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Temporal correlations between RBD-ACE2 blocking and binding antibodies to SARS-CoV-2 variants in CoronaVac-vaccinated individuals and their persistence in COVID-19 patients.
Antibodies play a crucial role in protection against SARS-CoV-2. Understanding the correlation between binding and functional antibodies is essential to determine whether binding antibody levels can reliably predict neutralizing activity. We assessed antibody responses in 111 individuals vaccinated with the inactivated vaccine CoronaVac and 111 COVID-19 patients in Thailand. Plasma levels of ACE2-blocking antibodies targeting the receptor-binding domain (RBD) of SARS-Co-V2 variants were measured before vaccination and at 14 and 28 days after the second dose using a multiplex surrogate virus neutralization test. Anti-spike and anti-nucleocapsid antibodies were quantified by electrochemiluminescence immunoassay, and anti-RBD IgG by ELISA. After vaccination, blocking, anti-spike, and IgG antibody levels increased but declined rapidly within a month, whereas antibody levels in COVID-19 patients increased and persisted. Blocking and anti-spike antibody correlated at day 14 post-vaccination but not at day 28. In COVID-19 patients, correlations were moderate at day 14, and stronger at day 28. Correlations were weaker for Omicron subvariants than for the ancestral strain and non-Omicron variants. The weak correlation between blocking and anti-RBD IgG suggests binding antibodies might not predict neutralizing activity. These findings highlight the temporal nature of CoronaVac-induced immunity and the need for booster doses and variant-adapted vaccine.
Safety and efficacy of single-dose primaquine to interrupt Plasmodium falciparum malaria transmission in children compared with adults: a systematic review and individual patient data meta-analysis.
BackgroundAdding a single dose of primaquine to artemisinin-based combination therapy (ACT) for the treatment of falciparum malaria can reduce the transmission of Plasmodium falciparum and could limit the spread of artemisinin partial resistance, including in Africa, where the disease burden is greatest. We aimed to compare the safety and efficacy of single-dose primaquine plus ACT between young children (aged <5 years) and older children (aged 5 years to <15 years) and adults (aged ≥15 years), and between low and moderate-to-high transmission areas.MethodsFor this systematic review and individual patient data meta-analysis, we searched PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, WHO Global Index Medicus, OpenGrey.eu, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform, from database inception to April 3, 2024, with no language restrictions. We included prospective studies on efficacy against falciparum malaria that enrolled at least one child younger than 15 years and involved a study group given a single dose of primaquine (≤0·75 mg/kg) plus ACT. Studies involving mass drug administration, healthy volunteers, or patients with severe malaria or mixed (with non-falciparum) infections were excluded. For inclusion in the efficacy analysis, data on transmission potential (as determined by gametocytaemia, infectivity, or both) at enrolment and follow-up (day 3, day 7, or day 14) were required; the safety analysis required data on haemoglobin concentrations or haematocrit values at enrolment and at one or more follow-up visits by day 7, any data on adverse events, or both. After independent screening of the search results by two reviewers, the investigators of eligible studies were invited to contribute individual patient data. We quantified day 7 gametocyte carriage, probability of infecting a mosquito, decreases (>25%) in haemoglobin concentration associated with anaemia, and adverse events until day 28 using regression analyses, with random study-site intercepts to account for clustered data. These analyses were registered with PROSPERO, CRD42021279363 (safety) and CRD42021279369 (efficacy).FindingsOf 5697 records identified by the search, 30 studies were eligible for analysis. Of these, individual patient data were shared for 23 studies, including 6056 patients from 16 countries: 1171 (19·3%) young children (aged <5 years), 2827 (46·7%) older children (aged 5 years to <15 years), and 2058 (34·0%) adults (aged ≥15 years). Adding a single low dose of primaquine (0·2-0·25 mg/kg) to ACTs reduced day 7 gametocyte positivity (adjusted odds ratio [aOR] 0·34, 95% CI 0·22-0·52; p<0·001) and infectivity to mosquitoes over time (aOR per day 0·02, 0·01-0·07, p<0·001). No difference was found in the effect of single low-dose primaquine both on gametocyte positivity in young children compared with older children (1·08, 0·52-2·23; p=0·84) and adults (0·50, 0·20-1·25; p=0·14) and between low-transmission and moderate-to-high transmission settings (1·07, 0·46-2·52; p=0·86), and on infectivity to mosquitoes in young children compared with older children (1·36, 0·07-27·71; p=0·84) and adults (0·31, 0·01-8·84; p=0·50) and between low-transmission and moderate-to-high transmission settings (0·18, 0·01-2·95; p=0·23). Gametocyte clearance was also similar for different ACTs (dihydroartemisinin-piperaquine vs artemether-lumefantrine) when combined with a primaquine target dose of 0·25 mg/kg (1·56, 0·65-3·79; p=0·32 at day 7). However, patients given a primaquine dose of less than 0·2 mg/kg with dihydroartemisinin-piperaquine were more likely to have gametocytaemia than those treated with artemether-lumefantrine (5·68, 1·38-23·48; p=0·016 at day 7). There was no increase in anaemia-associated declines in haemoglobin concentration (>25%) at a primaquine dose of 0·25 mg/kg, regardless of age group, transmission setting, and glucose-6-phosphate dehydrogenase status. The risks of adverse events of grade 2 or higher and of serious adverse events were similar between primaquine and no-primaquine groups, including in young children.InterpretationRegardless of malaria transmission intensity and age group, a single dose of 0·25 mg/kg primaquine is safe and efficacious for reducing P falciparum transmission. These findings underscore the need for primaquine formulations suitable for young children, and also provide supportive evidence to expand the use of single low-dose primaquine in regions with a moderate-to-high transmission rate that are threatened by artemisinin partial resistance.FundingThe EU and the Bill & Melinda Gates Foundation.
Leptospirosis, melioidosis, and rickettsioses in the vicious circle of neglect
The global priorities in the field of infectious diseases are constantly changing. While emerging viral infections have regularly dominated public health attention, which has only intensified after the COVID-19 pandemic, numerous bacterial diseases have previously caused, and continue to cause, significant morbidity and mortality—deserving equal attention. Three potentially life-threatening endemic bacterial diseases (leptospirosis, melioidosis, and rickettsioses) are a huge public health concern especially in low- and middle-income countries. Despite their continued threat, these diseases do not receive proportionate attention from global health organizations and are not even included on the WHO list of neglected tropical diseases (NTDs). This, in turn, has led to a vicious circle of neglect with continued, yet conceivably preventable, hospitalizations and deaths each year especially in the vulnerable population. This is a call from a group of multi-institutional experts on the urgent need to directly address the circle of neglect and raise support in terms of funding, research, surveillance, diagnostics, and therapeutics to alleviate the burden of these 3 diseases.
Experiences, perceptions and ethical considerations of the malaria infection study in Thailand.
BackgroundThailand has made significant progress in malaria control efforts in the past decade, with a decline in the number of reported cases. However, due to cross-border movements over the past 5 years, reported malaria cases in Thailand have risen. The Malaria Infection Study in Thailand (MIST) involves deliberate infection of healthy volunteers with Plasmodium vivax malaria parasites, and the assessment of the efficacy of potential vaccine and drug candidates in order to understand acquired protection against malaria parasites.MethodsThis paper drew from ethics and social science qualitative study called MIST-ETHICS embedded within the MIST studies. MIST-ETHICS aimed to describe and understand the experiences, perceptions and ethical considerations of the MIST studies. Data were obtained from semi-structured interviews and a focus group discussion. A total of 46 participants participated in MIST-ETHICS .ResultsThree major themes emerged: experiences and perceptions of MIST, reasons for joining MIST, and ethical considerations. We found that although compensation was a motivation for participation, this was secondary to it being beneficial to self (health checks; link to health networks; building merit) and others (medical research contribution; altruism). Participants expressed varied opinions regarding the requirement of a university degree as one of the inclusion criteria for MIST.ConclusionsOur study revealed widespread concerns about long-term health effects and safety. Ethical considerations, including obtaining valid informed consent and ensuring participant inclusivitiy, were deem essential. Despite some debate regarding eligibility criteria, most participants agreed that the informed consent process was robust, accompanied by a strong sense of responsibility to contribute to the greater good. We emphasize the importance of continuously gathering participants' feedback for quality control, such as improving information materials to clarify the purpose of initial phases, their contributing to later phases, and the rationale behind each selection criterion.Trial registrationThis manuscript is part of the clinical trials registered under ClinicalTrials.gov IDs NCT04083508 (MIST1) registered on 5 Sep 2019 and NCT05071079 (MIST2) registered on 28 July 2021. However, the manuscript pertains to a qualitative study that does not require trial registration.
Comparing HemoCue® and Quantitative Buffy Coat® and Coulter Counter-measured haemoglobin concentrations in African children with acute uncomplicated malaria: a Bland-Altman analysis.
BackgroundAnaemia is a deleterious consequence of malaria, and its accurate diagnosis is crucial for effective management. However, laboratory methods for measuring haemoglobin (Hb) concentration, like the Coulter Counter and the Quantitative Buffy Coat® (QBC®), are costly and not widely accessible in resource-limited settings. The point-of-care HemoCue® test is a cheaper alternative and suitable in rural areas. The study aimed to determine the level of agreement between Coulter Counter/QBC® vs. HemoCue®-measured Hb concentrations by Bland-Altman analysis.MethodsAs part of a randomized, placebo-controlled trial of single low-dose primaquine in Ugandan and Congolese children with acute uncomplicated Plasmodium falciparum malaria, Hb concentrations were measured on days 0, 3, 7, and 28 using Coulter Counter (Uganda, n = 1880 paired values), QBC® (DR Congo, n = 1984 paired values) and HemoCue® Hb-301™. The predefined clinically acceptable limits were set at ± 0.5 g/dL.ResultsThe Bland-Altman analysis showed that the HemoCue® minus Coulter Counter mean Hb difference was - 0.15 g/dL with lower and upper limits of agreement of - 3.68 g/dL and 3.39 g/dL, respectively. Corresponding HemoCue® minus QBC® values were - 0.23 g/dL, - 1.66 g/dL and 1.22 g/dL. Linear regression of Hb concentration differences vs. mean Hb concentrations showed negative correlations: r = - 0.43 and r = - 0.34 for HemoCue® vs. Coulter Counter and HemoCue® vs. QBC®, respectively.ConclusionsCompared to Coulter and QBC®, mean HemoCue® measured Hb concentrations were lower and, compared to the Coulter or QBC® methods, had an overall tendency to measure lower Hb concentrations with increasing Hb concentrations. Upper and lower limits of agreement were wider than the predefined clinically acceptable limits of ± 0.5 g/dL. HemoCue® should be used with caution in settings where decisions about blood transfusions are made.
Advancing artemisinin resistance monitoring using a high sensitivity ddPCR assay for Pfkelch13 mutation detection in Asia.
The spread of Pfkelch13 mutations in Southeast Asia threatens the effectiveness of artemisinin-based combination therapies (ACTs) for malaria. Previous studies revealed a high prevalence of key mutations, including C580Y, P574L, and R561H, emphasizing the need for the surveillance to combat drug resistance. This study, we developed a droplet digital PCR (ddPCR) assay for the rapid screening of common mutations including P441L, Y493H, P527H, G538V, R539T, I543T, R561H, P574L, C580Y, and A675V. The assay was designed to detect minor populations of mutant strain within multiple infection, offering high sensitivity and specificity using artificial mixtures of mutant and wild-type alleles. Field samples collected in Thailand during 2015-2020 and in 2023 (N = 130) were also analyzed to validate the assay in a real-world setting. The ddPCR assay demonstrated exceptional performance, with 100% sensitivity and 90% specificity. The R539T, R561H, and C580Y mutations were detected in clinical samples collected from several study sites in Thailand. Notably, the R561H mutation was detected in 100% of the P. falciparum isolates from Mae Hong Son, Thailand in 2023, underscoring the assay's utility in identifying critical mutations associated with drug resistance. Moreover, ddPCR can detect multiple parasite populations in clinical samples and can be used to analyze the ratios of wild-type and mutant alleles. These results validate the assay's ability to serve as a powerful tool for the early detection of minor allele frequencies, facilitating the timely implementation of interventions to curb the spread of ACT resistance. The ddPCR assays developed in this study provide a sensitive and specific method for detecting Pfkelch13 mutations, allowing the identification of minor parasite populations with artemisinin resistance. These assays enhance our ability to monitor and respond to malaria drug resistance, offering a crucial tool for early detection and contributing to global malaria elimination efforts.
Bringing the real world into the classroom through team-based live brief projects
Team-based project work in higher education provides opportunities to enhance collaborative learning, to strengthen students' academic skills in a work-related context, and to instil valuable transferable skills that relate to the modern workplace. This chapter explores existing literature on live briefs, their relevance to graduate employability, and how the involvement of external stakeholders can bring real-world experience into the classroom as part of a social constructivist approach to learning. Alongside an analysis of the different approaches documented in the literature, Live Brief examples are presented from a final-year undergraduate Computing and Software Engineering learning context within a higher education Institution based in England. The pedagogical underpinnings, benefits, ethical considerations, and challenges of live briefs are discussed along with other factors such as the value of student-staff-stakeholder partnerships, the importance of collaboration between academia and industry, potential applications of Generative Artificial Intelligence (GenAI), and the power of Social and Emotional Learning (SEL) through engagement with social issues.
History of scrub typhus in Indonesia.
Scrub typhus is a common but underrecognized cause of fever in the Asia-Pacific region. This review is the first to examine the history of scrub typhus in the context of notable historical events in Indonesia. Scrub typhus was first observed in 1902 and has since been documented through colonial and modern times. However, the available evidence is sparse. This lack of data is influenced by wider factors, including geopolitical climate and socio-economic factors. During the colonial era and World War II, research focused on economic and military interests. There were research gaps during the unstable period following independence in 1945. More research commenced only in the 1970s, mainly under the auspices of the Ministry of Health. Since 2000, there have been sporadic attempts to study scrub typhus on several major islands (Java, Sumatra, Sulawesi, Borneo, Bali). We found 51 relevant articles documenting the presence of the pathogen and its vectors, with only a single case confirmed with standard laboratory testing. This lack of data, combined with low awareness and diagnostic capacity, makes it difficult for policymakers to appreciate the impact of scrub typhus. Indonesia needs sustainable and continuous surveillance systems, infrastructure and research funding to ensure diseases of public health importance are not neglected.
Understanding the primary healthcare context in rural South and Southeast Asia: a village profiling study
Abstract Background Understanding contextual factors is critical to the success of health service planning and implementation. However, few contextual data are available at the village level in rural South and Southeast Asia. This study addressed the gap by profiling representative villages across seven sites in Thailand (n=3), Cambodia, Laos, Myanmar and Bangladesh. Methods Key informant surveys supplemented by other information sources were used to collect data from 687 villages on four key indicators (literacy rate, and percentages of attended deliveries, fully immunised children and latrine coverage), as well as access to various services. Data were analysed descriptively. Results Sites varied considerably. Five were highly diverse ethno-culturally and linguistically, and all relied on primary health centres and village health/malaria workers as the main providers of primary healthcare. These were generally bypassed by severely ill patients for urban first-level referral hospitals and private sector facilities. While >75% of villages were near primary schools, educational attainment was generally low. Over 70% of villages at each site had mobile phone coverage and availability of electricity was high (≥65% at all sites bar Myanmar). Conclusion These results illustrate the similarities and differences of villages in this region that must be considered in public health research and policymaking.
Community responses to a novel house design: A qualitative study of "Star Homes" in Mtwara, southeastern Tanzania.
IntroductionTo evaluate the impact of a novel design "Star Home" on the incidence of malaria, respiratory tract infections and diarrheal diseases among children, randomly selected households in Mtwara, Tanzania were offered a free, new Star Home. Drawing on longitudinal qualitative research that accompanied the Star Homes study, this article describes the experiences of residents and the wider community of living with these buildings.MethodsA total of four rounds of face-to-face interviews were undertaken with residents of Star Homes (n = 37), control (wattle/daub) homes (n = 21), neighboring households n = 6), community members (n = 17) and community leaders (n = 6). The use of Star Homes was also observed over these four time periods between 2021 and 2023. Interviews were conducted in Swahili, transcribed, and translated into English for thematic analysis.ResultsStar Homes residents appreciated several aspects of the Star Homes, including overall comfort, access to water and electricity, and clean toilets. There were concerns about some design elements, such as poorly closing doors, stoves perceived as inefficient, and the façade, which was susceptible to rainwater ingress. The houses were not always used as intended by their developers, for example, residents were sleeping downstairs instead of upstairs because of cold floors or difficulties using the stairs. Star Homes residents described how the structures triggered praise but also envy from other community members.ConclusionsThe findings highlight the need for close attention to the use of novel design houses and careful sensitization around the potential benefits of dwellings to ensure that the intended health impacts of interventions are achieved.
The predictive capacity of biomarkers for clinical pulmonary oedema in patients with severe falciparum malaria is low: a prospective observational study.
BackgroundPulmonary oedema is a feared and difficult to predict complication of severe malaria that can emerge after start of antimalarial treatment. Proinflammatory mediators are thought to play a central role in its pathogenesis.MethodsAn exploratory study was conducted to evaluate the predictive capacity of biomarkers for development of clinical pulmonary oedema in patients with severe falciparum malaria at two hospitals in Bangladesh. Plasma concentrations of interleukin-6 (IL-6), IL-8, tumour necrosis factor (TNF), soluble Receptor of Advanced Glycation End-products (sRAGE), surfactant protein-D (SP-D), club cell secretory protein (CC16), and Krebs von den Lungen-6 (KL-6) on admission were compared with healthy controls. Correlations between these biomarker and plasma lactate and Plasmodium falciparum histidine-rich protein 2 (PfHRP2) levels were evaluated. Receiver Operating Characteristic (ROC) curves were constructed to assess the predictive capacity for clinical pulmonary oedema of the biomarkers of interest.ResultsOf 106 screened patients with falciparum malaria, 56 were classified as having severe malaria with a mortality rate of 29%. Nine (16%) patients developed clinical pulmonary oedema after admission. Plasma levels of the biomarkers of interest were higher in patients compared to healthy controls. IL-6, IL-8, TNF, sRAGE, and CC16 levels correlated well with plasma PfHRP2 levels (rs = 0.39; P = 0.004, rs = 0.43; P = 0.001, rs = 0.54; P s = 0.44; P s = 0.43; P = 0.001, respectively). Furthermore, IL-6 and IL-8 levels correlated well with plasma lactate levels (rs = 0.37; P = 0.005, rs = 0.47; P ConclusionsIL-6, IL-8, TNF, sRAGE, SP-D, CC16 and KL-6 cannot be used in predicting clinical pulmonary oedema in severe malaria patients.
Submicroscopic malaria in pregnancy and associated adverse pregnancy events: A case-cohort study of 4,352 women on the Thailand–Myanmar border
Background Malaria in pregnancy detected by microscopy is associated with maternal anaemia, reduced fetal growth, and preterm birth, but the effects of lower density (i.e., submicroscopic) malaria infections are poorly characterised. This analysis was undertaken to investigate associations between submicroscopic malaria at the first antenatal care (ANC) visit and these adverse pregnancy events on the Thailand–Myanmar border. Methods Blood samples taken from refugee and migrant pregnant women presenting for their first ANC visit were analysed retrospectively for malaria using ultrasensitive PCR (uPCR, limit of detection 22 parasites/mL). The relationships between submicroscopic malaria and subsequent microscopically detectable malaria, anaemia, birth weight, and preterm birth were evaluated using inverse probability weighting for stratified random sampling. Results First ANC visit samples from 4,352 asymptomatic women (median gestational age 16.5 weeks) attending between October 1st 2012 and December 31st 2015 were analysed. The weighted proportion of women with submicroscopic malaria infection was 4.6% (95% CI 3.9–5.6), comprising 59.8% (49.5–69.4) Plasmodium vivax, 6.5% (4.0–10.5) Plasmodium falciparum, 1.8% (0.9–3.6) mixed, and 31.9% (22.2–43.5) infections which could not be speciated. Submicroscopic parasitaemia at first ANC visit was associated with subsequent microscopically detected malaria (adjusted hazard ratio [HR] 12.9, 95% CI 8.8–18.8, p < 0.001) and lower birth weight (adjusted predicted mean difference −275 g, 95% CI −510 to −40, p = 0.022). There was no association with preterm birth. Submicroscopic P. falciparum mono-infection (adjusted HR 2.8, 95% CI 1.2–6.6, p = 0.023) and coinfection with P. falciparum and P. vivax (adjusted HR 10.3, 95% CI 2.6–40.4, p = 0.001) was associated with increased risk of maternal anaemia, but submicroscopic P. vivax mono-infection was not. That uPCR was conducted for only a part of the cohort due to cost constraints is a limitation. Conclusions In low transmission settings, uPCR identifies substantially more malaria infections at antenatal screening than conventional diagnostic methods. On the Thailand–Myanmar border, submicroscopic malaria at first antenatal consultation was associated with higher risks of microscopically diagnosed malaria later in pregnancy, anaemia, and reduced birth weight.
Effectiveness and Safety of Erector Spinae Plane Block vs. Conventional Pain Treatment Strategies in Thoracic Surgery
Background: An erector spinae plane block (ESPB) has gained popularity due to its effectiveness and simplicity for pain relief. However, it is uncertain whether an ESPB provides superior analgesia after a VATS or thoracotomy compared to other regional and systemic analgesic techniques. Methods: A retrospective cohort study was conducted from January to June 2023 comparing an ESPB with intravenous combination analgesia (IV–CA) in VATS patients and with thoracic epidural analgesia (TEA) in thoracotomy patients. The primary endpoint was the opioid demand during the first two hours in the post-anesthesia care unit (PACU). The secondary outcomes included the pain scores and adverse events. Results: A total of 61.2% of the 165 included VATS patients and 56.9% of the 72 thoracotomy patients were treated with an ESPB. Following a VATS, an ESPB decreased the median piritramide demand (7.5 [3.0 to 12.0] vs. 10.5 [6.5 to 15.5] mg, p < 0.01). However, after a thoracotomy, an ESPB increased the median piritramide demand (12.0 [6.0 to 15.0] vs. 3.0 [0.0 to 9.0] mg, p < 0.01). The pain scores and adverse events were similar between the groups. Conclusions: An ESPB reduces the piritramide demand in VATS patients compared with IV–CA, providing similar pain relief. However, in thoracotomy patients, an ESPB is associated with an increased piritramide demand compared to TEA. An ESPB is an attractive add-on to IV–CA after a VATS, while TEA remains the gold standard after a thoracotomy.
Disease Severity and Effective Parasite Multiplication Rate in Falciparum Malaria
Abstract Patients presenting with severe falciparum malaria in a Bangladeshi tertiary hospital had higher total parasite burden, estimated by parasitemia and plasma PfHRP2, than uncomplicated malaria patients despite shorter fever duration. This suggests that higher parasite multiplication rates (PMR) contribute to causing the higher biomass found in severe disease. Compared with patients without a history of previous malaria, patients with previous malaria carried a lower parasite biomass with similar fever duration at presentation, suggesting that host immunity reduces the PMR.