Test Positivity Rate Research Articles

Effect of the second and third COVID-19 pandemic waves on routine outpatient malaria indicators and case management practices in Uganda: an interrupted time series analysis

BackgroundReports on the impact of COVID-19 pandemic on the quality of malaria care and burden in sub Saharan Africa have provided a mixed picture to date. The impact of the 2nd (Delta) and 3rd (Omicron) COVID-19 waves on outpatient malaria indicators and case management practices was assessed at three public health facilities with varying malaria transmission intensities in Uganda.MethodsIndividual level data from all patients presenting to the out-patient departments (OPD) of the three facilities (Kasambya, Walukuba and Lumino) between January 2019 and February 2022 were included in the analysis. Outcomes of interest included total number of outpatient (OPD) visits, proportion of patients suspected to have malaria, proportion of suspected malaria cases tested with a malaria diagnostic test, test positivity rates (TPR) and proportion of malaria cases prescribed artemether-lumefantrine (AL). Using the pre-COVID-19 trends between January 2019 and February 2020, interrupted time series analysis was used to predict the expected trends for these study outcomes during the 2nd wave (May 2021–August 2021) and 3rd wave (November 2021–February 2022). The observed trends of the study outcomes were compared with the expected trends.ResultsThere were no significant differences between the observed versus expected overall outpatient visits in the 2nd wave, however, a significant decline in OPD attendance was observed during the 3rd wave (15,101 vs 31,154; incidence rate ratio (IRR) = 0.48 [0.41–0.56]). No significant differences in the overall observed versus expected proportions of suspected malaria cases and test positivity rates in both COVID waves. However, a significant decrease in the overall proportion of suspected malaria cases tested with a malaria diagnostic test was observed during the 3rd wave (99.86% vs 99.99%; relative percent ratio [RPR] = 0.99 [0.99–0.99]). Finally, a significant decline in the overall proportion of malaria cases prescribed AL was observed during the 2nd wave (94.99% vs 99.85%; RPR = 0.95 [0.92–0.98]) but not the 3rd wave.ConclusionSignificant declines in OPD attendance and suspected malaria cases tested with malaria diagnostic test were observed during the 3rd COVID-19 wave, while AL prescription significantly reduced during the 2nd COVID-19 wave. These findings add to the body of knowledge highlighting the adverse impact of COVID-19 pandemic on the malaria which could explain the increase in the malaria burden observed during this period.

Incentivization of Sexually Transmitted Infection Testing at a Large Public University

Abstract Background According to the United States (U.S.) Centers for Disease Control and Prevention, more than 2.5 million cases of syphilis, gonorrhea, and chlamydia were reported in 2022, with notable increases in gonorrhea and chlamydia. The highest rates of chlamydia, gonorrhea, and syphilis were found in men and women of college age. This study compared free STI testing events to usual care with regard to patient socio-economic factors and testing positivity rates. Methods The Department of Student Health & Wellness at a large, public university offers routine testing at a low cost, flat rate, including chlamydia, gonorrhea, hepatitis C Ab, syphilis and HIV testing. Two weeks of free testing were held during calendar year 2023. Utilization and positivity rates between free testing and regular testing weeks were compared using Pearson’s chi squared and Fisher Exact tests. Results A total of 8705 tests were performed during routine testing weeks with associated cost averaging 174 tests per week as compared to 1177 tests for the free testing weeks averaging 589 tests per week. Testing uptake during free testing weeks was higher among females (65.6% (n = 772) vs. 55.1% (n = 4797); p < 0.001) and minorities such as, Black or African American [11.3% (n = 133) vs. 9.4% (n = 813); p = 0.02], Hispanic [11.4% (n = 134) vs. 9.2% (n = 798); p = 0.02] and Asian [13.1% (n = 154) vs. 8.8% (n = 763); p < 0.001] when compared to testing during regular weeks. Chlamydial infection positivity rate was lower during the free testing weeks [1.8% (n = 7)] vs. [3.9% (n = 123); p = 0.04]. Gonorrhea, hepatitis C, HIV, and Syphilis positivity rates did not differ between the two testing periods. Conclusions Free STI testing in the context of a large, public university Student Health Department shows increased utilization. The establishment of free testing weeks was associated with an increase in female students and minorities use of testing services at a large public university. Key messages • Incentivization can improve STI testing utilization among university students. • The establishment of STI free testing periods can increase the use of testing services among minority students and females.

Improving the yield of genetic testing in dilated cardiomyopathy using late gadolinium enhancement

Abstract Background Genetic testing has become an important tool in the work-up of dilated cardiomyopathy (DCM), aiding in family screening and providing information about prognosis and arrhythmic risk. Nonetheless, a significant proportion of patients with DCM present negative genetic test results. The "Madrid Score" was created to evaluate the likelihood of positive genetic tests and increase their yield in DCM patients. Purpose To determine if late gadolinium enhancement (LGE) assessment can improve the Madrid Score accuracy and increase the yield of genetic tests for DCM. Methods A single-centre retrospective study of patients diagnosed with DCM who underwent cardiac magnetic resonance (CMR) and genetic test between January 2017 and October 2023. The CMR imaging included the assessment of LGE. Multivariate logistic regression was performed and the model’s change in performance was evaluated when adding LGE. Results A total of 90 patients with the diagnosis of DCM underwent CMR and genetic test during the study period. Patient’s mean age was 51.0±14.6 years, and 57.1% were male. The genetic test was positive (G+) in 42 (46.7%), and negative (G-) in 48 (53.3%) patients. A variant of uncertain significance was present in 31 (34.4%), and these were included in the G- group. Most of the known independent predictors of a G+ given by the Madrid Score were significant in our cohort: Family history of DCM (OR: 4.82; CI: 1.73-11.60; p < 0.001), absence of hypertension (OR: 0.19; CI: 0.06-0.58; p < 0.001), absence of left bundle branch block (OR: 0.22; CI: 0.05-0.98; p = 0.047), and low electrocardiogram voltage in peripheral leads (OR: 3.13; CI: 0.87-11.26; p = 0.081). When analyzing the effect of LGE in the regression model (R2 = 0.622, p < 0.001), we found that the number of LGE segments (OR: 2.54; CI: 1.10-5.90; p = 0.031), and the presence of LGE in the anterior wall (OR: 3.01; CI: 1.42-12.04; p = 0.041), were associated with a higher rate of positive genetic tests. When comparing both regression models, the incorporation of LGE increased the prediction power of the standard Madrid Score, correctly predicting 82.0% of the tests in our sample, with a probability of a G+ result ranging from 2% when all predictors were absent to 84% when ≥6 predictors, including LGE, were present. Conclusion Our study suggests that LGE assessment may enhance the Madrid Score performance and consequently improve genetic testing decisions in DCM, potentially leading to better use of the limited resources in our health care system.

Evaluating the Implementation of Automated Malaria Rapid Diagnostic Test Readers in Health Facilities in the Democratic Republic of Congo: Process, Challenges, and Lessons Learned.

The WHO's Global Technical Strategy for malaria emphasizes the importance of reliable malaria surveillance systems to track disease burden and measure progress. A key indicator, the test positivity rate (TPR), largely depends on healthcare providers' adherence to rapid diagnostic test (RDT) results and their accurate reporting. To minimize healthcare providers' bias, this study explored the feasibility of using artificial intelligence (AI)-driven Deki Reader devices in the Democratic Republic of Congo. The devices were deployed in 144 health facilities across Haut Katanga, Kasai Central, and Sud Kivu provinces from January to December 2022. Healthcare providers performed malaria diagnostic tests using RDTs and reported the results through the routine system. In addition, they used the Deki Reader device, which automatically read, recorded, and transmitted the AI interpretation into a cloud database. The study compared TPRs from both sources to identify discrepancies. The study revealed the feasibility of using these devices but also identified several logistic and technical challenges. These included delays in device procurement due to COVID-19 pandemic and customs issues, emphasizing the need for better planning and coordination in future rollouts. Device malfunctions and the reliance on stable internet connectivity highlighted the importance of robust support systems and contingency plans. This study demonstrated both the benefits and challenges of implementing such digital health technologies in primary health facilities. Key considerations for successful deployment include careful planning, adequate training and supervision, and taking into account local infrastructure, especially internet connectivity.

Impacts of testing and immunity acquired through vaccination and infection on covid-19 cases in Massachusetts elementary and secondary students

BackgroundDuring the 2021–22 academic year, Massachusetts supported several in-school testing programs to facilitate in-person learning. Additionally, COVID-19 vaccines became available to all school-aged children and many were infected with SARS-CoV-2. There are limited studies evaluating the impacts of these testing programs on SARS-CoV-2 cases in elementary and secondary school settings. The aim of this state-wide, retrospective cohort study was to assess the impact of testing programs and immunity on SARS-CoV-2 case rates in elementary and secondary students.MethodsCommunity-level vaccination and cumulative incidence rates were combined with data about participation in and results of in-school testing programs (test-to-stay, pooled surveillance testing). School-level impacts of surveillance testing programs on SARS-CoV-2 cases in students were estimated using generalized estimating equations within a target trial emulation approach stratified by school type (elementary/middle/high). Impacts of immunity and vaccination were estimated using random effects linear regression.ResultsHere we show that among N = 652,353 students at 2141 schools participating in in-school testing programs, surveillance testing is associated with a small but measurable decrease in in-school positivity rates. During delta, pooled testing positivity rates are higher in communities with higher cumulative incidence of infection. During omicron, when immunity from prior infection became more prevalent, the effect reversed, such that communities with lower burden of infection during the earlier phases of the pandemic had higher infection rates.ConclusionsTesting programs are an effective strategy for supporting in-person learning. Fluctuating levels of immunity acquired via natural infection or vaccination are a major determinant of SARS-CoV-2 cases in schools.

Geospatial analysis of malaria burden in Kagera region, northwestern Tanzania using health facility and community survey data

Abstract Background Malaria transmission in Tanzania has declined significantly over the last two decades due to scaled-up control interventions. However, recent confirmation of artemisinin partial resistance (ART-R) in Kagera region in northwest Tanzania threatens the ongoing efforts to eliminate malaria in the country. This study was conducted according to the World Health Organization recommendation to generate evidence of malaria burden in areas with confirmed ART-R as the first step before developing a response strategy to the resistance. Methods We assessed the local burden of malaria in Kagera region by geospatial analysis, using data collected retrospectively from health facilities (HFs) and community surveys from 2015 to 2023 to identify malaria hotspots. Results From 2017 to 2023, a total of 8,124,363 suspected malaria cases were reported by HFs, and 2,983,717 (36.7%, 95% range across wards: 22.7 - 50.7%) tested positive by rapid diagnostic tests. Test positivity rates were similar among under-fives (33.1%, 95% range: 19.7–46.5%) and patients aged ≥5 years (33.7%, 95% range: 21.0–46.5%). Malaria prevalence was 10.0% (95% range across wards: 5.1–14.9%%, n=84,999/853,761) in pregnant women and 26.1% (95% range across wards: 11.7–40.6%, n=3,409/13,065) in school children. Despite high temporal variations, we identified hotspots and coldspots, including persistently high burden in 69/192 (35.9%) wards. Conclusion Malaria burden in Kagera exhibited high temporal and spatial heterogeneity, with school children showing the highest prevalence. This demographic pattern underlines the need for targeted interventions and provides evidence for developing an ART-R response for the region.

B-198 Rapid Molecular Detection of Respiratory Infections in Brazilian Hospitals and Outpatient Units: Insights from the Diagnostic Medicine and Health Network

Abstract Background Diagnosing agents causing respiratory infections remains a global challenge due to the numerous coexisting agents and similar symptoms. This study evaluates the epidemiology of viral and bacterial agents responsible for major respiratory infections through molecular detection in patients across various Brazilian hospital units served by a clinical diagnostic and health laboratory. Understanding the distribution and prevalence of these pathogens is crucial for effective diagnosis, treatment, and prevention strategies in the face of evolving epidemiological landscapes. Methods Utilizing an internal database, we conducted a comprehensive analysis of tests performed on the FilmArray® system. This system employs multiplex PCR technology, capable of simultaneously identifying 21 respiratory agents in a single sample obtained from nasopharyngeal and bronchial lavage specimens collected from diverse geographical regions across Brazil. The data for the examination of patient samples with respect to gender, age group, geographical regions, and the prevalence of various agents between January 2021 and April 2023 were retrieved from the database and analyzed. To ensure privacy, sensitive and individual data from all patients were meticulously preserved throughout the study. Results The analysis encompassed a diverse sample of 477 patients, originating from 26 cities across 11 Brazilian states, including Goiás, Minas Gerais, Mato Grosso, Pará, Paraná, Rio de Janeiro, São Paulo, Tocantins, Amazonas, Bahia, and Distrito Federal. The distribution of patients was nearly split between hospital settings (39.8%) and outpatient units, with hospital patients predominantly from departments such as internal medicine, cardiology, and nephrology. In contrast, outpatient samples were primarily requested by specialists in pulmonology and infectious diseases. The demographic profile revealed an average age of 36 years, with a majority male representation (54%). However, a notable shift occurred in the first four months of 2023, where females constituted 60.8% of the sample. The overall test positivity rate stood at 42.3%, with a significant detection of 71% (15 out of 21) of the surveyed respiratory agents at some point during the study period. The most frequently identified pathogens were Rhinovirus, Enterovirus, and SARS-CoV-2, collectively accounting for 55.1% of the positive findings. Additionally, mixed infections were observed in 29 (6%) of the patients, with combinations such as SARS-CoV-2 and Rhinovirus, SARS-CoV-2 and H3N2, and SARS-CoV-2 and RSV, among others, highlighting the complexity of respiratory infections. Conclusions The findings from this study underscore the critical role of advanced molecular diagnostics in the Brazilian clinical-laboratory landscape. The utilization of multiplex PCR technology has proven to be a pivotal tool in accurately identifying a wide array of respiratory pathogens, thereby enhancing the precision of diagnosis and treatment strategies. The detection of a high prevalence of agents such as Rhinovirus, Enterovirus, and SARS-CoV-2, along with the identification of mixed infections, highlights the complexity of respiratory infections and the necessity for robust diagnostic tools. This study not only contributes to the understanding of the epidemiology of respiratory infections in Brazil but also emphasizes the importance of continuous advancements in molecular diagnostics for better patient care and public health management.

Evaluation of e-NIHSS scale combined with HINTS for posterior circulation ischemic stroke with vestibular symptoms

Objective:To explore the predictive value of HINTS bedside examination and e-NIHSS scale for posterior circulation ischemia with vestibular symptoms. Methods:136 cases in total patients with acute vestibular syndrome（AVS） hospitalized in our hospital from April 2021 to April 2023 were selected as the study subjects, According to the classification of AVS etiology, patients with central AVS, namely posterior circulation ischemia（PCI）, were divided into case group（68 cases） and peripheral AVS patients were control group（68 cases）, Collect data and perform head impulse test-nystagmus-test of skew deviation test beside the bed, two doctors evaluated the NIHSS and e-NIHSS scales for PCI patients with vestibular symptoms respecb tively, and recorded the results after they were consistent, and improved the head MRI examination. Results:The positive rate of head pulse test in PCI patients with vestibular symptoms was 3 cases（4.41%）, and 60 cases（88.24%） with peripheral symptoms; The positive rate of nystagmus test in PCI group was 64 cases（94.12%） and peripheral 21 cases（30.88%）; The positive rate of eye deviation test in PCI group was 55 cases（80.88%） and peripheral 8 cases（11.76%）. Comparing the data with the consistency of the final diagnosis, the sensitivity was 97.0%, the specificity was 95.7%, and the accuracy was 0.963. It passed the Kappa consistency test Kappa=0.926（P<0.01）. The patients in PCI group were scored, in which the NIHSS score of brainstem group was 1.51±0.59, and the e-NIHSS score was 4.05±1.71（P<0.05）; The NIHSS score of cerebellar group was 1.42±0.62, and the e-NIHSS score was 3.86±1.59（P<0.05）; NIHSS score of thalamus group was 1.31±0.73, e-NIHSS score was 3.56±1.27 （P<0.05）; NIHSS score of non-focus group was 1.11±0.43, e-NIHSS score was 3.06±1.20 （P<0.01）. The difference between e-NIHSS score and NIHSS score in each group was statistically significant. Conclusion:HINTS examination is highly consistent with the final diagnosis of the gold standard. The e-NIHSS scoring scale has a higher detection rate than the NIHSS scoring scale for patients with posterior circulation ischemia mainly characterize〓by vestibular symptoms.

A cross-sectional study investigating malaria prevalence and associated predictors of infection among migrants to a newly established gold mining settlement in the Gambella Region of Ethiopia.

Malaria is a major disease burden in Ethiopia. Migration can influence malaria transmission dynamics, with individuals relocating from malaria-free highland regions to malarious lowlands potentially facing elevated risks of contracting malaria. Migrants may find it difficult to protect themselves against malaria and have limited access to diagnosis or treatment. Settlers in gold mining sites are one type of migrant and are often neglected in malaria research yet may have particularly high malaria risk. This study was a malaria prevalence survey among settlers in a new gold mining settlement in the highly malarious Gambella Region, Ethiopia. n = 590 people were surveyed for demographic information and their knowledge and practices of malaria. Participants were tested for malaria using rapid diagnostic tests and microscopy. Using logistic regressions, the influence of demographic characteristics on malaria infections and bed net access were analysed. A sub-sample of participants was interviewed to comprehend settlement living conditions and healthcare accessibility. The overall prevalence of Plasmodium falciparum was 37.5% (CI 32.4-42.3%). Young children were most likely to have malaria, with individuals aged 15-24 having 67% lower odds (aOR: 0.33; CI 0.13-0.86) of infection compared to those aged 1-4years old. Meanwhile, those age 25-plus had 75% decreased odds of malaria infection (aOR 0.25; CI 0.10-0.65). Individuals with bed nets had ~50% decreased odds of testing positive for falciparum malaria than those reporting having no bed net (aOR: 0.47; CI 0.22-0.97). Individuals who relocated from low elevation with high malaria test positivity rate areas were more prone to testing positive for malaria, as were those residing in densely populated households with multiple malaria cases. Conversely, individuals from higher elevations with low malaria test positivity rates, and those living in households with 5-10 occupants and < 2 malaria infections, were more likely to possess bed nets. This gold mining settlement provides an example of an oft-neglected atypical community where malaria is a significant, but under-addressed, health problem. Within this community, future interventions focused on distributing bed nets, particularly to larger households and those with children, have great potential to alleviate the malaria burden. Efforts should also be made to provide affordable, and accessible, early diagnosis and treatment.

Evaluation of Klebsiella pneumoniae pathogenicity through holistic gene content analysis

Klebsiella pneumoniae is a Gram-negative bacterium that causes both community- and healthcare-associated infections. Although various virulence factors and highly pathogenic phenotypes have been reported, the pathogenicity of K. pneumoniae is still not fully understood. In this study, we utilized whole-genome sequencing data of 168 clinical K. pneumoniae strains to assess pathogenicity. This work was based on the concept that the genetic composition of individual genomes (referred to as holistic gene content) of the strains may contribute to their pathogenicity. Holistic gene content analysis revealed two distinct groups of K. pneumoniae strains (‘major group’ and ‘minor group’). The minor group included strains with known highly pathogenic clones (ST23, ST375, ST65 and ST86). The minor group had higher rates of capsular genotype K1 and presence of nine specific virulence genes (rmpA, iucA, iutA, irp2, fyuA, ybtS, iroN, allS and clbA) compared to the major group. Pathogenicity was assessed using Galleria mellonella larvae. Infection experiments revealed lower survival rates of larvae infected with strains from the minor group, indicating higher virulence. In addition, the minor group had a higher string test positivity rate than the major group. Holistic gene content analysis predicted possession of virulence genes, string test positivity and pathogenicity as observed in the G. mellonella infection model. Moreover, the findings suggested the presence of as yet unrecognized genomic elements that are either involved in the acquisition of virulence genes or associated with pathogenicity.

Oral Chagas disease outbreak by bacaba juice ingestion: A century after Carlos Chagas' discovery, the disease is still hard to manage.

Orally transmitted acute Chagas disease (ACD) primarily affects low-visibility and low-income individuals in tropical and subtropical zones. Managing ACD remains challenging even after more than 100 years of its discovery. Its spread to non-endemic areas has made it a global health issue. The aim of this work is to demonstrate the difficulties encountered in handling a real-life situation. This report examines an outbreak of 39 cases of ACD due to oral transmission by bacaba juice ingestion that occurred in Pedro do Rosário, Maranhão, Brazil. A clinical and epidemiological investigation, including an entomological search, was conducted. Diagnosis criteria included positive peripheral blood smear (PBS), seroconversion of IgG, and a two-fold increase in IgG titer (laboratory criteria); and clinical findings, epidemiological exposure, and at least one positive IgG test (clinical-epidemiological criteria). In-house conventional polymerase chain reaction (PCR) was performed on 33 samples. All patients were treated with benznidazole. After 4.5 years, IgG levels were reassessed in 26 individuals. The mean age was 33.6 years, with no gender difference. The mean incubation period was 13.8 days, and the mean between symptom onset and treatment was 16.6 days. The most common symptoms were fever and lymphadenopathy (90%). Diagnostic success rates were 66.6% (laboratory criteria), 23% (clinical-epidemiological criteria), and 10.2% (high clinical suspicion despite negative tests). Test positivity rates were 69.7% (PBS), 91.4% (serology), and 100% (PCR). There were no deaths. Serological cure was achieved in 34.6% of cases, and IgG titers decreased in 15.3%. We encountered several barriers in managing ACD, including population vulnerability, reliance on outdated diagnostic techniques, lack of standardized molecular biology methods, and limited therapeutic options. This report underscores the importance of rapid surveillance and early treatment to prevent fatalities. We recommend the standardization of conventional PCR in diagnostic routines.

Post-Pandemic Epidemiology of Respiratory Infections among Pediatric Inpatients in a Tertiary Hospital in Shanghai, China.

After the removal of the three-year epidemic control restrictions, Chinese children were confronted with heightened risks of respiratory infections. We aimed to investigate the post-pandemic (2023) epidemiology of respiratory infections among pediatric inpatients in a tertiary hospital in Shanghai, China, and compare it with the pre-pandemic (2019) levels. A total of 2644 pediatric inpatients were enrolled based on discharge time and divided into group 2019 (n = 1442) and group 2023 (n = 1202). Information on the demographic characteristics, diagnoses, and pathogen test results (Mycoplasma pneumoniae, MP; Chlamydia pneumoniae, CP; Legionella pneumophila, LP; Influenza A, IFA; Influenza B, IFB; Parainfluenza virus, PIV; respiratory syncytial virus, RSV; Coxsackie virus, COX; Adenovirus, ADV; Epstein-Barr virus, EBV) was collected and analyzed. Significant increases were found in the overall test positivity rates (64.6% vs. 46.7%), mixed infection rates (17.4% vs. 9%), and proportion of severe cases (25.5% vs. 3.7%) after the pandemic than those before it. Compared with 2019, the incidences of MP, IFA, LP, RSV, and ADV remarkably increased, while those of IFB and COX decreased, with no obvious differences noted for CP, PIV, and EBV in 2023. A significantly higher MP-positive detection rate was noticed in children aged 1-6 years in 2023 than in 2019. The incidence of RSV infection began to rise in August 2023, earlier than the conventional epidemic season. Compared with the pre-pandemic levels, the overall test positivity rates of atypical pathogens and viruses among pediatric inpatients significantly increased, and alterations in the disease spectrum, epidemic season, and age of prevalence were observed after the COVID-19 pandemic.

The aldosterone renin ratio - high rates of positive tests, low rates of onward referral; a single centre quality improvement project

The aldosterone renin ratio - high rates of positive tests, low rates of onward referral; a single centre quality improvement project

Comparative Performance of Common Fecal Immunochemical Tests : A Cross-Sectional Study.

Despite widespread use of fecal immunochemical tests (FITs) for colorectal cancer (CRC) screening, data to guide test selection are limited. To compare the performance characteristics of 5 commonly used FITs, using colonoscopy as the reference standard. Cross-sectional study. (ClinicalTrials.gov: NCT03264898). Three U.S. academic medical centers and affiliated endoscopy units. Patients aged 50 to 85 years undergoing screening or surveillance colonoscopy. Participants completed 5 different FITs before their colonoscopy, including 4 qualitative tests (Hemoccult ICT, Hemosure iFOB, OC-Light S FIT, QuickVue iFOB) and 1 quantitative test (OC-Auto FIT, which was run at the manufacturer's threshold for positivity of >100 ng/mL). The primary outcome was test performance (sensitivity and specificity) for each of the 5 FITs for advanced colorectal neoplasia (ACN), defined as advanced polyps or CRC. Positivity rates, positive and negative predictive values, and rates of unevaluable tests were compared. Multivariable models were used to identify factors affecting sensitivity. A total of 3761 participants were enrolled, with a mean age of 62.1 years (SD, 7.8); 63.2% of participants were female, 5.7% were Black, 86.4% were White, and 28.7% were Hispanic. There were 320 participants with ACN (8.5%), including 9 with CRC (0.2%). The test positivity rate varied 4-fold (3.9% to 16.4%) across FITs. Rates of unevaluable FITs ranged from 0.2% to 2.5%. The sensitivity for ACN varied from 10.1% to 36.7%, and specificity varied from 85.5% to 96.6%. Differences in sensitivity between FITs were all statistically significantly different except between Hemosure iFOB and QuickVue iFOB, and specificity differences were all statistically significantly different from one another. In addition to FIT brand, distal location of ACN was also associated with higher FIT sensitivity. The study did not assess the programmatic sensitivity of annual FIT. Although considered a single class, FITs have varying test performance for detecting ACN and should not be considered interchangeable. National Institutes of Health.

Abstract P432: Screening for Primary Aldosteronism: Effect of Test and Cutoff Level on Positivity Rate

Background: The 2016 guidelines of the Endocrine Society proposed a screening test for primary aldosteronism (PA) based on an aldosterone renin ratio (ARR) ≥30. However, a plasma renin activity (PRA) suppressed to &lt;1 ng/mL/h may indicate PA status better than the ARR. Methods: We conducted a retrospective analysis to compare the effectiveness of various screening tests for PA in a cohort of 94,829 consecutive patients who underwent ARR testing at Quest Diagnostics. The tests that were compared include ARR ≥20, ARR ≥30, PRA &lt;1 ng/mL/h, and PRA &lt;0.5 ng/mL/h. This comparison was made because the ARR tests may not be highly sensitive, while the PRA tests may not be highly specific. We also analyzed differences in test volume and positivity rate by region, race, ethnicity, and the time of day when the test was performed. Results: We observed that PRA &lt;1 ng/mL/h identified 2.2 times as many PA cases as ARR ≥20 and 3.3 times as many cases as ARR ≥30. Likewise, PRA &lt;0.5 ng/mL/h identified 1.3 times as many cases as ARR ≥20 and 1.9 times as many cases as ARR ≥30 (Table). We also found that PA positivity rates using ARR ≥20, ARR ≥30, PRA &lt;1 ng/mL/h, and PRA &lt;0.5 ng/mL/h were higher for tests performed before noon than after noon. Additionally, positivity rates were similar across US regions, although the Midwest had lower positivity for ARR tests than PRA tests, and the West had lower positivity for PRA tests than ARR tests. The PRA-based test continued to be positive more frequently than the two ARR-based tests regardless of race; however, non-Hispanic Black patients had a higher positivity rate than Hispanic, non-Hispanic White, and Asian patients, irrespective of the test used. Conclusions: Our data show that compared to PRA &lt;1 ng/mL/h and &lt;0.5 ng/mL/h, the ARR screening tool set at ≥20 or ≥30 potentially misses many patients with PA. If future prospective studies confirm this finding, one of the two suppressed PRA-based tests could become the preferred screening tool for PA.

Diagnostic accuracy of truenat MTB plus for the detection of pulmonary and extrapulmonary tuberculosis

BackgroundThe diagnosis of Tuberculosis (TB) has been a challenge till the advent of rapid molecular diagnostic tests. The traditional diagnostic tests have its own limitations with regard to its performance or the turnaround time. Truenat MTB Plus assay, a battery-operated molecular assay developed in India has been introduced for its use in pulmonary TB (PTB). However, the diagnostic accuracy of the assay is not well studied in comparison with Mycobacterial culture, especially for extrapulmonary TB (EPTB). AimWe aimed at evaluating the diagnostic accuracy of Truenat MTB Plus assay for both PTB and EPTB comparing with culture for adult population. MethodsThe specimens from presumptive PTB and EPTB patients were processed for Truenat MTB Plus assay, solid or liquid culture and AFB staining. The electronic data of all the specimen reports collected retrospectively were analysed for the sensitivity and specificity. ResultsOut of the 736 samples which had valid culture reports, 364 (49.4 %) were respiratory and 372 (50.6 %) were extrapulmonary specimens. The test positivity rate for smear microscopy, Truenat MTB Plus assay and culture was 3.7 % (27), 8.2 % (60), 7.1 % (52) respectively. Of the 60 Truenat MTB Plus positive patients with TB, 33 (55 %) were PTB and 27 (45 %) were EPTB. We estimated overall sensitivity and specificity of Truenat MTB Plus as 90 % (95 % CI: 73.4–97.8) and 98. 2 (95 % CI:96–99.3) respectively for the detection of PTB. The overall sensitivity and specificity for EPTB was 81.8 % (95 % CI: 59.7–94.8) and 97.4 % (95 % CI: 95.1–98.8) respectively. ConclusionsTruenat MTB Plus assay has comparable diagnostic accuracy with other molecular assays. The Truenat MTB Plus assay can be used for the diagnosis of PTB and EPTB, especially in resource limited settings.

Oxidised low-density lipoprotein and antibodies against oxidised low-density lipoprotein in patients with antiphospholipid syndrome.

Recurrent thrombosis is one of the main clinical features of antiphospholipid syndrome (APS), and recent studies revealed that APS shares similar pathophysiological mechanisms with atherosclerosis. Oxidised low-density lipoprotein (OxLDL) and antibodies against OxLDL (anti-OxLDL) are involved in the development of atherosclerosis. This study aims to investigate the clinical significance of OxLDL and anti-OxLDL in APS patients. One hundred and seventy APS patients and 39 healthy controls (HC) were enrolled. Clinical and laboratory data were collected from Clinical Data Center of Peking University People's Hospital. OxLDL and anti-OxLDL were detected using enzyme-linked immunosorbent assay. Among the 170 APS patients, 106 had isolated thrombotic APS. Compared with HC, APS patients exhibited higher titres of OxLDL [413.86 (220.11-853.67) ng/mL vs. 45.54 (0-105.98) ng/mL, p<0.001] and anti-OxLDL [107.62 (75.68-174.18) U/L vs. 44.13 (18.44-79.76) U/L, p<0.001]. Also, APS patients exhibited a higher positivity rate for OxLDL (88.2% vs. 5.1%, p<0.001) and anti-OxLDL (84.1% vs. 36.5%, p<0.001) compared to HC. APS patients with elevated levels of OxLDL had a higher rate of LAC positivity (68.0% vs. 45.0%, p=0.042). Furthermore, APS patients with positive anti-OxLDL demonstrated a higher occurrence of venous thrombosis (46.2% vs. 18.5%, p=0.008) and a lower rate of Coomb's test positivity (52.6% vs. 76.2%, p=0.049). Multivariate logistic regression revealed that anti-OxLDL positivity (OR 12.424, 95%CI 1.108-139.330, p=0.041) were risk factors for venous thrombotic APS. This study indicates that the presence of anti-OxLDL may serve as potential markers for venous thrombosis in APS patients. OxLDL and anti-OxLDL may function as valuable biomarkers for monitoring APS.

Salivary CD44 and Total Protein Levels to Detect Risk for Oral and Oropharyngeal Cancer Recurrence

Oral and oropharyngeal cancer have low survival rates, and incidence continues to increase. To determine whether soluble CD44 and total protein (TP) are useful for monitoring head and neck cancer recurrence, either used in a point-of-care (POC) test or as individual laboratory-based biomarkers. This multi-institutional nonrandomized clinical trial testing a novel diagnostic/screening assay took place across the University of California, San Diego; Johns Hopkins University; the Greater Baltimore Medical Center; New York University; and the San Diego Veterans Affairs Hospital. Patients with newly biopsy-proven, untreated oral cavity and oropharyngeal cancer were enrolled. Patients were enrolled April 2017 to April 2019, and data were analyzed December 2022 to June 2023. POC salivary oral rinse test. Oral rinses were collected at pretreatment baseline and 3, 6, 12, and 18 months after completion of therapy; participants were then followed up for 3 years to define disease status. Associations of baseline characteristics with a positive test were evaluated by Fisher exact test. The association of a positive value on the CD44 or TP test with progression-free survival was evaluated in an adjusted multivariable proportional hazards model. Of 172 patients enrolled, the mean (SD) age was 62.5 (10.2) years, and 122 (70.9%) identified as male. Additionally, 92 patients (53.3%) had never smoked, 99 (57.6%) formerly or currently drank alcohol, and 113 (65.7%) presented with oropharyngeal cancers, which were positive for human papillomavirus in 95 (84.1%). Tumor site was associated with test results at baseline; patients with oral cavity cancer had a higher baseline positive POC test rate (47 of 51 [92.2%]) compared to patients with oropharyngeal cancer (85 of 110 [77.3%]). Using Cox regression models with CD44 or TP level as a time-varying covariate, a higher CD44 level showed a statistically significant association with a higher hazard of recurrence (hazard ratio, 1.06; 95% CI, 1.00-1.12), though the TP level was not statistically significant. In multivariate adjusted analysis, higher CD44 and TP levels were associated with increased hazard ratios of recurrence of 1.13 (95% CI, 1.04-1.22) and 3.51 (95% CI, 1.24-9.98), respectively. In this multi-institutional nonrandomized clinical trial of an assay, posttreatment longitudinal monitoring for elevated salivary CD44 and TP levels using an enzyme-linked immunosorbent assay-based laboratory test identified patients at increased risk of future cancer recurrence. The CD44 and TP rapid POC test holds some promise, but further development is needed for this indication. ClinicalTrials.gov Identifier: NCT03148665.

Short, stringent lockdowns halted SARS-CoV-2 transmissions in Danish municipalities

In late 2020, the focus of the global effort against the COVID-19 pandemic centered around the development of a vaccine, when reports of a mutated SARS-CoV-2 virus variant in a population of 17 million farmed mink came from Denmark, threatening to jeopardize this effort. Spillover infections of the new variant between mink and humans were feared to threaten the efficacy of upcoming vaccines. In this study the ensuing short-lived yet stringent lockdowns imposed in 7 of the countries 98 municipalities are analysed for their effectiveness to reduce SARS-CoV-2 infections. Synthetic counterfactuals are created for each of these municipalities using a weighted average combination of the remaining municipalities not targeted by the stringent measures. This allows for a clear overview regarding the development of test-positivity rates, citizen mobility behaviours and lastly daily infection numbers in response to the restrictions. The findings show that these targeted, short-term lockdowns significantly curtailed further infections, demonstrating a marked decrease, first in citizens mobility and then in daily cases when compared to their synthetic counterfactuals. Overall, the estimates indicate average reductions to infection numbers to be around 31%. This study underscores the potential of strict, yet severe lockdowns in breaking ongoing infection dynamics, by utilising a rare quasi-experimental design case that avoids bias introduced through treatment selection.

Cost analysis of cardiac MRI for cardiac transplant surveillance

National health expenditures in the United States have risen steadily since 1960. While lifesaving therapies exist for acquired and congenital heart diseases, for some children heart transplantation is their only chance for a period of durable survival. Like many advanced therapies, however, heart transplantation confers a significant cost to families and the health care system at large. Current heart transplant health surveillance relies on frequent cardiac catheterization with endomyocardial biopsy (cath-EMB) as periodic assessment of graft health and detection of possible life-threatening acute rejection. Cardiac magnetic resonance imaging (MRI) has emerged as a diagnostic tool which can characterize the myocardium, providing insights into graft health and potentially acute/chronic graft rejection. The PEACE study (R01-HL164995-02) aims to systematically evaluate the potential for using cardiac MRI parametric mapping as a pre-cath-EMB screening tool to alleviate both patient anxiety and discomfort, as well as the financial burden of cath-EMB. The PEACE trial aims to establish definitive evidence and criteria for determining when cath EMB is needed. For a technique to be practical in the real world, though, it must also be cost effective.Therefore, the goal of this current research is to determine a minimal set of measurement properties (positive predictive value (PPV), etc.) that cardiac MRI must attain to be cost-effective. These data will guide the decision-making for the PEACE trial results. Consistent with the recent emphasis on “Value MRI,” we sought to understand the potential Medicare savings, through economic cost analysis modeling, if cardiac MRI is used for cardiac transplant surveillance rather than cath-EMB surveillance. At even the most pessimistic positive test rate for MRI considered, these modeling results suggest substantial Medicare cost savings when using cardiac MRI parametric mapping as a screening tool for detecting acute cardiac rejection. Longitudinal cost savings are notable too.