Estimating household contact matrices structure from easily collectable metadata.

Contact matrices are a commonly adopted data representation, used to develop compartmental models for epidemic spreading, accounting for the contact heterogeneities across age groups. Their estimation, however, is generally time and effort consuming and model-driven strategies to quantify the contacts are often needed. In this article we focus on household contact matrices, describing the contacts among the members of a family and develop a parametric model to describe them. This model combines demographic and easily quantifiable survey-based data and is tested on high resolution proximity data collected in two sites in South Africa. Given its simplicity and interpretability, we expect our method to be easily applied to other contexts as well and we identify relevant questions that need to be addressed during the data collection procedure.

Prevalence and Factors Associated With Frailty Among Older Adults Living With HIV Compared to Their Uninfected Peers From the Kenyan Coast.

Objectives: a) To document the prevalence and correlates of frailty among older adults living with HIV (OALWH) and their uninfected peers, and b) Investigate HIV status as an independent predictor of frailty. Methods: This cross-sectional study was conducted between 2020 and 2021 at the Kenyan coast among 440 older adults aged ≥50 years (257 OALWH). Frailty was assessed using the Reported Edmonton Frail Scale. Logistic regression was used to examine the correlates of frailty. Results: The prevalence of frailty was significantly higher among OALWH (24%) than their uninfected peers (13%). HIV seropositivity was not independently associated with frailty. Sleeping difficulties, ageism, higher waist/hip ratio, visiting traditional healers, HIV treatment change/interruption, prolonged illness following HIV diagnosis, and self-reported diabetes were significantly associated with higher odds of frailty. Residing in larger households, having higher income, having friends, being male and light physical activities were significantly associated with reduced odds of frailty. Conclusion: The prevalence of frailty is elevated among OALWH; however, factors other than HIV are predominant, particularly psychosocial factors. Multicomponent interventions are needed to prevent/delay and manage frailty in this setting.

A individually randomized controlled trial comparing Healer-led vs. clinician- led training to improve personal protective equipment use among traditional healers in South Africa.

Like allopathic healthcare workers, healers are also exposed to patients' blood and body fluids. A widespread practice is the traditional "injection," in which the healer performs subcutaneous incisions to rub herbs directly into the bloodied skin, resulting in 1,500 blood exposures over their lifetime. We tested the impact of healer-led PPE training, staffed by trained traditional healers who reported using PPE during each risky clinical encounter vs. healthcare worker (HCW)-led PPE training sessions. We randomized 136 healers into one of the two study arms (67 in the healer-led group, 69 in the HCW-led group) and assessed the impact of trainer on PPE skills and use over a six-month period. All healers received one in-person day of didactic and practical training followed by three sessions at the healers' home. Participants were largely female (80%), averaged 51 years old, and practiced as a healer for an average of 17 years. Almost 44% either disclosed themselves as HIV+ or received a positive HIV test result at study initiation. Healers in the HCW arm showed equivalent PPE scores as those trained by traditional healers at baseline and at seven months. Healers in both arms self-reported high levels of glove use during"injections," with no statistical difference of use by study arm. When we assessed actual gloves and razor blades disposed of each month, a similar trend emerged. No one seroconverted during the study period. The need for PPE support among traditional healers cannot be ignored. Traditional healers can be trained to effectively disseminate PPE knowledge and skills to other traditional healers. With an estimated 200,000 traditional healers in South Africa, it is imperative that all of them have access to PPE training and supplies to prevent HIV, HCV, or HBV infections. Trial registration: ClinicalTrials.gov, NCT04440813. Registered 17 June 2020, https://clinicaltrials.gov/ct2/show/NCT04440813.

The Impact of Social Determinants of Health on the Treatment of Distal Radius Fracture.

BACKGROUND: Disparities in social determinants of health (SDH) have been shown to play an increasingly important role in the equitable delivery of health care. Distal radius fractures (DRFs) are among the most common upper-extremity injuries encountered. This study aims to examine the influence of economic, educational, social, environmental, and healthcare disparities on management of these injuries. METHODS: PearlDiver Mariner insurance claims database was analyzed for treatment patterns of DRF in patients aged 18 to 65 years based on the presence or absence of social determinants of health disparities (SDHDs). Outcome variables included the primary mode of management of DRF, including operative versus non-operative, as well as concomitant procedures. Multivariate logistic regression was used to compare fracture management modality in patients with and without SDHDs. RESULTS: Of 161 704 patients identified with DRF, 38.3% had at least 1 reported SDHD. The majority of SDHDs were economic. Patients identified with 1 or more SDHDs had a higher medical comorbidity index. Patients with environmental SDHD were more likely to receive non-operative management. Within any SDHD and economic subgroups, odds of operative management were higher. No relationship was identified between SDHD and concomitant procedures. CONCLUSIONS: The presence of environmental disparities in SDH may predispose patients disproportionately to non-operative management. The presence of SDHDs may influence medical decision-making in favor of open reduction and internal fixation in patients with DRF treated operatively. In treating at-risk populations, providers should be aware of the potential for implicit bias associated with SDHDs and prioritize shared decision-making between patients and physicians.

Nanoscale Rheology: Dynamic Mechanical Analysis over a Broad and Continuous Frequency Range Using Photothermal Actuation Atomic Force Microscopy.

Polymeric materials are widely used in industries ranging from automotive to biomedical. Their mechanical properties play a crucial role in their application and function and arise from the nanoscale structures and interactions of their constitutive polymer molecules. Polymeric materials behave viscoelastically, i.e., their mechanical responses depend on the time scale of the measurements; quantifying these time-dependent rheological properties at the nanoscale is relevant to develop, for example, accurate models and simulations of those materials, which are needed for advanced industrial applications. In this paper, an atomic force microscopy (AFM) method based on the photothermal actuation of an AFM cantilever is developed to quantify the nanoscale loss tangent, storage modulus, and loss modulus of polymeric materials. The method is then validated on styrene-butadiene rubber (SBR), demonstrating the method's ability to quantify nanoscale viscoelasticity over a continuous frequency range up to 5 orders of magnitude (0.2-20,200 Hz). Furthermore, this method is combined with AFM viscoelastic mapping obtained with amplitude modulation-frequency modulation (AM-FM) AFM, enabling the extension of viscoelastic quantification over an even broader frequency range and demonstrating that the novel technique synergizes with preexisting AFM techniques for quantitative measurement of viscoelastic properties. The method presented here introduces a way to characterize the viscoelasticity of polymeric materials and soft and biological matter in general at the nanoscale for any application.

Mid-life employment trajectories and subsequent memory function and rate of decline in rural South Africa, 2000-22.

AIM: To investigate mid-life employment trajectories in relation to later-life memory function and rate of decline in rural South Africa. METHODS: Data from the Agincourt Health and Socio-Demographic Surveillance System were linked to the 'Health and Ageing in Africa: A Longitudinal Study of an INDEPTH Community in South Africa' (HAALSI) in rural Agincourt, South Africa (N = 3133). Employment was assessed every 4 years over 2000-12 as being employed (0, 1, 2 and ≥3 time points), being employed in a higher-skill occupation (0, 1, 2 and ≥3 time points) and dynamic employment trajectories identified using sequence analysis. Latent memory z-scores were assessed over 2014-22. Mixed-effects linear regression models were fitted to examine the associations of interest. RESULTS: Sustained mid-life employment from 2000-12 (ß = 0.052, 95% CI: -0.028 to 0.132, 1 vs 0 time points; ß = 0.163, 95% CI: 0.077 to 0.250, 2 vs 0 time points; ß = 0.212, 95% CI: 0.128 to 0.296, ≥3 vs 0 time points) and greater time spent in a higher-skill occupation (ß = 0.077, 95% CI: -0.020 to 0.175, 1 vs 0 time points; ß = 0.241, 95% CI: 0.070 to 0.412, 2 vs 0 time points; ß = 0.361, 95% CI: 0.201 to 0.520, ≥3 vs 0 time points) were associated with higher memory scores in 2014/15, but not subsequent rate of memory decline. Moving from a lower-skill to higher-skill occupation was associated with higher memory function, but a faster rate of decline over 2014-22. CONCLUSIONS: Sustained mid-life employment, particularly in higher-skill occupations, may contribute to later-life memory function in this post-Apartheid South African setting.

Mental distress, food insecurity and university student dropout during the COVID-19 pandemic in 2020: evidence from South Africa.

Background: Student dropout has been a key issue facing universities for many years. The COVID-19 pandemic was expected to exacerbate these trends; however, international literature has produced conflicting findings. Limited literature from Africa has investigated the impact of COVID-19 on student dropout trends, despite the documented devastation, including increased risk of food insecurity and mental distress, caused by the pandemic. Objective: This work seeks to understand the impact of food insecurity and mental distress on student dropout during the COVID-19 pandemic. Methods: Using a cross-sectional research design, first-year undergraduate students from a large South African university were recruited via email to participate in a survey between September and October 2020. The Household Food Insecurity Access Scale (HFIAS) was used to measure food insecurity and the Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS) was used to measure mental distress. Multivariate regression was used to investigate factors associated with student dropout. Results: The student dropout rate was 10.5% (95% CI: 8.2-13.2). The prevalence of severe food insecurity was 25.7% (95% CI: 22.3-29.4) and the prevalence of severe mental distress symptoms was 26.7% (95% CI: 23.3-30.4). Dropout rates and levels of food insecurity were highest among students residing in remote areas during the lockdown at 19.2% and 43.6%, respectively. The multivariate logistic regression revealed that being male increased the probability of dropout almost three-fold (odds ratio (OR) = 2.70; 95% CI: 1.48-4.89, p =0.001)). Being moderately food insecure increased the odds of dropout more than two-fold (OR=2.50; 95% CI:1.12-5.55, p=0.025), and experiencing severe mental distress symptoms increased the odds of dropout seven-fold (OR=7.08; 95% CI:2.67-18.81, p<0.001). Conclusion: While acknowledging that various factors and complexities contribute to student dropout, the increased vulnerability to food insecurity and mental distress, stemming from issues such as widespread job losses and isolation experienced during the pandemic, may have also had an impact on dropout. This work reiterates the importance of directing additional support to students who are food insecure and those who are experiencing mental distress in order to mitigate university student dropout.

Systematic Review of Capsular Contracture Management following Breast Augmentation: An Update.

BACKGROUND: Capsular contracture is one of the most frequent indications for revision following breast augmentation. Management goals focus on restoring breast aesthetics and minimizing subsequent recurrence of capsular contracture. As new data emerge, close review of the data are merited to build evidence-based clinical guidelines to inform surgical practice and management of capsular contracture. METHODS: A systematic review of the MEDLINE, Embase, and Cochrane Database of Systematic Reviews databases was conducted to characterize the surgical management of capsular contracture in revision breast augmentations. The primary endpoint was capsular contracture recurrence rate. RESULTS: The review was conducted in November of 2021. Primary search revealed 14,163 results. Initial screening by title left 1223 articles. Abstract review left 90 articles for full-text review, of which 34 were ultimately included and were all observational in nature. CONCLUSIONS: Capsular contracture management remains an important topic, with limited high-level evidence for establishing clear evidence-based treatment guidelines. Although more evidence is required to assess the effects of capsulectomy, implant exchange, and plane change, these appear to be useful mechanisms for reducing recurrent capsular contracture. There is more evidence regarding the use of acellular dermal matrix, although this still requires long-term follow-up studies. New developments regarding textured implants limit the revision breast augmentation surgeon to smooth devices.

Magnetic resonance imaging findings in Kenyans and South Africans with active convulsive epilepsy: An observational study.

OBJECTIVE: Focal epilepsy is common in low- and middle-income countries. The frequency and nature of possible underlying structural brain abnormalities have, however, not been fully assessed. METHODS: We evaluated the possible structural causes of epilepsy in 331 people with epilepsy (240 from Kenya and 91 from South Africa) identified from community surveys of active convulsive epilepsy. Magnetic resonance imaging (MRI) scans were acquired on 1.5-Tesla scanners to determine the frequency and nature of any underlying lesions. We estimated the prevalence of these abnormalities using Bayesian priors (from an earlier pilot study) and observed data (from this study). We used a mixed-effect modified Poisson regression approach with the site as a random effect to determine the clinical features associated with neuropathology. RESULTS: MRI abnormalities were found in 140 of 240 (modeled prevalence = 59%, 95% confidence interval [CI]: 53%-64%) of people with epilepsy in Kenya, and in 62 of 91 (modeled prevalence = 65%, 95% CI: 57%-73%) in South Africa, with a pooled modeled prevalence of 61% (95% CI: 56%-66%). Abnormalities were common in those with a history of adverse perinatal events (15/23 [65%, 95% CI: 43%-84%]), exposure to parasitic infections (83/120 [69%, 95% CI: 60%-77%]) and focal electroencephalographic features (97/142 [68%, 95% CI: 60%-76%]), but less frequent in individuals with generalized electroencephalographic features (44/99 [44%, 95% CI: 34%-55%]). Most abnormalities were potentially epileptogenic (167/202, 82%), of which mesial temporal sclerosis (43%) and gliosis (34%) were the most frequent. Abnormalities were associated with co-occurrence of generalized non-convulsive seizures (relative risk [RR] = 1.12, 95% CI: 1.04-1.25), lack of family history of seizures (RR = 0.91, 0.86-0.96), convulsive status epilepticus (RR = 1.14, 1.08-1.21), frequent seizures (RR = 1.12, 1.04-1.20), and reported use of anti-seizure medication (RR = 1.22, 1.18-1.26). SIGNIFICANCE: MRI identified pathologies are common in people with epilepsy in Kenya and South Africa. Mesial temporal sclerosis, the most common abnormality, may be amenable to surgical correction. MRI may have a diagnostic value in rural Africa, but future longitudinal studies should examine the prognostic role.

SETD2 loss in renal epithelial cells drives epithelial-to-mesenchymal transition in a TGF-ß-independent manner.

Histone-lysine N-methyltransferase SETD2 (SETD2), the sole histone methyltransferase that catalyzes trimethylation of lysine 36 on histone H3 (H3K36me3), is often mutated in clear cell renal cell carcinoma (ccRCC). SETD2 mutation and/or loss of H3K36me3 is linked to metastasis and poor outcome in ccRCC patients. Epithelial-to-mesenchymal transition (EMT) is a major pathway that drives invasion and metastasis in various cancer types. Here, using novel kidney epithelial cell lines isogenic for SETD2, we discovered that SETD2 inactivation drives EMT and promotes migration, invasion, and stemness in a transforming growth factor-beta-independent manner. This newly identified EMT program is triggered in part through secreted factors, including cytokines and growth factors, and through transcriptional reprogramming. RNA-seq and assay for transposase-accessible chromatin sequencing uncovered key transcription factors upregulated upon SETD2 loss, including SOX2, POU2F2 (OCT2), and PRRX1, that could individually drive EMT and stemness phenotypes in SETD2 wild-type (WT) cells. Public expression data from SETD2 WT/mutant ccRCC support the EMT transcriptional signatures derived from cell line models. In summary, our studies reveal that SETD2 is a key regulator of EMT phenotypes through cell-intrinsic and cell-extrinsic mechanisms that help explain the association between SETD2 loss and ccRCC metastasis.

A Comparison of Treatment of OCD Lesions of the Capitellum With Osteochondral Autograft and Allograft Transplantation.

Osteochondritis dissecans (OCD) of the capitellum occurs relatively infrequently but can be found in young overhead-throwing athletes, most commonly in baseball players and gymnasts. Although non-operative management can effectively treat stable lesions, unstable lesions can lead to debilitating symptoms of the elbow and diminished quality of life without surgical intervention. This article reviews methods of treating OCD of the capitellum categorized by stability, size, and patient characteristics, and seeks to familiarize the reader with the appropriate selection of osteochondral allograft versus autograft in treating large, unstable lesions. We complement this review with 3 case examples, each using either an osteochondral autograft or allograft, and discuss the decision-making methodology used in each case.

Association of brain arterial diameters with demographic and anatomical factors in a multi-national pooled analysis of cohort studies.

BACKGROUND AND PURPOSE: Brain arterial diameters are markers of cerebrovascular disease. Demographic and anatomical factors may influence arterial diameters. We hypothesize that age, sex, height, total cranial volume (TCV), and persistent fetal posterior cerebral artery (fPCA) correlate with brain arterial diameters across populations. METHODS: Participants had a time-of-flight MRA from nine international cohorts. Arterial diameters of the cavernous internal carotid arteries (ICA), middle cerebral arteries (MCA), and basilar artery (BA) were measured using LAVA software. Regression models assessed the association between exposures and brain arterial diameters. RESULTS: We included 6,518 participants (mean age: 70 ± 9 years; 41% men). Unilateral fPCA was present in 13.2% and bilateral in 3.2%. Larger ICA, MCA, and BA diameters correlated with older age (Weighted average [WA] per 10 years: 0.18 mm, 0.11 mm, and 0.12 mm), male sex (WA: 0.24 mm, 0.13 mm, and 0.21 mm), and TCV (WA: for one TCV standard deviation: 0.24 mm, 0.29 mm, and 0.18 mm). Unilateral and bilateral fPCAs showed a positive correlation with ICA diameters (WA: 0.39 mm and 0.73 mm) and negative correlation with BA diameters (WA: -0.88 mm and -1.73 mm). Regression models including age, sex, TCV, and fPCA explained on average 15%, 13%, and 25% of the ICA, MCA, and BA diameter interindividual variation, respectively. Using height instead of TCV as a surrogate of head size decreased the R-squared by 3% on average. CONCLUSION: Brain arterial diameters correlated with age, sex, TCV, and fPCA. These factors should be considered when defining abnormal diameter cutoffs across populations.

Transient increased risk of influenza infection following RSV infection in South Africa: findings from the PHIRST study, South Africa, 2016-2018.

BACKGROUND: Large-scale prevention of respiratory syncytial virus (RSV) infection may have ecological consequences for co-circulating pathogens, including influenza. We assessed if and for how long RSV infection alters the risk for subsequent influenza infection. METHODS: We analysed a prospective longitudinal cohort study conducted in South Africa between 2016 and 2018. For participating households, nasopharyngeal samples were taken twice weekly, irrespective of symptoms, across three respiratory virus seasons, and real-time polymerase chain reaction (PCR) was used to identify infection with RSV and/or influenza. We fitted an individual-level hidden Markov transmission model in order to estimate RSV and influenza infection rates and their interdependence. RESULTS: Of a total of 122,113 samples collected, 1265 (1.0%) were positive for influenza and 1002 (0.8%) positive for RSV, with 15 (0.01%) samples from 12 individuals positive for both influenza and RSV. We observed a 2.25-fold higher incidence of co-infection than expected if assuming infections were unrelated. We estimated that infection with influenza is 2.13 (95% CI 0.97-4.69) times more likely when already infected with, and for a week following, RSV infection, adjusted for age. This equates to 1.4% of influenza infections that may be attributable to RSV in this population. Due to the local seasonality (RSV season precedes the influenza season), we were unable to estimate changes in RSV infection risk following influenza infection. CONCLUSIONS: We find no evidence to suggest that RSV was associated with a subsequent reduced risk of influenza infection. Instead, we observed an increased risk for influenza infection for a short period after infection. However, the impact on population-level transmission dynamics of this individual-level synergistic effect was not measurable in this setting.

Regional Anesthesia for Wrist Fractures and Dislocations: Are We Really Blocking Opioid Prescribing?

BACKGROUND: The aim of this study was to evaluate the impact of regional anesthesia for the treatment of wrist fractures or dislocation on opioid prescription-filling patterns. METHODS: Patients undergoing surgery for hand and wrist fractures or dislocations from 2010 to 2018 were identified by using a national insurance claims database. Patients were stratified by procedures conducted with and without regional anesthesia. Preoperative opioids were defined by a filled opioid prescription within 1 month prior to surgery, postoperative within 1 month following the surgery, and prolonged postoperative 3 to 6 months following surgery. Patients' demographic data, comorbidities, additional medications, 30-day emergency department (ED) visits, and hospital readmissions were analyzed. RESULTS: A total of 24 598 patients treated with and 115 199 patients treated without a regional nerve block for wrist fractures and dislocations were identified. Regional anesthesia was associated with greater postoperative opioid prescription but fewer prolonged postoperative prescriptions. There was an increased odds of all-cause 30-day ED visits but a decreased odds of 30-day hospital readmissions when patients received a regional nerve block prior to surgery. CONCLUSIONS: In this study, receiving regional anesthesia prior to surgical intervention for wrist fractures or dislocations was associated with increased filling of postoperative opioid prescriptions, but not prolonged postoperative opioid prescriptions. Additional investigation is needed to identify and implement nonnarcotic multimodal analgesia regimens that may help decrease usage of narcotic medications surrounding these procedures. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Atypical peripheral actin band formation via overactivation of RhoA and nonmuscle myosin II in mitofusin 2-deficient cells.

Cell spreading and migration play central roles in many physiological and pathophysiological processes. We have previously shown that MFN2 regulates the migration of human neutrophil-like cells via suppressing Rac activation. Here, we show that in mouse embryonic fibroblasts, MFN2 suppresses RhoA activation and supports cell polarization. After initial spreading, the wild-type cells polarize and migrate, whereas the Mfn2-/- cells maintain a circular shape. Increased cytosolic Ca2+ resulting from the loss of Mfn2 is directly responsible for this phenotype, which can be rescued by expressing an artificial tether to bring mitochondria and endoplasmic reticulum to close vicinity. Elevated cytosolic Ca2+ activates Ca2+/calmodulin-dependent protein kinase II, RhoA, and myosin light-chain kinase, causing an overactivation of nonmuscle myosin II, leading to a formation of a prominent F-actin ring at the cell periphery and increased cell contractility. The peripheral actin band alters cell physics and is dependent on substrate rigidity. Our results provide a novel molecular basis to understand how MFN2 regulates distinct signaling pathways in different cells and tissue environments, which is instrumental in understanding and treating MFN2-related diseases.

Navigating Life With HIV as an Older Adult on the Kenyan Coast: Perceived Health Challenges Seen Through the Biopsychosocial Model.

Objectives: This study explores the perceptions of adults living with HIV aged ≥50 years (recognized as older adults living with HIV-OALWH), primary caregivers and healthcare providers on the health challenges of ageing with HIV at Kilifi, a low literacy setting on the coast of Kenya. Methods: We utilized the biopsychosocial model to explore views from 34 OALWH and 22 stakeholders on the physical, mental, and psychosocial health challenges of ageing with HIV in Kilifi in 2019. Data were drawn from semi-structured in-depth interviews, which were audio-recorded and transcribed. A framework approach was used to synthesize the data. Results: Symptoms of common mental disorders, comorbidities, somatic symptoms, financial difficulties, stigma, and discrimination were viewed as common. There was also an overlap of perceived risk factors across the physical, mental, and psychosocial health domains, including family conflicts and poverty. Conclusion: OALWH at the Kenyan coast are perceived to be at risk of multiple physical, mental, and psychosocial challenges. Future research should quantify the burden of these challenges and examine the resources available to these adults.

Is This Going to Hurt, Doc? Predicting Pain with Corticosteroid Injections for Upper Extremity Conditions.

Corticosteroid injections (CSIs) are used in a wide variety of upper extremity pathologies for both diagnostic and treatment purposes. Many patients ask about pain associated with the procedure before agreeing to proceed. The purpose of this study was to correlate perceived pain tolerance and resilience with patient-reported injection pain during and immediately after injection. Methods: One-hundred patients indicated for a CSI for an upper extremity condition were recruited for the study. Patients completed a Brief Resilience Scale, Patient-Reported Outcomes Measurement Information System pain interference form, and assessment of pain tolerance before injection. Physicians predicted pain tolerance and resilience for each patient. Immediately after the procedure, patients completed a second survey, assessing pain during and 1 minute after injection. Results: Physician-predicted patient resilience and pain tolerance was lower than that self-reported by patients. Pain with injection was inversely correlated with physician-predicted pain tolerance and resilience but not with patient-reported pain tolerance. Injection pain ratings did not correspond with patients' willingness to undergo subsequent injections. Conclusions: Procedural pain is an important consideration for many patients, especially in awake procedures. Appropriate counseling is crucial to support informed consent and enhance patient outcomes. This study demonstrated that a physician's clinical experience can be used to predict a patient's pain with CSI and should be considered when counseling patients.

Effects of water movement and temperature on Rhizophydium infection of Planktothrix in a shallow hypereutrophic lake.

Grand Lake St. Marys (GLSM) is a popular recreational lake located in western Ohio, United States, generating nearly $150 million in annual revenue. However, recurring algal blooms dominated by Planktothrix agardhii, which can produce harmful microcystin toxins, have raised concerns about water safety and negatively impacted the local economy. Planktothrix agardhii is host to a number of parasites and pathogens, including an obligate fungal parasite in the Chytridiomycota (chytrids). In this study, we investigated the potential of these chytrid (Rhizophydium sp.) to infect P. agardhii blooms in the environment by modifying certain environmental conditions thought to limit infection prevalence in the wild. With a focus on temperature and water mixing, mesocosms were designed to either increase or decrease water flow compared to the control (water outside the mesocosm). In the control and water circulation mesocosms, infections were found infrequently and were found on less than 0.75% of the Planktothrix population. On the other hand, by decreasing the water flow to stagnation, chytrid infections were more frequent (found in nearly 3x as many samples) and more prevalent, reaching a maximum infection rate of 4.12%. In addition, qPCR coupled with 16S-18S sequencing was utilized to confirm the genetic presence of both host and parasite, as well as to better understand the effect of water circulation on the community composition. Statistical analysis of the data confirmed that chytrid infection was dependent on water temperature, with infections predominantly occurring between 19°C and 23°C. Additionally, water turbulence can significantly reduce the infectivity of chytrids, as infections were mostly found in stagnant mesocosms. Further, decreasing the water circulation promoted the growth of the cyanobacterial population, while increasing water agitation promoted the growth of green algae (Chlorophyta). This study starts to explore the environmental factors that affect chytrid pathogenesis which can provide valuable insights into controlling measures to reduce the prevalence of harmful algal blooms and improve water quality in GLSM and similarly affected waterbodies.