Rapid Diagnosis Test Research Articles

Rapid antigen detection test for diagnosis of post kala-azar dermal leishmaniasis: application of CL Detect™ rapid test for active case detection in the endemic area.

Post-kala-azar dermal leishmaniasis (PKDL) is a skin condition that occurs in a small percentage of people who have been cured of visceral leishmaniasis (VL), and contributes to transmission of VL. The rK39 rapid test cannot decisively diagnose PKDL due to presence of antileishmanial antibodies from past VL episodes. CL Detect™ Rapid Test, an in-vitro diagnostic test that detects Leishmania antigen peroxidoxin, was assessed for diagnosing PKDL. The CL Detect RDT had 73.3% sensitivity and 100% specificity in the study. The test can be used as a primary screening tool to monitor PKDL in endemic regions and identify active Leishmania infection.

A-301 Evaluation of Second-Generation Visby Medical Sexual Health Point-of-Care Test: Clinical Concordance, Analytical Error Rates, and Result Turnaround Time

Abstract Background Rapid testing for Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis may be useful for antibiotic stewardship initiatives. Our institution recently implemented the second-generation Visby Medical Sexual Health Test (Visby Gen2) for rapid diagnosis of STIs in our emergency department. Here we (1) compared result concordance of the (Visby Gen2) to the first-generation Visby Medical Sexual Health Click Test (Visby Gen1), (2) compared assay failure rates of the Visby Gen1 to Gen2 tests, and (3) compared result turnaround time (TAT) for clinically ordered rapid STI tests to central laboratory STI results. Methods Accuracy was assessed using residual clinical samples in Aptima buffer submitted for routine molecular STI testing (C. trachomatis, N. gonorrhoeae, and T. vaginalis) in the central laboratory on the Panther platform (Hologic). Aptima samples were diluted 1:33 in Visby collection buffer prior to testing on the Visby cartridge. Clinically reported results were used as reference results. Diluted samples with discordant results were re-tested on the reference method and the result from the dilution was used in calculations. Assay failure rates were calculated as the number of failed assays compared to the total assays performed. TAT for rapid and central lab testing was calculated as time of sample received in laboratory to time verified in laboratory information system. Results For Visby Gen1 we observed negative concordance of 100% (41/41) for C. trachomatis, 97.5% (39/40) for N. gonorrhoeae, and 97.1% (34/35) for T. vaginalis. Positive concordance was 91.7% (11/12) for C. trachomatis, 100% (11/11) for N. gonorrhoeae, and 100% (17/17) for T. vaginalis. For Visby Gen1 we observed a 10.5% (12/114) cartridge failure rate. For Visby Gen2, we observed negative concordance of 100% (59/59) for C. trachomatis, 100% (63/63) for N. gonorrhoeae, and 100% (55/55) for T. vaginalis while positive concordance was 100% (10/10) for C. trachomatis, 100% (6/6) for N. gonorrhoeae, and 90.9% (10/11) for T. vaginalis. The Visby Gen2 assay displayed a 4.9% (4/81) cartridge failure rate. Six weeks after implementing the Visby Gen2 assay in our ED, rapid STI panel TAT was 0.48 hours on average (n=20). In the central laboratory the average TAT was 22.31 hours (n=7892). Conclusions Assay concordance to reference method was similar for Visby Gen1 and Gen2 assays. The cartridge failure rate improved by 46.7% with the Gen2 assay which should decrease the need to repeat testing due to assay failure. Result TAT decreased by 97.8% when comparing rapid Visby results to central laboratory. Therefore, Visby STI testing using the Gen2 assay can provide accuracy and rapid results likely to facilitate more rapid patient management.

Prevalence of Malaria among Patients Visiting Public Hospitals in Mogadishu, Somalia-Cross-Sectional Study

Background: In tropical and subtropical areas, malaria is one of the main causes of death and morbidity. Malaria is a major worldwide health concern, especially in sub-Saharan Africa, which includes Somalia, where the majority of cases and deaths from the disease occur. Malaria has a negative impact on both public health and the economic growth of many developing nations. Examining and quantifying the prevalence of malaria among outpatients who have visited hospitals were the study's goal. Study was conducted between September, and November 2023. Methods: A structured questionnaire was administered to 278 were collected patients visit two general hospitals at single time with obtained consented, blood samples were diagnosis used by rapid diagnosis test (RDTs), this study was identified the species of plasmodium used standard keys. Thus, this study design was cross-sectional and quantitative study. The data source was primary information, and was nonrandom sampling. The data generated was analysis using percentage and present in graph forms. Chi- square was used to determine the degree of association between malaria prevalence and factors influencing its transmission, performed by (SPSS 20 version). Results: total of 278 was recruited to conduct the study at outpatient department OPD in two hospitals, Mogadishu, Somalia. Out of 278 persons examined for malaria parasites, 12 (4.3%) were positive. Females were more participated than males 185 (66.5%). The respondents were observed 43.5% use it most of the time sleep under mosquito net. Conclusion: The investigation clearly showed that the persons with malaria infection was minimal. Because the participants aware of the threat posed by mosquitoes in their area, they placed a strong emphasis on vector control measures as reduce the number of mosquito breeding sites. They also understood the significance of indoor residual spray (IRS), which is essential for both mosquito prevention and control.

Novel AI-driven Malaria Prediction for Optimizing Public Health Management

Malaria is an unmoving real common well-being apprehension in Asian nations like the Republic of India, where the state characterizes approximately 55% of the session events cutting-edge the infirmaries. They are usually distinguished by the absence of appropriate therapeutic care provision and the often late and error-prone diagnosis of the condition. In particular, commonly used devices such as the Rapid Diagnosis Test (RDT) are not completely dependable. They are primarily notable for their failure to provide adequate medical treatment and their tendency to diagnose the disease late and incorrectly. For example, widely used devices like the RDT are not consistent. To improve public health management actions, this work offers a unique augmented tree with penguin search optimization (AT+PSO) methodology for malaria forecasting. The suggested method combines the PSO algorithm with the augmented tree model, also known as random forest (RF). In the preprocessing stage, raw data samples are subjected to data normalization. Then, we applied the PSO to improve the characteristics of the RF model after successfully predicting malaria with the RF. The Python program is used to implement the suggested technique and analyze performance using a range of measures, including accuracy (0.988), sensitivity (0.987), specificity (0.991), F1-score (0.988), and MCC (0.975). In summary, our suggested approach produced the best results in terms of accuracy as opposed to other current strategies for predicting malaria to improve governance of public health.

Automated Urine Screening and Residual Antimicrobial Activity Test for Rapid Diagnosis of Urinary Tract Infections in Ambulatory Patients: A Laboratory Evaluation of HB&L Uroquattro Instrument

Automated Urine Screening and Residual Antimicrobial Activity Test for Rapid Diagnosis of Urinary Tract Infections in Ambulatory Patients: A Laboratory Evaluation of HB&L Uroquattro Instrument

Comparison of three rapid diagnostic tests for Plasmodium falciparum diagnosis in Ghana

BackgroundAccurate diagnosis and timely treatment are crucial in combating malaria.MethodsA total of 449 samples were screened for Plasmodium falciparum infection by expert microscopy, qPCR, and three RDTs, namely Rapigen Biocredit Malaria Ag Pf (detecting HRP2 and pLDH on separate bands), Abbott NxTek Eliminate Malaria Ag Pf (detecting HRP2), and SD Bioline Malaria Ag Pf (detecting HRP2). hrp2/3 deletion typing was done by digital PCR.Results45.7% (205/449) individuals tested positive by qPCR for P. falciparum with a mean parasite density of 12.5 parasites/μL. Using qPCR as reference, the sensitivity of microscopy was 28.3% (58/205), the Biocredit RDT was 52.2% (107/205), the NxTek RDT was 49.3% (101/205), and the Bioline RDT was 39.5% (81/205). When only samples with densities > 20 parasites/μL were included (n = 89), sensitivity of 62.9% (56/89) by microscopy, 88.8% (79/89) by Biocredit, 88.8% (79/89) by NxTek, and 78.7% (70/89) by Bioline were obtained. All three RDTs demonstrated specificities > 95%. The limits of detection (95% probability that a sample tested positive) was 4393 parasites/μL (microscopy), 56 parasites/μL (Biocredit, considering either HRP2 or pLDH), 84 parasites/μL (NxTek), and 331 parasites/μL (Bioline). None of the three qPCR-confirmed P. falciparum positive samples, identified solely through the pLDH target, or eight samples negative for all RDTs but qPCR-positive at densities > 20 parasites/µL carried hrp2/3 deletions.ConclusionThe Biocredit and NxTek RDTs demonstrated comparable diagnostic efficacies. All three RDTs performed better than microscopy.

Development of a new accurate lateral flow immunoassay for diagnosis of human leptospirosis.

The current diagnostic methods for leptospirosis diagnosis are technically complex and expensive, with limited applicability to specialized laboratories. Furthermore, they lack diagnostic accuracy in the acute stage of the disease, which coincides with a period when antibiotics are highly effective. New simple and accurate tests are mandatory to decentralize and improve diagnosis. Here, we introduced a new lateral flow immunoassay (Lepto-LF) for human leptospirosis. We conducted a double-blinded assay using 104 serum samples from patients with confirmed or discarded diagnosis for leptospirosis. The diagnostic performance of Lepto-LF was estimated across different ranges of days from onset of symptoms (dpo), considering the diagnostic algorithm as reference standard. Additionally, it was compared with the screening methods enzyme-linked immunosorbent assay (IgM-ELISA) and the slide agglutination test using temperature-resistant antigen (SATR). Lepto-LF exhibited perfect diagnostic performance with a Youden´s index J = 1 from 6 dpo in the acute phase. IgM-ELISA gave slightly lower accuracy with J = 0.91 and 95.5% of both sensitivity and specificity; while SATR showed a markedly inferior yield (J = 0.41, sensitivity = 95.5%, specificity = 45.5%). The performances remained consistent in the convalescence phase of the disease (> 10 dpo). Lepto-LF was found to be a reliable test for simple, rapid and early diagnosis of leptospirosis, resulting a promising tool for decentralizing leptospirosis diagnosis and enabling timely treatment of patients. In addition, Lepto-LF may be employed as confirmatory test, especially in remote areas and vulnerable contexts where the standard MAT is not available.

The forearm elevation-compression test: a novel test for carpal tunnel syndrome.

As the time available to spend with patients decreases, a rapid test for bedside diagnosis of carpal tunnel syndrome (CTS) could be useful. We describe the forearm elevation-compression test (FECT) in this context. The FECT was assessed in 40 patients with clinically suspected carpal tunnel syndrome and compared to Tinel's and Phalen's signs. Routine electromyography and nerve conduction tests (EMG/NCT) were performed in all cases. In addition, 85 healthy controls were examined by FECT and compared to the patient group. All three provocative tests, particularly FECT were frequently positive in suspected CTS. Neurophysiological tests were normal in 5 of 40 cases of clinically suspected CTS and the FECT was positive in all of these suggesting a positive predictive value of 87.5% if one accepts EMG/NCT as the reference. Amongst the healthy controls 18 of 85 (21.2%) were positive on the FECT suggestive of a high false positive rate or subclinical disease. It is proposed that the FECT is a useful addition to the clinical examination of suspected CTS. Although the positive rate may be falsely elevated this is offset by restricting the latency for tingling onset to 10 seconds or less (FECT2).

Evaluation of a Rapid Diagnostic Test (TUBEX-TF) for Diagnosis of Enteric Fever

Abstract Background and Aim: Enteric fever is a systemic febrile disease caused by Salmonella enterica serovars Typhi and Paratyphi. Culture provides a conclusive diagnosis of enteric fever. The main difficulties are a longer turnaround time and practicality in a developing nation with a huge population. The two RDTs that are now most often used are TUBEX-TF and Enterocheck-WB, where TUBEX-TF can identify IgM antibodies against S. Typhi and S. Paratyphi which are anti-O9 and anti-O2. The aim of this study was to evaluate the performance of the TUBEX-TF test in a typhoid fever endemic area of North India. Materials and Methods: In this cross-sectional study, we have performed TUBEX-TF, Enterocheck-WB /Immuno-chromatographic card test, Enzyme linked immunosorbent assay (ELISA), and Widal tests on the sera of 94 clinically suspected cases of enteric fever It was a cross-sectional comparative study that was carried out at a tertiary care institute in North India. In the present study, the ELISA test was taken as a comparative reference test. Results: ELISA, TUBEX-TF, Widal, and Immunochromatographic card test were performed on serum samples collected from 94 clinically suspected enteric fever cases, in which 50(53.19%) were positive by ELISA, 45 (47.87%) were positive by TUBEX- TF, 40 (42.5%) were positive by Typhidot and 19 (20.2%) were positive by Widal. For evaluation of TUBEX-TF, sensitivity specificity, diagnostic accuracy, positive predictive and negative predictive values, a comparison with IgM Anti-LPS ELISA test results was performed & it was found 75%,79.55%,80%,74.47%, and 77.17% respectively. Conclusion: We conclude that the TUBEX-TF test has a greater sensitivity and specificity than other rapid tests currently on the market. It is a simple, rapid test to diagnose enteric fever. The necessity for large-scale research to evaluate TUBEX-TF is necessary due to interviewer variances so that it can become a novel RDT test for the diagnosis of enteric fever.

Evidence of Plasmodium vivax circulation in western and eastern regions of Senegal: implications for malaria control

BackgroundMalaria elimination in Senegal requires accurate diagnosis of all Plasmodium species. Plasmodium falciparum is the most prevalent species in Senegal, although Plasmodium malariae, Plasmodium ovale, and recently Plasmodium vivax have also been reported. Nonetheless, most malaria control tools, such as Histidine Rich Protein 2 rapid diagnosis test (PfHRP2-RDT,) can only diagnose P. falciparum. Thus, PfHRP2-RDT misses non-falciparum species and P. falciparum infections that fall below the limit of detection. These limitations can be addressed using highly sensitive Next Generation Sequencing (NGS). This study assesses the burden of the four different Plasmodium species in western and eastern regions of Senegal using targeted PCR amplicon sequencing.MethodsThree thousand samples from symptomatic and asymptomatic individuals in 2021 from three sites in Senegal (Sessene, Diourbel region; Parcelles Assainies, Kaolack region; Gabou, Tambacounda region) were collected. All samples were tested using PfHRP2-RDT and photoinduced electron transfer polymerase chain reaction (PET-PCR), which detects all Plasmodium species. Targeted sequencing of the nuclear 18S rRNA and the mitochondrial cytochrome B genes was performed on PET-PCR positive samples.ResultsMalaria prevalence by PfHRP2-RDT showed 9.4% (94/1000) and 0.2% (2/1000) in Diourbel (DBL) and Kaolack (KL), respectively. In Tambacounda (TAM) patients who had malaria symptoms and had a negative PfHRP2-RDT were enrolled. The PET-PCR had a positivity rate of 23.5% (295/1255) overall. The PET-PCR positivity rate was 37.6%, 12.3%, and 22.8% in Diourbel, Kaolack, and Tambacounda, respectively. Successful sequencing of 121/295 positive samples detected P. falciparum (93%), P. vivax (2.6%), P. malariae (4.4%), and P. ovale wallikeri (0.9%). Plasmodium vivax was co-identified with P. falciparum in thirteen samples. Sequencing also detected two PfHRP2-RDT-negative mono-infections of P. vivax in Tambacounda and Kaolack.ConclusionThe findings demonstrate the circulation of P. vivax in western and eastern Senegal, highlighting the need for improved malaria control strategies and accurate diagnostic tools to better understand the prevalence of non-falciparum species countrywide.

Reliability of the rapid antigen test for diagnosis of SARS-CoV-2 in Tunisia.

Early and accurate diagnosis is crucial for preventing the spread of SARS-CoV-2 infection. The rapid antigen test was developed for testing infection, and it was necessary to assess its performance before widespread use in Tunisia. To evaluate the effectiveness of a rapid antigen test for the detection of SARS-CoV-2 in nasopharyngeal swabs in Tunisia. Nasopharyngeal samples were taken from COVID-19 suspected cases between October and December 2020 and tested using the Standard Q COVID-19 Ag test (SD-Biosensor, Republic of Korea) and real-time reverse transcription polymerase chain reaction (RT‑PCR). Overall, 4539 patients were tested. Of the total study population (N = 4539), 82.5% of positive samples remained positive with the rapid antigen test, while 20.2% (470/2321) of samples that were negative with rapid antigen test were confirmed positive with RT-PCR, giving a negative predictive value of 79.8% for the rapid antigen test. The sensitivity and negative predictive value of the rapid antigen test were 70.2% and 65.8%, respectively. These results improved to 96.4% and 92.8%, respectively, when considering the cycle threshold value by RT-PCR below 25. Although the rapid antigen test was less sensitive than RT-PCR, its ability to rapidly detect individuals with high viral loads makes it suitable for use during an epidemic.

Evaluation of non-invasive diagnostic tools for diarrhea: a systematic review of point-of-care tests and biomarkers.

Diarrhea is a prevalent condition affecting millions worldwide. However, current standard diagnostic methods have many drawbacks. This review examines various non-invasive point-of-care (POC) tests and biomarkers aiding rapid diagnosis of diarrhea from different causes. PubMed, PubMed Central, ScienceDirect, Cochrane Library, and Google Scholar were searched from 2013 to present for relevant literature. Two reviewers independently assessed included studies' quality using the Critical Appraisal Skills Programme (CASP) checklist. The search yielded 1453 studies, of which 39 were included after screening and applying eligibility criteria. Polymerase chain reaction (PCR) was the POC test in 25 studies, providing consistent sensitivity and specificity. For biomarkers, C-reactive protein (CRP), fecal calprotectin, and procalcitonin offered high sensitivity and specificity for conditions like acute pediatric diarrhea, microscopic colitis, and inflammatory diarrhea, respectively. PCR proved the ideal POC test for rapid diarrhea diagnosis, while the procalcitonin biomarker helps differentiate inflammatory from non-inflammatory diarrhea. Other reviewed tools also demonstrated promising diagnostic performance, though improvements in sensitivity, specificity, and usability are still needed.

Investigation of Sensitivity of Rapid Diagnosis Tests in Patients with Suspected Malaria.

Malaria has been eradicated in Türkiye as of 2010, but there are imported cases. In this study, we aimed to compare the diagnostic value of two rapid tests; SD Bioline Malaria Ag Pf/Pan (SD-Pf/Pan) and SD Bioline Malaria Ag Pf/Pv (SD-Pf/Pv) with microscopy and real time-polymerase chain reaction (RT-PCR). Blood samples were taken from all participants. Thick drop smears were prepared. Thick drop smears were examined for malaria positive/negative distinction under the light microscopy. Then, two rapid diagnostic tests (SD-Pf/Pan and SD-Pf/Pv) were performed. After DNA extraction from blood samples, RT-PCR was typed. The data were evaluated with SPSS 21 program of statistics. A total of 30 cases out of 66 suspected malaria cases were detected as positive with microscopy and RT-PCR. Twenty-seven patients were found positive with both SD-Pf/Pan and SD-Pf/Pv tests. Based on the microscopic results as a reference method, SD-Pf/Pan and SD-Pf/Pv rapid diagnostic tests had a 90% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 92.86% negative predictive value (NPV). Based on the RT-PCR results as a reference method, for detection of P. falciparum, both tests had a 95.65% sensitivity, 100% specificity, 100% PPV, and 88.89% NPV. Moreover, while SD-Pf/Pv had a sensitivity, specificity, PPV, and NPV of 100% in detection of P. vivax; SD-Pf/Pan has a 77.78% sensitivity of, 61.90% specificity of, 46.67% PPV, and 86.67% NPV SD-Pf/Pan for detection of PAN. As a result, high sensitivity and specificity were detected in both kits in the diagnosis of malaria infections caused by P. falciparum and P. vivax. Rapid diagnostic tests can be used safely in diagnosis however the diagnosis should be supported by microscopy and RT-PCR methods when they are applicable.

Analyzing Breakthrough Infections in a Tertiary Care Hospital: A Retrospective Study Utilizing RAT-Based Screening

Prompt diagnosis of coronavirus disease 2019 (COVID-19) is requisite due to the upsurge of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) cases globally. Real-time reverse-transcription polymerase chain reaction (rRT-PCR) remains as the gold standard for the diagnosis of SARS-CoV-2 due to its higher sensitivity and specificity. Regardless, due to its longer turnaround time and expertise, bed side testing rapid antigen based tests were developed in order for portable, rapid diagnosis of the disease. The present study delineates the utility of Rapid Antigen Testing (RAT) screening among symptomatic and asymptomatic patients in a tertiary care hospital. This is a retrospective data collection study from Indian Council of Medical Research (ICMR) portal by exporting the excel sheet from March 2021 to March 2022 who undergone COVID testing in a tertiary care diagnostics facility. The demographic and vaccination details of the individuals were extracted using ICMR Sample referral form (SRF) from all patients who are tested for RAT. Of the total 9898 patients tested for RAT, 392 and 9506 were vaccinated and unvaccinated, respectively. Among them, number of positives was 3% and 15% respectively. The odds ratio showed that the vaccinated individuals had 81.4% reduced risk of getting infection compared to unvaccinated individuals (OR-0.186; p=0.001). A significant difference was observed between the type of vaccine used and COVID infection, majority of them had taken Covishield (83.5%) followed by Covaxin (16%) [p=0.0005]. Males showed a marginally significant p trend with COVID infectivity (OR=1.114, p=0.073) too. RAT is useful as a screening test for rapid diagnosis of infection in patients who are more prone to spread the disease. As RAT is cost effective and had short-turnaround time, it can be recommended in areas with upsurge in SARS-CoV-2 cases to administer isolation and infection control measures.

Evaluation of the Performance of Rapid Diagnostic Tests for Malaria Diagnosis and Mapping of Different Plasmodium Species in Mali.

The first-line diagnosis of malaria in Mali is based on the use of rapid diagnostic tests (RDT) that detect the Histidin Rich Protein 2 (HRP2) antigen specific to Plasmodium falciparum. Our study, based on a real-time polymerase chain reaction (qPCR) gold standard, aimed to describe the distribution of the Plasmodium species in each administrative region of Mali and to assess the performance of RDTs. We randomly selected 150 malaria-negative and up to 30 malaria-positive RDTs in 41 sites distributed in 9 regions of Mali. DNA extracted from the RDT nitrocellulose strip was assayed with a pan-Plasmodium qPCR. Positive samples were then analyzed with P. falciparum-, P. malariae-, P. vivax-, or P. ovale-specific qPCRs. Of the 1496 RDTs, 258 (18.6%) were positive for Plasmodium spp., of which 96.9% were P. falciparum. The P. vivax prevalence reached 21.1% in the north. RDT displayed acceptable diagnostic indices; the lower CI95% bounds of Youden indices were all ≥0.50, except in the north (Youden index 0.66 (95% CI [0.44-0.82]) and 0.63 (95% CI [0.33-0.83]. Overall, RDT diagnostic indices are adequate for the biological diagnosis of malaria in Mali. We recommend the use of RDTs detecting P. vivax-specific antigens in the north.

Design and development of multiepitope chimeric antigens by bioinformatic and bacterial based recombinant expression methods, with potential application for bovine tuberculosis serodiagnosis

Bovine tuberculosis (bTB), which is caused by Mycobacterium bovis, is a single health concern, which causes economic losses, is a sanitary barrier and is a zoonotic concern. The golden-pattern intradermic tests have low sensitivity of about 50%. To fix this sensitivity problem, immunoassays could be a powerful tool. However, few studies produced antigens for bTB immunoassays, which needs improvements. Aim of this study was to produce multiepitope chimeric antigens (MCA) to use for bTB diagnosis. To achieve MCA design and development, extensive bibliographic search, antigenic epitope prediction, specificity, hydrophobicity, and 3D structure modeling analyses were performed, as well as cloning, expression and purification. Seven epitopes from four different target proteins (MPB-70, MPB-83, ESAT-6 and GroEL) were combined in five chimeras containing five repetitions of each epitope to enhance antibodies affinity. 3D predicted models revealed that all chimeras have a high percentage of disorder, which could enhance antibody recognition, although taking to protein instability. Each chimera was cloned into pET28a (+) expression plasmids and expressed in six Escherichia coli expression strains. Chimeras 3, 4 and 5 could be solubilized in 8 M urea and purified by ion exchange affinity chromatography. Against bTB positive and negative sera, purified chimera 5 had the best results in indirect dot blot and ELISA, as well as in lateral flow dot blot immunoassay. In conclusion, chimera 5, an MPB-83 containing MCA, could be used for further studies, aimed to develop a serologic or rapid test for bTB diagnosis.

Prevalence of Malaria Infection in Pregnant Women Attending Antenatal Clinics in Southern Senegal.

Despite marked progress in Senegal, three regions in the southeast part continue to have a high burden of malaria, but there have been no recent studies assessing the prevalence of malaria associated with pregnancy. This study aimed to determine the prevalence of malaria infection in pregnant women attending antenatal clinics in Senegal. During the malaria transmission season of 2019, pregnant women attending 11 health care facilities for a scheduled visit and those presenting unwell with signs of malaria were invited to participate in a malaria screening study. A finger prick blood sample was taken for malaria diagnosis by rapid diagnosis test (RDT) and polymerase chain reaction (PCR). A total of 877 pregnant women were enrolled, 787 for a scheduled antenatal consultation and 90 for an unscheduled consultation with signs of malaria. The prevalence of Plasmodium falciparum among the first group was 48% by PCR and 20% by RDT, and that among the second group was 86% by PCR and 83% by RDT. RDT sensitivity in capturing asymptomatic, PCR-positive infections was 9.2% but ranged from 83% to 94% among febrile women. The prevalence of infection by PCR in women who reported having received at least three doses of sulfadoxine pyrimethamine (SP) was 41.9% compared with 58.9% in women who reported they had not received any SP doses (prevalence ratio adjusted for gravidity and gestational age, 0.54; 95% CI, 0.41-0.73). The burden of P. falciparum infections remains high among pregnant women, the majority of which are not captured by RDT. More effective measures to prevent malaria infection in pregnancy are needed.

Clinical manifestations, diagnosis, and antimicrobial resistance of group A streptococci infections

Group A streptococci (GAS) cause diverse diseases ranging from mild to severe illnesses, and the global burden of GAS infections is enormous. Serological typing has been replaced by emm genotyping for the epidemiological study of GAS. Acute bacterial pharyngitis is a common illness, which requires either throat culture or rapid Ag test for diagnosis. Moreover, molecular point-of-care tests have been introduced owing to their higher sensitivity. Optimal diagnosis of bacterial pharyngitis is necessary for the adequate use of antibiotics. Although antimicrobial resistance (AMR) to erythromycin or clindamycin does not seem serious in Korea, it is very high in China, being reported at over 90%. Antibiotic surveillance and relevant education are necessary for primary clinical physicians and pediatricians. It is necessary to monitor AMR and develop a system for reporting the appearance of highly virulent diseases, such as necrotizing fasciitis or streptococcal toxic-shock syndrome, to the government authority.

Performance of the MeltPro TB assay as initial test for diagnosis of pulmonary tuberculosis with drug-resistance detection

BackgroundThe MeltPro TB assay (MeltPro) is a molecular rapid diagnostic test designed for detecting resistance to antituberculosis drugs. However, the performance of MeltPro as an initial diagnostic test for simultaneously detecting the presence of Mycobacterium tuberculosis (MTB) and drug resistance has not been evaluated. This study aims to assess the performance of MeltPro as initial diagnostic test for simultaneous detection of MTB and drug resistance in clinical samples from patients with presumptive pulmonary tuberculosis (PTB).MethodsA retrospective analysis was conducted on 1283 patients with presumptive PTB from two clinical centers, out of which 875 were diagnosed with PTB. The diagnostic accuracy of MeltPro, Xpert MTB/RIF (Xpert), and MGIT 960 for PTB detection was evaluated. Rifampicin (RIF), isoniazid (INH), ethambutol (EMB), streptomycin (STR), and fluoroquinolone (FQ) resistance were detected using MeltPro, with Xpert and/or the broth microdilution plate method (MYCOTB) results as references.ResultsFor the diagnosis of PTB, MeltPro showed a sensitivity of 69.0%, which was similar to Xpert (72.7%; P > 0.05) and higher than MGIT (58.1%; P < 0.001). The specificity of MeltPro was 97.1%, similar to Xpert (98.0%; P > 0.05). In smear-negative patients, MeltPro's sensitivity was 50.9%, similar to Xpert (56.5%; P > 0.05), and higher than MGIT (33.1%; P < 0.001). Based on Xpert and/or MYCOTB results, MeltPro exhibited a sensitivity and specificity of 98.3% and 99.2%, respectively, for detecting RIF resistance. Based on MYCOTB results, MeltPro's sensitivity for detecting resistance to INH, EMB, STR, and FQ was 96.4%, 89.1%, 97.5%, and 90.3%, respectively, with specificities of 96.0%, 96.0%, 95.2%, and 99.4%, respectively.ConclusionThe MeltPro TB assay could potentially be an effective alternative as the initial test for rapid diagnosis of PTB with drug-resistance detection in clinical practice.

Single-tube multiplex real-time PCR with EvaGreen and high-resolution melting analysis for diagnosis of α0-thalassemia--SEA,--THAI, and--CR type deletions.

Regions with a high prevalence of α-thalassemia (α-thal) require simple, rapid, and accurate tests for carrier screening and prenatal diagnosis. Diagnosis of multiple deletions in a single tube is necessary to clearly identify individuals with α0-thalassemia in the routine setting, especially in at-risk couples. Therefore, we aimed to develop a single-tube multiplex real-time PCR with EvaGreen and high-resolution melting (HRM) analysis for the identification of α0-thalassemia Southeast Asian (SEA), Thai and Chiang Rai (CR) type deletions. The results of the HRM analysis indicated that the amplified fragments from α0-thal--CR,--THAI,--SEA, and the wild-type α-globin gene had specific peak heights at mean melting temperature (Tm) values of 85.40°C, 86.50°C, 87.65°C, and 91.04°C, respectively. The frequencies of α0-thal--SEA,--THAI,--CR obtained from routine testing in 2,135 samples were 17.89%, 0.19% and 0.19%, respectively. This method would be useful for preventing Hb Bart's hydrops fetalis. Detection of multiple deletions in a single run is cost-effective, highly accurate and timesaving. This technique could enable wider α-thalassemia diagnosis in high prevalence areas and served as an example for thalassemia routine setting.