Diagnostics to support elimination of lymphatic filariasis-development of two target product profiles

As lymphatic filariasis (LF) programs move closer to established targets for validation elimination of LF as a public health problem, diagnostic tools capable of supporting the needs of the programs are critical for success. Known limitations of existing diagnostic tools make it challenging to have confidence that program endpoints have been achieved. In 2019, the World Health Organization (WHO) established a Diagnostic Technical Advisory Group (DTAG) for Neglected Tropical Diseases tasked with prioritizing diagnostic needs including defining use-cases and target product profiles (TPPs) for needed tools. Subsequently, disease-specific DTAG subgroups, including one focused on LF, were established to develop TPPs and use-case analyses to be used by product developers. Here, we describe the development of two priority TPPs for LF diagnostics needed for making decisions for stopping mass drug administration (MDA) of a triple drug regimen and surveillance. Utilizing the WHO core TPP development process as the framework, the LF subgroup convened to discuss and determine attributes required for each use case. TPPs considered the following parameters: product use, design, performance, product configuration and cost, and access and equity. Version 1.0 TPPs for two use cases were published by WHO on 12 March 2021 within the WHO Global Observatory on Health Research and Development. A common TPP characteristic that emerged in both use cases was the need to identify new biomarkers that would allow for greater precision in program delivery. As LF diagnostic tests are rarely used for individual clinical diagnosis, it became apparent that reliance on population-based surveys for decision making requires consideration of test performance in the context of such surveys. In low prevalence settings, the number of false positive test results may lead to unnecessary continuation or resumption of MDA, thus wasting valuable resources and time. Therefore, highly specific diagnostic tools are paramount when used to measure low thresholds. The TPP process brought to the forefront the importance of linking use case, program platform and diagnostic performance characteristics when defining required criteria for diagnostic tools

New approaches for conducting surveillance for lymphatic filariasis elimination programmes and implications for other neglected tropical diseases

Background: Lymphatic filariasis (LF), a mosquito-transmitted parasitic disease caused by filarial worms, is a leading cause of disability worldwide. In 1997, at the 50th World Health Assembly, a resolution was passed to eliminate LF as a public health problem by 2020. To reach established elimination targets, LF programmes conduct annual community-wide mass drug administration (MDA). At the start of the Global Programme to Eliminate Lymphatic Filariasis (GPELF), an estimated 120 million individuals were infected, and approximately 1.4 billion people were at risk for filarial infection. Since then, mainly through MDA programmes, the number of people at risk of infection has been reduced to 856.4 million. By the end of 2016, MDA had been implemented in 63 of 72 LF-endemic countries. Demonstrating success of LF programmes depends on rigorous monitoring and evaluation (M&E) of programme activities. As prevalence declines, it is important to identify sensitive diagnostic tools and robust surveillance strategies to detect any possible recrudescence of infection as early as possible. Existing recommendations for LF surveillance are adequate for making the decision to stop MDA, but may not be sufficient for documenting that elimination endpoints have been met. Programme strategies need to be refined in order to establish a more robust M&E framework. Goals and objectives: The overarching goal of this PhD thesis was to provide recommendations on approaches for conducting surveillance for LF elimination programmes. There were two interlinked objectives: (i) to determine the utility of serologic tools during the post-MDA surveillance period within communities that have received multiple rounds of LF MDA; and (ii) to determine the utility of the transmission assessment survey (TAS) and other activities during the post-MDA surveillance period as platforms for integrated disease surveillance. The specific aims were (i) to compare LF antigen and antifilarial antibody responses during the post-MDA surveillance period; (ii) to determine the appropriate age group(s) to monitor during the post-MDA period; (iii) to compare diagnostic tools for use during the surveillance period to determine the most appropriate diagnostic tool(s) to use for LF surveillance; and (iv) to assess the feasibility of using existing disease programme infrastructures as platforms for multi-disease surveillance. Methods: To compare the utility of parasitological and serological indicators for measuring LF programme endpoints, samples from participants (2-100 years old) in 10 sentinel sites in coastal Kenya were examined for circulating filarial antigen (CFA) and filarial antibodies. To evaluate the use of antibody responses as a way to measure the impact of MDA, serum samples collected at three time points from children 1-5 years of age in western Kenya were tested for antibody responses to two schistosome antigens by multiplex bead assay (MBA). In American Samoa, CFA and antibody results from children enrolled in LF TAS conducted 4 years apart were analysed to determine whether interruption of LF transmission has been achieved. A study was carried out in The Gambia among populations living in 15 villages with a history of high LF prevalence. Samples were collected and tested for CFA and filarial antibodies to evaluate the use of serological tools to confirm interruption of LF transmission. Published data from previously conducted studies in American Samoa were analysed to evaluate the relationship between human serological indicators and filarial DNA in mosquitoes. In Haiti, to evaluate the feasibility of using TAS as a platform to collect information about other tropical diseases, samples were collected to test for LF and malaria. In addition to LF testing, samples collected during the sentinel site surveys in coastal Kenya were used for the detection of antibodies against antigens from several parasitic infections as well as markers for immunity to vaccine-preventable diseases to determine the utility of integrated serosurveillance. Results: The overall prevalence of filarial antigenaemia in coastal Kenya was low (1.3%). CFA prevalence among children under 10 years old was very low (<1%). However, quantitative antibody levels among children were higher in areas with suspected LF transmission. Antibodies to Schistosoma spp. antigens among children declined after MDA. There was a significant decrease in the proportion of 1-year olds with positive antibody responses from 33.1% in year 1 to 13.2% in year 3. In American Samoa, a total of 1,134 and 864 children (5-10 years old) were enrolled in TAS 1 (2011) and TAS 2 (2015), respectively. Two CFA-positive children were identified in TAS 1, and one CFA-positive child was identified in TAS 2. In 2011, overall prevalence of antibody responses to Wb123, Bm14, and Bm33 was 1.0%, 6.8% and 12.0%, respectively. In 2015, overall prevalence of positive Bm14 and Bm33 responses declined significantly to 3.0% and 7.8%, respectively. However, there were persistent antibody responses in some schools. In The Gambia, a total of 2,612 dried blood spots (DBS) collected from individuals aged 1 year and above was tested for antibodies to Wb123 by enzyme-linked immunosorbent assay (ELISA). Overall, prevalence of Wb123 was low (1.5%). In seven of 15 villages, there were no Wb123-positive individuals identified. In American Samoa, there was a significant relationship between the presence of filarial DNA in mosquitoes and villages with individuals with responses to Wb123. It was feasible to add malaria testing to TAS in Haiti. A total of 16,655 children were tested for LF and 14,795 for malaria in 14 TAS. In Kenya, utilising a multiplex approach, antibody responses to 10 antigens representing six parasitic infections and three antigens to assess immunity to vaccine preventable diseases were generated from a single sample collected from each participant. Conclusions: As prevalence declines, using parasitological indicators to determine LF programme endpoints becomes challenging and there is a need to identify alternative indicators to use during the surveillance period. Results from this PhD thesis support the use of antibody tools to determine the status of LF transmission and suggest that serological tools can have a role in guiding programmatic decision-making. The absence of antibody responses strongly suggests that LF transmission has been interrupted and, in contrast, the presence of antibody in children is an important indicator that programmes have not reached elimination. Finally, existing LF programme activities can provide a platform both to introduce the use of antibody testing into TAS and to conduct integrated assessments

Laboratory evaluation of a rapid IgG4 antibody test (BLF Rapid™) for bancroftian filariasis

At the end phase of the Global Programme to Eliminate Lymphatic Filariasis, antibody testing may have a role in decision-making for bancroftian filariasis–endemic areas. This study evaluated the diagnostic performance of BLF Rapid ™ , a prototype immunochromatographic IgG4-based test using BmSXP recombinant protein, for detection of bancroftian filariasis. The test was evaluated using 258 serum samples, comprising 96 samples tested at Universiti Sains Malaysia (in-house) and 162 samples tested independently at three international laboratories in the USA and India, and two laboratories in Malaysia. The independent testing involved 99 samples from Wuchereria bancrofti microfilaria or antigen positive individuals and 63 samples from people who were healthy or had other infections. The in-house evaluation showed 100% diagnostic sensitivity and specificity. The independent evaluations showed a diagnostic sensitivity of 84–100% and 100% specificity (excluding non-lymphatic filarial infections). BLF Rapid has potential as a surveillance diagnostic tool to make “Transmission Assessment Survey”–stopping decisions and conduct post-elimination surveillance

Development of a Bamlanivimab Infusion Process in the Emergency Department for Outpatient COVID-19 Patients

The coronavirus disease 2019 (COVID-19) pandemic has prompted the creation of new therapies to help fight against the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Bamlanivimab is a SARS-CoV-2 monoclonal antibody that is administered as an intravenous infusion to ambulatory patients with mild or moderate COVID-19, but a concern that arose was deciding the optimal location for patients to receive the medication. This report describes the development and implementation of a bamlanivimab infusion center in the emergency department of three hospitals in Orange County, California, shortly after bamlanivimab received emergency use authorization. As a result, a total of 601 patients received bamlanivimab in one of these three emergency departments between December 2020 to April 2021. The emergency department was shown to be an optimal setting for administration of bamlanivimab due to its convenience, accessibility, and capabilities for monitoring patients

The Microenvironmental Effect in the Progression, Metastasis, and Dormancy of Breast Cancer: A Model System within Bone Marrow

Despite diagnostic advances, breast cancer remains the most prevalent cancer among women in the United States. The armamentarium of treatment options for metastatic disease is limited and mostly ineffective with regards to eradicating cancer. However, there have been novel findings in the recent literature that substantiate the function of the microenvironment in breast cancer progression and the support of metastasis to tertiary sites such as bone marrow. The uncovered significance of the microenvironment in the pathophysiology of breast cancer metastasis has served to challenge previously widespread theories and introduce new perspectives for the future research to eradicate breast cancer. This paper delineates the current understanding of the molecular mechanisms involved in the interactions between breast cancer cells and the microenvironment in progression, metastasis, and dormancy. The information, in addition to other mechanisms described in bone marrow, is discussed in the paper

Potential strategies for strengthening surveillance of lymphatic filariasis in American Samoa after mass drug administration: reducing ‘number needed to test’ by targeting older age groups, hotspots, and household members of infected persons

Under the Global Programme to Eliminate Lymphatic Filariasis (LF), American Samoa conducted mass drug administration (MDA) from 2000–2006. Despite passing Transmission Assessment Surveys (TAS) in 2011/2012 and 2015, American Samoa failed TAS-3 in 2016, with antigen (Ag) prevalence of 0.7% (95%CI 0.3–1.8%) in 6–7 year-olds. A 2016 community survey (Ag prevalence 6.2% (95%CI 4.4–8.5%) in age ≥8 years) confirmed resurgence. Using data from the 2016 survey, this study aims to i) investigate antibody prevalence in TAS-3 and the community survey, ii) identify risk factors associated with being seropositive for Ag and anti-filarial antibodies, and iii) compare the efficiency of different sampling strategies for identifying seropositive persons in the post-MDA setting. Antibody prevalence in TAS-3 (n = 1143) were 1.6% for Bm14 (95%CI 0.9–2.9%), 7.9% for Wb123 (95%CI 6.4–9.6%), and 20.2% for Bm33 (95%CI 16.7–24.3%); and in the community survey (n = 2507), 13.9% for Bm14 (95%CI 11.2–17.2%), 27.9% for Wb123 (95%CI 24.6–31.4%), and 47.3% for Bm33 (95%CI 42.1–52.6%). Multivariable logistic regression was used to identify risk factors for being seropositive for Ag and antibodies. Higher Ag prevalence was found in males (adjusted odds ratio [aOR] 3.01), age ≥18 years (aOR 2.18), residents of Fagali’i (aOR 15.81), and outdoor workers (aOR 2.61). Ag prevalence was 20.7% (95%CI 9.7–53.5%) in households of Ag-positive children identified in TAS-3. We used NNTestav (average number needed to test to identify one positive) to compare the efficiency of the following strategies for identifying persons who were seropositive for Ag and each antibody: i) TAS of 6–7 year-old children, ii) population representative surveys of older age groups, and iii) targeted surveillance of subpopulations at higher risk of being seropositive (older ages, householders of Ag-positive TAS children, and known hotspots). For Ag, NNTestav ranged from 142.5 for TAS, to <5 for households of index children. NNTestav was lower in older ages, and highest for Ag, followed by Bm14, Wb123 and Bm33 antibodies. We propose a multi-stage surveillance strategy, starting with population-representative sampling (e.g. TAS or population representative survey of older ages), followed by strategies that target subpopulations and/or locations with low NNTestav. This approach could potentially improve the efficiency of identifying remaining infected persons and residual hotspots. Surveillance programs should also explore the utility of antibodies as indicators of transmission

Potential use of antibodies to provide an earlier indication of lymphatic filariasis resurgence in post–mass drug ad ministration surveillance in American Samoa

Background: Under the Global Programme to Eliminate Lymphatic Filariasis (LF), American Samoa conducted 7 rounds of mass drug administration (MDA) between 2000 and 2006. The territory passed transmission assessment surveys (TASs) in 2011 (TAS-1) and 2015 (TAS-2). In 2016, the territory failed TAS-3, indicating resurgence. This study aims to determine if antibodies (Abs) may have provided a timelier indication of LF resurgence in American Samoa. Methods: We examined school-level antigen (Ag) and Ab status (presence/absence of Ag- and Ab-positive children) and prevalence of single and combined Ab responses to Wb123, Bm14, and Bm33 Ags at each TAS. Pearson chi-square test and logistic regression were used to examine associations between school-level Ab prevalence in TAS-1 and TAS-2 and school-level Ag status in TAS-3. Results: Schools with higher prevalence of Wb123 Ab in TAS-2 had higher odds of being Ag-positive in TAS-3 (odds ratio [OR] 24.5, 95% confidence interval [CI] 1.2–512.7). Schools that were Ab-positive for WB123 plus Bm14, Bm33, or both Bm14 and Bm33 in TAS-2 had higher odds of being Ag-positive in TAS-3 (OR 16.0–24.5). Conclusion: Abs could provide earlier signals of resurgence and enable a timelier response. The promising role of Abs in surveillance after MDA and decision making should be further investigated in other settings

Molecular Xenomonitoring Using Mosquitoes to Map Lymphatic Filariasis After Mass Drug Administration in American Samoa

Background: Mass drug administration (MDA) programs have dramatically reduced lymphatic filariasis (LF) incidence in many areas around the globe, including American Samoa. As infection rates decline and MDA programs end, efficient and sensitive methods for detecting infections are needed to monitor for recrudescence. Molecular methods, collectively termed ‘molecular xenomonitoring,’ can identify parasite DNA or RNA in human blood-feeding mosquitoes. We tested mosquitoes trapped throughout the inhabited islands of American Samoa to identify areas of possible continuing LF transmission after completion of MDA. Methodology/Principle Findings: Mosquitoes were collected using BG Sentinel traps from most of the villages on American Samoa’s largest island, Tutuila, and all major villages on the smaller islands of Aunu’u, Ofu, Olosega, and Ta’u. Real-time PCR was used to detect Wuchereria bancrofti DNA in pools of #20 mosquitoes, and PoolScreen software was used to infer territory-wide prevalences of W. bancrofti DNA in the mosquitoes. Wuchereria bancrofti DNA was found in mosquitoes from 16 out of the 27 village areas sampled on Tutuila and Aunu’u islands but none of the five villages on the Manu’a islands of Ofu, Olosega, and Ta’u. The overall 95% confidence interval estimate for W. bancrofti DNA prevalence in the LF vector Ae. polynesiensis was 0.20–0.39%, and parasite DNA was also detected in pools of Culex quinquefasciatus, Aedes aegypti, andAedes (Finlaya) spp. Conclusions/Significance: Our results suggest low but widespread prevalence of LF on Tutuila and Aunu’u where 98% of the population resides, but not Ofu, Olosega, and Ta’u islands. Molecular xenomonitoring can help identify areas of possible LF transmission, but its use in the LF elimination program in American Samoa is limited by the need for more efficient mosquito collection methods and a better understanding of the relationship between prevalence of W. bancrofti DNA in mosquitoes and infection and transmission rates in humans

Molecular Xenomonitoring Using Mosquitoes to Map Lymphatic Filariasis after Mass Drug Administration in American Samoa

BACKGROUND: Mass drug administration (MDA) programs have dramatically reduced lymphatic filariasis (LF) incidence in many areas around the globe, including American Samoa. As infection rates decline and MDA programs end, efficient and sensitive methods for detecting infections are needed to monitor for recrudescence. Molecular methods, collectively termed \u27molecular xenomonitoring,\u27 can identify parasite DNA or RNA in human blood-feeding mosquitoes. We tested mosquitoes trapped throughout the inhabited islands of American Samoa to identify areas of possible continuing LF transmission after completion of MDA. METHODOLOGY/PRINCIPLE FINDINGS: Mosquitoes were collected using BG Sentinel traps from most of the villages on American Samoa\u27s largest island, Tutuila, and all major villages on the smaller islands of Aunu\u27u, Ofu, Olosega, and Ta\u27u. Real-time PCR was used to detect Wuchereria bancrofti DNA in pools of ≤ 20 mosquitoes, and PoolScreen software was used to infer territory-wide prevalences of W. bancrofti DNA in the mosquitoes. Wuchereria bancrofti DNA was found in mosquitoes from 16 out of the 27 village areas sampled on Tutuila and Aunu\u27u islands but none of the five villages on the Manu\u27a islands of Ofu, Olosega, and Ta\u27u. The overall 95% confidence interval estimate for W. bancrofti DNA prevalence in the LF vector Ae. polynesiensis was 0.20-0.39%, and parasite DNA was also detected in pools of Culex quinquefasciatus, Aedes aegypti, and Aedes (Finlaya) spp. CONCLUSIONS/SIGNIFICANCE: Our results suggest low but widespread prevalence of LF on Tutuila and Aunu\u27u where 98% of the population resides, but not Ofu, Olosega, and Ta\u27u islands. Molecular xenomonitoring can help identify areas of possible LF transmission, but its use in the LF elimination program in American Samoa is limited by the need for more efficient mosquito collection methods and a better understanding of the relationship between prevalence of W. bancrofti DNA in mosquitoes and infection and transmission rates in humans

Development of an Emergency Medicine Pharmacy Intensity Score Tool

Purpose Emergency medicine pharmacists (EMPs) have been demonstrated to have a positive impact on patient outcomes in a variety of clinical scenarios in the emergency department (ED), yet their distribution across the nation is suboptimal. An emergency medicine pharmacy intensity score tool (EMPIST) would not only facilitate the quantification of EMP staffing needs and ideal resource deployment times, but would also allow practitioners to triage patient care activities. The purpose of this investigation was to develop an EMPIST and evaluate its relationship to EMP activities. Methods This was a multicenter, prospective, observational analysis of an EMPIST developed by practicing EMPs. EMPs prospectively documented their clinical activities during usual care for patients in their ED. Spearman’s rank-order correlation was used to determine any correlation between the EMPIST and pharmacist activities. Results In total, 970 EMP activities and 584 EMPIST items were documented in 352 patients by 7 EMPs across 7 different EDs. The most commonly documented EMP interventions performed were bedside monitoring (12.7%), initiation of nonantimicrobial therapy (12.6%), and antimicrobial therapy initiation and streamlining (10.6%). The total EMPIST was found to significantly correlate with EMP activities, and this correlation was consistent across both “diagnostic/presentation” and “medication” items (P \u3c 0.001 for all comparisons). Conclusion The EMPIST significantly correlated with EMP activities, with consistent correlation across all subgroups. Its utilization has the potential to enhance bedside clinical practice and optimize the deployment of limited EMP services. Additional investigations are needed to examine the validity of this tool and identify any relationship it may have to patient outcomes