Use Of Rapid Diagnostic Tests Research Articles

Plasmodium falciparum histidine-rich protein 2 and 3 gene deletion in the Mount Cameroon region

ObjectivePlasmodium falciparum produces histidine-rich protein 2/3 (Pfhrp2/3) genes that accumulate to high levels in the bloodstream and serve as a diagnostic and prognostic marker for falciparum malaria. Pfhrp2/3 gene deletions may lead to false-negative rapid diagnostic test (RDT) results. We aimed to determine the prevalence of pfhrp2/3 gene deletions in P. falciparum isolates and the implications for RDT use in the Mount Cameroon region. MethodsA cross-sectional hospital-based study with malaria diagnosis performed using microscopy, RDT and nested polymerase chain reaction (nPCR). In total, 324 P. falciparum microscopy positive individuals were enrolled and their samples confirmed positive for P. falciparum using 18SrRNA PCR. Samples that gave false-negative RDT results were analyzed to detect pfhrp2/3 exon 2 deletions. ResultsOf 324 positive microscopic and nPCR samples, 16 gave RDT false-negative results. Among the 324 P. falciparum positive isolates, exon 2 deletions were observed in 2.2% (7 of 324); 3 were negative for pfhrp2 gene, 2 for pfhrp3, and 2 for both pfhrp2 and pfhrp3 (double deletions). ConclusionP. falciparum isolates with pfhrp2/3 gene deletion were present in the parasite populations and may contribute to the RDT false-negative results in the Mount Cameroon region.

Prescreening with a Rapid Diagnostic Test Followed by a Confirmatory Qualitative Nucleic Acid Test Can Simplify Hepatitis C Diagnosis.

Asymptomatic hepatitis C virus (HCV) infection without treatment is associated with chronic liver diseases including hepatocellular carcinoma. A major obstacle to hepatitis C diagnosis leading to antiviral treatment in some developing countries is the complicated HCV testing required before treatment. To simplify an HCV test-to-treat strategy, which could lead to timely diagnosis and treatment at the point-of-care, we evaluated the performance of four anti-HCV rapid diagnostic tests (RDTs) (Abon, Blue Cross, Healgen, and SD Bioline). They yielded comparable sensitivity (80-83%), specificity (99-100%), and accuracy (90-91.5%). When we field-tested Abon in 4,769 residents of an HCV-endemic province in Thailand, 306 seropositive individuals (6.4%) were identified. In comparison, laboratory test using an automated commercial chemiluminescent microparticle immunoassay (Abbott ARCHITECT) identified slightly more seropositives (327% or 6.9%). Field implementation suggests that Abon was sensitive (88.7%), specific (99.6%), and accurate (98.9%). Furthermore, 82% (250/306) of Abon-positive samples had detectable HCV RNA as determined by nucleic acid test (Roche cobas). The same 250 samples out of 327 reactive in Abbott immunoassay also had detectable HCV RNA (mean RNA level: log 6.28 IU/mL, range: log 3.06- 7.78 IU/mL). The use of RDT followed by qualitative nucleic acid test can cost-effectively identify the majority of HCV seropositive individuals with active infection, which will obviate the need for expensive viral load quantification tests when simplifying HCV diagnosis for the test-to-treat program at the point-of-care.

Diagnostic Efficacy of COVID-19 Rapid Antigen Detection Card in Diagnosis of SARS-CoV-2.

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.

A portable brightfield and fluorescence microscope toward automated malarial parasitemia quantification in thin blood smears.

Malaria is often most endemic in remote regions where diagnostic microscopy services are unavailable. In such regions, the use of rapid diagnostic tests fails to quantify parasitemia measurements which reflect the concentration of Plasmodium parasites in the bloodstream. Thus, novel diagnostic and monitoring technologies capable of providing such information could improve the quality of treatment, monitoring, and eradication efforts. A low-cost, portable microscope for gathering quantitative parasitemia data from fluorescently stained thin blood smears is presented. The system employs bimodal imaging using components optimized for cost savings, system robustness, and optical performance. The microscope is novel for its use of monochromatic visible illumination paired with a long working distance singlet aspheric objective lens that can image both traditionally mounted and cartridge-based blood smears. Eight dilutions of red blood cells containing laboratory cultured wild-type P. falciparum were used to create thin smears which were stained with SYBR Green-1 fluorescent dye. Two subsequent images are captured for each field-of-view, with brightfield images providing cell counts and fluorescence images providing parasite localization data. Results indicate the successful resolution of sub-micron sized parasites, and parasitemia measurements from the prototype microscope display linear correlation with measurements from a benchtop microscope with a limit of detection of 0.18 parasites per 100 red blood cells.

The cost-effectiveness of using rapid diagnostic tests for the diagnosis of typhoid fever in patients with suspected typhoid fever: a systematic review

Introduction Despite the availability of several commercial rapid diagnostic tests (RDTs) developed to detect typhoid fever, the cost-effectiveness in resource-limited settings is unclear. This review aimed to explore the literature on typhoid economic evaluations in order to assess the cost-effectiveness of using typhoid RDTs in resource-limited settings. Areas covered A systematic review was conducted focusing on the identification of economic evaluations of typhoid RDTs to diagnose patients with suspected typhoid fever. Two studies were identified and included for narrative synthesis. Whilst highlighting a gap in the published literature, this review shows the use of typhoid RDTs to potentially be cost-effective in resource limited settings. Factors that appeared as significant in determining cost-effectiveness related to test characteristics (such as sensitivity, specificity and cost) and the prevalence of typhoid fever and should factor into any future evaluations. Expert opinion Concerted effort is needed in resource-limited settings with regards to medical device regulation to ensure that clinically effective and cost-effective typhoid RDTs are widely available and introduced into clinical practice. Typhoid modelling (with respect to typhoid testing and treatment strategies) represents an understudied area and further work is needed.

Detection of Neutralizing Antibodies against SARS-CoV-2 Post-Vaccination in Health Care Workers of a Large Tertiary Hospital in Spain by Using a Rapid Test LFIC and sVNT-ELISA.

The presence of neutralizing antibodies (NAbs) against SARS-CoV-2 represent a surrogate marker of immunologic protection in populations at high risk of infection such as healthcare workers caring for hospitalized patients with COVID-19. As recommended by CDC and the European CDC, the use of rapid diagnostic tests during population-based evaluations offers an opportunity to identify individuals with serologic evidence of natural infection or who have undergone vaccination. We carried out a cross-sectional study to assess the presence of neutralizing antibodies against SARS-CoV-2 among medical providers at an intensive care unit of a large referral hospital in Alicante, Spain. In addition, we tested for the presence of neutralizing antibodies compared to serum of uninfected individuals from a Biobank. We were also interested in evaluating the use of a rapid lateral flow immunochromatography (LFIC) test against a surrogate ELISA viral neutralization test (sVNT). This rapid test demonstrated a specificity of 1.000 95% CI (0.91–1.00) and the sensitivity of 0.987 95% CI (0.93–1.00). The negative predictive value was 95%. After six months, this rapid test demonstrated that those immunized with two doses of BioNTech/Pfizer vaccine, maintained optimal levels of neutralizing antibodies. We concluded that all Health Care Workers develop NAbs and the use of this rapid immunochromatographic test represents a potential tool to be used in population-based studies to detect serological antibody responses to vaccination. Vaccination policies could benefit from this tool to assess additional doses of vaccine or boosters among high-risk populations.

Qualitative evaluation of the new rapid point-of-care antigen Afias Covid-19/Flu Ag Combo assay

Background: An interim guidance document by the WHO (World Health Organization) suggests the use of rapid diagnostic tests based on antigen detection as an alternative to the real-time PCR test for the diagnosis of SARS-CoV2 infection, when the molecular RT-PCR test is not available, or the turnaround time is excessive, precluding its clinical and/or public health usefulness. Rapid antigenic tests are recommended when a minimum of 80% sensitivity and 97% specificity are ensured. Methods: Here we employ a new assay for screening applications based on lateral-flow immunofluorescence assay, with microfluidic technology (Boditech AFIAS COVID-19/Flu Ag Combo) on a point-of-care analyzer AFIAS-6 (BoditechMed. Inc.) and compare it with a reference molecular method and an alternative screening immunochromatographic method (Boditech AFIAS COVID-19 Ag). Our study was carried out on stored UTM (at -20°C) samples of patients admitted to Di Venere Hospital of Bari that were already tested with molecular methods. Results: The new AFIAS COVID-19 Flu/Ag Combo test reached a clinical sensitivity of 92% on positive samples with Ct< 30, and a clinical specificity of 97.9% on negative samples. Sensitivity is higher than the reference immunochromatographic test AFIAS COVID-19/Ag (92.0% vs 88.0%) while specificity remains unchanged (97.9% vs 98.0%). In addition the new AFIAS Combo test confirm the same negative predictive value (NPV, 95.9%) of the rapid reference test (AFIAS COVID 19-Ag) and an agreement with the molecular test of 95.9% (Cohen's k = 0.908). Conclusions: Considering its qualitative improvement, rapidity and ease of use we suggests AFIAS Combo test as a valid alternative to the reference lateral flow test (AFIAS COVID-19 Ag) and an adequate screening test. Keywords: SARS-CoV2; COVID-19; POCT; diagnosis; screening; immunoassay; rapid antigen test

Evaluation of an improved Giemsa staining technique for blood borne parasite in thick and thin blood film from dogs

Many a times the use of rapid diagnostic tests for blood borne parasites like trypanosomiasis and Babesiosis is increasingly being used, but the gold standard for its detection is still the use of microscopy both as reference and confirmatory diagnosis. To determine the effectiveness of the adjusted stock giemsa staining technique over the conventional methods. Venous Blood samples were collected from 10 dogs in EDTA and then used for the simultaneous preparation of two thin and thick smear slides, one stained according to Giemsa 1:20 dilution for 30 mins while the other was stained using the Stock Solution for 30seconds the diluted with buffered saline for 20seconds and rinsed. Fixation of the thin smear was done in a covered staining jar containing anhydrous methanol for 1 to 2 min, after which the slides were air-dried. From the result obtained from 10 dogs blood samples gotten from the veterinary clinic, the adjusted giemsa staining technique showed a positive differentiation when compared to the 1:20 dilution, a total of 7 blood samples tested positive for blood borne parasites, Trypanosoma evansi, Babesiosis cani and Heart worm. The highest percentage occurrence was T.evansi (40%), Babesiosis cani(20%) and Heart worm (10%).The adjusted Giemsa staining technique serves as a fast, easy and less complex alternative to the 1:20 dilution, where the solution has to be diluted from the stock solution and then stained, although the only disadvantage to this technique would be easy contamination of the stock solution, but the advantages here is that it saves time, quicker result output and better differentiation microscopically.

Malaria Prevalence and Treatment Seeking Behaviour of Campus Students in Mkpat Enin, Akwa Ibom State, Nigeria

Background: Malaria is still thriving despite efforts to eradicate the disease. This study aimed to determine the prevalence of malaria and treatment-seeking behaviour among university students in Ikot Akpaden campus of Akwa Ibom State University Methods: A cross-sectional study on 700 undergraduate students randomly selected was carried out between July to December 2017 in Akwa Ibom State University. Structured questionnaires were administered to collect data. Microscopy and Rapid Diagnostic Tests (RDT) were done to determine parasitaemia for students who voluntarily consented to be tested. Chi-square test at P< 0.05 was used to evaluate the prevalence of malaria and the differences in the student’s attitude on malaria treatment and prevention practices. Results: Of the 500 students who filled the questionnaire, 100 students consented to undergo the test, 56 (56%) were males, while 44 (44%) were females. Only15 students (17.86%) were positive for both microscopy and RDT. Malaria prevalence by microscopy (84%) was significantly higher than RDT (27%). Fever and head-ache were the most common symptoms recorded. RDT had a sensitivity of 17.86%, a specificity of 25%, a positive predictive value of 55.56%, and a negative predictive value of 5.48%. Conclusion: This study revealed a higher prevalence of malaria by microscopy than RDT among the students, indicating that the use of RDTs is limited. RDTS may have more usefulness in remote areas, but microscopy remains the reference technique. Overall, 96.2% knew about malaria while 85.3% knew mosquito bites cause malaria. The majority, 69.2%, of participants go for malaria test as the first action when malaria is suspected, 83% use antimalarial combination therapy medication, and 62.6% sought treatment of malaria immediately.

Determinants of malaria testing at health facilities: the case of Uganda

BackgroundThe World Health Organization (WHO) recommends prompt malaria diagnosis with either microscopy or malaria rapid diagnostic tests (RDTs) and treatment with an effective anti-malarial, as key interventions to control malaria. However, in sub-Saharan Africa, malaria diagnosis is still often influenced by clinical symptoms, with patients and care providers often interpreting all fevers as malaria. The Ministry of Health in Uganda defines suspected malaria cases as those with a fever. A target of conducting testing for at least 75% of those suspected to have malaria was established by the National Malaria Reduction Strategic Plan 2014–2020.MethodsThis study investigated factors that affect malaria testing at health facilities in Uganda using data collected in March/April 2017 in a cross-sectional survey of health facilities from the 52 districts that are supported by the US President’s Malaria Initiative (PMI). The study assessed health facility capacity to provide quality malaria care and treatment. Data were collected from all 1085 public and private health facilities in the 52 districts. Factors assessed included supportive supervision, availability of malaria management guidelines, laboratory infrastructure, and training health workers in the use of malaria rapid diagnostic test (RDT). Survey data were matched with routinely collected health facility malaria data obtained from the district health information system Version-2 (DHIS2). Associations between testing at least 75% of suspect malaria cases with several factors were examined using multivariate logistic regression.ResultsKey malaria commodities were widely available; 92% and 85% of the health facilities reported availability of RDTs and artemether–lumefantrine, respectively. Overall, 933 (86%) of the facilities tested over 75% of patients suspected to have malaria. Predictors of meeting the testing target were: supervision in the last 6 months (OR: 1.72, 95% CI 1.04–2.85) and a health facility having at least one health worker trained in the use of RDTs (OR: 1.62, 95% CI 1.04–2.55).ConclusionThe study findings underscore the need for malaria control programmes to provide regular supportive supervision to health facilities and train health workers in the use of RDTs.

Sensitivity and specificity of a rapid diagnostic test for chronic Chagas disease at a referral center in Brazil - can it be included as a standard serological diagnostic test in the clinical practice of a referral center?

Introduction: Chagas disease (CD) is a neglected tropical disease. In the chronic phase of CD, the diagnosis is essentially serologic. Conventional reactions are currently in use. More recently, the use of rapid diagnostic testing (RDT) is indicated when conventional techniques are not available. Objective: To evaluate the sensitivity and specificity of RDTs for chronic CD diagnosis. Methodology: Individuals under suspicion of CD were evaluated using ELISA, Chemiluminescence (ChLIA) and RDT tests. Results: The RDT showed 95.1% sensitivity and 96.7% specificity, respectively. Conclusion: The findings of the present study showed that RDT used in the diagnosis of CD at a referral center in Brazil were not able to detect all CD cases when compared to Elisa and ChLIA.

Provider views on rapid diagnostic tests and antibiotic prescribing for respiratory tract infections: A mixed methods study.

BackgroundRespiratory tract infections (RTIs) are often inappropriately treated with antibiotics. Rapid diagnostic tests (RDTs) have been developed with the aim of improving antibiotic prescribing but uptake remains low. The aim of this study was to examine provider knowledge, attitudes and behaviors regarding RDT use and their relationship to antibiotic prescribing decisions across multiple clinical departments in an urban safety-net hospital.MethodsWe conducted a mixed methods sequential explanatory study. Providers with prescribing authority (attending physicians, nurse practitioners and physician assistants) who had at least 20 RTI encounters from January 1, 2016 to December 31, 2018. Eighty-five providers completed surveys and 16 participated in interviews. We conducted electronic surveys via RedCap from April to July 2019, followed by semi-structured individual interviews from October to December 2019, to ascertain knowledge, attitudes and behaviors related to RDT use and antibiotic prescribing.ResultsSurvey findings indicated that providers felt knowledgeable about antibiotic prescribing guidelines. They reported high familiarity with the rapid streptococcus and rapid influenza tests. Familiarity with comprehensive respiratory panel PCR (RPP-respiratory panel PCR) and procalcitonin differed by clinical department. Qualitative interviews identified four main themes: providers trust their clinical judgment more than rapid test results; patient-provider relationships play an important role in prescribing decisions; there is patient demand for antibiotics and providers employ different strategies to address the demand and providers do not believe RDTs are implemented with sufficient education or evidence for clinical practice.ConclusionPrescribers are knowledgeable about prescribing guidelines but often rely on clinical judgement to make final decisions. The utility of RDTs is specific to the type of RDT and the clinical department. Given the low familiarity and clinical utility of RPP and procalcitonin, providers may require additional education and these tests may need to be implemented differently based on clinical department.

Assessment of Rapid Diagnostic Tests for Typhoid Diagnosis and Assessment of Febrile Illness Outbreaks in Fiji.

ABSTRACT.Typhoid is an endemic in Fiji with increases observed since the early 2000s and frequent outbreaks reported. We assessed the diagnostic accuracy of currently available typhoid rapid diagnostic tests (RDTs) (TUBEX, Typhidot Rapid, and Test-It assay) to establish their performance against blood culture in Fiji and to examine their suitability for rapid typhoid outbreak identification. The performance of RDTs was assessed in the public health reference laboratory in Suva, Fiji, according to the manufacturers’ instructions. A simulation was used to examine the potential use of RDTs for attribution of a febrile illness outbreak to typhoid. For the diagnostic evaluation, 179 patients were included; 49 had blood culture–confirmed typhoid, 76 had fever as a result of non-typhoid etiologies, and 54 were age-matched community controls. The median (interquartile range) age was 29 (20–46) years. Of the participants, 92 (51.4%) were male and 131 (73.2%) were indigenous Fijians. The sensitivities of the tests were 77.6% for TUBEX, 75.5% for Typhidot Rapid, and 57.1% for Test-It assay. The Test-It assay had the highest specificity of 93.4%, followed by Typhidot Rapid 85.5% and TUBEX 60.5%. Typhidot Rapid had the best performance in the simulation for attribution of a febrile illness outbreak to typhoid. Typhoid RDTs performed suboptimally for individual patient diagnosis due to low sensitivity and variable specificity. We demonstrate that RDTs could be useful in the field for rapid attribution of febrile illness outbreaks to typhoid. Typhidot Rapid had the best combination of sensitivity, specificity, positive and negative predictive values, cost, and ease of use for this purpose.

Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions among patients in the DRC enrolled from 2017 to 2018

Rapid diagnostic tests (RDTs) detecting histidine-rich protein 2 (HRP2) and HRP3 are widely used throughout sub-Saharan Africa (SSA) to diagnose Plasmodium falciparum malaria. However, multiple SSA countries have reported pfhrp2 and pfhrp3 (pfhrp2/3) gene deletions. Blood samples (n = 1109) collected from patients with P. falciparum infection from six health facilities throughout the Democratic Republic of the Congo (DRC) from March 2017 to January 2018 were evaluated for pfhrp2/3 deletions. Samples were assayed for HRP2, pan-Plasmodium LDH (pLDH) and aldolase (pAldolase) antigens by bead-based multiplex antigen assay. Samples with low HRP2 concentration compared to pLDH and pAldolase antigens were selected for further pfhrp2/3 genotyping PCRs. The majority of blood samples (93.3%, 1035/1109) had high concentrations of the HRP2 antigen. Single deletions of pfhrp2 were identified in 0.27% (3/1109) of screened samples, with one sample from each of the Kapolowe, Mikalayi, and Rutshuru study sites. A pfhrp3 single deletion (0.09%, 1/1109) was found in the Kapolowe site. Dual pfhrp2 and pfhrp3 deletions were not observed. Due to, the low numbers of pfhrp2 deletions and the sporadic locations of these deletions, the use of HRP2-based RDTs appears to still be appropriate for these locations in DRC.

Ten Years of Universal Testing: How the Rapid Diagnostic Test Became a Game Changer for Malaria Case Management and Improved Disease Reporting.

ABSTRACT.In 2010, the World Health Organization changed its guidance on malaria case management, recommending parasitological confirmation of all suspected cases before treatment with an antimalarial. This recommendation was in large part as a result of the availability of quality assured malaria rapid diagnostic tests (RDTs) that made it possible for malaria diagnosis to be performed by laboratory staff in all health facilities irrespective of the facility’s place in the tiered health system. Community health workers and other non-laboratory health workers who traditionally did not perform malaria testing due to the technical and logistic demands of smear microscopy were now able to test for malaria. The use of RDTs has led to substantial increases in testing rates, improved quality of case management, as well as more accurate reporting of malaria cases. Although current RDTs have limitations, they remain one of the most important tools in contemporary malaria control. Further improvements to existing products, such as increased sensitivity for non-falciparum tests, diversification of Plasmodium falciparum antigen targets, along with strengthened health system support for current RDTs will further enhance their utility in malaria control and prevention.

Validity of dipstick urinalysis for predicting urinary tract infection in febrile children aged 2-12 years in a tertiary care centre, South Kerala

Background: Urinary tract infection (UTI) warrants an early accurate diagnosis in children. Use of rapid diagnostic tests like urine dipstick and microscopy was found to be economical and effective. There is lack of sufficient studies on rapid diagnostic tests in developing countries like India. This study looked at the single as well as combination of parameters that provided maximum sensitivity and specificity, providing a better diagnostic criterion in detecting UTI. The objective was to assess the diagnostic validity of urinary dipstick in the diagnosis of UTI in comparison with urinary culture.Methods: This cross-sectional diagnostic evaluation study was conducted in a tertiary care centre in Southern Kerala. Total of 75 children between the age group of 2 years to 12 years who attended the paediatric OPD with the clinical features of UTI were included in this study. Two urine samples were obtained in sterile containers. The first urine sample was assessed with dipstick and the second sample was sent for culture to confirm the UTI. The results obtained were analysed using SPSS software.Results: Using culture as gold standard, the results for nitrate alone had lower sensitivity at 69.69%, specificity at 90.4%. The results for LE (LE) alone had higher sensitivity at 81.8%, specificity at 80.95% and the results for combined urine dipstick had higher sensitivity at 84.8% than individual nitrite and LE. The combined positive predictive value (PPV) was lower than individual nitrite and LE 75.6%. The combined negative predictive value (NPV) was higher than individual LE and nitrite at 86.8%.Conclusions: Dipstick urinalysis alone may not be a completely adequate screening tool for UTI. Since urine dipstick test has high sensitivity it can be used as a bedside tool in detecting UTI in children.

Evaluation of a Rapid Diagnostic Test Currently Being Used in the Management of Malaria in Patients of the Hia/Chu-Parakou and the Boko Zone Hospital in Northern Benin

Parasitological diagnosis is a fundamental element in the adequate management of the disease. In the last decade, there has been a resurgence of interest in the development of malaria Rapid Diagnostic Test (RDT) kits. This is the case with SD Bioline Malaria Ag Pf, which searches for HRP2 antigen by immunochromatography. The objective of this study is to compare the results of RDT SD Bioline Malaria Ag Pf in use with the results of Thick Gout (TG) in the biological diagnosis of malaria. This was a cross-sectional, descriptive and evaluative study carried out at the Hôpital d’Instruction des Armées-Center Hospitalier et Universitaire de Parakou and at the Boko zone hospital from April 20 to July 30, 2015. Patient identification, we used the non-probabilistic method and the convenience choice technique. The study involved 503 patients. The results of this study showed a good performance of the RDT SD Bioline Malaria Ag Pf. Among the 503 patients, 199 or 39.6% were positive for the RDT against 180 or 35.8% positive for the Thick Gout (TG). Sensitivity, specificity, positive and negative predictive values of the test compared to the thick film were respectively (91.7%, 89.5%, 82.9, 95) and the Kappa coefficient of 0.88 testifies a good match. False positive cases are noted in patients on treatment and even after recovery due to the persistence of the HRP2 antigen in the blood. However, it constitutes an interesting alternative to the management of malaria. At the end of this study, we suggest continuing the use of RDTs in health centers where microscopy is absent and/or reinforcing microscopy, and to strengthen staff training in the management of malaria cases.

Point-of-care tests detecting HIV nucleic acids for diagnosis of HIV-1 or HIV-2 infection in infants and children aged 18 months or less.

BackgroundThe standard method of diagnosing HIV in infants and children less than 18 months is with a nucleic acid amplification test reverse transcriptase polymerase chain reaction test (NAT RT‐PCR) detecting viral ribonucleic acid (RNA). Laboratory testing using the RT‐PCR platform for HIV infection is limited by poor access, logistical support, and delays in relaying test results and initiating therapy in low‐resource settings. The use of rapid diagnostic tests at or near the point‐of‐care (POC) can increase access to early diagnosis of HIV infection in infants and children less than 18 months of age and timely initiation of antiretroviral therapy (ART).ObjectivesTo summarize the diagnostic accuracy of point‐of‐care nucleic acid‐based testing (POC NAT) to detect HIV‐1/HIV‐2 infection in infants and children aged 18 months or less exposed to HIV infection.Search methodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL) (until 2 February 2021), MEDLINE and Embase (until 1 February 2021), and LILACS and Web of Science (until 2 February 2021) with no language or publication status restriction. We also searched conference websites and clinical trial registries, tracked reference lists of included studies and relevant systematic reviews, and consulted experts for potentially eligible studies.Selection criteriaWe defined POC tests as rapid diagnostic tests conducted at or near the patient site. We included any primary study that compared the results of a POC NAT to a reference standard of laboratory NAT RT‐PCR or total nucleic acid testing to detect the presence or absence of HIV infection denoted by HIV viral nucleic acids in infants and children aged 18 months or less who were exposed to HIV‐1/HIV‐2 infection. We included cross‐sectional, prospective, and retrospective study designs and those that provided sufficient data to create the 2 × 2 table to calculate sensitivity and specificity. We excluded diagnostic case control studies with healthy controls.Data collection and analysisWe extracted information on study characteristics using a pretested standardized data extraction form. We used the QUADAS‐2 (Quality Assessment of Diagnostic Accuracy Studies) tool to assess the risk of bias and applicability concerns of the included studies. Two review authors independently selected and assessed the included studies, resolving any disagreements by consensus. The unit of analysis was the participant. We first conducted preliminary exploratory analyses by plotting estimates of sensitivity and specificity from each study on forest plots and in receiver operating characteristic (ROC) space. For the overall meta‐analyses, we pooled estimates of sensitivity and specificity using the bivariate meta‐analysis model at a common threshold (presence or absence of infection).Main resultsWe identified a total of 12 studies (15 evaluations, 15,120 participants). All studies were conducted in sub‐Saharan Africa. The ages of included infants and children in the evaluations were as follows: at birth (n = 6), ≤ 12 months (n = 3), ≤ 18 months (n = 5), and ≤ 24 months (n = 1). Ten evaluations were field evaluations of the POC NAT test at the point of care, and five were laboratory evaluations of the POC NAT tests.The POC NAT tests evaluated included Alere q HIV‐1/2 Detect qualitative test (recently renamed m‐PIMA q HIV‐1/2 Detect qualitative test) (n = 6), Xpert HIV‐1 qualitative test (n = 6), and SAMBA HIV‐1 qualitative test (n = 3).POC NAT pooled sensitivity and specificity (95% confidence interval (CI)) against laboratory reference standard tests were 98.6% (96.1 to 99.5) (15 evaluations, 1728 participants) and 99.9% (99.7 to 99.9) (15 evaluations, 13,392 participants) in infants and children ≤ 18 months.Risk of bias in the included studies was mostly low or unclear due to poor reporting. Five evaluations had some concerns for applicability for the index test, as they were POC tests evaluated in a laboratory setting, but there was no difference detected between settings in sensitivity (−1.3% (95% CI −4.1 to 1.5)); and specificity results were similar.Authors' conclusionsFor the diagnosis of HIV‐1/HIV‐2 infection, we found the sensitivity and specificity of POC NAT tests to be high in infants and children aged 18 months or less who were exposed to HIV infection.

No Implementation Without Representation: Real-Time Pharmacist Intervention Optimizes Rapid Diagnostic Tests for Bacteremia at a Small Community Hospital.

Background: Rapid diagnostic tests (RDTs) for bacteremia allow for early antimicrobial therapy modification based on organism and resistance gene identification. Studies suggest patient outcomes are optimized when infectious disease (ID)-trained antimicrobial stewardship personnel intervene on RDT results. However, data are limited regarding RDT implementation at small community hospitals, which often lack access to on-site ID clinicians. Methods: This study evaluated the impact of RDTs with and without real-time pharmacist intervention (RTPI) at a small community hospital with local pharmacist training and asynchronous support from a remote ID Telehealth pharmacist. Time to targeted therapy (TTT) in patients with bacteremia was compared retrospectively across 3 different time periods: a control without RDT, RDT-only, and RDT with RTPI. Results: Median TTT was significantly faster in both the RDT with RTPI and RDT-only groups compared with the control group (2 vs 25 vs 51 hours respectively; P < .001). TTT was numerically faster for RDT with RTPI compared with RDT-only but did not reach statistical significance (P = .078). Median time to any de-escalation was significantly shorter for RDT with RTPI compared with both RDT-only (14 vs 33 hours; P = .012) and the control group (14 vs 45 hours; P < .001). Median length of stay was also significantly shorter in both RDT groups compared with the control group (4.0 vs 4.1 vs 5.5 hours; P = .013). Conclusion: This study supports RDT use for bacteremia in a small community hospital with ID Telehealth support, suggesting additional benefit with RTPI.

Evaluation of the combination of rapid diagnostic tests and microscopy for imported malaria surveillance in Anhui Province, China

Background: In the Anhui Province, China, efforts to interrupt the local malaria transmission were successful, with no endemic cases reported since 2014. Contrastingly, imported malaria cases are still being reported, indicating a disease reintroduction risk after years of elimination. A good surveillance system is key for avoiding the risk, detecting imported cases and possible cases associated with local transmission early. Therefore, rapid diagnostic tests (RDTs) were combined with microscopy to strengthen malaria surveillance in the province. Herein, we aimed to evaluate the efficacy of this surveillance strategy.Methods: We conducted a retrospective study using malaria surveillance data from January 2016 to June 2020. Epidemiological characteristics and diagnostic information were analysed using descriptive and comparative statistics. The diagnostic performance of the combined toolbox (Wondfo RDTs plus microscopy) was evaluated based on its sensitivity, specificity, positive and negative predictive values, and Cohen's kappa coefficient, using real-time polymerase chain reaction as the gold standard.Results: The combined toolbox displayed a higher overall sensitivity for malaria cases than that of microscopy alone (93.74% vs 89.37%; padj <0.05), which could detect 94.65%, 88.16%, 95.00%, and 100.00% of Plasmodium falciparum, P. ovale, P. vivax, and P. malariae infections, respectively. In clinical practice, Wondfo RDTs ability to detect P. falciparum infections was better than that of microscopy (97.55% vs 89.67%, padj < 0.05). In contrast, microscopy displayed a higher specificity than that of Wondfo RDTs (81.82% vs 63.28%, p adj <0.05). Moreover, the consistency between microscopy and the gold standard results was also better than that of RDTs (Kappa value:0.669 vs 0.596).Conclusions: The combination of microscopy and RDTs is an effective strategy for malaria surveillance because it possibly detected more P. falciparum infections due to the introduction of RDTs. In contrast, microscopy is complementary to some limitations related to the use of RDTs in field practice. Thus, monitoring malaria cases in non-endemic areas may require employing more than one diagnostic tool in surveillance strategies. Moreover, further understanding of the advantages and disadvantages of different detection methods is necessary for applying optimum combinations in field settings.