BACKGROUND
In low-resource settings, limited laboratory capacity adds to the burden of central nervous system (CNS) infections in children and spurs overuse of antibiotics. The commercially available BioFire® FilmArray® Meningitis/Encephalitis Panel (FA-ME) with its capability to simultaneously detect 14 pathogens in cerebrospinal fluid (CSF), could potentially narrow such a diagnostic gap.
METHODS
In Mbarara, Uganda, we compared clinical utility (clinical turnaround time [cTAT], microbial yield, and influence on patient outcome and antibiotic exposure) of FA-ME with bacterial culture, in children 0–12 years with suspected CNS infection.
RESULTS
Of 212 enrolled children, CSF was sampled from 194. All samples underwent bacterial culture, of which 193 also underwent FA-ME analyses. FA-ME analyses prospectively influenced care for 169 of the 193 patients, and they constituted an ‘Index group’. The remaining 43/212 patients constituted a ‘Reference group’. Of all 194 CSF-sampled patients, 87% (168) had received antibiotics before lumbar puncture. Median cTAT for FA-ME was 4.2 h, vs. two days for culture. Bacterial yield was 12% (24/193) and 1.5% (3/194) for FA-ME and culture, respectively. FA-ME viral yield was 12% (23/193). Fatality rate was 14% in the Index group vs. 19% in the Reference group (P = 0.20). From clinician receival of FA-ME results, median antibiotic exposure was 6 days for bacteria-negative vs. 13 days for bacteria-positive patients (P = 0.03). Median hospitalization duration was 7 vs. 12 days for FA-ME negative and positive patients, respectively (P < 0.01).
CONCLUSIONS
In this setting, clinical FA-ME utility was found in a higher and faster microbial yield and shortened hospitalization and antibiotic exposure of patients without CSF pathology. More epidemiologically customized pathogen panels may increase FA-ME utility locally, although its use in similar settings would require major cost reductions.
Severely malnourished patients can present with bilateral pitting oedema, which is a common sign of Kwashiorkor. However, bilateral pitting oedema can also be an expression of other pathologies. In Mali and DRC, the number of children presenting with bilateral pitting oedema at MSF (Médecins Sans Frontiers/Doctors Without Borders) hospitals are up to 30% (Mali) and 49% (DRC) higher than in other countries, however, the reasons underlying this trend are unknown. Through this qualitative study, we aimed to explore the perspectives and lived experiences of health professionals on the diagnosis and management of children with bilateral pitting oedema. Using a participatory approach, we conducted 21 in-depth interviews, and 2 focus groups with health professionals at MSF health facilities who had worked in the settings of Koutiala (Mali) and Rutshuru (DRC) for at least 6 months. The understanding of the bilateral pitting oedema phenomenon is complex. Health workers described clinical obstacles to reducing mortality, including: i) difficulties making the diagnosis due to a lack of specialized staff and insufficient resources, ii) challenges treating complications that may arise due to the complexity of the diseases associated with bilateral pitting oedema, and iii) lack of scientific evidence in the literature explaining the physiopathology of bilateral pitting oedema. Study participants shared several key recommendations for reducing mortality among children presenting with bilateral pitting oedema, including prevention of bilateral pitting oedema at the community level, standardization of the diagnostic process, strengthening of medical training, and better collaboration both within the medical teams and between teams and the children’s families.
Scanned: The global investments in computer-aided detection and ultraportable X-ray for tuberculosis
OBJECTIVES
Chest x‐ray (CXR) plays an important role in childhood tuberculosis (TB) diagnosis, but access to quality CXR remains a major challenge in resource‐limited settings. Digital CXR (d‐CXR) can solve some image quality issues and facilitate their transfer for quality control. We assess the implementation of introducing d‐CXR in 12 district hospitals (DHs) in 2021–2022 across Cambodia, Cameroon, Ivory Coast, Mozambique, Sierra Leone and Uganda as part of the TB‐speed decentralisation study on childhood TB diagnosis.
METHODS
For digitisation of CXR, digital radiography (DR) plates were setup on existing analogue radiography devices. d‐CXR were transferred to an international server at Bordeaux University and downloaded by sites' clinicians for interpretation. We assessed the uptake and performance of CXR services and health care workers' (HCW) perceptions of d‐CXR implementation. We used a convergent mixed method approach utilising process data, individual interviews with 113 HCWs involved in performing or interpreting d‐CXRs and site support supervision reports.
RESULTS
Of 3104 children with presumptive TB, 1642 (52.9%) had at least one d‐CXR, including 1505, 136 and 1 children with one, two and three d‐CXRs, respectively, resulting in a total of 1780 d‐CXR. Of them, 1773 (99.6%) were of good quality and 1772/1773 (99.9%) were interpreted by sites' clinicians. One hundred and sixty‐four children had no d‐CXR performed despite attending the radiography department: 126, 37 and 1 with one, two and three attempts, respectively. d‐CXRs were not performed in 21.6% (44/203) due to connectivity problem between the DR plate captor and the computer. HCW reported good perceptions of d‐CXR and of the DR plates provided. The main challenge was the upload to and download from the server of d‐CXRs due to limited internet access.
CONCLUSION
d‐CXR using DR plates was feasible at DH level and provided good quality images but required overcoming operational challenges.
Current malaria diagnostics are invasive, lack sensitivity, and rapid tests are plagued by deletions in target antigens. Here we introduce the Cytophone, an innovative photoacoustic flow cytometer platform with high-pulse-rate lasers and a focused ultrasound transducer array to noninvasively detect and identify malaria-infected red blood cells (iRBCs) using specific wave shapes, widths, and time delays generated from the absorbance of laser energy by hemozoin, a universal biomarker of malaria infection. In a population of Cameroonian adults with uncomplicated malaria, we assess our device for safety in a cross-sectional cohort (n = 10) and conduct a performance assessment in a longitudinal cohort (n = 20) followed for 30 ± 7 days after clearance of parasitemia. Longitudinal cytophone measurements are compared to point-of-care and molecular assays (n = 94). Cytophone is safe with 90% sensitivity, 69% specificity, and a receiver-operator-curve-area-under-the-curve (ROC-AUC) of 0.84, as compared to microscopy. ROC-AUCs of Cytophone, microscopy, and RDT compared to quantitative PCR are not statistically different from one another. The ability to noninvasively detect iRBCs in the bloodstream is a major advancement which offers the potential to rapidly identify both the large asymptomatic reservoir of infection, as well as diagnose symptomatic cases without the need for a blood sample.
BACKGROUND
Hepatitis C virus (HCV) antibody self-testing (HCVST) may help expand screening access and support HCV elimination efforts. Despite potential benefits, HCVST is not currently implemented in Pakistan. This study aimed to assess the usability and acceptability of HCVST in a high HCV prevalence informal settlement in Karachi, Pakistan.
METHODS
We performed a cross-sectional study in a hepatitis C clinic from April through June 2023. Participants were invited to perform a saliva-based HCVST (OraSure Technologies, USA) while following pictorial instructions. A study member evaluated test performance using a standardized checklist and provided verbal support if a step could not be completed. Perceived usability and acceptability were assessed using a semi-structured questionnaire. The HCVST was considered successful if the participant was able to complete all steps and correctly interpret test results. Overall concordance and positive and negative agreement were estimated in comparison with the HCVST result read by the study member (inter-reader concordance and agreement) and result of a second rapid HCV test (Abbott Diagnostics Korea Inc, South Korea) performed by a trained user (inter-operator concordance and agreement).
RESULTS
The study included 295 participants of which 97 (32%) were illiterate. In total, 280 (95%, 95% CI 92–97%) HCVSTs were successful. Overall, 38 (13%) people performed the HCVST without verbal assistance, 67 (23%) needed verbal assistance in one step, 190 (64%) in two or more. Assistance was most often needed in managing the test buffer and test reading times. The inter-reader concordance was 96% and inter-operator concordance 93%. Inter-reader and inter-operator positive percent agreement were 84 and 70%, respectively. All participants reported they would use HCVST again and would recommend it to friends and family.
CONCLUSION
Saliva-based HCVST was very well accepted in this clinic-based setting. However, many people requested verbal support in several steps, highlighting the need for clear instructions for use and test devices that are simple to use, particularly in low literacy settings. Moderately low positive percent agreement with the results of a rapid test performed by a trained user highlights potential uncertainty in the accuracy of HCVST in the hands of lay users.
Lassa fever is a viral haemorrhagic fever with few options for diagnosis and treatment; it is also under-researched with knowledge gaps on its epidemiology. A point-of-care bedside test diagnosing Lassa fever, adhering to REASSURED criteria, is not currently available but is urgently needed in west African regions with high Lassa fever burden. We aimed to assess the validity and feasibility of a rapid diagnostic test (RDT) to confirm Lassa fever in people in Nigeria.
METHODS
We estimated the diagnostic performance of the ReLASV Pan-Lassa RDT (Zalgen Labs, Frederick, MD, USA) as a research-use-only test, compared to RT-PCR as a reference standard, in 217 participants at a federal tertiary hospital in Abakaliki, Nigeria. We recruited participants between Feb 17, 2022, and April 17, 2023. The RDT was performed using capillary blood at the patient bedside and using plasma at the laboratory. The performance of the test, based on REASSURED criteria, was assessed for user friendliness, rapidity and robustness, sensitivity, and specificity.
FINDINGS
Participants were aged between 0 and 85 years, with a median age of 33·0 years (IQR 22·0-44·3), and 24 participants were younger than 18 years. 107 (50%) participants were women and 109 (50%) were men; one participant had missing sex data. Although the specificity of the Pan-Lassa RDT was high (>90%), sensitivity at bedside using capillary blood was estimated as 4% (95% CI 1-14) at 15 min and 10% (3-22) at 25 min, far below the target of 90%. The laboratory-based RDT using plasma showed better sensitivity (46% [32-61] at 15 min and 50% [36-64] at 25 min) but did not reach the target sensitivity. Among the 52 PCR-positive participants with Lassa fever, positive RDT results were associated with lower cycle threshold values (glycoprotein precursor [GPC] gene mean 30·3 [SD 4·3], Large [L] gene mean 32·3 [3·7] vs GPC gene mean 24·5 [3·9], L gene mean 28·0 [3·6]). Personnel conducting the bedside test procedure reported being hindered by the inconvenient use of full personal protective equipment and long waiting procedures before a result could be read.
INTERPRETATION
The Pan-Lassa RDT is not currently recommended as a diagnostic or screening tool for suspected Lassa fever cases. Marked improvement in sensitivity and user friendliness is needed for the RDT to be adopted clinically. There remains an urgent need for better Lassa fever diagnostics to promote safety of in-hospital care and better disease outcomes in low-resource settings.