Intestinal barrier disruption with Plasmodium falciparum infection in pregnancy and risk of preterm birth: a cohort study.

BACKGROUND: Malaria in early pregnancy is a risk factor for preterm birth and is associated with sustained inflammation and dysregulated angiogenesis across gestation. This study investigated whether malaria is associated with increased gut leak and whether this contributes to systemic inflammation, altered angiogenesis, and preterm birth. METHODS: We quantified plasma concentrations of gut leak markers, soluble CD14 (sCD14) and lipopolysaccharide binding protein (LBP) from 1339 HIV-negative pregnant Malawians at <24 weeks gestational age. We assessed the relationship of sCD14 and LBP concentrations with markers of inflammation, angiogenesis, and L-arginine bioavailability and compared them between participants with and without malaria, and with and without preterm birth. FINDINGS: Plasma concentrations of sCD14 and LBP were significantly higher in participants with malaria and were associated with parasite burden (p <0.0001, both analyses and analytes). The odds ratio for preterm birth associated with one log sCD14 was 2.67 (1.33 to 5.35, p = 0.006) and 1.63 (1.07-2.47, p = 0.023) for LBP. Both gut leak analytes were positively associated with increases in proinflammatory cytokines CRP, sTNFR2, IL18-BP, CHI3L1 and Angptl3 (p <0.05, all analytes) and sCD14 was significantly associated with angiogenic proteins Angpt-2, sENG and the sFLT:PlGF ratio (p <0.05, all analytes). sCD14 was negatively associated with L-arginine bioavailability (p <0.001). INTERPRETATION: Malaria in early pregnancy is associated with intestinal barrier dysfunction, which is linked to an increased risk of preterm birth. FUNDING: Open Philanthropy, Canadian Institutes of Health Research, Canada Research Chair program, European and Developing Countries Clinical Trials Partnership, Bill & Melinda Gates Foundation.

Inflammatory profiles in febrile children with moderate and severe malnutrition presenting at-hospital in Uganda are associated with increased mortality.

BACKGROUND: Children in Africa carry a disproportionate burden of malnutrition and infectious disease. Together, malnutrition and infection are major contributors to global child mortality; however, their collective impact on immune activation are not well described. METHODS: This was a secondary analysis of a prospective cohort study of children hospitalized with acute febrile illness at a single centre in Uganda. We investigated the association between malnutrition (determined using the mid-upper arm circumference, MUAC), immune activation (as measured by inflammatory markers IL-6, IL-8, CXCL10, CHI3L1, sTNFR1, Cystatin C, granzyme B, and sTREM-1), and mortality. FINDINGS: Of the 1850 children eligible for this secondary analysis, 71 (3.8%) and 145 (11.7%) presented with severe acute malnutrition (SAM, MUAC <115 mm) and moderate malnutrition (MUAC 115 to < 125 mm), respectively. SAM was associated with increased concentrations of CHI3L1, sTNFR1, Cystatin C, and sTREM-1, and decreased concentrations of CXCL10 and granzyme B, even after controlling for age, sex, and disease severity at presentation. There were 77 deaths (4.2%). SAM was associated with a 9.2-fold (95% CI 4.8-46), 17-fold (95% CI 3.9-74), and 13-fold (95% CI 3.5-52) increased odds of death in children with pneumonia, malaria, and diarrheal illness, respectively. Mediation analysis implicated sTREM-1 and CHI3L1 in the effect of SAM on mortality, suggesting that enhanced activation of these inflammatory pathways is associated with the increased mortality in undernourished children with pneumonia and malaria. INTERPRETATION: Collectively, these data highlight systemic inflammation as a common pathway associated with malnutrition and infection that could be targeted to mitigate the burden of acute febrile illness in LMICs. FUNDING: This work was supported in part by the Canadian Institutes of Health Research, and by kind donations from The Tesari Foundation and Kim Kertland. The funders had no role in design, analysis, or reporting of these studies.

Prognostic accuracy of biomarkers of immune and endothelial activation in Mozambican children hospitalized with pneumonia.

Pneumonia is a leading cause of child mortality. However, currently we lack simple, objective, and accurate risk-stratification tools for pediatric pneumonia. Here we test the hypothesis that measuring biomarkers of immune and endothelial activation in children with pneumonia may facilitate the identification of those at risk of death. We recruited children <10 years old fulfilling WHO criteria for pneumonia and admitted to the Manhiça District Hospital (Mozambique) from 2010 to 2014. We measured plasma levels of IL-6, IL-8, Angpt-2, sTREM-1, sFlt-1, sTNFR1, PCT, and CRP at admission, and assessed their prognostic accuracy for in-hospital, 28-day, and 90-day mortality. Healthy community controls, within same age strata and location, were also assessed. All biomarkers were significantly elevated in 472 pneumonia cases versus 80 controls (p<0.001). IL-8, sFlt-1, and sTREM-1 were associated with in-hospital mortality (p<0.001) and showed the best discrimination with AUROCs of 0.877 (95% CI: 0.782 to 0.972), 0.832 (95% CI: 0.729 to 0.935) and 0.822 (95% CI: 0.735 to 0.908), respectively. Their performance was superior to CRP, PCT, oxygen saturation, and clinical severity scores. IL-8, sFlt-1, and sTREM-1 remained good predictors of 28-day and 90-day mortality. These findings suggest that measuring IL-8, sFlt-1, or sTREM-1 at hospital presentation can guide risk-stratification of children with pneumonia, which could enable prioritized care to improve survival and resource allocation.

Soluble Urokinase-Type Plasminogen Activator Receptor as a Prognostic Marker of Ugandan Children at Risk of Severe and Fatal Malaria.

BACKGROUND: Current malaria diagnostic tests do not reliably identify children at risk of severe and fatal infection. Host immune and endothelial activation contribute to malaria pathogenesis. Soluble urokinase-type plasminogen activator receptor (suPAR) is a marker of these pathways. We hypothesized that measuring suPAR at presentation could risk-stratify children with malaria. METHODS: Plasma suPAR levels were determined in consecutive febrile children with malaria at presentation to hospital in Jinja, Uganda. We evaluated the accuracy of suPAR in predicting in-hospital mortality, and whether suPAR could improve a validated clinical scoring system (Lambaréné Organ Dysfunction Score [LODS]). RESULTS: Of the 1226 children with malaria, 39 (3.2%) died. suPAR concentrations at presentation were significantly higher in children who went on to die than in those who survived (P < .0001). suPAR levels were associated with disease severity (LODS: 0 vs 1, P = .001; 1 vs 2, P < .001; 2 vs 3, 0 vs 2, 1 vs 3, and 0 vs 3, P < .0001). suPAR concentrations were excellent predictors of in-hospital mortality (area under the receiver operating characteristic curve [AUROC], 0.92 [95% confidence interval {CI}, .91-.94]). The prognostic accuracy of LODS (AUROC, 0.93 [95% CI, .91-.94]) was improved when suPAR was added (AUROC, 0.97 [95% CI, .96-.98]; P < .0001). CONCLUSIONS: Measuring suPAR at presentation can identify children at risk of severe and fatal malaria. Adding suPAR to clinical scores could improve the recognition and triage of children at risk of death. suPAR can be detected with a point-of-care test and can now be evaluated in prospective trials.

Performance of host-response biomarkers to risk-stratify children with pneumonia in Bhutan.

Pneumonia is the leading cause of post-neonatal death amongst children under five years of age; however, there is no simple triage tool to identify children at risk of progressing to severe and fatal disease. Such a tool could assist for early referral and prioritization of care to improve outcomes and enhance allocation of scarce resources. We compared the performance of inflammatory and endothelial activation markers in addition to clinical signs or scoring scales to risk-stratify children hospitalized with pneumonia at the national referral hospital of Bhutan with the goal of predicting clinical outcome. Of 118 children, 31 evolved to a poor prognosis, defined as either mortality, admission in the paediatric intensive care unit, requirement of chest drainage or requirement of more than five days of oxygen therapy. Soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) was the best performing biomarker and performed better than clinical parameters. sTREM-1 levels upon admission had good predictive accuracy to identify children with pneumonia at risk of poor prognosis. Our findings confirm that immune and endothelial activation markers could be proactively used at first encounter as risk-stratification and clinical decision-making tools in children with pneumonia; however, further external validation is needed.

A biomarker assay to risk-stratify patients with symptoms of respiratory tract infection.

BACKGROUND: Patients who present to an emergency department (ED) with respiratory symptoms are often conservatively triaged in favour of hospitalisation. We sought to determine if an inflammatory biomarker panel that identifies the host response better predicts hospitalisation in order to improve the precision of clinical decision making in the ED. METHODS: From April 2020 to March 2021, plasma samples of 641 patients with symptoms of respiratory illness were collected from EDs in an international multicentre study: Canada (n=310), Italy (n=131) and Brazil (n=200). Patients were followed prospectively for 28 days. Subgroup analysis was conducted on confirmed coronavirus disease 2019 (COVID-19) patients (n=245). An inflammatory profile was determined using a rapid, 50-min, biomarker panel (RALI-Dx (Rapid Acute Lung Injury Diagnostic)), which measures interleukin (IL)-6, IL-8, IL-10, soluble tumour necrosis factor receptor 1 (sTNFR1) and soluble triggering receptor expressed on myeloid cells 1 (sTREM1). RESULTS: RALI-Dx biomarkers were significantly elevated in patients who required hospitalisation across all three sites. A machine learning algorithm that was applied to predict hospitalisation using RALI-Dx biomarkers had a mean±sd area under the receiver operating characteristic curve of 76±6% (Canada), 84±4% (Italy) and 86±3% (Brazil). Model performance was 82±3% for COVID-19 patients and 87±7% for patients with a confirmed pneumonia diagnosis. CONCLUSIONS: The rapid diagnostic biomarker panel accurately identified the need for inpatient care in patients presenting with respiratory symptoms, including COVID-19. The RALI-Dx test is broadly and easily applicable across many jurisdictions, and represents an important diagnostic adjunct to advance ED decision-making protocols.

Intestinal Injury in Ugandan Children Hospitalized With Malaria.

BACKGROUND: Severe malaria is associated with multiple organ dysfunction syndrome (MODS), which may involve the gastrointestinal tract. METHODS: In a prospective cohort study in Uganda, we measured markers of intestinal injury (intestinal fatty-acid binding protein [I-FABP] and zonula occludens-1 [ZO-1]) and microbial translocation (lipopolysaccharide binding protein [LBP] and soluble complement of differentiation 14 [sCD14]) among children admitted with malaria. We examined their association with biomarkers of inflammation, endothelial activation, clinical signs of hypoperfusion, organ injury, and mortality. RESULTS: We enrolled 523 children (median age 1.5 years, 46% female, 7.5% mortality). Intestinal FABP was above the normal range (≥400 pg/mL) in 415 of 523 patients (79%). Intestinal FABP correlated with ZO-1 (ρ = 0.11, P = .014), sCD14 (ρ = 0.12, P = .0046) as well as markers of inflammation and endothelial activation. Higher I-FABP levels were associated with lower systolic blood pressure (ρ = -0.14, P = .0015), delayed capillary refill time (ρ = 0.17, P = .00011), higher lactate level (ρ = 0.40, P < .0001), increasing stage of acute kidney injury (ρ = 0.20, P = .0034), and coma (P < .0001). Admission I-FABP levels ≥5.6 ng/mL were associated with a 7.4-fold higher relative risk of in-hospital death (95% confidence interval, 1.4-11, P = .0016). CONCLUSIONS: Intestinal injury occurs commonly in children hospitalized with malaria and is associated with microbial translocation, systemic inflammation, tissue hypoperfusion, MODS, and fatal outcome.

Immune and endothelial activation markers and risk stratification of childhood pneumonia in Uganda: A secondary analysis of a prospective cohort study.

BACKGROUND: Despite the global burden of pneumonia, reliable triage tools to identify children in low-resource settings at risk of severe and fatal respiratory tract infection are lacking. This study assessed the ability of circulating host markers of immune and endothelial activation quantified at presentation, relative to currently used clinical measures of disease severity, to identify children with pneumonia who are at risk of death. METHODS AND FINDINGS: We conducted a secondary analysis of a prospective cohort study of children aged 2 to 59 months presenting to the Jinja Regional Hospital in Jinja, Uganda between February 2012 and August 2013, who met the Integrated Management of Childhood Illness (IMCI) diagnostic criteria for pneumonia. Circulating plasma markers of immune (IL-6, IL-8, CXCL-10/IP-10, CHI3L1, sTNFR1, and sTREM-1) and endothelial (sVCAM-1, sICAM-1, Angpt-1, Angpt-2, and sFlt-1) activation measured at hospital presentation were compared to lactate, respiratory rate, oxygen saturation, procalcitonin (PCT), and C-reactive protein (CRP) with a primary outcome of predicting 48-hour mortality. Of 805 children with IMCI pneumonia, 616 had severe pneumonia. Compared to 10 other immune and endothelial activation markers, sTREM-1 levels at presentation had the best predictive accuracy in identifying 48-hour mortality for children with pneumonia (AUROC 0.885, 95% CI 0.841 to 0.928; p = 0.03 to p < 0.001) and severe pneumonia (AUROC 0.870, 95% CI 0.824 to 0.916; p = 0.04 to p < 0.001). sTREM-1 was more strongly associated with 48-hour mortality than lactate (AUROC 0.745, 95% CI 0.664 to 0.826; p < 0.001), respiratory rate (AUROC 0.615, 95% CI 0.528 to 0.702; p < 0.001), oxygen saturation (AUROC 0.685, 95% CI 0.594 to 0.776; p = 0.002), PCT (AUROC 0.650, 95% CI 0.566 to 0.734; p < 0.001), and CRP (AUROC 0.562, 95% CI 0.472 to 0.653; p < 0.001) in cases of pneumonia and severe pneumonia. The main limitation of this study was the unavailability of radiographic imaging. CONCLUSIONS: In this cohort of Ugandan children, sTREM-1 measured at hospital presentation was a significantly better indicator of 48-hour mortality risk than other common approaches to risk stratify children with pneumonia. Measuring sTREM-1 at clinical presentation may improve the early triage, management, and outcome of children with pneumonia at risk of death. TRIAL REGISTRATION: The trial was registered at clinicaltrial.gov (NCT04726826).

Cardiovascular signatures of COVID-19 predict mortality and identify barrier stabilizing therapies.

BACKGROUND: Endothelial cell (EC) activation, endotheliitis, vascular permeability, and thrombosis have been observed in patients with severe coronavirus disease 2019 (COVID-19), indicating that the vasculature is affected during the acute stages of SARS-CoV-2 infection. It remains unknown whether circulating vascular markers are sufficient to predict clinical outcomes, are unique to COVID-19, and if vascular permeability can be therapeutically targeted. METHODS: Prospectively evaluating the prevalence of circulating inflammatory, cardiac, and EC activation markers as well as developing a microRNA atlas in 241 unvaccinated patients with suspected SARS-CoV-2 infection allowed for prognostic value assessment using a Random Forest model machine learning approach. Subsequent ex vivo experiments assessed EC permeability responses to patient plasma and were used to uncover modulated gene regulatory networks from which rational therapeutic design was inferred. FINDINGS: Multiple inflammatory and EC activation biomarkers were associated with mortality in COVID-19 patients and in severity-matched SARS-CoV-2-negative patients, while dysregulation of specific microRNAs at presentation was specific for poor COVID-19-related outcomes and revealed disease-relevant pathways. Integrating the datasets using a machine learning approach further enhanced clinical risk prediction for in-hospital mortality. Exposure of ECs to COVID-19 patient plasma resulted in severity-specific gene expression responses and EC barrier dysfunction, which was ameliorated using angiopoietin-1 mimetic or recombinant Slit2-N. INTERPRETATION: Integration of multi-omics data identified microRNA and vascular biomarkers prognostic of in-hospital mortality in COVID-19 patients and revealed that vascular stabilizing therapies should be explored as a treatment for endothelial dysfunction in COVID-19, and other severe diseases where endothelial dysfunction has a central role in pathogenesis. FUNDING: This work was directly supported by grant funding from the Ted Rogers Center for Heart Research, Toronto, Ontario, Canada and the Peter Munk Cardiac Center, Toronto, Ontario, Canada.

Association of Clinical Signs, Host Biomarkers and Etiology With Radiological Pneumonia in Bhutanese Children.

Diagnosing pneumonia and identifying those requiring antibiotherapy remain challenging. Chest radiographs (CXR) are often used as the reference standard. We aimed to describe clinical characteristics, host-response biomarkers and etiology, and assess their relationship to CXR findings in children with pneumonia in Thimphu, Bhutan. Children between 2 and 59 months hospitalized with WHO-defined pneumonia were prospectively enrolled and classified into radiological endpoint and non-endpoint pneumonia. Blood and nasopharyngeal washing were collected for microbiological analyses and plasma levels of 11 host-response biomarkers were measured. Among 149 children with readable CXR, 39 (26.2%) presented with endpoint pneumonia. Identification of respiratory viruses was common, with no significant differences by radiological outcomes. No clinical sign was suggestive of radiological pneumonia, but children with radiological pneumonia presented higher erythrocyte sedimentation rate, C-reactive protein and procalcitonin. Markers of endothelial and immune activation had little accuracy for the reliable identification of radiological pneumonia.

COVID-19 risk stratification algorithms based on sTREM-1 and IL-6 in emergency department.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has led to surges of patients presenting to emergency departments (EDs) and potentially overwhelming health systems. OBJECTIVE: We sought to assess the predictive accuracy of host biomarkers at clinical presentation to the ED for adverse outcome. METHODS: Prospective observational study of PCR-confirmed COVID-19 patients in the ED of a Swiss hospital. Concentrations of inflammatory and endothelial dysfunction biomarkers were determined at clinical presentation. We evaluated the accuracy of clinical signs and these biomarkers in predicting 30-day intubation/mortality, and oxygen requirement by calculating the area under the receiver-operating characteristic curve and by classification and regression tree analysis. RESULTS: Of 76 included patients with COVID-19, 24 were outpatients or hospitalized without oxygen requirement, 35 hospitalized with oxygen requirement, and 17 intubated/died. We found that soluble triggering receptor expressed on myeloid cells had the best prognostic accuracy for 30-day intubation/mortality (area under the receiver-operating characteristic curve, 0.86; 95% CI, 0.77-0.95) and IL-6 measured at presentation to the ED had the best accuracy for 30-day oxygen requirement (area under the receiver-operating characteristic curve, 0.84; 95% CI, 0.74-0.94). An algorithm based on respiratory rate and sTREM-1 predicted 30-day intubation/mortality with 94% sensitivity and 0.1 negative likelihood ratio. An IL-6-based algorithm had 98% sensitivity and 0.04 negative likelihood ratio for 30-day oxygen requirement. CONCLUSIONS: sTREM-1 and IL-6 concentrations in COVID-19 in the ED have good predictive accuracy for intubation/mortality and oxygen requirement. sTREM-1- and IL-6-based algorithms are highly sensitive to identify patients with adverse outcome and could serve as early triage tools.

Host-Based Prognostic Biomarkers to Improve Risk Stratification and Outcome of Febrile Children in Low- and Middle-Income Countries.

Fever is one of the leading causes for pediatric medical consultation and the most common symptom at clinical presentation in low- and middle-income countries (LMICs). Most febrile episodes are due to self-limited infections, but a small proportion of children will develop life-threatening infections. The early recognition of children who have or are progressing to a critical illness among all febrile cases is challenging, and there are currently no objective and quantitative tools to do so. This results in increased morbidity and mortality among children with impending life-threatening infections, whilst contributing to the unnecessary prescription of antibiotics, overwhelming health care facilities, and harm to patients receiving avoidable antimicrobial treatment. Specific fever origin is difficult to ascertain and co-infections in LMICs are common. However, many severe infections share common pathways of host injury irrespective of etiology, including immune and endothelial activation that contribute to the pathobiology of sepsis (i.e., pathogen "agnostic" mechanisms of disease). Importantly, mediators of these pathways are independent markers of disease severity and outcome. We propose that measuring circulating levels of these factors can provide quantitative and objective evidence to: enable early recognition of severe infection; guide patient triage and management; enhance post-discharge risk stratification and follow up; and mitigate potential gender bias in clinical decisions. Here, we review the clinical and biological evidence supporting the clinical utility of host immune and endothelial activation biomarkers as components of novel rapid triage tests, and discuss the challenges and needs for developing and implementing such tools.

Is Malaria an Important Cause of Death among Adults?

A long-held assumption has been that nearly all malaria deaths in high-transmission areas are of children younger than 5 years and pregnant women. Most global malaria mortality estimates incorporate this assumption in their calculations. In 2010, the Indian Million Death Study, which assigns cause of death by verbal autopsy (VA), challenged the reigning perception, producing a U-shaped mortality age curve, with rates rising after age 45 years in areas of India with substantial malaria transmission. Similar patterns are seen in Africa in the International Network for the Demographic Evaluation of Populations and Their Health (INDEPTH) network, also relying on VA. Whether these results are accurate or are misidentified deaths can be resolved by improving the evidence for assigning causes for adult acute infectious deaths in high malaria transmission areas. The options for doing so include improving the accuracy of VA and adding postmortem biological evidence, steps we believe should be initiated without delay.

Malaria in Pregnancy and Adverse Birth Outcomes: New Mechanisms and Therapeutic Opportunities.

Malaria infection during pregnancy is associated with adverse birth outcomes but underlying mechanisms are poorly understood. Here, we discuss the impact of malaria in pregnancy on three pathways that are important regulators of healthy pregnancy outcomes: L-arginine-nitric oxide biogenesis, complement activation, and the heme axis. These pathways are not mutually exclusive, and they collectively create a proinflammatory, antiangiogenic milieu at the maternal-fetal interface that interferes with placental function and development. We hypothesize that targeting these host-response pathways would mitigate the burden of adverse birth outcomes attributable to malaria in pregnancy.

Validation of a screening kit to identify environmental lead hazards.

In many states, environmental lead hazards are evaluated only after a lead-poisoned child has been identified. This passive approach is problematic because only a small fraction of children are tested for lead and those with elevated blood lead levels may have irreversible developmental damage. In order to reverse this paradigm, a new lead screening kit was developed. In this study, we validated the accuracy of the kit compared to the conventional methods. Forty-five participants used the kit to collect 3 dust, 3 soil and 2 paint samples in their homes. A researcher performed an in-situ analysis of the lead content in the paint and soil using a portable X-ray fluorescence (XRF) spectrometer. The soil, paint, and dust samples collected by the participants were then analyzed by XRF ex-situ. A strong linear correlation was found between the in-situ and ex-situ measurements for soil and dust samples, and a reasonable correlation was obtained for lead content of paint samples. The kit had very high degrees of specificity (true negative rate) and sensitivity (true positive rate) for detecting hazardous levels of lead in soil and dust samples. The agreement was more moderate for paint samples because some of the paint chips provided gave different readings from the front or back surface, but in-situ XRF only reads from the front surface. Overall, the kit gave a sensitivity of 87%, a specificity of 98% and an accuracy of 96% for detection of environmental lead hazards in samples collected from the home by untrained citizens. This suggests that widespread and inexpensive lead screening could be used to successfully identify hazards and ultimately decrease environmental lead exposure in children.

The Impact of Infection in Pregnancy on Placental Vascular Development and Adverse Birth Outcomes.

Healthy fetal development is dependent on nutrient and oxygen transfer via the placenta. Optimal growth and function of placental vasculature is therefore essential to support in utero development. Vasculogenesis, the de novo formation of blood vessels, and angiogenesis, the branching and remodeling of existing vasculature, mediate the development and maturation of placental villi, which form the materno-fetal interface. Several lines of evidence indicate that systemic maternal infection and consequent inflammation can disrupt placental vasculogenesis and angiogenesis. The resulting alterations in placental hemodynamics impact fetal growth and contribute to poor birth outcomes including preterm delivery, small-for-gestational age (SGA), stillbirth, and low birth weight (LBW). Furthermore, pathways involved in maternal immune activation and placental vascularization parallel those involved in normal fetal development, notably neurovascular development. Therefore, immune-mediated disruption of angiogenic pathways at the materno-fetal interface may also have long-term neurological consequences for offspring. Here, we review current literature evaluating the influence of maternal infection and immune activation at the materno-fetal interface and the subsequent impact on placental vascular function and birth outcome. Immunomodulatory pathways, including chemokines and cytokines released in response to maternal infection, interact closely with the principal pathways regulating placental vascular development, including the angiopoietin-Tie-2, vascular endothelial growth factor (VEGF), and placental growth factor (PlGF) pathways. A detailed mechanistic understanding of how maternal infections impact placental and fetal development is critical to the design of effective interventions to promote placental growth and function and thereby reduce adverse birth outcomes.

The pharmacological and functional characterization of the serotonergic system in Anopheles gambiae and Aedes aegypti: influences on flight and blood-feeding behavior.

Aedes aegypti and Anopheles gambiae harbor the causative agents of diseases such as dengue fever and malaria, afflicting human morbidity and mortality worldwide. Given the worldwide emergence of resistance to insecticides, the current mainstay for vector control, identification of alternative modes of action for future insecticides is paramount. The serotonergic (5-HT) system has been documented to impact physiological mechanisms involved in disease transmission, suggesting its potential as a new mode of action target for future insecticide development. Target 5-HT receptors were cloned and expressed in the HEK293 cell line for functional and pharmacological characterization. Manipulation of the 5-HT system through microinjection of compounds suggests its involvement in the modulation of flight performance and blood-feeding behavior. By attenuating these two determinants of vectorial capacity, transmission and burden of disease could effectively be reduced. Considering these positive global health implications, the 5-HT system is a compelling target for the novel insecticide pipeline.

Inconsistent screening for lead endangers vulnerable children: policy lessons from South Bend and Saint Joseph County, Indiana, USA.

Lead exposure is a major health hazard affecting children and their growth and is a concern in many urban areas around the world. One such city in the United States (US), South Bend Indiana, gained attention for its high levels of lead in blood and relatively low testing rates for children. We assessed current lead screening practices in South Bend and the surrounding St. Joseph County (SJC). The 2005-2015 lead screening data included 18,526 unique children. Lead screening rates ranged from 4.7 to 16.7%. More than 75% of children had 'elevated blood lead levels' (EBLL) ≥ 1 micrograms per deciliter (µg/Dl) and 9.7% had an EBLL ≥ 5 µg/dL. Over 65% of the census tracts in SJC had mean EBLL ≥ 5 µg/dL, suggesting widespread risk. Inconsistent lead screening rates, coupled with environmental and societal risk factors, put children in SJC at greater risk for harmful lead exposure than children living in states with provisions for universal screening. Indiana and other states should adhere to the US Centers for Disease Control's guideline and use universal lead testing to protect vulnerable populations.

The search for novel insecticide targets in the post-genomics era, with a specific focus on G-protein coupled receptors.

Insects are considered pests globally, implicated in the destruction of agricultural fields and transmission of pathogens that cause deadly human diseases, such as dengue, Zika and malaria. The diversity of the insecticide arsenal has remained stagnant for decades, but the recent rise of insecticide resistance fueled the discovery of novel modes of action, and the power of genomics has reinvigorated this search. This review discusses the importance of comparative and functional insect genomics in the identification of potential gene targets for an insecticidal mode of action with low off-target toxicity. Due to the global participation in the sequencing and annotation of insect genomes, the targeting of specific genes with molecular tools like RNAi and CRISPR/Cas9 for genome engineering and consequent functional identification and validation has become more efficient. While there are multiple avenues to explore for insecticidal candidates, this review identifies G-protein coupled receptors as attractive targets, and hones in on the octopamine and dopamine receptors due to their potential.