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Malaria rapid diagnostic tests (RDTs), which detect Plasmodium falciparum (Pf)-specific histidine-rich protein-2 (HRP2), have increasing importance for the diagnosis and control of malaria, especially also in regions where routine diagnosis by microscopy is not available. HRP2-based RDTs have a similar sensitivity to expert microscopy, but their reported low specificity can lead to high false positivity rates, particularly in high-endemic areas. Despite the widespread use of RDTs, models investigating the dynamics of HRP2 clearance following Pf treatment focus rather on short-term clearance of the protein. The goal of this observational cohort study was to determine the long-term kinetic of HRP2-levels in peripheral blood after treatment of uncomplicated malaria cases with Pf mono-infection using a 3-day course of artesunate/amodiaquine. HRP2 levels were quantified at enrollment and on days 1, 2, 3, 5, 7, 12, 17, 22, and 28 post-treatment initiation. The findings reveal an unexpectedly prolonged clearance of HRP2 after parasite clearance from capillary blood. Terminal HRP2 half-life was estimated to be 9 days after parasite clearance using a pharmacokinetic two-compartmental elimination model. These results provide evidence that HRP2 clearance has generally been underestimated, as the antigen remains detectable in capillary blood for up to 28 days following successful treatment, influencing RDT-based assessment following a malaria treatment for weeks. A better understanding of the HRP2 clearance dynamics is critical for guiding the diagnosis of malaria when relying on RDTs., Importance: Detecting Plasmodium falciparum , the parasite responsible for the severest form of malaria, typically involves microscopy, polymerase chain reaction (PCR), or rapid diagnostic tests (RDTs) targeting the histidine-rich protein 2 or 3 (HRP2/3). While microscopy and PCR quickly turn negative after the infection is cleared, HRP2 remains detectable for a prolonged period. The exact duration of HRP2 persistence had not been well defined. Our study in Gabon tracked HRP2 levels over 4 weeks, resulting in a new model for antigen clearance. We discovered that a two-compartment model accurately predicts HRP2 levels, revealing an initial rapid reduction followed by a much slower elimination phase that can take several weeks. These findings are crucial for interpreting RDT results, as lingering HRP2 can lead to false positives, impacting malaria diagnosis and treatment decisions., Competing Interests: The authors declare no conflict of interest.

Introduction: Serological testing is needed to better understand the epidemiology of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Rapid diagnostic tests (RDTs) have been developed to detect specific antibodies, IgM and IgG, to the virus. The performance of 25 of these RDTs was evaluated. Methods: A serological reference panel of 50 positive and 100 negative plasma specimens was developed from SARS-CoV-2 PCR and antibody positive patients and pre-pandemic SARS-CoV-2-negative specimens collected in 2016. Test performance of the 25 RDTs was evaluated against this panel. Results: A total of 10 RDTs had a sensitivity ≥98%, while 13 RDTs had a specificity ≥98% to anti-SARS-CoV-2 IgG antibodies. Four RDTs (Boson, MultiG, Standard Q, and VivaDiag) had both sensitivity and specificity ≥98% to anti-SARS-CoV-2 IgG antibodies. Only three RDTs had a sensitivity ≥98%, while 10 RDTs had a specificity ≥98% to anti-SARS-CoV-2 IgM antibodies. Three RDTs (Autobio, MultiG, and Standard Q) had sensitivity and specificity ≥98% to combined IgG/IgM. The RDTs that performed well also had perfect or almost perfect inter-reader agreement. Conclusions: This evaluation identified three RDTs with a sensitivity and specificity to IgM/IgG antibodies of ≥98% with the potential for widespread antibody testing in Uganda.

Abstract Background Chagas disease remains a significant public health problem in Latin America. There are only two chemotherapy drugs, nifurtimox and benznidazole, and both may have severe side effects. After complete chemotherapy of acute cases, seropositive diagnosis may revert to negative. However, there are no definitive parasitological or serological biomarkers of cure. Methods Following a pilot study with seven Bolivian migrants to Spain, we tested 71 serum samples from chronic patients (mean age 12.6 years) inhabiting the Argentine Chaco region. Benznidazole chemotherapy (5–8 mg/kg day, twice daily for 60 days) was administered during 2011–2016. Subsequently, pre-and post-chemotherapy serum samples were analysed in pairs by IgG1 and IgG ELISA using two different antigens and Chagas Sero K-SeT rapid diagnostic tests (RDT). Molecular diagnosis by kDNA-PCR was applied to post-treatment samples. Results Pilot data demonstrated IgG1 antibody decline in three of seven patients from Bolivia 1 year post-treatment. All Argentine patients in 2017 (averaging 5 years post-treatment), except one, were positive by conventional serology. All were kDNA-PCR-negative. Most (91.5%) pre-treatment samples were positive by the Chagas Sero K-SeT RDT, confirming the predominance of TcII/V/VI. IgG1 and IgG of Argentine patients showed significant decline in antibody titres post-chemotherapy, with either lysate (IgG, P = 0.0001, IgG1, P = 0.0001) or TcII/V/VI peptide antigen (IgG, P = 0.0001, IgG1, P = 0.0001). IgG1 decline was more discriminative than IgG. Antibody decline after treatment was also detected by the RDT. Incomplete treatment was associated with high IgG1 post-treatment titres against lysate (P = 0.013), as were IgG post-treatment titres to TcII/V/VI peptide (P = 0.0001). High pre-treatment IgG1 with lysate was associated with Qom ethnicity (P = 0.045). No associations were found between gender, age, body mass index and pre- or post-treatment antibody titres. Conclusions We show that following chemotherapy of early chronic Chagas disease, significant decline in IgG1 antibody suggests cure, whereas sustained or increased IgG1 is a potential indicator of treatment failure. Due to restricted sensitivity, IgG1 should not be used as a diagnostic marker but has promise, with further development, as a biomarker of cure. Graphical abstract We show that following chemotherapy of early chronic Chagas disease, a significant decline in IgG1 antibody suggests cure, whereas sustained or increased IgG1 is a potential indicator of treatment failure. Due to restricted sensitivity, IgG1 should not be used as a diagnostic marker but has promise, with further development, as a biomarker of cure.

Abstract Background The diagnosis of malaria, using microscopy or rapid diagnostic tests (RDTs), requires the collection of capillary blood. This procedure is relatively simple to perform but invasive and poses potential risks to patients and health workers, arising from the manipulation of potentially infectious bodily fluids. Less or non-invasive diagnostic tests, based on urine, saliva or requiring no sampling, have the potential to generate less discomfort for the patient and to offer simpler and less risky testing procedures that could be safely performed by untrained staff or even self-performed. To explore the potential acceptance and perceived value of such non-invasive tests, an online, international survey was conducted to gather feedback from National Malaria Control Programme (NMCP) representatives. Methods An online survey comprising nineteen questions, available in English, French or Spanish, was emailed to 300 individuals who work with NMCPs in malaria-endemic countries. Answers were collected between November and December 2017; responses were qualitatively analysed to identify key themes and trends and quantitatively analysed to determine average values stratified by region. Results Responses were received from 70 individuals, from 33 countries. Approximately half of the respondents (52 %) considered current blood-based tests for malaria to be minimally invasive and non-problematic in their setting. For these participants, non-invasive tests would only be of interest if they brought additional performance improvements, as compared with the performance of microscopy and RDTs. Most respondents were of the view that saliva-based (80 %) and urine-based (66 %) tests would be more readily acceptable among children than blood-based tests. Potential use-case scenarios of interest for both saliva- and urine-based tests were ease-of-testing by community health workers, additional surveillance, self-testing, and outbreak investigation. Many respondents (41 %) thought that if saliva-based tests retailed at

BackgroundPlasmodium knowlesi causes zoonotic malaria across Southeast Asia. First-line diagnostic microscopy cannot reliably differentiate P. knowlesi from other human malaria species. Rapid diagnostic tests (RDTs) designed for P. falciparum and P. vivax are used routinely in P. knowlesi co-endemic areas despite potential cross-reactivity for species-specific antibody targets.MethodsTen RDTs were evaluated: nine to detect clinical P. knowlesi infections from Malaysia, and nine assessing limit of detection (LoD) for P. knowlesi (PkA1-H.1) and P. falciparum (Pf3D7) cultures. Targets included Plasmodium-genus parasite lactate dehydrogenase (pan-pLDH) and P. vivax (Pv)-pLDH.ResultsSamples were collected prior to antimalarial treatment from 127 patients with microscopy-positive PCR-confirmed P. knowlesi mono-infections. Median parasitaemia was 788/µL (IQR 247-5,565/µL). Pan-pLDH sensitivities ranged from 50.6% (95% CI 39.6–61.5) (SD BIOLINE) to 87.0% (95% CI 75.1–94.6) (First Response® and CareStart™ PAN) compared to reference PCR. Pv-pLDH RDTs detected P. knowlesi with up to 92.0% (95% CI 84.3-96.7%) sensitivity (Biocredit™). For parasite counts ≥200/µL, pan-pLDH (Standard Q) and Pv-pLDH RDTs exceeded 95% sensitivity. Specificity of RDTs against 26 PCR-confirmed negative controls was 100%. Sensitivity of six highest performing RDTs were not significantly different when comparing samples taken before and after (median 3 hours) antimalarial treatment. Parasite ring stages were present in 30% of pre-treatment samples, with ring stage proportions (mean 1.9%) demonstrating inverse correlation with test positivity of Biocredit™ and two CareStart™ RDTs.For cultured P. knowlesi, CareStart™ PAN demonstrated the lowest LoD at 25 parasites/µL; LoDs of other pan-pLDH ranged from 98 to >2000 parasites/µL. Pv-pLDH LoD for P. knowlesi was 49 parasites/µL. No false-positive results were observed in either P. falciparum-pLDH or histidine-rich-protein-2 channels.ConclusionSelected RDTs demonstrate sufficient performance for detection of major human malaria species including P. knowlesi in co-endemic areas where microscopy is not available, particularly for higher parasite counts, although cannot reliably differentiate among non-falciparum malaria.

Rapid testing for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) of patients presenting to emergency departments (EDs) facilitates the decision for isolation on admission to hospital wards. Differences in the sensitivity of molecular assays have implications for diagnostic workflows. This study evaluated the performance of the cobas® Liat® RT-PCR, which is routinely used as the initial test for ED patients in our hospitals, compared with the eazyplex® RT-LAMP. A total of 378 oropharyngeal and nasal swabs with positive Liat® results were analysed. Residual sample aliquots were tested using NeuMoDx™, cobas® RT-PCR, and the eazyplex® assay. Patients were divided into asymptomatic (n = 157) and symptomatic (n = 221) groups according to the WHO case definition. Overall, 14% of positive Liat® results were not confirmed by RT-PCR. These samples were mainly attributed to 26.8% of asymptomatic patients, compared to 3.8% of the symptomatic group. Therefore, positive Liat® results were used to provisionally isolate patients in the ED until RT-PCR results were available. The eazyplex® assay identified 62% and 90.6% of RT-PCR-confirmed cases in asymptomatic and symptomatic patients, respectively. False-negative eazyplex® results were associated with RT-PCR Ct values > 30, and were more frequent in the asymptomatic group than in the symptomatic group (38.1% vs. 5.1%, respectively). Both the Liat® and eazyplex® assays are suitable for testing symptomatic patients. Their use in screening asymptomatic patients depends on the need to exclude any infection or identify those at high risk of transmission.

Background Rapid diagnostic tests (RDTs) have been extensively evaluated and play an important role in malaria diagnosis. However, the accuracy of RDTs for malaria diagnosis in patients with sickle cell disease (SCD) is unknown. Methods We compared the performance of a histidine rich protein 2 (HRP-2)-based RDT (First Response) and a lactate dehydrogenase (LDH)-based RDT (Optimal) with routine microscopy as reference standard in 445 children with SCD and an acute febrile illness in Accra, Ghana. Results The overall sensitivity, specificity, and positive and negative predictive values of the HRP-2-based RDTs were 100%, 95.7%, 73.8%, and 100%, respectively. Comparable values for the LDH-based RDTs were 91.7%, 99.5%, 95.7%, and 99.0%, respectively. A total of 423 results were true in both tests, 1 result was false in both tests, 16 results were false in the HRP-2 test only, and 5 were false in the LDH test only (McNemar test, P  = .03). At follow-up, 73.7% (28/38), 52.6% (20/38), 48.6% (17/35), and 13.2% (5/38) of study participants were HRP-2 positive on days 14, 28, 35, and 42, respectively, compared with 0%, 2.6% (1/38), 2.9% (1/35), and 2.6% (1/38) for LDH. Conclusion The HRP2-based RDT fulfilled World Health Organization criteria for malaria diagnosis in patients with SCD and may provide diagnostic evidence for treatment to begin in cases in which treatment would otherwise have begun presumptively based on symptoms, whereas LDH-based RDTs may be more suitable as a confirmatory test in low-parasitemic subgroups, such as patients with SCD. [ABSTRACT FROM AUTHOR]

Background: Hepatitis C virus (HCV) screening is critical to HCV elimination efforts. Simplified diagnostics are required for low-resource settings and difficult-to-reach populations. This retrospective study assessed performance of rapid diagnostic tests (RDTs) for detection of HCV antibodies.Methods: Two lots of 13 RDTs were evaluated at 3 laboratories using archived plasma samples from 4 countries (Nigeria, Georgia, Cambodia, and Belgium). HCV status was determined using 3 reference tests according to a composite algorithm. Sensitivity and specificity were evaluated in HIV-infected and HIV-uninfected populations. Operational characteristics were also assessed.Results: In total, 1710 samples met inclusion criteria. In HIV-uninfected samples (n = 384), the majority of RDTs had sensitivity ≥98% in 1 or both lots and most RDTs had specificity ≥99%. In HIV-infected samples (n = 264), specificity remained high but sensitivity was markedly lower than in HIV-uninfected samples; only 1 RDT reached >95%. The majority of HIV-infected samples for which sensitivity was low did not have detectable HCV viral load/core antigen. Interreader variability, lot-to-lot variability, and rate of invalid runs were low for all RDTs (<2%).Conclusions: HCV RDTs should be evaluated in the intended target population, as sensitivity can be impacted by population factors such as HIV status.Clinical Trials Registration: NCT04033887. [ABSTRACT FROM AUTHOR]

Effective control of infectious diseases is facilitated by informed decisions that require accurate and timely diagnosis of disease. For malaria, improved access to malaria diagnostics has revolutionized malaria control and elimination programmes. However, for COVID-19, diagnosis currently remains largely centralized and puts many low- and middle-income countries (LMICs) at a disadvantage. Malaria and COVID-19 are infectious diseases that share overlapping symptoms. While the strategic responses to disease control for malaria and COVID-19 are dependent on the disease ecologies of each disease, the fundamental need for accurate and timely testing remains paramount to inform accurate responses. This review highlights how the roll-out of rapid diagnostic tests has been fundamental in the fight against malaria, primarily within the Asia Pacific and along the Greater Mekong Subregion. By learning from the successful elements of malaria control programmes, it is clear that improving access to point-of-care testing strategies for COVID-19 will provide a suitable framework for COVID-19 diagnosis in not only the Asia Pacific, but all malarious countries. In malaria-endemic countries, an integrated approach to point-of-care testing for COVID-19 and malaria would provide bi-directional benefits for COVID-19 and malaria control, particularly due to their paralleled likeness of symptoms, infection control strategies and at-risk individuals. This is especially important, as previous disease pandemics have disrupted malaria control infrastructure, resulting in malaria re-emergence and halting elimination progress. Understanding and combining strategies may help to both limit disruptions to malaria control and support COVID-19 control. [ABSTRACT FROM AUTHOR]

Objectives: Hepatitis C virus (HCV) affects 58 million worldwide and > 79% of people remain undiagnosed. Rapid diagnostic tests (RDTs) for HCV can help improve diagnosis and treatment rates. Nevertheless, the high price and infrastructure needed to use current molecular HCV RDT options present a barrier to widespread use-particularly in low- and middle-income countries. We evaluated the performance and cost-effectiveness of a theoretical core antigen (cAg) RDT for HCV viremia confirmation, which requires fewer resources.Methods: We adapted a previously validated microsimulation model to simulate HCV disease progression and outcomes under different HCV testing algorithms in Georgia and Malaysia. We compared standard of care testing with laboratory-based ribonucleic acid HCV to a cAg-based RDT for HCV confirmation. We simulated a cohort of 10 000 adults in each country, with an HCV-ribonucleic acid prevalence of 5.40% in Georgia and 1.54% in Malaysia. We projected the cumulative healthcare costs, quality-adjusted life-years, and diagnosis coverage rates over a lifetime horizon.Results: Compared with the standard of care testing, the cAg-based RDT would increase quality-adjusted life-years by 270 in Georgia and 259 in Malaysia per 10 000 people. The high diagnosis rate and treatment rate of the cAg-based RDT result in substantial cost savings because of averted HCV sequelae management costs. Cost savings are $281 000 for Georgia and $781 000 for Malaysia.Conclusions: We found that a cAg-based RDT for HCV could improve the diagnosis rate and result in cost savings. Such a test could have a substantial impact on the feasibility and cost of HCV elimination. [ABSTRACT FROM AUTHOR]

"I will not permit considerations of age, disease or disability, creed, ethnic origin, gender, nationality, political affiliation, race, sexual orientation, social standing or any other factor to intervene between my duty and my patient." Obliged by the aforementioned oath, no medical practitioner shall sit in a moral judgment on any patient but will treat their illness to the best of their ability whatever the circumstances. A clear concord was yet to be authorized after the World Health Organization (WHO) declared the global pandemic of severe acute respiratory syndrome coronavirus 2infection. As a diagnostic modality, WHO recommended real-time reverse transcription–polymerase chain reaction (RT-PCR) as a reliable test; however, its availability in a deprived nation like ours became a major restraining factor. Despite an asset of having high specificity, RT-PCR for coronavirus disease 2019has its own liability of having low sensitivity. Henceforth, as time passed by, the validity of the rapid diagnostic tests was put into question. In later months, a few centers around our periphery started conducting RT-PCR, but the time taken to obtain the result was long-drawn-out process and the patient who needed urgent neurosurgical intervention at Annapurna Neurological Institute and Allied Sciences had to wait. We would like to share our expedition through peaks and valleys of managing 215 patients during the vicious circle of lockdown and global pandemic. [ABSTRACT FROM AUTHOR]

Introduction The rapid surge of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) cases globally makes it essential for rapid diagnosis of coronavirus disease 2019 (COVID-19). Real-time reverse-transcription polymerase chain reaction (rtRT-PCR) remains as the gold standard to detect COVID-19 cases because of its greater sensitivity and specificity. However, because of its prolonged turnaround time and technical expertise, recommendations have been made to employ the use of rapid diagnostic test for rapid diagnosis and to curb the spread of the disease. Methods This prospective study was performed in a tertiary COVID-19 care hospital located amidst the semi-urban settings. Both nasopharyngeal and throat swabs collected from the COVID 19 suspected study participants were subjected to both COVID 19 rtRT-PCR and rapid antigen testing. Results Of the total 599 samples tested by rtRT-PCR, 310 (52%) were positive and 289 (48%) tested negative for SARS-CoV-2. Of the 599 samples tested by rapid antigen test (RAT), 230 (38%) were positive and 369 (62%) were negative. The overall sensitivity and specificity of our study kit was found to be 74.19 and 100%, respectively. The sensitivity of the RAT greatly overlaps with the viral load which is determined by the cycle threshold (CT) values of SARS-CoV-2, E gene, and RdRp gene. Conclusion RAT yields rapid results within a short-turnaround time and found to be cost effective. Therefore, this test can be adopted in areas with rapid surge in SARS-CoV-2 cases which can help to rapidly identify the positive cases and to implement isolation and infection control measures. [ABSTRACT FROM AUTHOR]

Rapid diagnostic tests have been developed recently for rapid species or resistance genes identification, offering the potential to improve the selection of appropriate antibiotics. The newly developed FilmArray Blood Culture Identification 2 (BCID2) panel, which can identify more species and resistance genes, such as extended-spectrum beta-lactamase, is expected to make an impact on antimicrobial practice. The consecutive 50 inpatients with Gram-negative bacilli bacteremia were enrolled to this retrospective single-center study. In addition to the existing FilmArray Blood Culture Identification (BCID) panel, we have implemented BCID2 panel for positive blood culture. The sensitivity and specificity of BCID and BCID2 panel were respectively calculated, and a simulation study of time to effective, optimal and de-escalation therapy was performed based on BCID or BCID2 result. A total of 52 Gram-negative organisms in 50 patients were identified from blood cultures. Of these, 45 (87%) organisms were detected by BCID2 panel, which was more than BCID panel (41 organisms, 79%). BCID2 panel detected 5 CTX-M genes, which were concordant with conventional method. The time to effective therapy did not differ between BCID arm and BCID2 arm; however, the median time to optimal therapy (34 h in BCID arm and 26 h in BCID2 arm, P = 0.0007) and the median time to de-escalation therapy (42 h in BCID arm and 22 h in BCID2 arm, P = 0.0005) were significantly shortened. This simulation study of BCID2 panel showed high sensitivity and specificity, and the potential impact on shortening the time to optimal and de-escalation therapy. [ABSTRACT FROM AUTHOR]

Introduction: Hepatitis C virus (HCV) has posed a major public health problem globally. Since majority of HCV infected patients are asymptomatic, diagnosis of HCV infection is mainly based on the detection of anti-HCV antibodies by the Enzyme Linked Immunosorbent Assay (ELISA) or Rapid Diagnostic Tests (RDTs) and HCV Ribonucleic Acid (RNA) by real time Polymerase Chain Reaction (PCR) of serum or plasma samples. Aim: To assess the performance of RDT and 4th generation ELISA against real time reverse transcriptase PCR for the detection of HCV. Materials and Methods: A hospital-based cross-sectional study was carried out in the Virology Section, Department of Microbiology, Jawaharlal Nehru Institute of Medical Sciences (JNIMS), Imphal, Manipur, India, for a period of two years from June 2019 to May 2021. The study included 3,254 plasma samples from suspected cases of HCV monoinfection, and HCV/HIV co-infection. The plasma samples were subjected to anti-HCV antibodies by RDT (SD BIOLINE, South Korea) and 4th generation ELISA (Monolisa™ HCV Ag-Ab ULTRA, Bio-Rad, France), and HCV RNA by real time PCR. Data analysis was done using descriptive statistics, and performance of the assays was evaluated by using Cohen kappa test (1) and Receiver Operating Characteristic (ROC) curve. Results: PCR is considered as the gold standard test. HCV was detected by RDT in 453 (13.92%), ELISA in 413 (12.69%) and RT-PCR in 367 (11.28%) samples. The present study demonstrated sensitivity of 97.55% and specificity of 96.71% with Positive Predictive Value (PPV) of 79.03% by HCV-RDT. The 4th generation ELISA showed high sensitivity of 99.46% and specificity of 98.34%. Using ROC curve, the area under the curve was 81% for ELISA with diagnostic accuracy of 98.46%. Conclusion: 4th generation ELISA is more sensitive and specific than RDT for the detection of HCV infection. Confirmatory HCV-RNA assay could be performed to clear doubts related to false-positive and false-negative findings of the primary screening assays. [ABSTRACT FROM AUTHOR]

Introduction: The rapid transmission of coronavirus disease 2019 (COVID-19) requires a fast, accurate, and affordable detection method. Despite doubts of their diagnostic accuracy, rapid diagnostic tests (RDTs) are used worldwide due to their practicality. This systematic review aims to determine the diagnostic accuracy of antibody-based RDTs in detecting COVID-19.Material and methods: A literature search was carried out on five journal databases using the PRISMA-P 2015 method. We included all studies published up to February 2021. The risk of bias was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Diagnostic Test Accuracy Studies. Data regarding peer-review status, study design, test kit information, immunoglobulin class, target antigen, and the number of samples were extracted and tabulated. We estimated the pooled sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with a 95% confidence interval.Results: Thirty-three studies met the eligibility criteria. The pooled data results showed that the combined detection method of IgM or IgG had the highest sensitivity and NPV, which were 73.41% (95% CI: 72.22-74.57) and 75.34% (95% CI: 74.51-76.16), respectively. The single IgG detection method had the highest specificity and PPV of 96.68% (95% CI: 96.25-97.07) and 95.97% (95% CI: 95.47-96.42%), respectively.Conclusions: Antibody-based RDTs are not satisfactory as primary diagnostic tests but have utility as a screening tool. [ABSTRACT FROM AUTHOR]

We aimed to compare the differences in testing performance of extraction‐based polymerase chain reaction (PCR) assays, elution‐based direct PCR assay, and rapid antigen detection tests for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). We used nasopharyngeal swab samples of patients with coronavirus disease 2019 (COVID‐19). We used the MagNA Pure 24 System (Roche Diagnostics K.K.) or magLEAD 12gC (Precision System Science Co., Ltd.) for RNA extraction, mixed the concentrates with either the LightMix Modular SARS‐CoV PCR mixture (Roche Diagnostics K.K.) or Takara SARS‐CoV‐2 direct PCR detection kit (Takara Bio Inc.), and amplified it using COBAS® z480 (Roche Diagnostics K.K.). For elution‐based PCR, we directly applied clinical samples to the Takara SARS‐CoV‐2 direct PCR detection kit before the same amplification step. Additionally, we performed Espline SARS‐CoV‐2 (Fuji Rebio Co., Ltd.) for rapid diagnostic test (RDT), and used Lumipulse SARS‐CoV‐2 antigen (Fuji Rebio Co., Ltd.) and Elecsys SARS‐CoV‐2 antigen (Roche Diagnostics K.K.) for automated antigen tests (ATs). Extraction‐based and elution‐based PCR tests detected the virus up to 214–216 and 210 times dilution, respectively. ATs remained positive up to 24–26 times dilution, while RDT became negative after 22 dilutions. For 153 positive samples, positivity rates of the extraction‐based PCR assay were 85.6% to 98.0%, while that of the elution‐based PCR assay was 73.2%. Based on the RNA concentration process, extraction‐based PCR assays were superior to elution‐based direct PCR assays for detecting SARS‐CoV‐2. [ABSTRACT FROM AUTHOR]

Background: Precision public health (PPH) can maximize impact by targeting surveillance and interventions by temporal, spatial, and epidemiological characteristics. Although rapid diagnostic tests (RDTs) have enabled ubiquitous point-of-care testing in low-resource settings, their impact has been less than anticipated, owing in part to lack of features to streamline data capture and analysis. Objective: We aimed to transform the RDT into a tool for PPH by defining information and data axioms and an information utilization index (IUI); identifying design features to maximize the IUI; and producing open guidelines (OGs) for modular RDT features that enable links with digital health tools to create an RDT-OG system. Methods: We reviewed published papers and conducted a survey with experts or users of RDTs in the sectors of technology, manufacturing, and deployment to define features and axioms for information utilization. We developed an IUI, ranging from 0% to 100%, and calculated this index for 33 World Health Organization–prequalified RDTs. RDT-OG specifications were developed to maximize the IUI; the feasibility and specifications were assessed through developing malaria and COVID-19 RDTs based on OGs for use in Kenya and Indonesia. Results: The survey respondents (n=33) included 16 researchers, 7 technologists, 3 manufacturers, 2 doctors or nurses, and 5 other users. They were most concerned about the proper use of RDTs (30/33, 91%), their interpretation (28/33, 85%), and reliability (26/33, 79%), and were confident that smartphone-based RDT readers could address some reliability concerns (28/33, 85%), and that readers were more important for complex or multiplex RDTs (33/33, 100%). The IUI of prequalified RDTs ranged from 13% to 75% (median 33%). In contrast, the IUI for an RDT-OG prototype was 91%. The RDT open guideline system that was developed was shown to be feasible by (1) creating a reference RDT-OG prototype; (2) implementing its features and capabilities on a smartphone RDT reader, cloud information system, and Fast Healthcare Interoperability Resources; and (3) analyzing the potential public health impact of RDT-OG integration with laboratory, surveillance, and vital statistics systems. Conclusions: Policy makers and manufacturers can define, adopt, and synergize with RDT-OGs and digital health initiatives. The RDT-OG approach could enable real-time diagnostic and epidemiological monitoring with adaptive interventions to facilitate control or elimination of current and emerging diseases through PPH. [ABSTRACT FROM AUTHOR]

Background: Schistosomiasis and soil-transmitted helminths (STHs) contribute high disease burdens amongst the neglected tropical diseases (NTDs) and are public health problems in Angola. This study reports the prevalence, intensity and risk factors for schistosomiasis and STH infection in Huambo, Uige and Zaire provinces, Angola, to inform a school-based preventive chemotherapy program. Methods: A two-stage cluster design was used to select schools and schoolchildren to participate in parasitological and water, sanitation and hygiene (WASH) surveys across Huambo, Uige, and Zaire provinces. Point-of-care circulating cathodic antigen and urinalysis rapid diagnostic tests (RDTs) were used to determine the prevalence of Schistosoma mansoni and S. haematobium, respectively. Kato-Katz was used to identify and quantify STH species and quantify and compare with RDTs for S. mansoni. Urine filtration was used to quantify and compare with RDTs for S. haematobium. Descriptive statistics were used for prevalence and infection intensity of schistosomiasis and STH infection. Performance of RDTs was assessed through specificity and Cohen's Kappa agreement with microscopy. A multivariate regression analysis was used to determine demographic and WASH factors associated with schistosomiasis and STH infection. Results: A total 575 schools and 17,093 schoolchildren participated in the schistosomiasis survey, of which 121 schools and 3649 schoolchildren participated in the STH survey. Overall prevalence of S. mansoni was 21.2% (municipality range 0.9–74.8%) and S. haematobium 13.6% (range 0–31.2%), with an overall prevalence of schistosomiasis of 31.4% (range 5.9–77.3%). Overall prevalence of Ascaris lumbricoides was 25.1% (range 0–89.7%), hookworm 5.2% (range 0–42.6%), and Trichuris trichiura 3.6% (range 0–24.2%), with an overall prevalence of STH infection of 29.5% (range 0.8–89.7%). Ecological zone and ethnicity were factors associated with schistosomiasis and STH infection, with older age and female sex additional risk factors for S. haematobium. Conclusions: Most municipalities met World Health Organization defined prevalence thresholds for a schistosomiasis preventive chemotherapy program. A STH preventive chemotherapy program is indicated for nearly all municipalities in Uige and select municipalities in Huambo and Zaire. The association between ecological zone and ethnicity with schistosomiasis and STH infection necessitates further evaluation of home and school environmental, sociodemographic and behavioural factors to inform targeted control strategies to complement preventive chemotherapy programs. [ABSTRACT FROM AUTHOR]

This cross-sectional study aimed to assess the performances of a rapid diagnostic test (RDT)—the AllTest Malaria p.f./p.v., microscopy, and nested polymerase chain reaction (PCR) for diagnosing Plasmodium falciparum malaria in 400 febrile patients from a low-transmission region (Jazan) in southwestern Saudi Arabia. Diagnostic performance of all three methods was compared using microscopy and nested PCR as reference methods. Overall, 42 (10.5%), 48 (12.0%), and 57 (14.3%) samples were found positive by microscopy, RDT, and PCR, respectively. With PCR as reference method, the RDT showed higher sensitivity (79% vs. 71.9%), similar specificity (99.1% vs. 99.7%), and better NLR (0.20 vs. 0.27) and area under the curve (89.0% vs. 85.8%) than microscopy. The sensitivity of RDT and microscopy decreased as age increased, and false negatives were associated with low parasite density. In addition, the sensitivity of RDT and microscopy was higher in non-Saudi than in Saudi participants. Against microscopy, both RDT and PCR showed high sensitivity (83.3% vs. 97.6%), specificity (96.4% vs. 95.5%), and NPVs (98.0% vs. 99.7%), but reduced PPVs (72.9% vs. 71.9%), respectively. The results showed that the performance of the AllTest Malaria p.f./p.v RDT was better than that of microscopy in diagnosing P. falciparum malaria among febrile patients in the Jazan region when nested PCR was used as the reference. However, further studies are required to assess malaria diagnostic methods among asymptomatic individuals in the region. [ABSTRACT FROM AUTHOR]

Background: The accuracy and reliability of rapid diagnostic tests are critical for monitoring and diagnosing SARS-CoV-2 infection in the general population. This study aimed to evaluate the analytical performance of the BIOSYNEX COVID-19 Ag BSS (Biosynex Swiss SA, Fribourg, Switzerland) antigen rapid diagnostic test (BIOSYNEX Ag-RDT), which targets the SARS-CoV-2 N-nucleocapsid protein for the diagnosis of COVID-19. The Ag-RDT was compared with a real-time RT-PCR (rtRT-PCR) as gold standard for performance measurement. Methods: Two nasopharyngeal flocked swabs were prospectively collected simultaneously in March and April 2021 from 967 individuals aged ≥ 18 years tested for SARS-CoV-2 in two private laboratories, Paris, France. Results: Overall, the Ag-RDT demonstrated high sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 81.8%, 99.6%, 96.6%, and 97.5%, respectively. The agreement (97.0%), reliability assessed using Cohen's κ-coefficient (0.87), and accuracy evaluated using Youden index (J) (81.6%) in detecting SARS-CoV-2 were high. The analytical performance of the Ag-RDT remained high when there was significant viral shedding (i.e., N gene Ct values ≤ 33 on reference RT-PCR). The sensitivity was only 55.2% in case of low or very low viral excretion (Ct > 33). Conclusions: The BIOSYNEX Ag-RDT is a promising, potentially simple diagnostic tool, especially in symptomatic COVID-19 patients with substantial viral excretion in the nasopharynx. [ABSTRACT FROM AUTHOR]

Abstract Background Deletion of pfhrp2 and/or pfhrp3 genes cause false negatives in malaria rapid diagnostic test (RDT) and threating malaria control strategies. This systematic review aims to assess the main methodological aspects in the study of pfhrp2 and pfhrp3 gene deletions and its global epidemiological status, with special focus on their distribution in Africa; and its possible impact in RDT. Methods The systematic review was conducted by examining the principal issues of study design and methodological workflow of studies addressing pfhrp2 deletion. Meta-analysis was applied to represent reported prevalences of pfhrp2 and pfhrp3 single and double deletion in the World Health Organization (WHO) region. Pooled-prevalence of deletions was calculated using DerSimonnian-Laird random effect model. Then, in-deep analysis focused on Africa was performed to assess possible variables related with these deletions. Finally, the impact of these deletions in RDT results was analysed combining reported information about RDT sensitivity and deletion prevalences. Results 49 articles were included for the systematic review and 37 for the meta-analysis, 13 of them placed in Africa. Study design differs significantly, especially in terms of population sample and information reported, resulting in high heterogeneity between studies that difficulties comparisons and merged conclusions. Reported prevalences vary widely in all the WHO regions, significantly higher deletion were reported in South-Central America, following by Africa and Asia. Pfhrp3 deletion is more prevalent (43% in South-Central America; 3% in Africa; and 1% in Asia) than pfhrp2 deletion (18% in South-Central America; 4% in Africa; and 3% in Asia) worldwide. In Africa, there were not found differences in deletion prevalence by geographical or population origin of samples. The prevalence of deletion among false negatives ranged from 0 to 100% in Africa, but in Asia and South-Central America was only up to 90% and 48%, respectively, showing substantial relation between deletions and false negatives. Conclusion The concerning prevalence of pfhrp2, pfhrp3 and pfhrp2/3 gene deletions, as its possible implications in malaria control, highlights the importance of regular and systematic surveillance of these deletions. This review has also outlined that a standardized methodology could play a key role to ensure comparability between studies to get global conclusions.

Abstract Background Seasonal influenza leads to significant morbidity and mortality. Rapid self-tests could improve access to influenza testing in community settings. We aimed to evaluate the diagnostic accuracy of a mobile app-guided influenza rapid self-test for adults with influenza like illness (ILI), and identify optimal methods for conducting accuracy studies for home-based assays for influenza and other respiratory viruses. Methods This cross-sectional study recruited adults who self-reported ILI online. Participants downloaded a mobile app, which guided them through two low nasal swab self-samples. Participants tested the index swab using a lateral flow assay. Test accuracy results were compared to the reference swab tested in a research laboratory for influenza A/B using a molecular assay. Results Analysis included 739 participants, 80% were 25–64 years of age, 79% female, and 73% white. Influenza positivity was 5.9% based on the laboratory reference test. Of those who started their test, 92% reported a self-test result. The sensitivity and specificity of participants’ interpretation of the test result compared to the laboratory reference standard were 14% (95%CI 5–28%) and 90% (95%CI 87–92%), respectively. Conclusions A mobile app facilitated study procedures to determine the accuracy of a home based test for influenza, however, test sensitivity was low. Recruiting individuals outside clinical settings who self-report ILI symptoms may lead to lower rates of influenza and/or less severe disease. Earlier identification of study subjects within 48 h of symptom onset through inclusion criteria and rapid shipping of tests or pre-positioning tests is needed to allow self-testing earlier in the course of illness, when viral load is higher.

Advanced diagnostic materials, such as aptamers, are required due to the scarcity of efficient diagnostic antibodies and the low sensitivity of rapid diagnostic kits at detecting the malaria parasite, Plasmodium falciparum. Two peptides M2.9 [(KPTAEQTESPELQSAPEN) and M2.17 (KILFNVYSPLGCTCECWV)] were designed using simple epitope prediction tools and modified against the merozoite surface antigen 2 of P. falciparum (Pf. MSP2) by 3-dimensional modeling based on binding affinity. Based on five prediction tools for hydropathy, M2.17 was selected as an appropriate capture peptide. A peptide-based fluorescence-linked immunosorbent assay (FLISA) and a peptide pair-based fluorescent immunochromatographic test strip (FICT) were developed to detect P. falciparum 3D7 (drug-sensitive) and P. falciparum K1 (multi drugs-resistant) strains. Bioinformatic analysis of two peptides demonstrated the potential binding affinity with the merozoite surface protein 2 of P. falciparum (Pf.MSP2) with a positive hydropathy value. The limit of detection (LOD) of FLISA was 10 parasites/μL and of a peptide pair-linked rapid FICT system was 5 and 200 parasites/μL for P. falciparum 3D7 and K1, respectively. Compared to commercial rapid detection systems (RDTs), a peptide pair-linked FICT system exhibited a 20-fold greater efficiency in detecting P. falciparum 3D7 and specifically discriminated another protozoan spp. A peptide pair-linked rapid diagnostic strip could be an alternative to conventional RDTs for monitoring wild-type and drug-resistant malaria parasites. [Display omitted] [ABSTRACT FROM AUTHOR]

BACKGROUND: The performance of Plasmodium falciparum-specific histidine-rich protein 2-based rapid diagnostic tests (RDTs) to evaluate suspected malaria in low-endemicity settings has not been well characterized. METHODS: Using dried blood spot samples from patients with suspected malaria at 37 health facilities from 2012 to 2014 in the low-endemicity country of Swaziland, we investigated the diagnostic accuracy of histidine-rich protein 2-based RDTs using qualitative polymerase chain reaction (PCR) (nested PCR targeting the cytochrome b gene) and quantitative PCR as reference standards. To explore reasons for false-negative and/or false-positive results, we used pfhrp2/3-specific PCR and logistic regression analyses of potentially associated epidemiological factors. RESULTS: From 1353 patients, 93.0% of RDT-positive (n = 185) and 31.2% of RDT-negative samples (n = 340) were available and selected for testing. Compared with nested PCR, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RDTs were 51.7%, 94.1%, 67.3%, and 89.1%, respectively. After exclusion of samples with parasite densities

ABSTRACT Burkholderia pseudomallei is the causative agent of melioidosis, a life-threatening disease common in Southeast Asia and northern Australia. Melioidosis often presents with nonspecific symptoms and has a fatality rate of upwards of 70% when left untreated. The gold standard for diagnosis is culturing B. pseudomallei from patient samples. Bacterial culture, however, can take up to 7 days, and its sensitivity is poor, at roughly 60%. The successful administration of appropriate antibiotics is reliant on rapid and accurate diagnosis. Hence, there is a genuine need for new diagnostics for this deadly pathogen. The Active Melioidosis Detect (AMD) lateral flow immunoassay (LFI) detects the capsular polysaccharide (CPS) of B. pseudomallei. The assay is designed for use on various clinical samples, including serum and urine; however, there are limited data to support which clinical matrices are the best candidates for detecting CPS. In this study, concentrations of CPS in paired serum and urine samples from melioidosis patients were determined using a quantitative antigen capture enzyme-linked immunosorbent assay. In parallel, samples were tested with the AMD LFI, and the results of the two immunoassays were compared. Additionally, centrifugal concentration was performed on a subset of urine samples to determine if this method may improve detection when CPS levels are initially low or undetectable. The results indicate that while CPS levels varied within the two matrices, there tended to be higher concentrations in urine. The AMD LFI detected CPS in 40.5% of urine samples, compared to 6.5% of serum samples, suggesting that urine is a preferable matrix for point-of-care diagnostic assays. IMPORTANCE Melioidosis is very challenging to diagnose. There is a clear need for a point-of-care assay for the detection of B. pseudomallei antigen directly from patient samples. The Active Melioidosis Detect lateral flow immunoassay detects the capsular polysaccharide (CPS) of B. pseudomallei and is designed for use on various clinical samples, including serum and urine. However, there are limited data regarding which clinical matrix is preferable for the detection of CPS. This study addresses this question by examining quantitative CPS levels in paired serum and urine samples and relating them to clinical parameters. Additionally, centrifugal concentration was performed on a subset of urine samples to determine whether this might enable the detection of CPS in samples in which it was initially present at low or undetectable levels. These results provide valuable insights into the detection of CPS in patients with melioidosis and suggest potential ways forward in the diagnosis and treatment of this challenging disease.

IntroductionInfection by the hepatitis C virus (HCV) is an important cause of chronic liver disease, considered a public health problem worldwide with high morbidity and mortality due to limited access to diagnostic tests in developing countries. Only a small percentage know their infection status and receive timely treatment. It is critical to make diagnostic tests for HCV infection accessible and to provide timely treatment, which not only reduces the spread of infection but also stops the progression of HCV disease without symptoms.ObjectiveTo determine the prevalence of chronic infection by HCV in patients with risk factors by using rapid tests in Cartagena, Colombia, and describe their epidemiological characteristics.MethodologyA cross-sectional descriptive observational study was carried out on asymptomatic adults with risk factors for HCV infection in the city of Cartagena between December 2017 and November 2019. A rapid immunochromatographic test was performed to detect antibodies, characterizing the population.ResultsIn total, 1,023 patients were identified who met the inclusion criteria, 58.5% women and 41.4% men, obtaining nine positive results, confirming chronic infection with viral load for HCV, finding seven cases of genotype 1b and two genotype 1a.ConclusionIn our study, a prevalence of hepatitis C infection of 0.9% was found in asymptomatic individuals with risk factors, which allows us to deduce that the active search for cases in risk groups constitutes a pillar for the identification of the disease, the initiation of antiviral therapy, and decreased morbidity and mortality.

Introduction: Hepatitis C virus (HCV) has posed a major public health problem globally. Since majority of HCV infected patients are asymptomatic, diagnosis of HCV infection is mainly based on the detection of anti-HCV antibodies by the Enzyme Linked Immunosorbent Assay (ELISA) or Rapid Diagnostic Tests (RDTs) and HCV Ribonucleic Acid (RNA) by real time Polymerase Chain Reaction (PCR) of serum or plasma samples. Aim: To assess the performance of RDTs and fourth generation ELISA against real time reverse transcriptase PCR for the detection of HCV. Materials and Methods: A hospital-based cross-sectional study was carried out in the Virology Section, Department of Microbiology, Jawaharlal Nehru Institute of Medical Sciences (JNIMS), Imphal, Manipur, India, for a period of two years from June 2019 to May 2021. The study included 3,254 plasma samples from suspected cases of HCV monoinfection, and HCV/HIV co-infection. The plasma samples were subjected to anti-HCV antibodies by RDTs (SD BIOLINE, South Korea) and fourth generation ELISA (Monolisa™ HCV Ag-Ab ULTRA, Bio-Rad, France), and HCV RNA by real time PCR. Data analysis was done using descriptive statistics, and performance of the assays was evaluated by using Cohen kappa test (κ) and Receiver Operating Characteristic (ROC) curve. Results: PCR is considered as the gold standard test. HCV was detected by RDTs in 453 (13.92%), ELISA in 413 (12.69%) and RT-PCR in 367 (11.28%) samples. The present study demonstrated sensitivity of 97.55% and specificity of 96.71% with Positive Predictive Value (PPV) of 79.03% by HCV-RDT. The fourth generation ELISA showed high sensitivity of 99.46% and specificity of 98.34%. Using ROC curve, the area under the curve was 81% for ELISA with diagnostic accuracy of 98.46%. Conclusion: Fourth generation ELISA is more sensitive and specific than RDTs for the detection of HCV infection. Confirmatory HCV-RNA assay could be performed to clear doubts related to false-positive and false-negative findings of the primary screening assays.

Most rapid diagnostic tests for Plasmodium falciparum malaria target the Histidine-Rich Proteins 2 and 3 (HRP2 and HRP3). Deletions of the hrp2 and hrp3 genes result in false-negative tests and are a threat for malaria control. A novel assay for molecular surveillance of hrp2/hrp3 deletions was developed based on droplet digital PCR (ddPCR). The assay quantifies hrp2, hrp3, and a control gene with very high accuracy. The theoretical limit of detection was 0.33 parasites/µl. The deletion was reliably detected in mixed infections with wild-type and hrp2-deleted parasites at a density of >100 parasites/reaction. For a side-by-side comparison with the conventional nested PCR (nPCR) assay, 248 samples were screened in triplicate by ddPCR and nPCR. No deletions were observed by ddPCR, while by nPCR hrp2 deletion was observed in 8% of samples. The ddPCR assay was applied to screen 830 samples from Kenya, Zanzibar/Tanzania, Ghana, Ethiopia, Brazil, and Ecuador. Pronounced differences in the prevalence of deletions were observed among sites, with more hrp3 than hrp2 deletions. In conclusion, the novel ddPCR assay minimizes the risk of false-negative results (i.e., hrp2 deletion observed when the sample is wild type), increases sensitivity, and greatly reduces the number of reactions that need to be run.

Objectives: We herein assessed the analytical performances of the antigen-rapid diagnostic test (Ag-RDT) SIENNA™ COVID-19 Antigen Rapid Test Cassette (Nasopharyngeal Swab) (Salofa Oy, Salo, Finland), targeting the SARS-CoV-2 N nucleocapsid protein, for the diagnosis of COVID-19 in hospitalized patients with suspected SARS-CoV-2 infection, by reference to real-time RT-PCR (rRT-PCR). Methods: Nasopharyngeal swabs were collected from patients with COVID-19-like illness during the second epidemic wave in Paris, France, among which 100 and 50 were positive and negative for SARS-CoV-2 RNA, respectively. Results: Overall, the Ag-RDT showed high sensitivity, specificity, positive and negative predictive values of 90.0%, 100.0%, 100.0% and 98.1%, respectively, as well as high or almost perfect agreement (93.3%), reliability assessed by Cohen’s κ coefficient (0.86), and accuracy assessed by Youden’s J index (90%) to detect SARS-CoV-2. The analytical performances of the Ag-RDT remained high in the event of significant viral excretion (i.e., N gene Ct values ≤33 by reference rtRT-PCR), while the sensitivity of the Ag-RDT dropped to 69.6% with low or very low viral shedding (Ct > 33). Conclusions: The SIENNA™ Ag-RDT presents excellent analytical performances for viral loads ≤33 Ct, classically corresponding to situations of symptomatic COVID-19 and/or proven contagiousness.

Abstract Background Artemether/lumefantrine (AL), sold under the brand name Coartem, is the most common artemisinin-based combination therapy for the treatment of malaria. Drug-induced oculogyric crisis is a neurological disorder characterized by frequent upward deviations of the eye. In the literature, no cases of Coartem-induced oculogyric crisis have been reported in Ghana. Case presentation A 19-year-old male patient, who presented fever measuring 37.9 °C, general body pains, and weakness was prescribed with antimalarial therapy artemether/lumefantrine, Coartem®, from a local pharmacy. Just after initiation of treatment, the patient complained of double vision, involuntary upward eye deviation, and inability to close both eyes. The patient was diagnosed with Coartem-induced oculogyric crisis and was treated with the cessation of the causing agent and intramuscular injection of promethazine hydrochloride. Conclusions When a patient exhibits a neurological disorder, such as oculogyric crisis, with normal conscious state and normal vital signs, special attention should be given to obtaining a history of recently administered medications. Clinicians should recognize adverse reactions to drugs based on a thorough patient history and examination. The goal of this report was to present Coartem-induced oculogyric crisis.

Abstract Background Malaria remains a significant health challenge in sub-Saharan Africa, with early diagnosis critical to reducing its morbidity and mortality. Despite the increasing Plasmodium spp. diagnostic capabilities, access to testing is limited in some cases by the almost absolute requirement for blood from potentially infected subjects as the only sample source for all conventional methods. A rapid test on non-invasive specimen with comparable performance to microscopy for the screening or diagnosis of all participants is invaluable. This study sought to compare conventional and non-invasive diagnostic tools for detecting Plasmodium falciparum. Methods This was a cross-sectional study, carried out between March and August 2019 to evaluate and compare the diagnostic performance of a PfHRP2/pLDH-based malaria rapid diagnostic test (mRDT) on patients’ blood, saliva and urine relative to conventional light microscopy and nested PCR at outpatient clinics in the Buea and Tiko health districts of Southwestern Cameroon. The significance of differences in proportions was explored using the Pearson’s χ 2 test whereas differences in group means were assessed using analyses of variance. Results A total of 359 individuals of both sexes, aged 1–92 years, were enrolled into the study. Of the 301 individuals tested by light microscopy and mRDTs on blood, saliva and urine, 84 (27.9%), 81 (26.9%), 87 (28.9%) and 107 (35.5%) respectively were positive. However, only 34.3%, 90.5%, 91.4%, 83.9% and 65.4% febrile, light microscopy and mRDT positives on blood, saliva and urine respectively had P. falciparum infection as confirmed by PCR. The sensitivity and specificity of presumptive diagnosis, light microscopy and mRDT on blood, saliva and urine were 86.9% and 19.7%, 77.8% and 96.1%, 75.8% and 96.6%, 74.5% and 93.1%, and 70.7% and 81.8%, respectively. The agreement between mRDT on saliva (k = 0.696) and microscopy (k = 0.766) compared to PCR was good. Conclusion The study highlighted the low performance of presumptive diagnosis, reinforcing the need for parasitological tests prior to antimalarial therapy. The higher PfHRP2/pLDH mRDT parasite detection rates and sensitivity in saliva compared to urine suggests that the former is a practical adjunct to or alternative worth optimising for the routine diagnosis of malaria. Graphic Abstract Flow chart for diagnosis of P. falciparum infection by light microscopy, rapid diagnostic tests and nested PCR.

Abstract Background Malaria rapid diagnostic tests have become a primary and critical tool for malaria diagnosis in malaria-endemic countries where Plasmodium falciparum Histidine Rich Protein 2-based rapid diagnostic tests (PfHRP2-based RDTs) are widely used. However, in the last decade, the accuracy of PfHRP2-based RDTs has been challenged by the emergence of P. falciparum strains harbouring deletions of the P. falciparum histidine rich protein 2 (pfhrp2) gene, resulting in false-negative results. In the Democratic Republic of Congo (D.R. Congo), little is known about the prevalence of the pfhrp2 gene deletion among P. falciparum isolates infecting symptomatic patients, especially in low to moderate transmission areas where pfhrp2 deletion parasites are assumed to emerge and spread. Here we determine the local prevalence and factors associated with pfhrp2 gene deletions among symptomatic malaria patients in the Kwilu Province of the D.R. Congo. Methods We used secondary data from a prospective health facility-based cross-sectional study conducted in 2018. Blood was collected for microscopy, PfHRP2-RDT, and spotted onto Whatman filter paper for downstream genetic analysis. Genomic DNA was extracted and used to perform PCR assays for the detection and confirmation of pfhrp2 gene deletions. Fischer’s exact and the Kruskal–Wallis tests were applied to look for associations between potential explanatory variables and the pfhrp2 gene deletion with a level of statistical significance set at P

Abstract Background There are a variety of approaches being used for malaria surveillance. While active and reactive case detection have been successful in localized areas of low transmission, concerns over scalability and sustainability keep the approaches from being widely accepted. Mobile health interventions are poised to address these shortcomings by automating and standardizing portions of the surveillance process. In this study, common challenges associated with current data aggregation methods have been quantified, and a web-based mobile phone application is presented to reduce the burden of reporting rapid diagnostic test (RDT) results in low-resource settings. Methods De-identified completed RDTs were collected at 14 rural health clinics as part of a malaria epidemiology study at Macha Research Trust, Macha, Zambia. Tests were imaged using the mHAT web application. Signal intensity was measured and a binary result was provided. App performance was validated by: (1) comparative limits of detection, investigated against currently used laboratory lateral flow assay readers; and, (2) receiver operating characteristic analysis comparing the application against visual inspection of RDTs by an expert. Secondary investigations included analysis of time-to-aggregation and data consistency within the existing surveillance structures established by Macha Research Trust. Results When compared to visual analysis, the mHAT app performed with 91.9% sensitivity (CI 78.7, 97.2) and specificity was 91.4% (CI 77.6, 97.0) regardless of device operating system. Additionally, an analysis of surveillance data from January 2017 through mid-February 2019 showed that while the majority of the data packets from satellite clinics contained correct data, 36% of data points required correction by verification teams. Between November 2018 and mid-February 2019, it was also found that 44.8% of data was received after the expected submission date, although most (65.1%) reports were received within 2 days. Conclusions Overall, the mHAT mobile app was observed to be sensitive and specific when compared to both currently available benchtop lateral flow readers and visual inspection. The additional benefit of automating and standardizing LFA data collection and aggregation poses a vital improvement for low-resource health facilities and could increase the accuracy and speed of data reporting in surveillance campaigns.

Introduction The rapid transmission of Coronavirus disease 2019 (COVID-19) requires a fast, accurate, and affordable detection method. Despite doubts of its diagnostic accuracy, Rapid Diagnostic Test (RDT) is world-widely used in consideration for its practicality. This systematic review aims to determine the diagnostic accuracy of antibody-based RDT in detecting COVID-19.The rapid transmission of coronavirus disease 2019 (COVID-19) requires a fast, accurate, and affordable detection method. Despite doubts of their diagnostic accuracy, rapid diagnostic tests (RDTs) are used worldwide due to their practicality. This systematic review aims to determine the diagnostic accuracy of antibody-based RDTs in detecting COVID-19. Material and methods A literature search was carried out on five journal databases using the PRISMA-P 2015 method. We included all studies published up to February 2021. The risk of bias was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Diagnostic Test Accuracy Studies. Data regarding peer-review status, study design, test kit information, immunoglobulin class, target antigen, and the number of samples were extracted and tabulated. We estimated the pooled sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with a 95% confidence interval. Results Thirty-three studies met the eligibility criteria. The pooled data results showed that the combined detection method of IgM or IgG had the highest sensitivity and NPV, which were 73.41% (95% CI: 72.22–74.57) and 75.34% (95% CI: 74.51–76.16), respectively. The single IgG detection method had the highest specificity and PPV of 96.68% (95% CI: 96.25–97.07) and 95.97% (95% CI: 95.47–96.42%), respectively. Conclusions Antibody-based RDTs are not satisfactory as primary diagnostic tests but have utility as a screening tool.

Abstract Background Efficient monitoring and control of coronavirus disease 2019 (COVID-19) require access to diagnostic tests, and serological diagnostic testing is desirable. In the current study, antibodies were investigated in patients recently diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods Cross-sectional data were obtained from 245 patients in whom SARS-CoV-2 infection had been confirmed via real-time reverse transcriptase-polymerase chain reaction between March and October 2020. Serum samples were acquired between 2 and 60 days following the onset of COVID-19 symptoms or the first detection of SARS-CoV-2 in asymptomatic patients. All specimens were tested simultaneously using an IgM/IgG rapid diagnostic test (RDT), IgG nucleocapsid protein-based chemiluminescent microparticle immunoassay (CMIA), IgG, and IgA spike protein-based enzyme-linked immunosorbent assays (ELISAs). Blood donor samples obtained in 2018 were used as negative controls. Results The sensitivity and specificity of the RDT IgG were compared with the IgG immunoassays as standards. The RDT IgG exhibited 97.5% sensitivity and 89.4% specificity compared with a CMIA IgG, 98.4% sensitivity, and 78.8% specificity compared with an ELISA IgG. IgM, IgG, and IgA seropositivity rates were low between 1 and 2 weeks after COVID-19 symptom onset or the detection of SARS-CoV-2 RNA. IgM seropositivity rate began decreasing after 4 weeks, whereas IgG and IgA seropositivity rate remained at appreciable levels over the 8-week study period. No cross-reactivity with seasonal coronaviruses was detected. Conclusions IgG RDT alone or combined with molecular diagnostic tests may be useful for identifying recent SARS-CoV-2 infection.

Objectives: There is a high demand for SARS-CoV-2 testing to identify COVID-19 cases. Real-time quantitative PCR (qRT-PCR) is the recommended diagnostic test but a number of constraints prevent its widespread implementation, including cost. The aim of this study was to evaluate a low cost and easy to use rapid antigen test for diagnosing COVID-19 at the point of care. Methods: Nasopharyngeal swabs from suspected COVID-19 cases and low-risk volunteers were tested with the STANDARD Q COVID-19 Ag Test and the results were compared with the qRT-PCR results. Results: In total, 262 samples were collected, including 90 qRT-PCR positives. The majority of samples were from males (89%) with a mean age of 34 years and only 13 (14%) of the positives were mildly symptomatic. The sensitivity and specificity of the antigen test were 70.0% (95% confidence interval (CI): 60–79) and 92% (95% CI: 87–96), respectively, and the diagnostic accuracy was 84% (95% CI: 79–88). The antigen test was more likely to be positive for samples with qRT-PCR Ct values ≤29, with a sensitivity of 92%. Conclusions: The STANDARD Q COVID-19 Ag Test performed less than optimally in this evaluation. However, the test may still have an important role to play early in infection when timely access to molecular testing is not available but the results should be confirmed by qRT-PCR.

Introduction: Tuberculosis (TB) is one of the most prevalent respiratory diseases in the world. In 2020 there were at least 9.9 million new infections, with 1.5 million deaths. Approximately 10% of people infected with Mycobacterium tuberculosis develop the disease during the first 2 to 5 years after infection. In South America, the diagnosis of Latent Tuberculosis Infections (LTBI) continues to be performed through the Mantoux tuberculin skin test (TST). Objective: The objective of our study was to compare the sensitivity of a new immunofluorescence IGRA test against a widely available IGRA kit on the market. Material and method: Close contact with infectious TB patients, HIV patients, or immunocompromised for another cause were recruited. Two interferon-gamma release assay (IGRA) diagnostic kits were used and compared with TST. Results: 76 patients were recruited, 93.42% were Chilean nationality, and 98.68% of the patients did not have immunosuppression. The sensitivity of the new technique was 88.89%, and the specificity was 92.50% in the study population compared to the IGRA previously used. In the subgroup older than 36 years, the sensitivity was 95.65%, and the specificity was 89.47%. Conclusion: IGRA techniques are a new resource in clinical laboratories to make an accurate diagnosis of LTBI in the region of the Americas. In our population, the greatest benefit of this new IGRA would be observed in people over 36 years of age, where the sensitivity of the technique was like that of the currently available test.

Plasmodium falciparum parasites carrying deletions of histidine-rich protein 2 and 3 genes, pfhrp2 and pfhrp3, respectively, are likely to escape detection via HRP2-based rapid diagnostic tests (RDTs) and, consequently, treatment, posing a major risk to both the health of the infected individual and malaria control efforts. This study assessed the frequency of pfhrp2- and pfhrp3-deleted strains at four different study sites in Central Africa (number of samples analyzed: Gabon N = 534 and the Republic of Congo N = 917) and West Africa (number of samples analyzed: Nigeria N = 466 and Benin N = 120) using a highly sensitive multiplex qPCR. We found low prevalences for pfhrp2 (1%, 0%, 0.03% and 0) and pfhrp3 single deletions (0%, 0%, 0.03% and 0%) at all study sites (Gabon, the Republic of Congo, Nigeria and Benin, respectively). Double-deleted P. falciparum were only found in Nigeria in 1.6% of all internally controlled samples. The results of this pilot investigation do not point towards a high risk for false-negative RDT results due to pfhrp2/pfhrp3 deletions in Central and West African regions. However, as this scenario can change rapidly, continuous monitoring is essential to ensure that RDTs remain a suitable tool for the malaria diagnostic strategy.

The current study reports on the development of a rapid and cost-effective TB-antigen diagnostic test for the detection of Mycobacterium biomarkers from non-sputum-based samples. Two gold nanoparticle (AuNP)-based rapid diagnostic tests (RDTs) in the form of lateral flow immunoassays (LFIAs) were developed for detection of immunodominant TB antigens, the 6 kDa early secreted antigen target EsxA (ESAT-6) and the 10 kDa culture filtrate protein EsxB (CFP-10). AuNPs were synthesized using the Turkevich method and characterized by UV-vis spectrophotometer and transmission electron microscope (TEM). The AuNP–detection probe conjugation conditions were determined by comparing the stability of 14 nm AuNPs at different pH conditions, following salt challenge. Thereafter, ESAT-6 and CFP-10 antibodies were conjugated to the AuNPs and used for the colorimetric detection of TB antigens. Selection of the best detection and capture antibody pairs was determined by Dot spotting. The limits of detection (LODs) for the LFIAs were evaluated by dry testing. TEM results showed that the 14 nm AuNPs were mostly spherical and well dispersed. The ESAT-6 LFIA prototype had an LOD of 0.0625 ng/mL versus the CFP-10 with an LOD of 7.69 ng/mL. Compared to other studies in the literature, the LOD was either similar or lower, outperforming them. Moreover, in some of the previous studies, an enrichment/extraction step was required to improve on the LOD. In this study, the LFIAs produced results within 15 min and could be suitable for use at PoCs either in clinics, mobile clinics, hospitals or at home by the end user. However, further studies need to be conducted to validate their use in clinical samples.

M. tuberculosis is the single infectious agent responsible for most deaths worldwide outside of pandemics. Diseases due to non-tuberculous mycobacteria (NTM) are increasing in many regions of the world. The two molecular assays GenoType CM direct® (GTCMd) (Bruker, Billerica, MA, USA) and VisionArray Myco® (VAM) (ZytoVision, Bremerhaven, Germany) are based on the DNA/DNA hybridization technique, and allow for the identification of tuberculous and the most clinically relevant non-tuberculous mycobacterial species from clinical specimens. We evaluated the performance of both assays for the identification of mycobacteria from 65 clinical specimens of 65 patients and compared it with the results of conventional culture. Based on conventional culture that recovered 37 mycobacterial isolates including 11 tuberculous and 26 NTM isolates, sensitivity, specificity, positive predictive value and negative predictive value were 89.2%, 81.5%, 86.8% and 84.6% for GTCMd and 73.0%, 96.3%, 96.4% and 72.2% for VAM. Additionally, GTCMd identified mycobacteria from five and VAM from one culture-negative sample. Both assays identified a mycobacterium in one sample overgrown by other microorganisms. Two M. abscessus subsp. abscessus isolates grown from culture were identified as M. chelonae by GTCMd assay. In conclusion, both assays improve the rapid identification of mycobacteria directly from clinical specimens. [ABSTRACT FROM AUTHOR]

Chronic infection with hepatitis B virus (HBV) is a leading cause of morbidity and death, especially in sub-Saharan Africa (SSA), where approximately 60 million adults are infected. More than 90% of these patients are unaware of their HBV status. Scaling-up of HBV screening programs in SSA are essential to increase diagnosis, linkage to care, and access to treatment, and will ultimately reduce HBV disease burden to achieve WHO hepatitis elimination targets. Such scale up will rely on inexpensive rapid point-of-care (POC) tests, especially in remote areas where gold standard serological assays are not routinely available. This review discusses the diagnostic performance and clinical utility of the Determine™ (Abbott, USA) hepatitis B surface Antigen (HBsAg) POC test for improving HBV screening in SSA, in light with others available HBsAg rapid tests. The Determine™ HBsAg POC test has demonstrated relatively good diagnostic accuracy at the low cost, in the African field and laboratory and should be used for large scale mass screening of HBV infection in Africa. [ABSTRACT FROM AUTHOR]

Background: Strongyloidiasis, a nematode infection which is mainly caused by Strongyloides stercoralis in humans, can lead to a fatal syndrome in immunocompromised individuals. Its diagnosis is challenging due to the absence of a diagnostic gold standard. The infection is highly prevalent in migrants from endemic countries in tropical and subtropical areas, and a rapid diagnostic test would be helpful for screening purposes. The aim of this study was to estimate the accuracy of a novel immunochromatographic test (ICT) for the diagnosis of S. stercoralis infection. Methods: A single-centre diagnostic accuracy study was undertaken using well-characterized frozen sera available from the biobank of a referral hospital for parasitic diseases in Italy. The included sera were from migrants from sub-Saharan Africa, and matching results were available for agar plate culture and/or polymerase chain reaction for S. stercoralis; moreover, the results of both a commercial enzyme-linked immunosorbent assay test and an in-house immunofluorescence test for strongyloidiasis were made available. Laboratory staff who read the ICT results were blinded as regards the results of the other tests. Two readers independently read the ICT, and a third one was involved when results were discrepant. The accuracy of the ICT was assessed both against the results of the panel of faecal tests and by latent class analysis (LCA). Results: Agreement between the readers was excellent [Cohen's κ = 92.7%, 95% confidence interval (CI) 88.3–97.1%]. When assessed against the results of the faecal tests, the sensitivity and specificity of the ICT were 82.4% (95% CI 75.7–89.0%) and 73.8% (95% CI 66.8–80.9%), respectively. According to the LCA, the sensitivity and specificity were 86.3% (95% CI 80.1–92.5%) and 73.9% (95% CI 67.0–80.8%), respectively. Conclusions: The results of the ICT demonstrated ease of interpretation. The accuracy proved good, though the sensitivity might be further improved for screening purposes. [ABSTRACT FROM AUTHOR]

Palutop®+4 Optima is the newest rapid diagnostic test (RDT) to identify malaria with 4-line tests by detecting three malaria proteins, which are HRP-2, Pv-LDH and pLDH. Recently, microscopy provides the key standard among all the available malaria tests. However, it has many drawbacks while RDT with 4-line tests is still rare. This investigation would like to look for the diagnostic value from the Palutop®+4 Optima in comparison with microscopy and RT PCR as a gold standard and to utilise it in determining the cut-off parasitemia index. The samples, 105 whole blood samples were generated from the Merauke General Hospital, in Papua during November 2018 - June 2019 having fulfilled both inclusion and exclusion criteria. The examination of the samples was performed by thick and thin dropping which then analysed by employing the test kits, which were RT PCR and Palutop®+4 Optima. Compared to microscopy, Palutop®+4 Optima displayed Sn 100%, Sp 98.04%, PPV 98.18%, NPV 100%, LR+=51 and LR-=0, with the diagnostic accuracy at 99.05%. Meanwhile, in comparison with RT PCR, it presented a Sn 75.34%, Sp 100%, PPV 100%, NPV 64%, LR+= - and LR-=0.25 with diagnostic accuracy at 82.86%. The cut-off of parasitemia index in Palutop® + 4 Optima based on the ROC curve could not be determined. A very high sensitivy was exhibited by Palutop®+4 Optima's diagnostic value along with a high specificity in indicating the antigens of malaria, P. vivax, P. falciparum mixed Plasmodium infection. [ABSTRACT FROM AUTHOR]

Carbapenem-resistant Acinetobacter baumannii group organisms (CRAB) are challenging because the choice between targeted, new antibiotic drug options and hygiene measures should be guided by a timely identification of resistance mechanisms. In CRAB, acquired class-D carbapenemases (CHDLs) are active against meropenem and imipenem. If PCR methods are not the first choice, phenotypic methods have to be implemented. While promising, the carbapenemase inactivation method (CIM) using meropenem-hydrolysis is, however, hampered by poor performance or overly long time-to-result. We developed a rapid CIM (rCIM-A) with good performance using ertapenem, imipenem, and meropenem disks, 2-h permeabilization and incubation with the test strain in trypticase soy broth, and a read-out of residual carbapenem activity after 6 h, and optionally after 16–18 h. Using clinical isolates and type-strains of Acinetobacter (n = 67) not harboring carbapenemases (n = 28) or harboring acquired carbapenemases (n = 39), the sensitivity of detection was 97.4% with the imipenem disk after 6 h at a specificity of 92.9%. If the inhibition zone around the ertapenem disk at 6 h was 6 or ≤26 mm at 16–18 h, or ≤25.5 mm for meropenem, the specificity was 100%. Because of the high negative predictive value, the rCIM-A seems particularly appropriate in areas of lower CRAB-frequency. [ABSTRACT FROM AUTHOR]

Background: Progress towards malaria elimination has stagnated, partly because infections persisting at low parasite densities comprise a large reservoir contributing to ongoing malaria transmission and are difficult to detect. This study compared the performance of an ultrasensitive rapid diagnostic test (uRDT) designed to detect low density infections to a conventional RDT (cRDT), expert microscopy using Giemsa-stained thick blood smears (TBS), and quantitative polymerase chain reaction (qPCR) during a controlled human malaria infection (CHMI) study conducted in malaria exposed adults (NCT03590340). Methods: Blood samples were collected from healthy Equatoguineans aged 18–35 years beginning on day 8 after CHMI with 3.2 × 103 cryopreserved, infectious Plasmodium falciparum sporozoites (PfSPZ Challenge, strain NF54) administered by direct venous inoculation. qPCR (18s ribosomal DNA), uRDT (Alere™ Malaria Ag P.f.), cRDT [Carestart Malaria Pf/PAN (PfHRP2/pLDH)], and TBS were performed daily until the volunteer became TBS positive and treatment was administered. qPCR was the reference for the presence of Plasmodium falciparum parasites. Results: 279 samples were collected from 24 participants; 123 were positive by qPCR. TBS detected 24/123 (19.5% sensitivity [95% CI 13.1–27.8%]), uRDT 21/123 (17.1% sensitivity [95% CI 11.1–25.1%]), cRDT 10/123 (8.1% sensitivity [95% CI 4.2–14.8%]); all were 100% specific and did not detect any positive samples not detected by qPCR. TBS and uRDT were more sensitive than cRDT (TBS vs. cRDT p = 0.015; uRDT vs. cRDT p = 0.053), detecting parasitaemias as low as 3.7 parasites/µL (p/µL) (TBS and uRDT) compared to 5.6 p/µL (cRDT) based on TBS density measurements. TBS, uRDT and cRDT did not detect any of the 70/123 samples positive by qPCR below 5.86 p/µL, the qPCR density corresponding to 3.7 p/µL by TBS. The median prepatent periods in days (ranges) were 14.5 (10–20), 18.0 (15–28), 18.0 (15–20) and 18.0 (16–24) for qPCR, TBS, uRDT and cRDT, respectively; qPCR detected parasitaemia significantly earlier (3.5 days) than the other tests. Conclusions: TBS and uRDT had similar sensitivities, both were more sensitive than cRDT, and neither matched qPCR for detecting low density parasitaemia. uRDT could be considered an alternative to TBS in selected applications, such as CHMI or field diagnosis, where qualitative, dichotomous results for malaria infection might be sufficient. [ABSTRACT FROM AUTHOR]

Background: Ayeyarwady Region in Myanmar has made significant progress towards malaria elimination, with cases decreasing from 12,312 in 2015 to 122 in 2019. As transmission declines, malaria becomes increasingly focalized both in geographic hotspots and among population groups sharing certain risk factors. Developing a thorough profile of high-risk activities associated with malaria infections is critical to ensure intervention approaches are evidence-based. Methods: A test-negative study was conducted from September 2017 to May 2018 in Ngaputaw, Pathein and Thabaung townships in Ayeyarwady Region. Patients that presented to selected public facilities or community health volunteers with fever answered survey questions on demographic and behavioural risk factors, including exposure to malaria interventions, and were assigned to case and control groups based on the result of a malaria rapid diagnostic test. A random-effects logistic regression model adjusted for clustering at the facility level, as well as any variables along the causal pathway described by a directed acyclic graph, was used to determine odds ratios and association with malaria infections. Results: A total of 119 cases and 1744 controls were recruited from 41 public facilities, with a mean age of 31.3 and 63.7% male. Higher risk groups were identified as males (aOR 1.8, 95% CI 1.2–2.9) and those with a worksite located within the forest (aOR 2.8, 95% CI 1.4–5.3), specifically working in the logging (aOR 2.7, 95% CI 1.5–4.6) and rubber plantation (aOR 3.0, 95% CI 1.4–6.8) industries. Additionally, links between forest travel and malaria were observed, with risk factors identified to be sleeping in the forest within the past month (aOR 2.6, 95% CI 1.1–6.3), and extended forest travel with durations from 3 to 14 days (aOR 8.6, 95% CI 3.5–21.4) or longer periods (aOR 8.4, 95% CI 3.2–21.6). Conclusion: Malaria transmission is highly focalized in Ayeyarwady, and results illustrate the need to target interventions to the most at-risk populations of working males and forest goers. It will become increasingly necessary to ensure full intervention coverage of at-risk populations active in forested areas as Myanmar moves closer to malaria elimination goals. [ABSTRACT FROM AUTHOR]

Background: Community case management of malaria (CCMm) is an equity-focused strategy that complements and extends the reach of health services by providing timely and effective management of malaria to populations with limited access to facility-based healthcare. In Kenya, CCMm involves the use of malaria rapid diagnostic tests (RDT) and treatment of confirmed uncomplicated malaria cases with artemether lumefantrine (AL) by community health volunteers (CHVs). The test positivity rate (TPR) from CCMm reports collected by the Ministry of Health in 2018 was two-fold compared to facility-based reports for the same period. This necessitated the need to evaluate the performance of CHVs in conducting malaria RDTs. Methods: The study was conducted in four counties within the malaria-endemic lake zone in Kenya with a malaria prevalence in 2018 of 27%; the national prevalence of malaria was 8%. Multi-stage cluster sampling and random selection were used. Results from 200 malaria RDTs performed by CHVs were compared with test results obtained by experienced medical laboratory technicians (MLT) performing the same test under the same conditions. Blood slides prepared by the MLTs were examined microscopically as a back-up check of the results. A Kappa score was calculated to assess level of agreement. Sensitivity, specificity, and positive and negative predictive values were calculated to determine diagnostic accuracy. Results: The median age of CHVs was 46 (IQR: 38, 52) with a range (26–73) years. Females were 72% of the CHVs. Test positivity rates were 42% and 41% for MLTs and CHVs respectively. The kappa score was 0.89, indicating an almost perfect agreement in RDT results between CHVs and MLTs. The overall sensitivity and specificity between the CHVs and MLTs were 95.0% (95% CI 87.7, 98.6) and 94.0% (95% CI 88.0, 97.5), respectively. Conclusion: Engaging CHVs to diagnose malaria cases under the CCMm strategy yielded results which compared well with the results of qualified experienced laboratory personnel. CHVs can reliably continue to offer malaria diagnosis using RDTs in the community setting. [ABSTRACT FROM AUTHOR]

Background: Cryptococcal meningitis (CM) and tuberculosis (TB) remain leading causes of hospitalization and death amongst people living with HIV, particularly those with advanced HIV disease. In hospitalized patients, prompt diagnosis of these diseases may improve patient outcomes. The advanced HIV rapid diagnostic tests such as determine TB urine lipoarabinomannan lateral flow assay (urine LAM), urine X-pert MTB/RIF assay (urine X-pert), and serum/blood cryptococcal antigen test (serum CrAg) are recommended but frequently not available in many resource-limited settings. We describe our experience providing these tests in a routine hospital setting.Method: From 1 August 2016 to 31 January 2017, a prospective cohort study to diagnose TB and Cryptococcal meningitis using point of care tests was conducted in the medical wards at Kamuzu Central Hospital, in Lilongwe, Malawi. The tests offered were PIMA CD4 cell count, serum CrAg, urine LAM, and urine X-pert. The testing was integrated into an existing HIV/TB treatment room on the wards and performed close to admission time. Patients were followed until discharge or death in the ward.Results: We included 438 HIV-positive patients; 76% had a previously known HIV diagnosis (87% already on ART). We measured CD4 count in 365/438 (83%), serum CrAg in 301/438 (69%), urine LAM in 363/438 (83%), and urine X-pert in 292/438 (67%). The median CD4 count was 144 cells/ml (IQR 46-307). Serum CrAg positivity rate was 23 /301 (8%) and CM was confirmed by CSF Crag in 13/23 (56%). The majority of CM patients 9/13 (69%) started antifungal therapy within two days of diagnosis. Urine LAM and urine X-pert positivity rates were 81/363(22%) and (14/292 (5%) respectively. The positivity rate of urine LAM was higher in patients with low CD4 cell counts (< 100 cells/ml) and low BMI (< 18.5). Most patients with positive urine LAM started TB treatment on the same day. Despite the early diagnosis and treatment of TB and CM, the inpatient mortality was high; 30% and 25% respectively.Conclusion: Although advanced HIV rapid diagnostic tests are recommended, one key challenge in implementation is the limited trained personnel administering the tests. Despite the effective use of the point of care tests in the clinical care of hospitalized TB and CM patients, mortality among these patients remained unacceptably high. Henceforth we need to train other cadres apart from nurses, clinicians, and laboratory technicians to conduct the tests. There is an urgent need to identify and modify other risks of death from TB and CM.Trial Registration: Malawi National Health Science Research committee: Protocol # 1144. Registered 2 July 2014 and University Of North Carolina IRB #: UNCPM 21412, approved 13th October 2014. [ABSTRACT FROM AUTHOR]