The 10-year health impact, economic impact, and return on investment of the South African molecular diagnostics programme for HIV, Tuberculosis and SARS-CoV-2 (preprint)

To ensure there is adequate investment into diagnostics, an understanding of the magnitude of impact and return on investment is necessary. We therefore sought to understand the health and economic impacts of the molecular diagnostic programme in South Africa, to deepen the under-standing on the broad value of diagnostics and guide future healthcare investments. We calcu-lated the 10-year (where data were available) total cost and DALYs averted associated with molecular diagnosis of molecular TB testing (2013-2022), HIV viral load monitoring (2013-2022), early infant diagnosis of HIV infection (2013-2022), and SARS-CoV-2 testing (2020-2022). We then calculated the economic value associated with those health gains and subsequent return on investment. Since the inception of the molecular diagnostics programme in South Africa, 3,035,782 DALYs have been averted as a direct consequence of this pro-gramme. This has generated an estimated $20.5 billion in economic value due to these health gains. The return on investment varied by specific diagnostic test (19.0 for tuberculosis, 1.4 for HIV viral load testing, 64.8 for early infant diagnosis of HIV, and 2.5 for SARS-CoV-2), for an average of 9.9 for the entire molecular diagnostics programme between 2013 and 2022- or $9.9 of value for each $1 invested. The molecular diagnostics programme in South Africa gen-erated a significant amount of health gains and economic value associated with these health gains, and the return-on-investment rivals other high-impact public health interventions such as childhood vaccination. Consequently, the molecular diagnostics programme in South Africa is highly impactful, and will continue to be an excellent investment of South African public health expenditure.

How South Africa Used National Cycle Threshold (Ct) Values To Continuously Monitor SARS-CoV-2 Laboratory Test Quality (preprint)

The high demand for SARS-CoV-2 tests but limited supply to South African laboratories early in the COVID19 pandemic, resulted in a heterogenous diagnostic footprint of open and closed molecular testing platforms. Novel approaches were required to monitor test quality especially during the introduction of newly circulating variants. The National Health Laboratory Service centrally collected cycle threshold (Ct) values from 1,497,669 test results reported from six commonly used PCR assays in 36 months, and visually monitored changes in their median Ct within a 28-day centered moving average for each assays’ gene targets. This continuous quality monitoring rapidly identified delayed hybridization of RdRp in the Allplex™ SARS-CoV-2 assay due to the Delta (B.1.617.2) variant; S-gene target failure in the TaqPath™ COVID-19 assay due to B.1.1.7 (Alpha) and the B.1.1.529 (Omicron); and recently E-gene delayed hybridization in the Xpert® Xpress SARS-CoV-2 due to XBB.1.5. This near “real-time” monitoring helped inform the need for sequencing and the importance of multiplex molecular nucleic acid amplification technology designs used in diagnostics for patient care. This continuous quality monitoring approach at the granularity of Ct values should be included in ongoing surveillance and with application to other disease use cases that rely on molecular diagnostics.

Rapid Evaluation of the Xpert ® Xpress CoV-2 Plus and Xpert® Xpress CoV-2/Flu/RSV Plus Tests (preprint)

The Xpert® Xpress SARS-CoV-2 and Xpert® Xpress SARS-CoV-2/Flu/RSV tests were rapidly developed and widely used during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. In response to emerging genetic variability, a new SARS-CoV-2 target (RNA-dependent RNA-polymerase) has been added to both tests: Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus test. A rapid evaluation of both tests was performed in South Africa, using residual respiratory specimens. Residual respiratory specimens (n=125) were used to evaluate the Xpert® Xpress CoV-2 plus test and included 50 genotyped specimens. The Xpert® Xpress CoV-2/Flu/RSV plus test was assessed using 45 genotyped SARS-CoV-2 specimens, ten influenza A, ten Influenza B and twenty respiratory syncytial virus specimens. Results were com-pared to in-country standard of care tests. Genotyped specimens tested the performance of the test under pressure from circulating SARS-CoV-2 variants of concern. Reference material was included to assess the test limits and linearity. The Xpert® Xpress CoV-2 plus test performance compared to reference results across residual respiratory specimens was good (positive per-centage agreement (PPA)=95.2%, negative percentage agreement (NPA)=95.0%) The Xpert® Xpress CoV-2/Flu/RSV plus test showed good performance across all residual respiratory specimens (PPA=100%, NPA=98.3%). All genotyped variants of concern were detected by both tests. The Xpert® Xpress CoV-2 plus and Xpert® Xpress CoV-2/Flu/RSV plus tests can be used to diagnose SARS-CoV-2, and to diagnose and differentiate SARS-CoV-2, influenza A, influenza B and respiratory syncytial virus respectively. The NPA was lower than the recommended 99%, but was influenced by the low number of negative specimens tested. The variants of concern assessed did not affect test performance. It is recommended that sites perform their own assessments compared to in-country standard of care tests.

Cocoa honey: agro-industrial waste or underutilized cocoa by-product?

ABSTRACT The global cocoa and chocolate market is projected to reach EUR 169 billion by 2026 due to factors such as the growth of confectionery products in Asian countries and increased demand for premium cocoa-based products. In addition, there is an increasing demand for products with high cocoa content and organic chocolates. International commodity price fluctuations and the COVID-19 pandemic have had negative impact on global market prices also influencing the efficiency of circular economy. Therefore, cocoa production chain faces the challenge of finding sustainable ways to increase production while meeting the demands of modern society. Innovative developments in this area include adding value to residues, which account for approximately 80% of the fruit. Cocoa honey is a translucent juice produced during the cocoa fermentation process, with chemical and sensory characteristics similar to cocoa pulp. This juice has high contents of pectin, minerals, and fructose and technological potential to develop new products is foreseen. Its sweet taste, for instance, can be exploited in food preparations as a natural substitute for refined sugar. This review aimed to elucidate the nutritional, technological, and economic importance of the use of this edible underutilized by-product through innovative applications in the food and beverage industry.Image, graphical abstract

COVID-19 pandemic and pediatric dentistry: Fear, eating habits and parent's oral health perceptions.

BACKGROUND: Severe measures have been implemented around the world to reduce COVID-19 spread with a significant impact on family dynamics. AIM: To assess the impact of the pandemic on fear, dietary choices and oral health perceptions of parents. DESIGN: questionnaire containing 19 questions was remotely applied to 1003 parents of children aged 0-12 years. The questions addressed topics regarding changes in daily routine, dietary habits, fear level, oral health, and variation of income during the pandemic. Data analysis included the description of the relative and absolute frequencies of the variables. Association tests were performed using Fisher's exact and Kruskal-Wallis tests. RESULTS: 73% of respondents reported income loss. Five hundred sixty-eight people denied seeking medical or dental care. 61.5% of respondents revealed changes in the dietary pattern; most of them mentioned an increase in food intake. Most parents (66.6%) would only seek urgent dental care. There was an association between parents' willingness to take their children to dental appointments with the fear level (p < 0.001). CONCLUSIONS: Most families have experienced changes in daily routine and eating habits during the pandemic. Parents fear COVID-19 and it impacts their behavior regarding seeking dental care for their children.

Evolution and epidemic spread of SARS-CoV-2 in Brazil (preprint)

Brazil currently has one of the fastest growing SARS-CoV-2 epidemics in the world. Due to limited available data, assessments of the impact of non-pharmaceutical interventions (NPIs) on virus transmission and epidemic spread remain challenging. We investigate the impact of NPIs in Brazil using epidemiological, mobility and genomic data. Mobility-driven transmission models for Sao Paulo and Rio de Janeiro cities show that the reproduction number (Rt) reached below 1 following NPIs but slowly increased to values between 1 to 1.3 (1.0 - -1.6). Genome sequencing of 427 new genomes and analysis of a geographically representative genomic dataset from 21 of the 27 Brazilian states identified >100 international introductions of SARS-CoV-2 in Brazil. We estimate that three clades introduced from Europe emerged between 22 and 27 February 2020, and were already well-established before the implementation of NPIs and travel bans. During this first phase of the epidemic establishment of SARS-CoV-2 in Brazil, we find that the virus spread mostly locally and within-state borders. Despite sharp decreases in national air travel during this period, we detected a 25% increase in the average distance travelled by air passengers during this time period. This coincided with the spread of SARS-CoV-2 from large urban centers to the rest of the country. In conclusion, our results shed light on the role of large and highly connected populated centres in the rapid ignition and establishment of SARS-CoV-2, and provide evidence that current interventions remain insufficient to keep virus transmission under control in Brazil.