Circulation of yellow fever virus in Benin city, Edo state Nigeria.

Yellow fever (YF) is one of the most acute viral hemorrhagic diseases of the 18th and 19th centuries, which continues to cause severe morbidity and mortality in Africa. After 21 years of no reported cases of yellow fever in Nigeria, till 2017 where a case was confirmed in Kwara State, also in November 2018,WHO was informed of a cluster of suspected yellow fever cases and deaths in Edo state, Nigeria. The study was among all age group attending health centres in Benin City, Edo state. A total of 280 blood samples were collected from consented febrile patients and were screened for antibodies to Zika virus using rapid diagnostic test (RDT) kits. Blood samples positive to Zika virus (IgM/IgG RDT), were subjected to molecular characterization. Using the flavividae family primers, six (6) samples where confirmed positive by Hemi-nested reverse transcription PCR (hnRT-PCR) sequencing. Nucleotide sequence blast revealed the sequenceswere similar to Yellow fever virus strains. Phylogenetic analysis revealed that the yellow fever virus sequences are closely related to the African strains. Despite the safe and effective yellow fever vaccine, yellow fever virus is seen to be in circulation, hence the need for continues mass vaccination.

Comparison of SD Bioline Malaria Ag Pf/Pan and Acro Malaria P.f./P.v./Pan with Microscopy and Real Time PCR for the Diagnosis of Human Plasmodium Species.

The early diagnosis of malaria is crucial to controlling morbidity and mortality. The World Health Organization (WHO) recommends diagnosing malaria either using light microscopy or a malaria rapid diagnostic test (RDT). Most RDTs use antibodies to detect two P. falciparum histidine-rich proteins named PfHRP2 and PfHRP3. However, false-negative results are known to occur due to the poor performance of RDTs depending on the species and the deletion of the Pfhrp2 and Pfhrp3 genes. This study evaluated new malaria RDTs for the detection of the human Plasmodium species. The Acro Malaria P.f./P.v./Pan Rapid Test Cassette allows the qualitative detection of parasite antigens, such as PfHRP2 specific to Plasmodium falciparum, PvLDH specific to Plasmodium vivax, and/or panLDH Plasmodium genus lactate dehydrogenase, in the blood of infected individuals. This RDT was assessed against 229 samples collected from imported malaria cases, mainly from Africa. The samples were previously diagnosed using light microscopy and RDT (SD Malaria Ag P.f./Pan, SD Bioline Alere Abbott), then confirmed using real time PCR. The two RDTs were evaluated using a comparison with real time PCR as the reference method, and their performances were compared with each other. Compared to SD RDT, the Acro RDT showed a better sensitivity to P. falciparum (96.8% vs. 89.8%), P. vivax (78.6% vs. 64.3%), P. ovale (73.7% vs. 5.3%), and P. malariae (20.0% vs. 0%). The respective specificities of the Acro RDT and SD RDT are 90.7% vs. 95.3% to P. falciparum, 100% to P. vivax, and 100% vs. 100% to Plasmodium genus. Therefore, Acro RDT showed better performance in the identification of P. ovale and low parasitaemia of P. falciparum. In addition, Acro RDT has the advantage of detecting PvLDH-specific antigens. The Acro Malaria RDT presents the benefits of detecting a P. falciparum antigen (PfHRP2) and a P. vivax antigen (PvLDH) with high sensitivity (96.8% and 73.7%, respectively) and specificity (90.7% and 100%, respectively). Acro Malaria P.f./P.v./Pan rapid diagnostic tests could be effectively used in endemic areas, especially when microscopic examination cannot be performed.

Cost-effectiveness analysis of a multiplex lateral flow rapid diagnostic test for acute non-malarial febrile illness in rural Cambodia and Bangladesh.

Background: Multiplex lateral flow rapid diagnostic tests (LF-RDTs) may aid management of patients with acute non-malarial febrile illness (NMFI) in rural south and southeast Asia. We aimed to evaluate the cost-effectiveness in Cambodia and Bangladesh of a putative, as-yet-undeveloped LF-RDT capable of diagnosing enteric fever and dengue, as well as measuring C-reactive protein (CRP) to guide antibiotic prescription, in primary care patients with acute NMFI. Methods: A country-specific decision tree model-based cost-effectiveness analysis was conducted from a health system plus limited societal perspective considering the cost of antimicrobial resistance. Parameters were based on data from a large observational study on the regional epidemiology of acute febrile illness, published studies, and procurement price lists. Costs were expressed in US$ (value in 2022), and cost-effectiveness evaluated by comparing incremental cost-effectiveness ratios with conservative opportunity cost-based willingness-to-pay thresholds and the more widely used threshold of per capita gross domestic product (GDP). Findings: Compared to standard of care, LF-RDT-augmented clinical assessment was dominant in Cambodia, being more effective and cost-saving. The cost per disability-adjusted life year (DALY) averted in Bangladesh was US$482, slightly above the conservative opportunity cost-based willingness-to-pay threshold of US$388 and considerably lower than the GDP-based threshold of US$2687. The intervention remained dominant in Cambodia and well below the GDP-based threshold in Bangladesh when antimicrobial resistance costs were disregarded. Interpretation: These findings provide guidance for academic, industry, and policymaker stakeholders involved in acute NMFI diagnostics. While definitive conclusions cannot be made in the absence of established thresholds, our results suggest that similar results are highly likely in some target settings and possible in others. Funding: Wellcome Trust, UK Government, Royal Australasian College of Physicians, and Rotary Foundation.

Communication: Evaluation of the Humasis COVID-19 Antigen Rapid Diagnostic Test for the Diagnosis of SARS-CoV-2 Infection.

OBJECTIVE: We assessed the performance of the Humasis COVID-19 AgHS Test (Humasis, Korea), a novel antigen rapid diagnostic test (Ag-RDT) based on lateral flow immunoassay. METHODS: 85 SARS-CoV-2-positive and 155 SARS-CoV-2-negative nasopharyngeal swab specimens confirmed by rRT-PCR were tested using the Humasis and PBCheck Ag-RDTs. The analytical specificity of the Humasis Ag-RDT was evaluated using 27 strains of human respiratory pathogens. RESULTS: The overall sensitivity and specificity were 72.9% and 99.4% for the Humasis Ag-RDT and 64.7% and 100% for the PBCheck Ag-RDT, respectively. The sensitivity for specimens with Ct≤25 was 100% for both Ag-RDTs. The Humasis Ag-RDT showed no cross-reactivity with other respiratory pathogens. CONCLUSION: Our data suggests that the Humasis Ag-RDT can be a useful diagnostic tool for the detection of SARS-CoV-2 infection.

Lesson Learned from Mass Antibody Rapid Diagnostic Used in the Early COVID-19 Pandemic in Indonesia Contributors.

Introduction: Laboratory examination is extremely important in handling the COVID-19 pandemic. In the first era of the pandemic, the molecular and antigen tests were limited. Hence, at that time, it was necessary to carry out antibody Rapid Diagnostic Tests (RDT). However, many antibody RDTs were yet to obtain Food and Drug Authorization (FDA)'s approval. Purpose: Therefore, The Indonesian Association of Clinical Pathology and Medical Laboratory (PDS PatKLIn) decided to conduct a validity test of RDT antibodies to find out the quality of SARS-CoV-2 diagnosis performance based on these RDTs used. Patient and Methods: This is a descriptive observational design with diagnostic analysis. The retrospective secondary data were collected from 34 provinces in Indonesia from May to June 2020. Data analysis was carried out on the sensitivity and specificity values of each antibody RDT brand to the RT-PCR result and analyzed descriptive data. Results: The amount of secondary data of antibody RDT and RT-PCR results collected was 139,908, consisting of 59 RDT brands of which 44% were authorized by The Indonesian COVID-19 Response Acceleration Task Force (Gugus Tugas Percepatan Penanganan COVID-19 Indonesia). There were huge variations of SARS-CoV-2 antibody RDT performance between total antibody types (sensitivity 59.18%, specificity 62%), IgM RDT (sensitivity 16-100%, specificity 7-97%), and RDT IgG (sensitivity 33-96%, specificity 19-100%). Conclusion: The variations in the RDT antibodies'performance can cause errors in diagnosis leading to significant material and immaterial losses. Therefore, cooperation from various parties is needed for the pre- and post-marketing surveillance process to assess the performance and the characteristics of each RDT kit and other diagnostic methods to assist the rapid pandemic response process.

Assessment of the Performance of Lactate Dehydrogenase-Based Rapid Diagnostic Test for Malaria in Djibouti in 2022-2023.

Until 2020, Djiboutian health authorities relied on histidine-rich protein-2 (HRP2)-based rapid diagnostic tests (RDTs) to establish the diagnosis of Plasmodium falciparum. The rapid spread of P. falciparum histidine-rich protein-2 and -3 (pfhrp2/3) gene-deleted parasite strains in Djibouti has led the authorities to switch from HRP2-based RDTs to lactate dehydrogenase (LDH)-based RDTs targeting the plasmodial lactate dehydrogenase (pLDH) specific for P. falciparum and P. vivax (RapiGEN BIOCREDIT Malaria Ag Pf/Pv pLDH/pLDH) in 2021. This study was conducted with the primary objective of evaluating the diagnostic performance of this alternative RDT. Operational constraints related, in particular, to the implementation of this RDT during the COVID-19 pandemic were also considered. The performance of BIOCREDIT Malaria Ag Pf/Pv (pLDH/pLDH) RDT was also compared to our previously published data on the performance of two HRP2-based RDTs deployed in Djibouti in 2018-2020. The diagnosis of 350 febrile patients with suspected malaria in Djibouti city was established using two batches of RapiGEN BIOCREDIT Malaria Ag Pf/Pv (pLDH/pLDH) RDT over a two-year period (2022 and 2023) and confirmed by real-time quantitative polymerase chain reaction. The sensitivity and specificity for the detection of P. falciparum were 88.2% and 100%, respectively. For P. vivax, the sensitivity was 86.7% and the specificity was 100%. Re-training and closer supervision of the technicians between 2022 and 2023 have led to an increased sensitivity to detect P. falciparum (69.8% in 2022 versus 88.2% in 2023; p < 0.01). The receiver operating characteristic curve analysis highlighted a better performance in the diagnosis of P. falciparum with pLDH-based RDTs compared with previous HRP2-based RDTs. In Djibouti, where pfhrp2-deleted strains are rapidly gaining ground, LDH-based RDTs seem to be more suitable for diagnosing P. falciparum than HRP2-based RDTs. Awareness-raising and training for technical staff have also been beneficial.

The diagnostic performance evaluation of Panbio and STANDARD Q coronavirus disease 2019 antigen tests against real-time polymerase chain reaction in southern Ethiopia.

The coronavirus disease 2019 (COVID-19) pandemic has created a public health crisis. This study aimed to evaluate the diagnostic performance of the Panbio and STANDARD Q COVID-19 antigen rapid diagnostic tests (RDTs) against the real-time polymerase chain reaction (RT-PCR) at one of the largest hospitals in southern Ethiopia. Nasopharyngeal samples, which were collected during the pandemic from individuals suspected of COVID-19 and stored at - 70 °C, were analyzed in June and July 2022. The performance of the Panbio COVID-19 antigen tests was evaluated in 200 randomly selected nasopharyngeal samples (100 positives and 100 negatives for severe acute respiratory syndrome 2 by RT-PCR). The STANDARD Q test was evaluated using 100 positive and 50 negative samples. The respective sensitivity, specificity, positive predictive value and negative predictive values were 88%, 99%, 98.9% and 89.2% for the Panbio test and 91%, 98%, 98.9% and 84.5%, for the STANDARD Q test. The kappa values were 0.87 for the Panbio and 0.86 for the STANDARD Q test. Based on the findings presented here, the RDTs could be utilized as an alternative to conventional RT-PCR when it is challenging to diagnose COVID-19 owing to a lack of time, skilled lab personnel, or suitable equipment or electricity.

The basic reproduction number (R0) of ebola virus disease: A systematic review and meta-analysis.

BACKGROUND: Ebola virus disease (Ebola) is highly pathogenic, transmissible, and often deadly, with debilitating consequences. Superspreading within a cluster is also possible. In this study, we aim to document Ebola basic reproduction number (R0): the average number of new cases associated with an Ebola case in a completely susceptible population. METHODS: We undertook a systematic review and meta-analysis. We searched PubMed, EMBASE, and Web of Science for studies published between 1976 and February 27, 2023. We also manually searched the reference lists of the reviewed studies to identify additional studies. We included studies that reported R0 during Ebola outbreaks in Africa. We excluded studies that reported only the effective reproduction number (Rt). Abstracting data from included studies was performed using a pilot-tested standard form. Two investigators reviewed the studies, extracted the data, and assessed quality. The pooled R0 was determined by a random-effects meta-analysis. R0 was stratified by country. We also estimated the theoretically required immunization coverage to reach herd-immunity using the formula of (1-1/R0) × 100 %. RESULTS: The search yielded 2042 studies. We included 53 studies from six African countries in the systematic review providing 97 Ebola mean R0 estimates. 27 (with 46 data points) studies were included in the meta-analysis. The overall pooled mean Ebola R0 was 1.95 (95 % CI 1.74-2.15), with high heterogeneity (I2 = 99.99 %; τ2 = 0.38; and p < 0.001) and evidence of small-study effects (Egger's statistics: Z = 4.67; p < 0.001). Mean Ebola R0 values ranged from 1.2 to 10.0 in Nigeria, 1.1 to 7 in Guinea, 1.14 to 8.33 in Sierra Leone, 1.13 to 5 in Liberia, 1.2 to 5.2 in DR Congo, 1.34 to 2.7 in Uganda, and from 1.40 to 2.55 for all West African countries combined. Pooled mean Ebola R0 was 9.38 (95 % CI 4.16-14.59) in Nigeria, 3.31 (95 % CI 2.30-4.32) in DR Congo, 2.0 (95 % CI 1.25-2.76) in Uganda, 1.83 (95 % CI 1.61-2.05) in Liberia, 1.73 (95 % CI 1.47-2.0) in Sierra Leonne, and 1.44 (95 % CI 1.29-1.60) in Guinea. In theory, 50 % of the population needs to be vaccinated to achieve herd immunity, assuming that Ebola vaccine would be 100 % effective. CONCLUSIONS: Ebola R0 varies widely across countries. Ebola has a much wider R0 range than is often claimed (1.3-2.0). It is possible for an Ebola index case to infect more than two susceptible individuals.

Comparison of 6 aptamer-aptamer pairs on rapid detection of SARS-CoV-2 by lateral flow assay.

BACKGROUND: SARS-CoV-2 is a threat for humanity. Both the Spike (S) protein and its receptor binding domain (sRBD) are extensively used for the rapid detection. Although real time reverse transcription polymerase chain reaction (rRT-PCR) is mostly used method for the molecular detection of SARS-CoV-2, rapid assays for antigenic detection is always needed. Lateral flow assays (LFAs) are the most commonly used tests for this purpose and aptamers having stability and long shelf life are used as capture reagents. OBJECTIVE: This study aimed to develop the LFAs based on the aptamer pairs for the antigenic detection of SARS-CoV-2 with naked eye. METHODS: Gold nanoparticles (AuNPs) were used as label and six sandwich models by three different aptamers were prepared using 4 µM and 8 µM probes and two kinds of membranes for developing the LFAs. RESULTS: 8 µM probe concentration and M2 membrane showed the best recognition of both the synthetic sRBD and SARS-CoV-2 coming from the naso/oropharingeal swabs by designed LFAs as 100% sensitivity and 93,3% specifity compared to the antibody detecting LFAs. CONCLUSIONS: Our developed strip assays based on aptamer pairs recognized the target, directly in a 5-6 minutes with naked eye. It was also concluded that aptamer pairs, membrane types, assay buffers and probe concentrations have significant role in the detection of SARS-CoV-2 by LFAs. HIGHLIGHTS: The detection of SARS-CoV-2 in clinical samples was demonstrated with the best aptamer pairs, sensitively and selectively among the designed 6 aptamer pairs for LFAs. Developed LFAs can be an alternative method to the conventional antibody based LFAs for SARS-CoV-2 detection.

Assessment of pre-referral treatment for malaria, diarrhea, and pneumonia by rural community health workers in Southwestern Uganda: a cross-sectional study.

BACKGROUND: Pre-referral treatment aims to stabilize the child's condition before transferring them to a higher level of healthcare. This study explored pre-referral treatment for diarrhea, malaria and pneumonia in children U5. The study aims to assess pre-referral treatment practices among community health workers (CHWs) for children aged 2 to 59 months diagnosed with malaria, diarrhea, and pneumonia. METHODS: Conducted in 2023, this study employed a quantitative retrospective analysis of secondary data gathered from March 2014 to December 2018. Among the subjects, 171 patients received pre-referral treatment, serving as the foundation for categorical data analysis, presenting proportions and 95% confidence intervals across different categories. RESULTS: In this cohort, 90 (53%) of the 177 children U5 were male, and age distribution showed 39 (23%), 70 (41%), and 62 (36%) in the 2-11 months, 12-35 months, and 36-60 months categories, respectively. Rapid Diagnostic Test (RDT) malaria results indicated a negative outcome in 83(60%) and positive in 55 (40%) of cases. Symptomatically, 45 (26%) had diarrhea, 52 (30%) exhibited fast breathing, and 109 (63%) presented with fever. Furthermore, 59 (35%) displayed danger signs, while 104 (61%) sought medical attention within 24 h. CONCLUSION: The study analyzed a sample of 171 children under 5 years old to assess various characteristics and variables related to pre-referral treatment. The findings reveal notable proportions in gender distribution, age categories, RDT results, presence of diarrhea, fast breathing, fever, danger signs, and timely medical visits. The results highlight the need to strengthen pre-referral treatment interventions and enhance iCCM programs.

Comparison of the Diagnostic Performances of Five Different Tests in Diagnosing Visceral Leishmaniasis in an Endemic Region of Ethiopia.

The lack of accurate and feasible diagnostic tests poses a significant challenge to visceral leishmaniasis (VL) healthcare services in endemic areas. To date, various VL diagnostic tests have been or are being developed, and their diagnostic performances need to be assessed. In the present study, the diagnostic performances of rk39 RDT, the direct agglutination test (DAT), microscopy, loop-mediated isothermal amplification (LAMP), and miniature direct-on-blood polymerase chain reaction-nucleic acid lateral flow immunoassay (mini-dbPCR-NALFIA) were assessed using quantitative polymerase chain reaction (qPCR) as the reference test in an endemic region of Ethiopia. In this study, 235 suspected VL cases and 104 non-endemic healthy controls (NEHCs) were recruited. Among the suspected VL cases, 144 (61.28%) tested positive with qPCR. The sensitivities for rk39 RDT, DAT, microscopy, LAMP assay, and mini-dbPCR-NALFIA were 88.11%, 96.50%, 76.58%, 94.33%, and 95.80%, respectively. The specificities were 83.33%, 97.96%, 100%, 97.38%, and 98.92% for rk39 RDT, DAT, microscopy, LAMP assay, and mini-dbPCR-NALFIA, respectively. In conclusion, rk39 RDT and microscopy exhibited lower sensitivities, while DAT demonstrated excellent performance. LAMP and mini-dbPCR-NALFIA showed excellent performances with feasibility for implementation in remote endemic areas, although the latter requires further evaluation in such regions.

Temporal Trend of the SARS-CoV-2 Omicron Variant and RSV in the Nasal Cavity and Accuracy of the Newly Developed Antigen-Detecting Rapid Diagnostic Test.

The aim of this work is to analyze the viral titers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and respiratory syncytial virus (RSV) at the anterior nasal site (ANS) and nasopharyngeal site (NS), evaluate their virological dynamics, and validate the usefulness of a newly developed two-antigen-detecting rapid antigen diagnostic test (Ag-RDT) that simultaneously detects SARS-CoV-2 and RSV using clinical specimens. This study included 195 asymptomatic to severely ill patients. Overall, 668 specimens were collected simultaneously from the ANS and NS. The cycle threshold (Ct) values calculated from real-time polymerase chain reaction were used to analyze temporal changes in viral load and evaluate the sensitivity and specificity of the Ag-RDT. The mean Ct values for SARS-CoV-2-positive, ANS, and NS specimens were 28.8, 28.9, and 28.7, respectively. The mean Ct values for RSV-positive, ANS, and NS specimens were 28.7, 28.8, and 28.6, respectively. SARS-CoV-2 and RSV showed the same trend in viral load, although the viral load of NS was higher than that of ANS. The sensitivity and specificity of the newly developed Ag-RDT were excellent in specimens collected up to 10 days after the onset of SARS-CoV-2 infection and up to 6 days after the onset of RSV infection.

Comparable performance of antigen-detecting rapid test by healthcare worker-collected and self-collected swabs for SARS-CoV-2 diagnostic: A systematic review and meta-analysis.

Usage of self-screening tests has become increasingly relevant in public health perspective for early detection of SARS-CoV-2 infection in the transitioning era of the COVID-19 pandemic into an endemic. This study was designed to compare the diagnostic accuracy of self-conducted and health professional-conducted SARS-CoV-2 rapid antigen tests (Ag-RDTs) and whether the sample was taken from anterior nasal or nasal mid-turbinate. Eligible comparative Ag-RDTs accuracy studies were retrieved from electronic databases systematically, in accordance with PRISMA. Selected studies were assessed for risk of bias using QUADAS-2 and QUADAS-C. In total, we selected five out of 1952 studies retrieved using the keywords. The overall sensitivity for the self-collected nasal swab method and healthcare worker-collected nasopharyngeal swab method was 79% (95% CI 68-87; I2  = 62%) and 83% (95% CI 75-89; I2  = 32%), respectively, which was not statistically different (p = 0.499). Nasal mid-turbinate swabs have a significantly higher sensitivity compared to anterior nasal swabs (p < 0.01). Both sampling methods represent high and comparable specificity values of 98% (95% CI 97-99; I2  = 0%) and 99% (95% CI 98-99; I2  = 0%). Positive predictive value (range 90%-99%) and negative predictive value (range 87%-98%) were equivalent for both methods. Our findings indicated the accuracy of self-collected Ag-RDT on nasal swabs was comparable to those performed by healthcare worker-collected on nasopharyngeal swabs. Self-collected Ag-RDT could be considered as a transmission prevention method in the transition of COVID-19 pandemic.

Implementation of a pharmacy-driven rapid bacteremia response program.

PURPOSE: This report describes a comprehensive pharmacy-driven rapid bacteremia response program. SUMMARY: This novel program positioned the pharmacy department at a large, community health system to receive and respond to critical microbiologic diagnostic testing results, 24/7/365. The program empowered pharmacists to provide centralized, comprehensive care including assessing blood culture Gram stain results, adjusting antibiotic therapy per protocol, ordering repeat blood cultures, analyzing and interpreting rapid molecular diagnostic test results, placing orders for contact isolation, and communicating antibiotic recommendations to the treatment team. In the first year after program implementation, 2,282 blood culture Gram stains and 2,046 rapid diagnostic test results were called in to the pharmacy department. The program reduced the median time to effective therapy in patients who did not already have active antimicrobial orders from over 10 hours to less than 1 hour. Based on the Gram stain results, antibiotics were started per protocol in 34.2% of patients. Based on the rapid molecular diagnostic test results, adjustments were made to antibiotic regimens in 55.7% of cases after discussion with a provider. Of these adjustments, 39.9% were for escalation of antibiotics and 37.7% were for de-escalation of antibiotics. CONCLUSION: By expanding the scope of pharmacy practice, barriers to optimizing clinical care were overcome.

Electrochemical Paper-Based Nanobiosensor for Rapid and Sensitive Detection of Monkeypox Virus.

Monkeypox virus (MPXV) infection was classified as a public health emergency of international concern by the World Health Organization (WHO) in 2022, being transmitted between humans by large respiratory droplets, in contact with skin lesions, fomites, and sexually. Currently, there are no available accessible and simple-to-use diagnostic tests that accurately detect MPXV antigens for decentralized and frequent testing. Here, we report an electrochemical biosensor to detect MPXV antigens in saliva and plasma samples within 15 min using accessible materials. The electrochemical system was manufactured onto a paper substrate engraved by a CO2 laser machine, modified with gold nanostructures (AuNS) and a monoclonal antibody, enabling sensitive detection of A29 viral protein. The diagnostic test is based on the use of electrochemical impedance spectroscopy (EIS) and can be run by a miniaturized potentiostat connected to a smartphone. The impedimetric biosensing method presented excellent analytical parameters, enabling the detection of A29 glycoprotein in the concentration ranging from 1 × 10-14 to 1 × 10-7 g mL-1, with a limit of detection (LOD) of 3.0 × 10-16 g mL-1. Furthermore, it enabled the detection of MPXV antigens in the concentration ranging from 1 × 10-1 to 1 × 104 PFU mL-1, with an LOD of 7.8 × 10-3 PFU mL-1. Importantly, no cross-reactivity was observed when our device was tested in the presence of other poxvirus and nonpoxvirus strains, indicating the adequate selectivity of our nanobiosensor for MPXV detection. Collectively, the nanobiosensor presents high greenness metrics associated with the use of a reproducible and large-scale fabrication method, an accessible and sustainable paper substrate, and a low volume of sample (2.5 µL), which could facilitate frequent testing of MPXV at point-of-care (POC).

Development of an Immunochromatography Assay to Detect Marburg Virus and Ravn Virus.

The recent outbreaks of Marburg virus disease (MVD) in Guinea, Ghana, Equatorial Guinea, and Tanzania, none of which had reported previous outbreaks, imply increasing risks of spillover of the causative viruses, Marburg virus (MARV) and Ravn virus (RAVV), from their natural host animals. These outbreaks have emphasized the need for the development of rapid diagnostic tests for this disease. Using monoclonal antibodies specific to the viral nucleoprotein, we developed an immunochromatography (IC) assay for the rapid diagnosis of MVD. The IC assay was found to be capable of detecting approximately 102-4 50% tissue culture infectious dose (TCID50)/test of MARV and RAVV in the infected culture supernatants. We further confirmed that the IC assay could detect the MARV and RAVV antigens in the serum samples from experimentally infected nonhuman primates. These results indicate that the IC assay to detect MARV can be a useful tool for the rapid point-of-care diagnosis of MVD.

Seroprevalence of SARS-CoV-2 antibodies and associated risk factors during the second wave of infection in a university community in Cameroon.

Background: The COVID-19 pandemic has caused a public health emergency in all sectors of society, including universities and other academic institutions in Cameroon. However, little is known concerning the real prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among student communities during the second wave of infection in Cameroon. This study aimed to estimate SARS-CoV-2 antibodies seroprevalence among participants in a university community in Cameroon. Methodology: A cross-sectional study was conducted from March to April 2021 in 547 students aged ≥18 years during a mass diagnostic campaign at the School of Health Sciences of the Catholic University of Central Africa (ESS/UCAC). The anti-SARS-CoV-2 antibody screening was done using the Panbio™ COVID-19 IgG/IgM Rapid Diagnostic Test. Results: The overall seroprevalence of SARS-CoV-2 antibodies was 27%, of which 89.9% (n = 133) was IgG, 6.7% (n = 10) IgM and 3.4% (n = 5) IgG/IgM positive. The undergraduate students represented 79% (432/547) of the total population and were highly positive with anti-SARS-CoV-2 antibodies 30% (130/432) as compared with postgraduate students 20% (23/115). The total antibody seropositivity was higher in males (34.4%) than females (24.9%). Several factors were associated with an increased risk of SARS-CoV-2 seroprevalence including the male gender (OR: 1.61 [95% confidence interval, CI 1.0-2.4]), specialization to medical laboratory (OR: 2.8 [95% CI 1.1-7.1]) and nursing sciences (OR: 2.6 [95% CI 1.1-6.2]). Conclusion: Our findings point to extensive and underreported circulation of SARS-CoV-2 in a university community during the second wave of infection in Cameroon, which likely resulted in artificially low case counts.

Estimation of parasitaemia in imported falciparum malaria using the results of a combined rapid diagnostic test. No big help from haematological parameters.

BACKGROUND: Microscopy continues to be the mainstay for the evaluation of parasitaemia in malaria but requires laboratory support and microbiological experience. Other fast and simple methods are necessary. METHODS: A retrospective observational study of imported malaria treated from July-2007 to December-2020 was carried out to evaluate the association between the degree of parasitaemia and both rapid diagnostic tests (RDT) reactivity patterns and haematological parameters. Plasmodium falciparum monoinfections diagnosed by peripheral blood smear and/or polymerase chain reaction (PCR),which also had a positive RDT result in the same blood sample, were included in the study. RESULTS: A total of 273 patients were included. Most of them were male (n = 256; 93.8%) and visiting friends and relatives (VFR) travellers (n = 252; 92.3%). Patients with plasmodial lactate dehydrogenase (pLDH) or aldolase and histidine-rich protein 2 (HRP-2) co-reactivity (Pan/Pf pattern) had a parasitaemia range between 0 and 37% while those with just HRP-2 reactivity (P. falciparum pattern) had ranges between 0 and 1%. Not a single case of P. falciparum pattern was found for parasitaemia ranges greater than 1%, showing a negative predictive value of 100% for high parasitaemia. All the correlations between haematological parameters and parasitaemia resulted to be weak, with a maximum rho coefficient of -0.35 for lymphocytes and platelets, and of 0.40 for neutrophils-to-lymphocytes count ratio. Multivariate predictive models were constructed reflecting a poor predictive capacity. CONCLUSIONS: The reactivity pattern of RDT allows a rapid semi-quantitative assessment of P. falciparum parasitaemia in travellers with imported malaria, discriminating patients with lower parasite loads. Haematological parameters were not able to estimate parasitaemia with sufficient precision.

Implementation of the Revised National Malaria Control Guidelines: Compliance and Challenges in Public Health Facilities in a Southern Nigerian State.

Background: There has been a concerted effort to reduce malaria burden and bring malaria related mortality to zero. The objectives of this survey were to assess the level of adherence to the current revised malaria control guidelines in the public health facilities in Cross River State of Nigeria and to identify the challenges as well as suggest ways for improvement in treatment outcomes. Methods: This was a mixed observational and qualitative survey conducted in 32 public health facilities from 21st to 25th June 2022. Treatment records on malaria were assessed for adherence to the National guidelines. In-depth interviews were conducted with 36 key informants and 4 purposefully selected stakeholders to identify the successes and challenges. Quantitative data were summarized and presented in simple proportions and percentages while qualitative information was recorded, the transcripts thematically coded, analyzed and presented using NVivo 11 software. Results: The survey revealed that vector control program was poorly implemented across the state. For case management, presumptive treatment was frequently practiced especially at secondary health facilities for uncomplicated malaria. More than 60% of uncomplicated malaria were being treated with parenteral artemether instead of oral artemisinin combination therapy (ACTs) as recommended. Severe malaria were not treated with Intravenous (IV) Artesunate as first line drug in about 40% of the secondary health facilities. Key successes were noted in malaria management in pregnancy. Major challenges identified include: stock out of commodities, shortage of clinical man power, and low trust in parasitological diagnosis. Conclusion: The survey showed that adherence to the key recommendations in various categories of malaria control among health care providers in the public health facilities was below expectation. Malaria preventive treatment in pregnancy with SP fared better perhaps because of its inclusion in ANC packages.

Experiences of healthcare personnel on the efficacy of artemisinin-based combination therapy and malaria diagnosis in hospitals in Uganda.

BACKGROUND: The risk of widespread resistance to artemisinin-based combination therapy (ACT) remains high in Uganda following detection of Plasmodium falciparum parasites with delayed artemisinin clearance genotype and phenotype. Establishment of context specific interventions to mitigate emergence and spread of artemisinin resistance is thus key in the fight against malaria in the country. The aim of this study was to explore the experiences of healthcare personnel on malaria diagnosis and self-reported efficacy of ACT in the management of malaria symptomatic patients in hospitals in low and high malaria transmission settings in Uganda. METHODS: This was a qualitative study in which data was collected from healthcare personnel in hospitals using key informant interviews. The key informant interview guide was developed, pre-tested prior to use and covered the following areas, (i) sociodemographic characteristics, (ii) malaria diagnosis (clinical and parasite based), (iii) quality-assured artemisinin-based combination therapy, (iv) malaria patient follow-up, (v) artemisinin resistance, (vi) anti-malarial self-medication. Data was entered in Atlas.ti ver 9.0 and analysis done following a framework criterion. RESULTS: A total of 22 respondents were interviewed of which 16 (72.7%) were clinicians. Majority, 81.8% (18/22) of the respondents were male. The following themes were developed from the analysis, malaria diagnosis (procedures and challenges), use of malaria laboratory test results, malaria treatment in hospitals, use of quality assured ACT (QAACT) in malaria treatment, and efficacy of ACT in malaria treatment. CONCLUSION: Most healthcare personnel-initiated malaria treatment after a positive laboratory test. Cases of malaria patients who report remaining symptomatic after prior use of ACT exist especially in high malaria transmission settings in Uganda. There is need for regular monitoring of artemisinin resistance emergence and spread in the country.