Rapid point-of-care CD4 testing at mobile units and linkage to HIV care: an evaluation of community-based mobile HIV testing services in South Africa

Healthcare access in humanitarian settings: Mobile services successes and limits in Afghanistan

With an ever-increasing number of humanitarian emergencies being declared around the globe, identifying effective methods to provide healthcare access to affected communities is all the more relevant to health practitioners. Mobile health services have been widely implemented by international and national actors to reach underserved communities in humanitarian contexts. Nonetheless, little rigorous evidence exists on the effects of such services. Our work contributes to filling the knowledge gap by studying the role of mobile health teams (MHTs) in Afghanistan after the institution of the Taliban De Facto Authority in 2021. We conduct correlational and quasi-experimental analysis of country-wide survey data and matched with geo-localised information on MHTs and their related service delivery points (SDPs) - at least in part of the country - from WHO and UNICEF. Our findings show mobile services enhance recent access to health care by about 11 percentage points (about 14% over comparison) based on our preferred model. We also identify a decreasing effect of number of MHTs and SDPs on healthcare access. Our results indicate that higher number of mobile services do not necessarily translate to better access, although strong differences exist between underserved and better served areas within the country.

Assessment of POC CD4 Detecting Mode in District or County Labs - Jiangsu Province, China, 2021

Objective

This study seeks to explore efficient and multiple-item detection modes in new-style HIV labs, as well as access the accuracy and reliability of CD4 cell count detected by point of care (POC) to analyze POC work feasibility in district or county labs.

Methods

POC devices adopted in grassroots-level labs and flow cytometers adopted in prefecture-level labs were used to analyze the same group of blood samples. The individual results were collected and compared for parametric tests in correlation and consistency.

Results

The Pearson correlation coefficients (r) between results detected by FACSPresto and those by FACSCalibur, FACSVia, FACSCantoII, and EPICSXL were 0.922, 0.938, 0.914, and 0.823, respectively; the average deviations were -25.64, 24.68, 3.05, and 70.97 cells/μL, respectively; the Pearson correlation coefficient (r) between results by Pima and FACSCalibur, FACSVia, FACSCantoII, and EPICSXL were 0.900, 0.950, 0.954, and 0.876, respectively; and the average deviations were -73.99, -40.78, -29.32, and -22.75 cells/μL, respectively.

Discussion

Strong positive correlations and good consistency were observed between the CD4 count tested by POC and flow cytometers. These findings provide theoretical support for new-style HIV labs and one-stop services, which can provide shorter testing duration and simpler testing processes, so that the most comprehensive testing results can be obtained in the shortest amount of time.

Establishing the cost of Xpert MTB/RIF mobile testing in high-burden peri-mining communities in South Africa

Background

Globally, tuberculosis remains a major cause of mortality, with an estimated 1.3 million deaths per annum. The Xpert MTB/RIF assay is used as the initial diagnostic test in the tuberculosis diagnostic algorithm. To extend the national tuberculosis testing programme in South Africa, mobile units fitted with the GeneXpert equipment were introduced to high-burden peri-mining communities.

Objective

This study sought to assess the cost of mobile testing compared to traditional laboratory-based testing in a peri-mining community setting.

Methods

Actual cost data for mobile and laboratory-based Xpert MTB/RIF testing from 2018 were analysed using a bottom-up ingredients-based approach to establish the annual equivalent cost and the cost per result. Historical cost data were obtained from supplier quotations and the local enterprise resource planning system. Costs were obtained in rand and reported in United States dollars (USD).

Results

The mobile units performed 4866 tests with an overall cost per result of $49.16. Staffing accounted for 30.7% of this cost, while reagents and laboratory equipment accounted for 20.7% and 20.8%. The cost per result of traditional laboratory-based testing was $15.44 US dollars (USD). The cost for identifying a tuberculosis-positive result using mobile testing was $439.58 USD per case, compared to $164.95 USD with laboratory-based testing.

Conclusion

Mobile testing is substantially more expensive than traditional laboratory services but offers benefits for rapid tuberculosis case detection and same-day antiretroviral therapy initiation. Mobile tuberculosis testing should however be reserved for high-burden communities with limited access to laboratory testing where immediate intervention can benefit patient outcomes.

Point-of-care serological assays for delayed SARS-CoV-2 case identification among health-care workers in the UK: a prospective multicentre cohort study

BACKGROUND

Health-care workers constitute a high-risk population for acquisition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Capacity for acute diagnosis via PCR testing was limited for individuals with mild to moderate SARS-CoV-2 infection in the early phase of the COVID-19 pandemic and a substantial proportion of health-care workers with suspected infection were not tested. We aimed to investigate the performance of point-of-care and laboratory serology assays and their utility in late case identification, and to estimate SARS-CoV-2 seroprevalence.

METHODS

We did a prospective multicentre cohort study between April 8 and June 12, 2020, in two phases. Symptomatic health-care workers with mild to moderate symptoms were eligible to participate 14 days after onset of COVID-19 symptoms, as per the Public Health England (PHE) case definition. Health-care workers were recruited to the asymptomatic cohort if they had not developed PHE-defined COVID-19 symptoms since Dec 1, 2019. In phase 1, two point-of-care lateral flow serological assays, the Onsite CTK Biotech COVID-19 split IgG/IgM Rapid Test (CTK Bitotech, Poway, CA, USA) and the Encode SARS-CoV-2 split IgM/IgG One Step Rapid Test Device (Zhuhai Encode Medical Engineering, Zhuhai, China), were evaluated for performance against a laboratory immunoassay (EDI Novel Coronavirus COVID-19 IgG ELISA kit [Epitope Diagnostics, San Diego, CA, USA]) in 300 samples from health-care workers and 100 pre-COVID-19 negative control samples. In phase 2 (n=6440), serosurveillance was done among 1299 (93·4%) of 1391 health-care workers reporting symptoms, and in a subset of asymptomatic health-care workers (405 [8·0%] of 5049).

FINDINGS

There was variation in test performance between the lateral flow serological assays; however, the Encode assay displayed reasonable IgG sensitivity (127 of 136; 93·4% [95% CI 87·8-96·9]) and specificity (99 of 100; 99·0% [94·6-100·0]) among PCR-proven cases and good agreement (282 of 300; 94·0% [91·3-96·7]) with the laboratory immunoassay. By contrast, the Onsite assay had reduced sensitivity (120 of 136; 88·2% [95% CI 81·6-93·1]) and specificity (94 of 100; 94·0% [87·4-97·8]) and agreement (254 of 300; 84·7% [80·6-88·7]). Five (7%) of 70 PCR-positive cases were negative across all assays. Late changes in lateral flow serological assay bands were recorded in 74 (9·3%) of 800 cassettes (35 [8·8%] of 400 Encode assays; 39 [9·8%] of 400 Onsite assays), but only seven (all Onsite assays) of these changes were concordant with the laboratory immunoassay. In phase 2, seroprevalence among the workforce was estimated to be 10·6% (95% CI 7·6-13·6) in asymptomatic health-care workers and 44·7% (42·0-47·4) in symptomatic health-care workers. Seroprevalence across the entire workforce was estimated at 18·0% (95% CI 17·0-18·9).

INTERPRETATION

Although a good positive predictive value was observed with both lateral flow serological assays and ELISA, this agreement only occurred if the pre-test probability was modified by a strict clinical case definition. Late development of lateral flow serological assay bands would preclude postal strategies and potentially home testing. Identification of false-negative results among health-care workers across all assays suggest caution in interpretation of IgG results at this stage; for now, testing is perhaps best delivered in a clinical setting, supported by government advice about physical distancing.

FUNDING

None.