-COVID-19, were associated with favorable disease outcome and negatively correlated with the development of long COVID at 1 yr post-infection. Chemokine antibodies were also present in HIV-1 infection and autoimmune disorders, but they targeted different chemokines compared with COVID-19. Monoclonal antibodies derived from COVID-19 convalescents that bound to the chemokine N-loop impaired cell migration. Given the role of chemokines in orchestrating immune cell trafficking, naturally arising chemokine antibodies may modulate the inflammatory response and thus bear therapeutic potential.

Extracorporeal life support without systemic anticoagulation: a nitric oxide-based non-thrombogenic circuit for the artificial placenta in an ovine model.

BACKGROUND: Clinical translation of the extracorporeal artificial placenta (AP) is impeded by the high risk for intracranial hemorrhage in extremely premature newborns. The Nitric Oxide Surface Anticoagulation (NOSA) system is a novel non-thrombogenic extracorporeal circuit. This study aims to test the NOSA system in the AP without systemic anticoagulation. METHODS: Ten extremely premature lambs were delivered and connected to the AP. For the NOSA group, the circuit was coated with DBHD-N2O2/argatroban, 100 ppm nitric oxide was blended into the sweep gas, and no systemic anticoagulation was given. For the Heparin control group, a non-coated circuit was used and systemic anticoagulation was administered. RESULTS: Animals survived 6.8 ± 0.6 days with normal hemodynamics and gas exchange. Neither group had any hemorrhagic or thrombotic complications. ACT (194 ± 53 vs. 261 ± 86 s; p < 0.001) and aPTT (39 ± 7 vs. 69 ± 23 s; p < 0.001) were significantly lower in the NOSA group than the Heparin group. Platelet and leukocyte activation did not differ significantly from baseline in the NOSA group. Methemoglobin was 3.2 ± 1.1% in the NOSA group compared to 1.6 ± 0.6% in the Heparin group (p < 0.001). CONCLUSIONS: The AP with the NOSA system successfully supported extremely premature lambs for 7 days without significant bleeding or thrombosis. IMPACT: The Nitric Oxide Surface Anticoagulation (NOSA) system provides effective circuit-based anticoagulation in a fetal sheep model of the extracorporeal artificial placenta (AP) for 7 days. The NOSA system is the first non-thrombogenic circuit to consistently obviate the need for systemic anticoagulation in an extracorporeal circuit for up to 7 days. The NOSA system may allow the AP to be implemented clinically without systemic anticoagulation, thus greatly reducing the intracranial hemorrhage risk for extremely low gestational age newborns. The NOSA system could potentially be applied to any form of extracorporeal life support to reduce or avoid systemic anticoagulation.

The role of fetal hemoglobin in the artificial placenta: A premature ovine model.

INTRODUCTION: A radical paradigm shift in the treatment of premature infants failing conventional treatment is to recreate fetal physiology using an extracorporeal Artificial Placenta (AP). The aim of this study is to evaluate the effects of changing fetal hemoglobin percent (HbF%) on physiology and circuit function during AP support in an ovine model. METHODS: Extremely premature lambs (n = 5) were delivered by cesarean section at 117-121 d estimated gestational age (EGA) (term = 145d), weighing 2.5 ± 0.35 kg. Lambs were cannulated using 10-14Fr cannulae for drainage via the right jugular vein and reinfusion via the umbilical vein. Lambs were intubated and lungs were filled with perfluorodecalin to a meniscus with a pressure of 5-8 cm H2O. The first option for transfusion was fetal whole blood from twins followed by maternal red blood cells. Arterial blood gases were used to titrate AP support to maintain fetal blood gas values. RESULTS: The mean survival time on circuit was 119.6 ± 39.5 h. Hemodynamic parameters and lactate were stable throughout. As more adult blood transfusions were given to maintain hemoglobin at 10 mg/dL, the HbF% declined, reaching 40% by post operative day 7. The HbF% was inversely proportional to flow rates as higher flows were required to maintain adequate oxygen saturation and perfusion. CONCLUSIONS: Transfusion of adult blood led to decreased fetal hemoglobin concentration during AP support. The HbF% was inversely proportional to flow rates. Future directions include strategies to decrease the priming volume and establishing a fetal blood bank to have blood rich in HbF.

Undiagnosing St Joan: She Does Not Need a Medical or Psychiatric Diagnosis.

ABSTRACT: This article traces the history of Joan of Arc through her brief life that includes leading an army in defense of France at the age of 17 and ending with her death at the stake at the age of 19. In her activities, St Joan reported that she was guided by voices and visions in which she communicated with venerated spiritual figures such as St Michael and St Margaret. Questions have arisen about the nature of these experiences, and various medical and psychiatric diagnoses have been offered by contemporary experts. In our effort to evaluate the diagnostic proposals, we have examined the incidence of voices and visions in the Middle Ages, and we have followed that with a review of nonpathologic voice-hearing in our own era. We then move on to an analysis of some proposed medical and psychiatric diagnoses, all of which we find unconvincing. With this background, we argue that St Joan does not warrant a medical or psychiatric diagnosis. Such a conclusion, however, leaves us with another issue, that of Joan's achievements. How do we understand an adolescent being able to lead an army? Addressing this question proves more difficult than deciding whether St Joan warrants a diagnosis. In addition to her achievements in the war against Britain, Joan of Arc stands out as both the most documented person in Western civilization up until her era, and as the only person who has been both condemned and canonized by the Catholic Church.

Persistent Symptoms, Lyme Disease, and Prior Trauma.

ABSTRACT: One prior study suggests that traumatic events before Lyme disease play an important role in symptom severity. We examined this hypothesis among 60 individuals with persistent symptoms after Lyme disease using validated measures of trauma history, mental and physical symptoms, and functional status. Analysis of variance with Tukey-Kramer multiple comparisons test revealed that a greater number of traumatic events were significantly associated with greater symptom severity on the scales of mood (stress, depression, and anxiety), cognition, multisystem symptom burden, and functional status (mental and physical), but not on measures of pain and fatigue. The effect sizes-meaningful but not large (0.17-0.29)-were mostly produced by comparison with individuals reporting multiple prior traumatic events, representing half of the posttreatment Lyme disease syndrome (PTLDS) group. In conclusion, although PTLDS may be exacerbated by past trauma, trauma plays a role in only a subgroup of PTLDS. Whether addressing prior trauma can improve outcomes in this subgroup requires study.

Pediatric and neonatal extracorporeal life support: current state and continuing evolution.

The use of extracorporeal life support (ECLS) for the pediatric and neonatal population continues to grow. At the same time, there have been dramatic improvements in the technology and safety of ECLS that have broadened the scope of its application. This article will review the evolving landscape of ECLS, including its expanding indications and shrinking contraindications. It will also describe traditional and hybrid cannulation strategies as well as changes in circuit components such as servo regulation, non-thrombogenic surfaces, and paracorporeal lung-assist devices. Finally, it will outline the modern approach to managing a patient on ECLS, including anticoagulation, sedation, rehabilitation, nutrition, and staffing.

DSM-5 Personality Disorders and Traits in Patients With Severe Health Anxiety.

Severe health anxiety (SHA)/hypochondriasis (HY) is often associated with personality pathology; however, studies report inconsistent results. In general populations, 12% have a personality disorder (PD). We assessed physician-referred psychiatric outpatients with SHA enrolled for a treatment study (n = 84) with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) axis II (SCID-II), Personality Inventory for DSM-5 (PID-5), Whiteley Index 7, and Short Health Anxiety Inventory, and the healthy controls (n = 84) with PID-5 only. There were 71.4% of the patients who met criteria for PDs: avoidant (22.6%), obsessive-compulsive (16.7%), depressive (16.7%), dependent (7.1%), paranoid (3.6%), borderline (2.4%), and not otherwise specified (32.1%). Severity of personality pathology was associated with severity of health anxiety. In group comparisons, PID-5 trait domains of negative affectivity, detachment, low antagonism, and low disinhibition, and facets of anxiousness, separation insecurity, and low attention seeking emerged as unique predictors of SHA. Personality pathology is common among individuals with SHA/HY. Further research is needed to understand the nature of the relationship between health anxiety and personality pathology and to determine whether treatments that target both SHA/HY and personality pathology will improve short- and long-term outcomes.

Varieties of Religious (Non)Affiliation: A Primer for Mental Health Practitioners on the "Spiritual but Not Religious" and the "Nones".

Given changing demographics of religiosity and spirituality, this article aims to help clinicians understand contemporary trends in patient religious and spiritual orientation. It first identifies and describes the evolving varieties of religio-spiritual orientation and affiliation, as identified in survey studies. Particular attention is given to the examination of those who identify as spiritual but not religious (SBNR) and None (i.e., no religious affiliation), which is important to mental health practice because many patients now identify as SBNR or None. Next, empirical data are considered, including what the literature reveals regarding mental health outcomes and SBNRs and Nones. We conclude with a summary of the main points and five recommendations that mental health practitioners and researchers need to consider regarding this increasingly large portion of the population.

Religion and Psychiatry in the Age of Neuroscience.

In recent decades, an evolving conversation among religion, psychiatry, and neuroscience has been taking place, transforming how we conceptualize religion and how that conceptualization affects its relation to psychiatry. In this article, we review several dimensions of the dialogue, beginning with its history and the phenomenology of religious experience. We then turn to neuroscientific studies to see how they explain religious experience, and we follow that with two related areas: the benefits of religious beliefs and practices, and the evolutionary foundation of those benefits. A final section addresses neuroscientific and evolutionary accounts of the transcendent, that is, what these fields make of the claim that religious experience connects to a transcendent reality. We conclude with a brief summary, along with the unresolved questions we have encountered.

Depressive Symptoms and Suicidal Ideation Among Symptomatic Patients With a History of Lyme Disease vs Two Comparison Groups.

BACKGROUND: Depression has been reported in 8-45% of patients with posttreatment Lyme symptoms (PTLS), but little is known about suicidal ideation in these patients. METHOD: Depression and suicidal ideation were assessed using the Beck Depression Inventory (BDI-II). Scores from the PTLS group (n = 81) were compared to those from 2 other groups: HIV+ patients being treated for fatigue (n = 70), and a nonpatient comparison group (NPCG; n = 44). ANOVA and t-tests were used to compare groups; logistic regression was used to identify the strongest correlates of suicidal ideation. RESULTS: Mean BDI-II scores fell in the mildly depressed range for PTLS and HIV+ patients, with both groups having higher depression scores than the NPCG. Suicidal ideation was reported by 19.8% of the PTLS patients and 27.1% of the HIV+ patients, a nonsignificant difference. Among those with mild or no depression, suicidal ideation was uncommon (6.5% PTLS and 11.9% HIV+). Among the patients with moderate-to-severe depression, suicidal ideation was more common (63.2% of 19 PTLS and 50% of 28 HIV+); among these, 2 with PTLS and 1 with HIV+ expressed suicidal intent. Further, 4.5% (n = 2) of the NPCG had suicidal ideation, each had scores in the moderate-to-severe depression range. Higher scores on the cognitive symptoms subscale of the BDI-II predicted greater likelihood of suicidal ideation across patient groups. CONCLUSION: As expected, suicidal ideation is increased among patients who are depressed. The fact that 1 in 5 patients with PTLS reported suicidal ideation highlights the importance of screening for depression and suicidality to optimize patient care.

Routine Use of Distal Arterial Perfusion in Pediatric Femoral Venoarterial Extracorporeal Membrane Oxygenation.

Lower-extremity ischemia is a significant complication in children on femoral venoarterial extracorporeal membrane oxygenation (VA ECMO). Our institution currently routinely uses distal perfusion catheters (DPCs) in all femoral arterial cannulations in attempts to reduce ischemia. We performed a single-center, retrospective review of pediatric patients supported with femoral VA ECMO from January 2005 to November 2015. The outcomes of patients with prophylactic DPC placement at cannulation (prophylactic DPC) were compared to a historical group with DPCs placed in response only to clinically evident ischemic changes (reactive DPC). Ischemic complication requiring invasive intervention (fasciotomy or amputation) was the primary outcome. Twenty-nine patients underwent a total of 31 femoral arterial cannulations, 17 with prophylactic DPC and 14 with reactive DPC. Ischemic complications requiring invasive intervention developed in 2 of 17 (12%) prophylactic DPC patients versus 4 of 14 (29%) reactive DPC. In the reactive DPC group, 7 of 14 (50%) had ischemic changes postcannulation, six underwent DPC placement, and three out of six of these patients still required invasive intervention. One of the seven patients had ischemic changes, did not undergo DPC, and required amputation. While a greater percentage of patients in the prophylactic group was cannulated during extracorporeal cardiopulmonary resuscitation (ECPR), statistical significance was not otherwise demonstrated. We demonstrate feasibility of superficial femoral artery (SFA) access in pediatric patients. We note fewer ischemic complications with prophylactic DPC placement, and observe that salvaging a limb with a reactive DPC was only successful 50% of the time. Although there was no statistical difference in the primary outcome between the two groups, limitations and confounding factors include small sample size and a greater percentage of patients in the prophylactic DPC group cannulated with ECPR in progress.

Cyberchondria: Parsing Health Anxiety From Online Behavior.

BACKGROUND: Individuals with questions about their health often turn to the Internet for information about their symptoms, but the degree to which health anxiety is related to online checking, and clinical variables, remains unclear. The clinical profiles of highly anxious Internet checkers, and the relationship to checking behavior itself, have not previously been reported. OBJECTIVE: In this article, we test the hypothesis, derived from cognitive-behavioral models, that individuals with higher levels of illness anxiety would recall having experienced worsening anxiety after reassurance-seeking on the Internet. METHOD: Data from 731 volunteers who endorsed engaging in online symptom-searching were collected using an online questionnaire. Severity of health anxiety was assessed with the Whiteley Index, functional impairment with the Sheehan Disability Scale, and distress recall during and after searching with a modified version of the Clinician׳s Global Impairment scale. Multiple regression analyses were conducted to determine variables contributing to distress during and after Internet checking. RESULTS: Severity of illness anxiety on the Whiteley Index was the strongest predictor of increase in anxiety associated with, and consequent to, online symptom-searching. Individuals with high illness anxiety recalled feeling worse after online symptom-checking, whereas those with low illness anxiety recalled relief. Longer-duration online health-related use was associated with increased functional impairment, less education, and increased anxiety during and after checking. CONCLUSION: Because individuals with moderate-high levels of illness anxiety recall experiencing more anxiety during and after searching, such searching may be detrimental to their health. If replicated in controlled experimental settings, this would suggest that individuals with illness anxiety should be advised to avoid using the Internet for illness-related information.

The Relationship of Hypochondriasis to Anxiety, Depressive, and Somatoform Disorders.

BACKGROUND: Though the phenotype of anxiety about medical illness has long been recognized, there continues to be debate as to whether it is a distinct psychiatric disorder and, if so, to which diagnostic category it belongs. OBJECTIVE: Our objective was to investigate the pattern of psychiatric comorbidity in hypochondriasis (HC) and to assess the relationship of health anxiety to anxiety, depressive, and somatoform disorders. METHODS: Data were collected as part of a clinical trial on treatment methods for HC. In all, 194 participants meeting criteria for Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) HC were assessed by sociodemographic variables, results of structured diagnostic interviews, and validated instruments for assessing various symptom dimensions of psychopathology. RESULTS: Most of the individuals with HC had comorbid psychiatric illness; the mean number of comorbid diagnoses was 1.4, and 35.1% had HC as their only diagnosis. Participants were more likely to have only comorbid anxiety disorders than only comorbid depressive or somatoform disorders. Multiple regression analysis of continuous measures of symptoms revealed the strongest correlation of health anxiety with anxiety symptoms, and a weaker correlation with somatoform symptoms; in multiple regression analysis, there was no correlation between health anxiety and depressive symptoms. CONCLUSION: Our findings suggest that the entity of health anxiety (HC in DSM-IV and illness anxiety disorder in DSM-5) is a clinical syndrome distinct from other psychiatric disorders. Analysis of comorbidity patterns and continuous measures of symptoms suggest that its appropriate classification is with anxiety rather than somatoform or mood disorders.

Specific glycoforms of MUC5AC and endorepellin accurately distinguish mucinous from nonmucinous pancreatic cysts.

Specific protein glycoforms may be uniquely informative about the pathological state of a cyst and may serve as accurate biomarkers. Here we tested that hypothesis using antibody-lectin sandwich arrays in broad screens of protein glycoforms and in targeted studies of candidate markers. We profiled 16 different glycoforms of proteins captured by 72 different antibodies in cyst fluid from mucinous and nonmucinous cysts (n = 22), and we then tested a three-marker panel in 22 addition samples and 22 blinded samples. Glycan alterations were not widespread among the proteins and were mainly confined to MUC5AC and endorepellin. Specific glycoforms of these proteins, defined by reactivity with wheat germ agglutinin and a blood group H antibody, were significantly elevated in mucinous cysts, whereas the core protein levels were not significantly elevated. A three-marker panel based on these glycoforms distinguished mucinous from nonmucinous cysts with 93% accuracy (89% sensitivity, 100% specificity) in a prevalidation sample set (n = 44) and with 91% accuracy (87% sensitivity, 100% specificity) in independent, blinded samples (n = 22). Targeted lectin measurements and mass spectrometry analyses indicated that the higher wheat germ agglutinin and blood group H reactivity was due to oligosaccharides terminating in GlcNAc or N-acetyl-lactosamine with occasional α1,2-linked fucose. The results show that MUC5AC and endorepellin glycoforms may be highly specific and sensitive biomarkers for the differentiation of mucinous from nonmucinous pancreatic cysts.

A comparison of lyme disease serologic test results from 4 laboratories in patients with persistent symptoms after antibiotic treatment.

BACKGROUND: As the incidence of Lyme disease (LD) has increased, a number of "Lyme specialty laboratories" have emerged, claiming singular expertise in LD testing. We investigated the degree of interlaboratory variability of several LD serologic tests-whole cell sonicate (WCS) enzyme-linked immunosorbent assay (ELISA), immunoglobulin M (IgM) and immunoglobulin G (IgG) Western blots (WBs), and an ELISA based on the conserved sixth region of variable major protein-like sequence expressed (C6)-that were performed at 1 university laboratory, 1 commercial laboratory, and 2 laboratories that specialize in LD testing. METHODS: Serum samples from 37 patients with posttreatment Lyme syndrome, as well as 40 medically healthy controls without prior LD, were tested independently at the 4 laboratories. RESULTS: In general, there was little difference among the laboratories in the percentage of positive test results on the ELISAs and IgG WBs, although the number of discordant results was often high. When in-house criteria for positivity were used at the 2 specialty laboratories, specificity at 1 laboratory declined considerably on both the IgM and IgG WBs. The Centers for Disease Control and Prevention (CDC) 2-tiered criteria improved overall concordance. At the 2 laboratories that performed the C6 ELISA, the percentage of positive tests was comparable to that of the WCS ELISA while providing higher specificity. The IgM WB performed poorly in our patient population of individuals with later-stage illness, a result consistent with previous studies. CONCLUSIONS: Although there was surprisingly little difference among the laboratories in percentage of positive results on most assays using CDC criteria, interlaboratory variability was considerable and remains a problem in LD testing.

Bartonella species bacteremia in association with adult psychosis.

Introduction: The potential role of pathogens, particularly vector-transmitted infectious agents, as a cause of psychosis has not been intensively investigated. We have reported a potential link between Bartonella spp. bacteremia and neuropsychiatric symptoms, including pediatric acute onset neuropsychiatric syndrome and schizophrenia. The purpose of this study was to further assess whether Bartonella spp. exposure or infection are associated with psychosis. Methods: In a blinded manner, we assessed the presence of anti-Bartonella antibodies by indirect immunofluorescence assays (IFA), and infection by amplification of bacterial DNA from blood by quantitative polymerase chain reaction (qPCR), digital PCR (dPCR), and droplet digital PCR (ddPCR) in 116 participants. Participants were categorized into one of five groups: 1) controls unaffected by psychosis (n = 29); 2) prodromal participants (n = 16); 3) children or adolescents with psychosis (n = 7); 4) adults with psychosis (n = 44); and 5) relatives of a participant with psychosis (n = 20). Results: There was no significant difference in Bartonella spp. IFA seroreactivity between adults with psychosis and adult controls unaffected by psychosis. There was a higher proportion of adults with psychosis who had Bartonella spp. DNA in the bloodstream (43.2%) compared to adult controls unaffected by psychosis (14.3%, p = 0.021). The Bartonella species was determined for 18 of the 31 bacteremic participants, including infection or co-infection with Bartonella henselae (11/18), Bartonella vinsonii subsp. berkhoffii (6/18), Bartonella quintana (2/18), Bartonella alsatica (1/18), and Bartonella rochalimae (1/18). Discussion: In conjunction with other recent research, the results of this study provide justification for a large national or international multi-center study to determine if Bartonella spp. bacteremia is more prevalent in adults with psychosis compared to adults unaffected by psychosis. Expanding the investigation to include a range of vector-borne and other microbial infections with potential CNS effects would enhance knowledge on the relationship between psychosis and infection.

A Pumpless Pediatric Artificial Lung Maintains Function for 72 h Without Systemic Anticoagulation Using the Nitric Oxide Surface Anticoagulation System.

BACKGROUND: Children with end-stage lung disease are commonly managed with extracorporeal life support (ECLS) as a bridge to lung transplantation. A pumpless artificial lung (MLung) is a portable alternative to ECLS and it allows for ambulation. Both ECLS and pumpless artificial lungs require systemic anticoagulation which is associated with hemorrhagic complications. We tested the MLung with a novel Nitric Oxide (NO) Surface Anticoagulation (NOSA) system, to provide local anticoagulation for 72 h of support in a pediatric-size ovine model. METHODS: Four mini sheep underwent thoracotomy and cannulation of the pulmonary artery (inflow) and left atrium (outflow), recovered and were monitored for 72hr. The circuit tubing and connectors were coated with the combination of an NO donor (diazeniumdiolated dibutylhexanediamine; DBHD-N2O2) and argatroban. The animals were connected to the MLung and 100 ppm of NO was added to the sweep gas. Systemic hemodynamics, blood chemistry, blood gases, and methemoglobin were collected. RESULTS: Mean device flow was 836 ± 121 mL/min. Device outlet saturation was 97 ± 4%. Pressure drop across the lung was 3.5 ± 1.5 mmHg and resistance was 4.3 ± 1.7 mmHg/L/min. Activated clotting time averaged 170 ± 45s. Methemoglobin was 2.9 ± 0.8%. Platelets declined from 590 ± 101 at baseline to 160 ± 90 at 72 h. NO flux (x10-10 mol/min/cm2) of the NOSA circuit averaged 2.8 ± 0.6 (before study) and 1.9 ± 0.1 (72 h) and across the MLung 18 ± 3 NO flux was delivered. CONCLUSION: The MLung is a more portable form of ECLS that demonstrates effective gas exchange for 72 h without hemodynamic changes. Additionally, the NOSA system successfully maintained local anticoagulation without evidence of systemic effects.

Prevalence of Powassan Virus Seropositivity Among People with History of Lyme Disease and Non-Lyme Community Controls in the Northeastern United States.

Introduction: Lyme disease (LD) affects ∼476,000 people each year in the United States. Symptoms are variable and include rash and flu-like symptoms. Reasons for the wide variation in disease outcomes are unknown. Powassan virus (POWV) is a tick-borne flavivirus that causes disease ranging from asymptomatic infection to encephalitis, neurologic damage, and death. POWV and LD geographic case distributions overlap, with Ixodes species ticks as the common vectors. Clinical ramifications of coinfection or sequential infection are unknown. Objectives: This study's primary objective was to determine the prevalence of POWV-reactive antibodies in sera samples collected from previously studied cohorts of individuals with self-reported LD history residing in the Northeastern United States. As a secondary objective, we studied clinical differences between people with self-reported LD history and low versus high POWV antibody levels. Methods: We used an enzyme-linked immunosorbent assay (ELISA) to quantify IgG directed at the POWV envelope (E) protein domain III in 538 samples from individuals with self-reported LD history and 16 community controls. The samples were also tested with an ELISA assay to quantify IgG directed at the POWV NS1 protein. Results: The percentage of individuals with LD history and possible evidence of POWV exposure varied depending on the assay utilized. We found no significant difference in clinical symptoms between those with low or high POWV IgG levels in the in-house assay. Congruence of the EDIII and NS1 assays was low with only 12% of those positive in the in-house EDIII ELISA testing positive in the POWV NS1 ELISA. Conclusions: The results highlight the difficulty in flavivirus diagnostic testing, particularly in the retrospective detection of flavivirus exposure. The findings suggest that a prospective study with symptomatic patients using approved clinical testing is necessary to address the incidence and clinical implications of LD and POWV co-infection or sequential infection.

Human antibodies in Mexico and Brazil neutralizing tick-borne flaviviruses.

Flaviviruses such as dengue virus (DENV), Zika virus (ZIKV), and yellow fever virus (YFV) are spread by mosquitoes and cause human disease and mortality in tropical areas. In contrast, Powassan virus (POWV), which causes severe neurologic illness, is a flavivirus transmitted by ticks in temperate regions of the Northern hemisphere. We find serologic neutralizing activity against POWV in individuals living in Mexico and Brazil. Monoclonal antibodies P002 and P003, which were derived from a resident of Mexico (where POWV is not reported), neutralize POWV lineage I by recognizing an epitope on the virus envelope domain III (EDIII) that is shared with a broad range of tick- and mosquito-borne flaviviruses. Our findings raise the possibility that POWV, or a flavivirus closely related to it, infects humans in the tropics.