Recent insights into egg quality and larval vitality of the European eel Anguilla anguilla.

To date, the eel industry still depends on wild-caught juveniles that are grown to marketable size. There is an urgent need to close the eel life cycle in captivity to make aquaculture independent of the natural population. With this artificial reproduction protocol, yolk-sac larvae can be produced but egg quality may be impaired. Low survival rates and high deformity rates are frequently observed during the first week after hatching. Over the past four years, we have conducted studies with the aim to optimize the artificial reproduction protocol, thereby focussing on increasing egg and larval quality. Weekly carp or salmon pituitary extract (PE) treatment was successfully replaced with recombinant gonadotropins (rGTHs) to mature female eels and produce larvae. 17α,20ß-dihydroxy-4-pregnen-3-one (DHP) was replaced with upstream precursor progesterone (P) to induce the endogenous production of DHP by the female eel. DHP and P were found equally potent in inducing oocyte maturation and ovulation. The effects of antibiotics on larval survival and the occurrence of deformities were investigated. Antibiotic treatment increased survival and decreased the occurrence of deformities indicating bacterial infection as an important cause. A deformity determination key for young eel larvae has been developed that provides a framework of reference for larval deformities which will be instrumental with gaining insights on the reasons behind each larval deformity. These improvements of the artificial reproduction protocol and hatchery practices will contribute to the production of robust eel larvae that survive, grow and metamorphose into juveniles that will later be able to reproduce in captivity.

A validation study of the Occupational Depression Inventory in Poland and Ukraine.

This study examined the psychometric and structural properties of the Polish and Ukrainian versions of the Occupational Depression Inventory (ODI). We relied on two samples of Polish employees (NSample1 = 526, 47% female; NSample2 = 164, 64% female) and one sample of Ukrainian employees (NSample3 = 372, 73% female). In all samples, the ODI exhibited essential unidimensionality and high total-score reliability (e.g., McDonald's omegas > 0.90). The homogeneity of the scale was strong (e.g., 0.59 ≤ scale-level Hs ≤ 0.68). The ODI's total scores thus accurately ranked individuals on a latent occupational depression continuum. We found evidence of complete measurement invariance across our samples, a prerequisite for between-group comparisons involving observed scores. Looking into the criterion validity of the ODI, we found occupational depression to correlate, in the expected direction, with resilience and job-person fit in six areas of working life-workload, control, rewards, community, fairness, and values. The prevalence of occupational depression was estimated at 5% in Sample 1, 18% in Sample 2, and 3% in Sample 3. Our findings support the use of the ODI's Polish and Ukrainian versions. This study adds to a growing corpus of research suggesting that the ODI is a robust instrument.

The burnout-depression conundrum: investigating construct-relevant multidimensionality across four countries and four patient samples.

This research seeks to contribute to the ongoing discussion about the distinctive nature of burnout and depression. In a first study, we relied on employee samples from four European countries (N = 5199; 51.27% women; Mage = 43.14). In a second study, we relied on a large sample of patients (N = 5791; 53.70% women; Mage = 39.54) who received a diagnosis of burnout, depressive episode, job strain, or adaptation disorder. Across all samples and subsamples, we relied on the bifactor exploratory structural equation modelling to achieve an optimal disaggregation of the variance shared across our measures of burnout and depression from the variance uniquely associated with each specific subscale included in these measures. Our results supported the value of this representation of participants' responses, as well as their invariance across samples. More precisely, our results revealed a strong underlying global factor representing participants' levels of psychological distress, as well as the presence of equally strong specific factors supporting the distinctive nature of burnout and depression. This means that, although both conditions share common ground (i.e. psychological distress), they are not redundant. Interestingly, our results also unexpectedly suggested that suicidal ideation might represent a distinctive core component of depression.

Clinical management of contrast-induced neurotoxicity: a systematic review.

BACKGROUND: Contrast-induced neurotoxicity (CIN) is an increasingly recognised complication following endovascular procedures utilising contrast. It remains poorly understood with heterogenous clinical management strategies. The aim of this review was to identify commonly employed treatments for CIN to enhance clinical decision making. METHODS: A systematic search of Embase (1947-2022) and Medline (1946-2022) was conducted. Articles describing (i) patients with a clinical diagnosis of CIN, (ii) with radiological exclusion of other pathologies, (iii) detailed report of treatments, and (iv) discharge outcomes, were included. Data relating to demographics, procedure, symptoms, treatment and outcomes were extracted. RESULTS: A total of 73 patients were included, with a median age of 64 years. The most common procedures were cerebral angiography (42.5%) and coronary angiography (42.5%), and the median volume of contrast administered was 150 ml. The most common symptoms were cortical blindness (38.4%) and reduced consciousness (28.8%), and 84.9% of patients experienced complete resolution at the time of discharge. Management included intravenous fluids to dilute contrast in the cerebrovasculature (54.8%), corticosteroids to reduce blood-brain barrier damage (47.9%), antiseizure (16.4%) and sedative (16.4%) medications. Mannitol (13.7%) was also utilised to reduce cerebral oedema. Intensive care admission was required for 19.2% of patients. No statistically significant differences were observed between treatment and discharge outcomes. CONCLUSIONS: The clinical management of CIN should be considered on a patient-by-patient basis, but may consist of aggressive fluid therapy alongside corticosteroids, as well as other supportive therapy as required. Further examination of CIN management is required to define best practice.

The psychometric properties of the Burnout Assessment Tool in Norway: A thorough investigation into construct-relevant multidimensionality.

OBJECTIVE: The World Health Organization recognizes burnout as an occupational issue. Nevertheless, accurately identifying employee burnout remains a challenging task. To complicate matters, current measures of burnout have demonstrated limitations, prompting the development of the Burnout Assessment Tool (BAT). Given these circumstances, conducting an in-depth examination of the BAT's construct-relevant multidimensionality is crucial. METHOD: This study focuses on both the original 23-item BAT and the short 12-item version, using modern factor analytic methods to investigate reliability, validity, and measurement invariance in a representative sample from Norway (n = 493; 49.54% women). RESULTS: Our findings revealed that the bifactor exploratory structural equation modeling solution (burnout global factor and four specific burnout component factors) best explained the data for both BAT versions. All factors demonstrated adequate omega coefficients, with the global factor showing exceptional strength. Both BAT versions correlated highly with each other and with another burnout measure, suggesting convergent validity. Furthermore, both BAT versions achieved full (strict) measurement invariance based on gender. Finally, our results showed that burnout acts as a mediator in our proposed job demands-resources model as preliminary evidence of predictive validity. CONCLUSIONS: The study validates the Burnout Assessment Tool in the Norwegian context. The study supports the reliability, validity, and unbiased nature of the tool across genders. The findings also reinforce the importance of job demands and resources, along with burnout as a key mediator, in understanding workplace dynamics in accordance with job demands-resources theory.

Big number, big body: Jersey numbers alter body size perception.

Vision has been shown to be an active process that can be shaped by top-down influences. Here, we add to this area of research by showing a surprising example of how visual perception can be affected by cognition (i.e., cognitive penetration). Observers were presented, on each trial, with a picture of a computer-generated football player and asked to rate the slenderness of the player on an analog scale. The results of two experiments showed that observers perceived athletes wearing small jersey numbers as more slender than those with high numbers. This finding suggests that the cognition of numbers quantitatively alters body size perception. We conjecture that this effect is the result of previously learned associations (i.e., prior expectations) affecting perceptual inference. Such associations are likely the result of implicit learning of the statistical regularities of number and size attributes co-occurrences by the nervous system. We discuss how these results are consistent with previous research on statistical learning and how they fit into the Bayesian framework of perception. The current finding supports the notion of top-down influences of cognition on perception.

The induction of oocyte maturation and ovulation in the European eel (Anguilla anguilla): in vitro and in vivo comparison of progesterone with 17α,20ß-dihydroxy-4-pregnen-3-one.

Ovulation in European eel is induced by injection of 17α,20ß-dihydroxy-4-pregnen-3-one (DHP) as the maturation-inducing hormone (MIH). Female eels need to ovulate within 18 h after injection to release good quality eggs. Progesterone (P), as an upstream precursor of DHP, may promote endogenous DHP production and improve egg quality. The purpose of this study was therefore to compare treatment of P with DHP on batch level, in vitro, to determine dose-response effects, and in vivo, at a single dose. For the in vitro experiment, ovarian tissue was extracted and placed in culture plates containing hormone-free medium and media supplemented with the treatment: DHP at 1, 10 and 100 ng mL-1, or P at 10, 100 and 1,000 ng mL-1. At the start of incubation, the folliculated oocytes were sampled for histology, microscopy and qPCR. After incubation for 12 and 18 h, the oocytes were sampled for microscopy and qPCR analysis. For the in vivo experiment, females were either injected with DHP or P at a dose of 2 mg kg-1 to assess their effects on ovulation and reproductive success. At the moment of release, eggs were sampled for RNA sequencing to compare effects of DHP and P on the expression of genes involved in egg quality aspects. Remaining eggs were fertilized and larval viability was recorded. Both DHP and P were able to induce GVBD (DHP at 10 and 100 ng mL-1, P at 100 and 1,000 ng mL-1) in vitro. Expression of genes involved in oocyte maturation and ovulation was similar in vitro for both DHP and P treatments. Regarding the in vivo results, RNAseq results reflected similar DHP and P effects on the expression of genes involved in egg quality aspects. Females injected with either DHP or P ovulated, released eggs, and were equally able to produce larvae without any differences in reproductive success. Our results support the conclusion that DHP and P work equally well in vitro and in vivo. P is more attractive to apply as the price is 3,000 times lower than the price of DHP.

Current knowledge and perspectives of contrast-induced neurotoxicity: A survey of Australian clinicians.

BACKGROUND: Contrast-induced Neurotoxicity (CIN) is an increasingly recognised complication following endovascular procedures. It remains a relatively unexplored clinical entity, and we sought to characterise clinician perspectives towards CIN, as well as identify gaps in knowledge and provide directions for future research. METHODS: An online survey was distributed to members of the Australian and New Zealand Society of Neuroradiology, as well as several Australian tertiary hospitals. Questions related to clinical exposure to CIN, diagnosis, management and pathophysiology were explored. Descriptive analysis was conducted on survey responses, and statistical analysis was performed using Chi-square and Fisher's exact test as appropriate. RESULTS: A total of 95 survey responses were recorded (26.8% response rate). Only 28.4% of respondents were comfortable in diagnosing CIN, and even fewer (24.2%) were comfortable in independently managing CIN patients. Based on clinician opinion, symptoms including impaired consciousness and cortical blindness were thought to be most associated with CIN, whilst the radiological findings of parenchymal oedema and cortical enhancement were considered to be most indicative of CIN. Most clinicians agreed that further investigation is required related to pathophysiology (86.3%), diagnosis (83.2%), and treatment (82.1%). CONCLUSION: CIN is a poorly understood complication following endovascular procedures. Significant gaps in clinical understanding are evident, and further investigation is vital to improve diagnosis and management.

Burnout of emergency nurses in a South African context: the role of job demands and resources, and capabilities.

Emergency nurses are prone to burnout due to the nature of their profession and working environment, potentially putting their sustainable employability at risk and so too the care provided by and success of emergency departments. Psychological research has predominantly focused on samples drawn from western, educated, industrialized, rich, and democratic (WEIRD) societies, concerning a small part of the world population. Consequently, this study investigated emergency nurses' burnout in a non-WEIRD society and assessed the role of job demands-resources and work capabilities on their burnout levels. A total of 204 emergency nurses in a South African context participated in a cross-sectional survey. The Job Demands-Resources Scale, the Capability Set for Work Questionnaire, and the Burnout Assessment Tool-Short Form were administered. Using and developing knowledge and skills and building and maintaining meaningful relationships were the strongest work capabilities of emergency nurses. In contrast, earning a good income, involvement in important decisions, and contributing to something valuable were the weakest capabilities. Latent class analysis resulted in three capability sets: a robust capability set, an inadequate capability set, and a weak capability set. Regarding job resources, emergency nurses with a robust capability set reported better relationships with their supervisors and higher job autonomy than the inadequate and weak capability sets. In addition, emergency nurses with a robust capability set reported better co-worker relationships and better access to good equipment than those with a weak capability set. Nurses with an inadequate capability set experienced significantly more challenging job demands than the other two sets. Finally, nurses with a weak capability set (compared to the robust capability set) experienced significantly higher levels of exhaustion and mental distance. Improving emergency nurses' job resources (especially relationships with co-workers and supervisors, job autonomy, and equipment sufficiency) would increase their capabilities, decreasing their burnout levels, especially exhaustion and mental distance.

Safety and effectiveness of spinal dural defect repair in the management of superficial siderosis: A systematic review and patient-level analysis.

OBJECTIVE: Superficial siderosis (SS) is a disabling neurodegenerative condition that may be caused by spinal dural defects. Surgical repair is increasingly performed, however clinical outcomes remain unclear. METHODS: A systematic search of PubMed, MEDLINE, and EMBASE was conducted (inception to February 2020). Studies reporting cases of (i) superficial siderosis, (ii) spinal dural defect, (iii) and surgical closure of the defect were included. Demographic characteristics, clinical presentation, operative technique and clinical outcome were extracted for patient-level analysis. RESULTS: A total of 26 publications were included, which reported 38 patients with a median age of 58 years, and a male predominance (78.9 %). Ataxia (85.7 %) and hearing loss (80.0 %) were the most common presenting symptoms. The causative dural defect was most commonly ventral in location (91.7 %) and most commonly identified by CT myelography (48.6 %). Operative technique was highly variable and included primary suture, fibrin glue, dural substitute, or tissue (fat or muscle) graft. Clinical improvement was reported in 21 %, with stabilisation of symptoms in the majority (66 %) and clinical deterioration in 13.2 %. Surgical complications were observed in 7.9 %. CONCLUSION: In patients with superficial siderosis and spinal dural defect, operative closure leads to improvement or stabilisation of symptoms in the vast majority (87%) of patients.

Is it time to rethink microsurgical training for the treatment of intracranial aneurysms in Australia?

BACKGROUND: Case volume and complexity for microsurgical treatment of cerebral aneurysms have changed due to the growing use of endovascular therapy in clinical practice. The authors sought to quantify the clinical exposure of Australian neurosurgery trainees to cerebral aneurysm microsurgery. METHODS: This observational, retrospective cross-sectional study examined the Australian National Hospital Morbidity database for all admissions related to microsurgical and endovascular treatment of aneurysmal subarachnoid haemorrhage (aSAH) and unruptured intracranial aneurysms (UIAs) for the years 2008 to 2018. Procedural volumes were compared with neurosurgical trainee figures to investigate the rate of procedural exposure relative to the neurosurgical workforce. RESULTS: A total of 8,874 (41.6%) microsurgical procedures (3,662 for aSAH, 5,212 for UIAs), and 12,481 (58.4%) endovascular procedures (6,018 for aSAH, 6,463 for UIAs) were performed. Trainee exposure to microsurgery in aSAH declined from 9.1 to 7.3 cases per trainee per annum (mean 7.7), with case complexity confined mostly to simple anterior circulation aneurysms. There are significant state-by-state differences in the preferred treatment modality for aSAH. During the same study period, the number of microsurgical cases for UIAs increased (from 8.9 to 13.5 cases per trainee per annum, mean 11.0). Significantly more endovascular procedures are performed than microsurgery (10.7 to 17.0, mean 12.7 cases, for aSAH; 8.0 to 21.5, mean 13.7 cases, for UIAs). CONCLUSIONS: Trainee exposure to open aneurysm surgery for aSAH have significantly declined in both case volume and complexity. There is an overall increase in the number of surgeries for elective aneurysms, but this varies widely from state-to-state.

Quantifying mangrove leaf area index from Sentinel-2 imagery using hybrid models and active learning.

Mangrove forests provide vital ecosystem services. The increasing threats to mangrove forest extent and fragmentation can be monitored from space. Accurate spatially explicit quantification of key vegetation characteristics of mangroves, such as leaf area index (LAI), would further advance our monitoring efforts to assess ecosystem health and functioning. Here, we investigated the potential of radiative transfer models (RTM), combined with active learning (AL), to estimate LAI from Sentinel-2 spectral reflectance in the mangrove-dominated region of Ngoc Hien, Vietnam. We validated the retrieval of LAI estimates against in-situ measurements based on hemispherical photography and compared against red-edge NDVI and the Sentinel Application Platform (SNAP) biophysical processor. Our results highlight the performance of physics-based machine learning using Gaussian processes regression (GPR) in combination with AL for the estimation of mangrove LAI. Our AL-driven hybrid GPR model substantially outperformed SNAP (R2 = 0.77 and 0.44 respectively) as well as the red-edge NDVI approach. Comparing two canopy RTMs, the highest accuracy was achieved by PROSAIL (RMSE = 0.13 m2.m-2, NRMSE = 9.57%, MAE = 0.1 m2.m-2). The successful retrieval of mangrove LAI from Sentinel-2 can overcome extensive reliance on scarce in-situ measurements for training seen in other approaches and present a more scalable applicability by relying on the universal principles of physics in combination with uncertainty estimates. AL-based GPR models using RTM simulations allow us to adapt the genericity of RTMs to the peculiarities of distinct ecosystems such as mangrove forests with limited ancillary data. These findings bode potential for retrieving a wider range of vegetation variables to quantify large-scale mangrove ecosystem dynamics in space and time.

Cytoreductive Surgery for Primary Central Nervous System Lymphoma: Is it time to consider extent of resection?

BACKGROUND: Cytoreductive surgery for Primary Central Nervous System Lymphoma (PCNSL) is controversial and is not routinely practiced. Cumulative literature in recent years, however, suggests a potential survival benefit associated with a greater extent of resection. METHODS: A retrospective single institution cohort analysis of 58 consecutive patients with PCNSL was conducted between January 2011 and December 2020. Demographic, clinical, and radiographic characteristics were compared between patients with and without cytoreductive surgery following diagnosis of PCNSL. The primary outcome measures were progression-free survival (PFS) and overall survival (OS). Secondary outcome measures included time to remission (TTR), time to chemotherapy (TTC) and response to initial chemotherapy (RIC). RESULTS: Forty-six patients (79.3 %) received stereotactic biopsy and 12 (20.6 %) underwent cytoreductive surgery. There was a trend towards longer OS (29.8 vs 22.3 months, p = 0.672), shorter TTR (4.0 vs 4.7 months, p = 0.362), and greater complete or near-complete radiographic RIC (81.8 % vs 67.6 %, p = 0.367) for patients undergoing cytoreductive surgery. This correlated with a lesser need for whole brain radiotherapy (WBRT) (8.3 % vs 19.6 %, p = 0.359). CONCLUSION: Our data suggests a potential benefit of cytoreductive surgery for selected patients diagnosed with PCNSL. Although not statistically significant, there was a trend towards improved OS, reduced TTR, greater RIC, and reduced WBRT requirement. Further studies with better randomization and statistical power are needed to validate this correlation.

Steroid implants for the induction of vitellogenesis in feminized European silver eels (Anguilla anguilla L.).

Assisted propagation of the European eel will lead to a closed production cycle supplying the aquaculture industry with juvenile glass eels. Females require long-term weekly treatment with pituitary extract (PE), which is stressful and causes abnormalities in oogenesis. We tested the effects of 17α-methyltestosterone (17 MT), as potent androgen activating the androgen receptor, and 17ß-estradiol (E2), as an inducer of vitellogenesis, to shorten the duration of PE treatment.Four groups of feminized eels were subjected to a simulated migration and subsequent injection with implants containing 17 MT (17 MT-group), E2 (E2-group) or 17 MT plus E2 (17 MT + E2-group) to test for synergistic effects, or without any steroids as controls (C-group). The effects of a 2-months treatment were investigated by determining the eye index (EI), hepatosomatic and gonadosomatic index (HSI and GSI, respectively), plasma steroid concentrations by liquid chromatography mass spectrometry (LCMS), gonadal histology, expression of androgen receptors a and b (ara, arb); estrogen receptor 1 (esr1); FSH receptor (fshr); vitellogenin receptor (vtgr) and aromatase (cyp19), and the required number of weekly PE injections to fully mature. For many parameters, both the 17 MT and E2 groups showed an increase vs. controls, with the 17 MT + E2 group showing a synergistic effect, as seen for EI, GSI (3.4 for 17 MT and for E2, 6.6 for 17 MT + E2), oocyte diameter and ara, arb and esr1 expression. Concentrations of almost all focal steroids decreased with simulated migration and steroid treatment. Only eels of the 17 MT-group showed increased expression of cyp19 and of fshr, while fshr expression increased 44-fold in the 17 MT + E2 group, highlighting that co-implantation is most effective in raising fshr mRNA levels. Specific for eels of the E2 groups were vitellogenesis-associated changes such as an increase of HSI, plasma E2, and presence of yolk in the oocytes. Steroid treatments reduced the duration of PE treatment, again synergistically for co-implantation. In conclusion, E2 is necessary to start vitellogenesis, but 17 MT has specific effects on cyp19 and fshr expression. The combination is necessary for synergistic effects and as such, steroid implants could be applied in assisted reproduction protocols for European eel to improve oocyte quality leading to the production of more vital larvae.

Autonomy-supportive agents: whose support matters most, and how does it unfold in the workplace?

Managers and colleagues satisfy others' need for autonomy, but employees can also satisfy their own need by engaging in autonomy crafting practices. Although all three sources of autonomy support can benefit employee outcomes, they may not be equally beneficial. Furthermore, their benefits may not be straightforward, but rather a psychological process unfolding. To test these assumptions, the aim of the present study was twofold: to determine whether the different sources of support explained significantly different amounts of variance in autonomy satisfaction when compared and to understand the psychological process through which autonomy support from three sources influenced performance, more specifically, whether autonomy support indirectly affected performance through perceived autonomy satisfaction and work engagement in serial. In a sample of 278 employees, autonomy support from others (especially managers) and autonomy crafting played a role in autonomy satisfaction. Furthermore, the results indicated that autonomy support was associated with performance through its serial associations with autonomy satisfaction and work engagement. The results emphasized the importance of autonomy support for performance, enabling organizations to proactively design interventions to improve engagement and performance. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-022-03550-9.

The psychometric properties and measurement invariance of the Burnout Assessment Tool (BAT-23) in South Africa.

BACKGROUND: Burnout is an increasing public health concern that afflicts employees globally. The measurement of burnout is not without criticism, specifically in the context of its operational definition as a syndrome, also recently designated as such by the World Health Organisation. The Burnout Assessment Tool (BAT-23) is a new measure for burnout that addresses many of the criticisms surrounding burnout scales. The aim of this study is to determine the validity, reliability, and measurement invariance of the BAT-23 in South Africa. METHOD: A quantitative, cross-sectional survey, approach was taken (n = 1048). Latent variable modelling was implemented to investigate the construct-relevant multidimensionality that is present in the BAT. For measurement invariance, the configural, metric, scalar, and strict models were tested. RESULTS: The analyses showed that the hierarchical operationalisation of BAT-assessed burnout was the most appropriate model for the data. Specifically, a bifactor ESEM solution. Composite reliability estimates were all well above the cut-off criteria for both the global burnout factor and the specific factors. The measurement invariance tests showed that gender achieved not only strong invariance, but also strict invariance. However, ethnicity initially only showed strong invariance, but a test of partial strict invariance did show that the mean scores could be fairly compared between the groups when releasing certain constraints. CONCLUSIONS: The BAT-23 is a valid and reliable measure to investigate burnout within the Southern African context.

Epidemiological Comparison of Four COVID-19 Waves in the Democratic Republic of the Congo, March 2020-January 2022.

PURPOSE: Nationwide analyses are required to optimise and tailor activities to control future COVID-19 waves of resurgence continent-wide. We compared epidemiological and clinical outcomes of the four COVID-19 waves in the Democratic Republic of Congo (DRC). METHODS: This retrospective descriptive epidemiological analysis included data from the national line list of confirmed COVID-19 cases in all provinces for all waves between 9 March 2020 and 2 January 2022. Descriptive statistical measures (frequencies, percentages, case fatality rates [CFR], test positivity rates [TPR], and characteristics) were compared using chi-squared or the Fisher-Irwin test. RESULTS: During the study period, 72,108/445,084 (16.2%) tests were positive, with 9,641/56,637 (17.0%), 16,643/66,560 (25.0%), 24,172/157,945 (15.3%), and 21,652/163,942 (13.2%) cases during the first, second, third, and fourth waves, respectively. TPR significantly decreased from 17.0% in the first wave to 13.2% in the fourth wave as did infection of frontline health workers (5.2% vs. 0.9%). CFR decreased from 5.1 to 0.9% from the first to fourth wave. No sex- or age-related differences in distributions across different waves were observed. The majority of cases were asymptomatic in the first (73.1%) and second (86.6%) waves, in contrast to that in the third (11.1%) and fourth (31.3%) waves. CONCLUSION: Despite fewer reported cases, the primary waves (first and second) of the COVID-19 pandemic in the DRC were more severe than the third and fourth waves, with each wave being associated with a new SARS-CoV-2 variant. Tailored public health and social measures, and resurgence monitoring are needed to control future waves of COVID-19.