SARS-CoV-2 exposure in Malawian blood donors: an analysis of seroprevalence and variant dynamics between January 2020 and July 2021

Background By August 2021, the COVID-19 pandemic has been less severe in sub-Saharan Africa than elsewhere. In Malawi, there have been three subsequent epidemic waves. We therefore aimed to describe the dynamics of SARS-CoV-2 exposure in Malawi. Methods We measured the seroprevalence of anti-SARS-CoV-2 antibodies amongst randomly selected blood transfusion donor sera in Malawi from January 2020 to July 2021 using a cross-sectional study design. In a subset, we also assessed in vitro neutralisation against the original variant (D614G WT) and the Beta variant. Results A total of 5085 samples were selected from the blood donor database, of which 4075 (80.1%) were aged 20–49 years. Of the total, 1401 were seropositive. After adjustment for assay characteristics and applying population weights, seropositivity reached peaks in October 2020 (18.5%) and May 2021 (64.9%) reflecting the first two epidemic waves. Unlike the first wave, both urban and rural areas had high seropositivity in the second wave, Balaka (rural, 66.2%, April 2021), Blantyre (urban, 75.6%, May 2021), Lilongwe (urban, 78.0%, May 2021), and Mzuzu (urban, 74.6%, April 2021). Blantyre and Mzuzu also show indications of the start of a third pandemic wave with seroprevalence picking up again in July 2021 (Blantyre, 81.7%; Mzuzu, 71.0%). More first wave sera showed in vitro neutralisation activity against the original variant (78% [7/9]) than the beta variant (22% [2/9]), while more second wave sera showed neutralisation activity against the beta variant (75% [12/16]) than the original variant (63% [10/16]). Conclusion The findings confirm extensive SARS-CoV-2 exposure in Malawi over two epidemic waves with likely poor cross-protection to reinfection from the first on the second wave. The dynamics of SARS-CoV-2 exposure will therefore need to be taken into account in the formulation of the COVID-19 vaccination policy in Malawi and across the region. Future studies should use an adequate sample size for the assessment of neutralisation activity across a panel of SARS-CoV-2 variants of concern/interest to estimate community immunity.

Comparison between acupuncture therapy and gabapentin for chronic pain: a pilot study

Background: We examined whether the effect of true electroacupuncture on pain and functionality in chronic pain participants can be differentiated from that of medication (gabapentin) by analyzing quantitative sensory testing (QST). Methods: We recruited chronic back and neck pain participants who received six sessions (twice weekly) of true electroacupuncture versus sham electroacupuncture or 3 weeks of gabapentin versus placebo treatment. QST profiles, pain scores, and functionality profile were obtained at baseline (visit 1) and after three sessions (visit 4) or six sessions (visit 7) of acupuncture or 3 weeks of gabapentin or placebo. Results: A total of 50 participants were analyzed. We found no differences in QST profile changes (p = 0.892), pain reduction (p = 0.222), or functionality (p = 0.254) between the four groups. A major limitation of this pilot study was the limited number of study participants in each group. Conclusion: This pilot study suggests that a large-scale clinical study with an adequate sample size would be warranted to compare acupuncture and medication therapy for chronic pain management. Trial registration number: NCT01678586 (ClinicalTrials.gov).

Techniques of hollow maxillary dentures: a literature review

Clinically, the management of severy atrophic maxilla might represent a significant challenge for the attending dentists and surgeons to successfully perform and achieve fabricated complete maxillary dentures. Making a hollow denture base for these defects has also been previously reported as a valid approach that can be used to decrease the weight of the maxillary prosthesis. Many modalities have been proposed for these procedures with favorable outcomes, and variable events of disadvantages and adverse events. This literature review aims to collect enough evidence regarding the different reported techniques of the hollow maxillary denture, according to the different studies. Many techniques have been previously reported as using magnets, using implants, intramucosal inserts, springs, suction disks, lightweight dentures, and modified impression techniques. Many materials have been previously used with the 3D spacers of the lightweight denture techniques as dental stone, silicon putty, cellophane-wrapped asbestos, light-body coated gauze, modeling clay, salt, thermocol, caramel, and glycerine soap. Favoring one of the modalities over the other requires the inauguration of future studies with an adequate sample size to validate the efficacy and safety of these modalities. All of this information is furtherly discussed within the manuscript based on the collected evidence from the different studies in the literature.

The Sampling Conundrum in Qualitative Research: Can Saturation Help Alleviate the Controversy and Alleged Subjectivity in Sampling?

Sampling is one of the most controversial matters in qualitative research. Qualitative researchers have often been denounced for not giving adequate rationalisations for their sample size resolutions. This study aimed to provide an extensive review of sampling methods used in qualitative research and discuss the extent to which saturation might help alleviate the issues concerning these methods, sample size sufficiency and when to sample. The study specifically honed on the sampling adequacy (how big or how small should a sample be), the sampling techniques used and whether sample sizes should be delineated a priori, posteriori or during analysis. Having highlighted, the paradoxically nature of these aspects, through an overview of the sampling process, the researcher explored saturation as a tool to alleviate the challenges and the lack of objectivity in sampling in qualitative research. The overall findings were that, saturation does provide same degree of transparency and quality in sampling, but the concept is not immune to controversy, guidelines on how to apply it or achieve it remain foggy and contestable among researchers. Discussions are in most cases oversimplified and comparatively unknowledgeable. The answer to the research question, was that, what really constitutes an adequate sample size is only answerable within the context of the study, scientific paradigm, epistemological stance, ontological and methodological assumptions of the research conducted. Contextualisation of the mode of saturation adopted, clear articulation of the research methodology and transparent reporting of the whole process is key to enhance the role of saturation in alleviating subjectivity in sampling. This paper sought to make a contribution to the on-going methodological discourse on how qualitative researchers can justify their sampling decisions.

The Addition of Endometrial Injury to Freeze-All Strategy in Women with Repeated Implantation Failures

(1) Background: Recurrent implantation failure (RIF) after IVF remains a challenging topic for fertility specialists and a frustrating reality for patients with infertility. Various approaches have been investigated and applied towards the improvement of clinical outcomes. Through a nonrandomized clinical trial, we evaluated the effect of the combination of hysteroscopic endometrial injury and the freeze-all technique on pregnancy parameters in a cohort of RIF patients; (2) Methods: The study group comprised of 30 patients with RIF that underwent a hysteroscopic endometrial injury prior to a frozen embryo transfer cycle; another 30 patients with RIF, comprising the control group, underwent a standard frozen cycle with no adjuvant treatment before. Live birth comprised the primary outcome. Logistic and Poisson regression analyses were implemented to reveal potential independent predictors for all outcomes. (3) Results: Live birth rates were similar between groups (8/30 vs. 3/30, p = 0.0876). Biochemical and clinical pregnancy and miscarriages were also independent of the procedure (p = 0.7812, p = 0.3436 and p = 0.1213, respectively). The only confounding factor that contributed to biochemical pregnancy was the number of retrieved oocytes (0.1618 ± 0.0819, p = 0.0481); (4) Conclusions: The addition of endometrial injury to the freeze-all strategy in infertile women with RIF does not significantly improve pregnancy rates, including live birth. A properly conducted RCT with adequate sample size could give a robust answer.

Vertical transmission of Severe Acute Respiratory Syndrome Coronavirus 2: A scoping review

Introduction The evidence for vertical transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is not well established. Therefore, the objective of this review is to summarize emerging evidence on the vertical transmission of Severe Acute Respiratory Syndrome Coronavirus 2. Methods We conducted a systematic search in PubMed, CINAHL, Web of Science, SCOPUS, and CENTRAL. Likewise, a search for preprint publications was conducted using MedRxiv and Research Square. Studies that addressed vertical transmission of SARS-CoV-2 (concept) among pregnant women infected by Covid-19 (population) in any setting (community, hospital, or home) in any country or context were considered for inclusion. Any types of studies or reports published between December 2019 and September 2020 addressing the effects of SARS-CoV-2 on pregnant women and their newborn babies were included. Studies were screened for eligibility against the inclusion criteria for the review by two reviewers. Results We identified 51 studies reporting 336 newborns screened for COVID-19. From the 336 newborns screened for COVID-19, only 15 (4.4%) were positive for throat swab RT-PCR. All neonates with positive throat swab RT-PCR were delivered by cesarean section. Among neonates with throat swab SARS-CoV-2 positive only five (33.3%) had concomitant placenta, amniotic fluid, and cord blood samples tested, of which only one amniotic fluid sample is positive for RT PCR. Five neonates had elevated IgG and IgM but without intrauterine tissue tested. Four neonates had chest imaging suggestive of COVID-19 pneumonia. Conclusion Currently there is not enough evidence on vertical virologic transmission of COVID-19 infection during the third trimester of pregnancy. Additionally, there is no evidence to support cesarean delivery, abstaining from breast feeding nor mother and infant separation. Further research involving an adequate sample size of breast milk, placenta, amniotic fluid, and cord blood to ascertain the possibility of vertical transmission and breast milk transfer is needed.

Digital Slickline: Case Studies Highlighting Impact of Real-Time Slickline and Efficiency Improvements Compared to Traditional Slickline & E-Line Interventions

Digital Slickline (DSL) using radio frequency (RF) communications has been deployed in the field since late 2016 and has completed more than 600 jobs, and 2000 runs globally. Several papers have been published outlining how DSL has been deployed for eline replacement services such as perforating, explosive and non-explosive plug setting, production logging, and various other services. What has been less discussed are the efficiencies with surface readout (SRO) downhole data during typical slickline (SL) interventions where jarring is the prominent feature. RF DSL was introduced to the market in late 2016, and since this time, the split between SL and eline replacement services has been relatively consistent at 60/40. The separation isn't unreasonable as most interventions start as SL to prepare the well, move to a diagnostic or well repair phase, and close-out with SL to bring the well back onto production. Case histories presented will outline how SRO in-situ data give operations confidence tasks were completed as planned on gas lift change-outs and non-typical functions like a smart hole finder for leak detection. Today, we have an adequate sample size to validate the efficiency improvements deploying RF DSL compared to the traditional SL/eline intervention model. The one rig up setup off a small footprint slickline unit has proven to save multiple hours depending on the intervention complexity, and the number of eline rig up & rig down sequences eliminated. As the technology gains acceptance, the tool portfolio has continuously expanded, and we have started to leverage opportunities on traditional slickline services to minimize deferred production. Efficiency savings are well documented, but the paper will also detail the polymer-coated cable performance, with focus on breaking strength, corrosive parameters, wellbore fluid compatibility and new critical performance indicators completed before each job. We will close out by summarizing some of the newer technologies that will continue the improved efficiency theme.

Cross-Sectional Seroepidemiologic Study of Coronavirus Disease 2019 (COVID-19) among Close Contacts, Children, and Migrant Workers in Shanghai

(1) Background: Along with an increasing risk caused by migrant workers returning to the urban areas for the resumption of work and production and growing epidemiological evidence of possible transmission during the incubation period, a study of Coronavirus Disease 2019 (COVID-19) is warranted among key populations to determine the serum antibody against the SARS-CoV-2 and the carrying status of SARS-CoV-2 to identify potential asymptomatic infection and to explore the risk factors. (2) Method: This is a cross-sectional seroepidemiologic study. Three categories of targeted populations (close contacts, migrant workers who return to urban areas for work, and school children) will be included in this study as they are important for case identification in communities. A multi-stage sampling method will be employed to acquire an adequate sample size. Assessments that include questionnaires and blood, nasopharyngeal specimens, and feces collection will be performed via home-visit survey. (3) Ethics and Dissemination: The study was approved by the Institute Review Board of School of Public Health, Fudan University (IRB#2020-04-0818). Before data collection, written informed consent will be obtained from all participants. The manuscripts from this work will be submitted for publication in quality peer-reviewed journals and presented at national or international conferences.

Profiles of Amino Acid in Indonesian Neonates

Background: Amino acid profiles in newborns is a sign of its nutritional status and it reflects the protein intake of the mother before and during pregnancy. The amino acid level is also a predictor of improved growth velocity and the only tool for diagnosis of amino acid disorder in suspected individuals. In Indonesia, based on National Basic Health Research year 2018, 48.8% of pregnant mother has anemia and 13% babies were underweight. Determining amino acid profiles is important to differentiate pathologic from normal condition in newborn population. There are only a few reports with adequate sample size on amino acid profiles in newborns from South East Asian Countries and none from the Indonesian population. Methods: This is the first descriptive study in Indonesia newborns population determining the profiles of amino acid concentration from dried blood spot (DBS) sample by liquid chromatography-tandem-mass spectrometry (LC-MS/MS) system. This study used DBS sample obtained from the newborns’ heel pricks, which is easier to store and handle in Indonesia’s landscape. This will allow samples from remote area to be safely transported to referral laboratory. Results: A total of 993 healthy newborns from 25 provinces and districts in Indonesia were included in this study. All samples were stored at -20oC and analyzed within 1 month. The amino acid concentration profile was summarized as 95% reference interval determined using nonparametric method. The result for most amino acid was only slightly different from previously reported reference from various population which was presumably caused by food preference. This study’s result is expected to be implemented in Indonesian population. Conclusions: Determining the amino acid profile in neonates using DBS is dependable. The result from this study is expected to be applied in our center and other referral hospital for inborn error of metabolism screening.

Determinazione della numerosità campionaria

Determining the adequate sample size for a clinical trial is crucial in the design of an epidemiological study. In fact the question about the number of subjects need to study is common for clinical investigators, because a correct sample size is fundamental to obtain reliable findings. The larger the sample size under study, the greater the chance of detecting, as statistically significant, a clinically important effect it exists. This issue is related to the precision and the power of a study in measuring the difference between treatments being studied, the validity and accuracy of a diagnostic test, the occurrence of a disease. However, conducting a study with an adequate sample size is fundamental not only in statistical terms, but also from an ethical point of view. It is unjustifiable to expose patients to the risks of a research if the study has not the necessary preconditions to obtain findings useful to substantial scientific progress. Calculating sample size depends on several issues, such as the type of sampling method, the type of the study, the desired power and level of confidence fixed for the study. The aim of this article is to summarize the criterions for defining the appropriate sample size and to present some examples of methods for its calculating. (Epidemiology_statistics)