Chronic lateral ankle ligament instability - Current evidence and recent management advances.

Lateral ankle sprain is a common injury with a substantial negative impact on physical function, quality of life and health economic burden. Chronic lateral ankle instability (CLAI) as a sequela of lateral ankle sprain can lead to the development of posttraumatic ankle osteoarthritis in the long term. In this article, we explore the epidemiology, burden and definition of CLAI for the appropriate clinical assessment and imaging evaluation of patients with lateral ankle sprain and CLAI. Following that, recent advances and evidence on management of CLAI is critically distilled and summarized.

Sterility of antibiotic-admixed peritoneal dialysis solution over time.

BACKGROUND: Intraperitoneal antibiotics may be required daily for up to three weeks to treat peritoneal dialysis (PD)-related peritonitis. In some jurisdictions, antibiotic-admixed PD solutions are required to be used within 24 h due to concerns regarding microbial contamination and growth. This requires patients to attend the PD unit daily or alternatively for staff to perform home delivery with associated transport, staffing and cost implications. OBJECTIVE: The aim of this study was to determine if significant microbial growth occurs in PD solutions following their injection with antibiotic or sterile water. METHODS: Twelve PD solution bags were admixed with cefazolin sodium 1 g, diluted in 10 mL sterile water, while a further 12 PD solution bags were admixed with 10 mL sterile water using aseptic technique (AT) under supervision. All bags were stored at room temperature. Three bags from each experimental group were sampled for microbiologic culture at 0-, 24-, 48- and 72-h intervals. RESULTS: One sterile water admixed bag sampled at 24 h yielded a Corynebacterium spp. after microbiologic culture. A repeat specimen from the same bag at day nine returned a negative culture result. All other sterile water and cefazolin admixed bags returned negative culture results at all time points. CONCLUSIONS: Antibiotic-admixed PD solutions prepared using AT and stored at room temperature remained sterile for up to 72 h. This suggests that patients can be safely issued with a supply of antibiotic-admixed PD bags for up to three days at a time.

A Method for Studying Social Signal Learning of the Waggle Dance in Honey Bees.

Honey bees use a complex form of spatial referential communication. Their waggle dance communicates to nestmates the direction, distance, and quality of a resource by encoding celestial cues, retinal optic flow, and relative food value into motion and sound within the nest. This protocol was developed to investigate the potential for social learning of this waggle dance. Using this protocol, we showed that correct waggle dancing requires social learning. Bees (Apis mellifera) that did not follow any dances before they first danced produced significantly more disordered dances, with larger waggle angle divergence errors, and encoded distance incorrectly. The former deficits improved with experience, but distance encoding was set for life. The first dances of bees that could follow other dancers had none of these impairments. Social learning, therefore, shapes honey bee signaling, as it does communication in human infants, birds, and multiple other vertebrate species. However, much remains to be learned about insects' social learning, and this protocol will help to address knowledge gaps in the understanding of sophisticated social signal learning, particularly in understanding the molecular bases for such learning. Key features It was unclear if honey bees (Apis mellifera) could improve their waggle dance by following experienced dancers before they first waggle dance. Honey bees perform their first waggle dances with more errors if they cannot follow experienced waggle dancers first. Directional and disorder errors improved over time, but distance error was maintained. Bees in experimental colonies continued to communicate longer distances than control bees. Dancing correctly, with less directional error and disorder, requires social learning. Distance encoding in the honey bee dance is largely genetic but may also include a component of cultural transmission.

Hospitalizations Among Adults With CKD in Public Renal Specialty Practices: A Retrospective Study From Queensland, Australia.

Rationale & Objective: Little is known about hospital admissions in nondialysis patients with chronic kidney disease (CKD) before death or starting kidney replacement therapy (KRT). Study Design: Retrospective observational cohort study. Setting & Participants: Hospitalizations among 7,201 patients with CKD from 10 public renal clinics in Queensland (QLD), enrolled in the CKD.QLD registry starting in May 2011, were followed for 25,496.34 person-years until they started receiving KRT or died, or until June 30, 2018. Predictors: Demographic and clinical characteristics of patients with CKD. Outcomes: Hospital admissions. Analytical Approach: We evaluated the association of demographic and clinical features with hospitalizations, length of hospital stay, and cost. Results: Approximately 81.5% of the patients were admitted at least once, with 42,283 admissions, costing Australian dollars (AUD) 231 million. The average number of admissions per person-year was 1.7, and the cost was AUD 9,060, 10 times and 2 times their Australian averages, respectively. Single (1-day) admissions constituted 59.2% of all the hospital episodes, led by neoplasms (largely chemotherapy), anemia, CKD-related conditions and eye conditions (largely cataract extractions), but only 14.8% of the total costs. Approximately 41% of admissions were >1-day admissions, constituting 85.2% of the total costs, with cardiovascular conditions, respiratory conditions, CKD-related conditions, and injuries, fractures, or poisoning being the dominant causes. Readmission within 30 days of discharge constituted >42% of the admissions and 46.8% costs. Admissions not directly related to CKD constituted 90% of the admissions and costs. More than 40% of the admissions and costs were through the emergency department. Approximately 19% of the hospitalized patients and 27% of the admissions did not have kidney disease mentioned as either principal or associate causes. Limitations: Variable follow-up times because of different dates of consent. Conclusions: The hospital burden of patients with CKD is mainly driven by complex multiday admissions and readmissions involving comorbid conditions, which may not be directly related to their CKD. Strategies to prevent these complex admissions and readmissions should minimize hospital costs and outcomes. Plain-Language Summary: We analyzed primary causes, types, and costs of hospitalizations among 7,201 patients with chronic kidney disease (CKD) from renal speciality clinics across Queensland, Australia, over an average follow-up of 3.54 years. The average annual cost per person was $9,060, and was the highest in those with more advanced CKD, higher age, and with diabetes. More than 85% of costs were driven by more complex hospitalizations with longer length of stay. Cardiovascular disease was the single largest contributor for hospitalizations, length of hospital stay, and total costs. Readmission within 30 days of discharge, particularly for the same disorder, and multiday admissions should be the main targets for mitigation of hospital costs in this population.

The Diagnostic Performance of a Clinical Diagnosis of Diabetic Kidney Disease.

BACKGROUND: Diabetic kidney disease (DKD), a common cause of CKD and kidney failure, is usually diagnosed clinically. However, there is little evidence comparing the performance of a clinical diagnosis to biopsy-proven diagnosis. PURPOSE OF THE STUDY: Diagnostic performance of a clinical diagnosis was determined in a group of patients with diabetes and chronic kidney disease who underwent kidney biopsy after an initial clinical diagnosis. METHODS: A data analysis of 54 patients who were part of a study cohort for a prospective analysis of cardiovascular and kidney outcomes and who had undergone kidney biopsy after an initial clinical diagnosis of DKD or non-DKD (NDKD) at enrolment was used. We determined the sensitivity, specificity, and positive and negative predictive values of a clinical diagnosis of DKD. RESULTS: A total of 37 of 43 patients clinically diagnosed with DKD also had biopsy-proven DKD, whilst only 1 of 11 patients who had clinically diagnosed NDKD had biopsy-proven DKD. Sensitivity was 97.4%, specificity was 62.5%, positive predictive value 86%, and negative predictive value 90.9%. Comparable values were obtained when analysis was restricted to those with primary rather than secondary diagnosis of DKD or when restricted to those with only DKD found at biopsy. CONCLUSION: A clinical diagnosis of DKD has high sensitivity and is unlikely to overlook cases but may lead to overdiagnosis.

An inhibitory signal associated with danger reduces honeybee dopamine levels.

Positive and negative experiences can alter animal brain dopamine levels.1 When first arriving at a rewarding food source or beginning to waggle dance and recruit nestmates to food, honeybees have increased brain dopamine levels, indicating a desire for food.2 We provide the first evidence that an inhibitory signal, the stop signal, which counters waggle dancing and is triggered by negative events at the food source, can decrease head dopamine levels and dancing, independent of the dancer having any negative experiences. The hedonic value of food can therefore be depressed simply by the receipt of an inhibitory signal. Increasing the brain dopamine levels reduced the aversive effects of an attack, increasing the time that bees spent subsequently feeding and waggle dancing and decreasing their stop signaling and time spent in the hive. Because honeybees regulate food recruitment and its inhibition at the colony level, these results highlight the complex integration of colony information with a basic and highly conserved neural mechanism in mammals and insects.2 VIDEO ABSTRACT.

Can visual cortex non-invasive brain stimulation improve normal visual function? A systematic review and meta-analysis.

Objective: Multiple studies have explored the use of visual cortex non-invasive brain stimulation (NIBS) to enhance visual function. These studies vary in sample size, outcome measures, and methodology. We conducted a systematic review and meta-analyses to assess the effects of NIBS on visual functions in human participants with normal vision. Methods: We followed the PRISMA guidelines, and a review protocol was registered with PROSPERO before study commencement (CRD42021255882). We searched Embase, Medline, PsychInfo, PubMed, OpenGrey and Web of Science using relevant keywords. The search covered the period from 1st January 2000 until 1st September 2021. Comprehensive meta-analysis (CMA) software was used for quantitative analysis. Results: Fifty studies were included in the systematic review. Only five studies utilized transcranial magnetic stimulation (TMS) and no TMS studies met our pre-specified criteria for meta-analysis. Nineteen transcranial electrical stimulation studies (tES, 38%) met the criteria for meta-analysis and were the focus of our review. Meta-analysis indicated acute effects (Hedges's g = 0.232, 95% CI: 0.023-0.442, p = 0.029) and aftereffects (0.590, 95% CI: 0.182-0.998, p = 0.005) of tES on contrast sensitivity. Visual evoked potential (VEP) amplitudes were significantly enhanced immediately after tES (0.383, 95% CI: 0.110-0.665, p = 0.006). Both tES (0.563, 95% CI: 0.230-0.896, p = 0.001) and anodal-transcranial direct current stimulation (a-tDCS) alone (0.655, 95% CI: 0.273-1.038, p = 0.001) reduced crowding in peripheral vision. The effects of tES on visual acuity, motion perception and reaction time were not statistically significant. Conclusion: There are significant effects of visual cortex tES on contrast sensitivity, VEP amplitude, an index of cortical excitability, and crowding among normally sighted individuals. Additional studies are required to enable a comparable meta-analysis of TMS effects. Future studies with robust experimental designs are needed to extend these findings to populations with vision loss. Clinical trial registration: ClinicalTrials.gov/, identifier CRD42021255882.

Defining honeybee subspecies in an evolutionary context warrants strategized conservation.

Despite the urgent need for conservation consideration, strategic action plans for the preservation of the Asian honeybee, Apis cerana Fabricius, 1793, remain lacking. Both the convergent and divergent adaptations of this widespread insect have led to confusing phenotypical traits and inconsistent infraspecific taxonomy. Unclear subspecies boundaries pose a significant challenge to honeybee conservation efforts, as it is difficult to effectively prioritize conservation targets without a clear understanding of subspecies identities. Here, we investigated genome variations in 362 worker bees representing almost all populations of mainland A. cerana to understand how evolution has shaped its population structure. Whole-genome single nucleotide polymorphisms (SNPs) based on nuclear sequences revealed eight putative subspecies, with all seven peripheral subspecies exhibiting mutually exclusive monophyly and distinct genetic divergence from the widespread central subspecies. Our results demonstrated that most classic morphological traits, including body size, were related to the climatic variables of the local habitats and did not reflect the true evolutionary history of the organism. Thus, such morphological traits were not suitable for subspecific delineation. Conversely, wing vein characters showed relative independence to the environment and supported the subspecies boundaries inferred from nuclear genomes. Mitochondrial phylogeny further indicated that the present subspecies structure was a result of multiple waves of population divergence from a common ancestor. Based on our findings, we propose that criteria for subspecies delineation should be based on evolutionary independence, trait distinction, and geographic isolation. We formally defined and described eight subspecies of mainland A. cerana. Elucidation of the evolutionary history and subspecies boundaries enables a customized conservation strategy for both widespread and endemic honeybee conservation units, guiding colony introduction and breeding.

Social signal learning of the waggle dance in honey bees.

Honey bees use a complex form of spatial referential communication. Their "waggle dance" communicates the direction, distance, and quality of a resource to nestmates by encoding celestial cues, retinal optic flow, and relative food value into motion and sound within the nest. We show that correct waggle dancing requires social learning. Bees without the opportunity to follow any dances before they first danced produced significantly more disordered dances with larger waggle angle divergence errors and encoded distance incorrectly. The former deficit improved with experience, but distance encoding was set for life. The first dances of bees that could follow other dancers showed neither impairment. Social learning, therefore, shapes honey bee signaling, as it does communication in human infants, birds, and multiple other vertebrate species.

The Development, Implementation, and Evaluation of a Pharmacist-Managed Therapeutic Drug Monitoring (TDM) Service for Vancomycin-A Pilot Study.

BACKGROUND: In recent years, pharmacists in Australia have been able to expand their scope to include the provision of a range of services. Although evidence has demonstrated the benefits of pharmacist-managed TDM services, recent studies have shown that these services are not prominent within Australia and that the current TDM workflow may not be optimal. METHODS: An interventional pilot study was conducted of a pharmacist-managed TDM program for vancomycin at a tertiary hospital in Australia. RESULTS: In total, 15 pharmacists participated in the program. They performed 50.5% of the medication-related pathology over the intervention period. Pharmacist involvement in the TDM process was more likely to lead to appropriate TDM sample collection (OR 87.1; 95% CI = 11.5, 661.1) and to an appropriate dose adjustment (OR 19.1; 95% CI = 1.7, 213.5). Pharmacists demonstrated increased confidence after the education and credentialling package was provided. CONCLUSIONS: This study demonstrated that a credentialling package for pharmacists can improve knowledge, skills, and confidence around the provision of pharmacist-managed TDM services for vancomycin. This may lead to the evolution of different roles and workflows enabling pharmacists to contribute more efficiently to improving medication safety and use.

Spatial Methods for Inferring Extremes in Dengue Outbreak Risk in Singapore.

Dengue is a major vector-borne disease worldwide. Here, we examined the spatial distribution of extreme weekly dengue outbreak risk in Singapore from 2007 to 2020. We divided Singapore into equal-sized hexagons with a circumradius of 165 m and obtained the weekly number of dengue cases and the surface characteristics of each hexagon. We accounted for spatial heterogeneity using max-stable processes. The 5-, 10-, 20-, and 30-year return levels, or the weekly dengue case counts expected to be exceeded once every 5, 10, 20, and 30 years, respectively, were determined for each hexagon conditional on their surface characteristics remaining constant over time. The return levels were higher in the country's east, with the maximum weekly dengue cases per hexagon expected to exceed 51 at least once in 30 years in many areas. The surface characteristics with the largest impact on outbreak risk were the age of public apartments and the percentage of impervious surfaces, where a 3-year and 10% increase in each characteristic resulted in a 3.8% and 3.3% increase in risk, respectively. Vector control efforts should be prioritized in older residential estates and places with large contiguous masses of built-up environments. Our findings indicate the likely scale of outbreaks in the long term.

Pharmacist-Managed Therapeutic Drug Monitoring Programs within Australian Hospital and Health Services-A National Survey of Current Practice.

Pharmacist-managed therapeutic drug monitoring (TDM) services have demonstrated positive outcomes in the literature, including reduced duration of therapy and decreased incidence of the adverse effects of drug therapy. Although the evidence has demonstrated the benefits of these TDM services, this has predominately been within international healthcare systems. The extent to which pharmacist-managed TDM services exist within Australia, and the roles and responsibilities of the pharmacists involved compared to their counterparts in other countries, remains largely unknown. A cross-sectional online survey was conducted evaluating pharmacist-managed TDM programs within Australian hospital and healthcare settings. Pharmacist perceptions were also explored about the strengths, weaknesses, opportunities, and barriers associated with implementing a pharmacist-managed TDM service. A total of 92 surveys were returned, which represents a response rate of 38%. Pharmacist-managed TDM programs were present in 15% of respondents. It is only in the minority of hospitals where there is a pharmacist-managed service, with pharmacists involved in recommending pathology and medication doses. The programs highlighted improved patient outcomes but had difficulty maintaining the educational packages and training. For hospitals without a service, a lack of funding and time were highlighted as barriers. Based on the findings of this survey, there is minimal evidence of pharmacist-managed TDM models within Australian hospital and health services. A standardized national approach to pharmacist-managed TDM services and recognition of this specialist area for pharmacists could be a potential solution to this.

Chronic kidney disease in public renal practices in Queensland, Australia, 2011-2018.

AIM: To describe adults with (non-dialysis) chronic kidney disease (CKD) in nine public renal practice sites in the Australian state of Queensland. METHODS: 7,060 persons were recruited to a CKD Registry in May 2011 and until start of kidney replacement therapy (KRT), death without KRT or June 2018, for a median period of 3.4 years. RESULTS: The cohort comprised 7,060 persons, 52% males, with a median age of 68 yr; 85% had CKD stages 3A to 5, 45.4% were diabetic, 24.6% had diabetic nephropathy, and 51.7% were obese. Younger persons mostly had glomerulonephritis or genetic renal disease, while older persons mostly had diabetic nephropathy, renovascular disease and multiple diagnoses. Proportions of specific renal diagnoses varied >2-fold across sites. Over the first year, eGFR fell in 24% but was stable or improved in 76%. Over follow up, 10% started KRT, at a median age of 62 yr, most with CKD stages 4 and 5 at consent, while 18.8% died without KRT, at a median age of 80 yr. Indigenous people were younger at consent and more often had diabetes and diabetic kidney disease and had higher incidence rates of KRT. CONCLUSION: The spectrum of characteristics in CKD patients in renal practices is much broader than represented by the minority who ultimately start KRT. Variation in CKD by causes, age, site and Indigenous status, the prevalence of obesity, relative stability of kidney function in many persons over the short term, and differences between those who KRT and die without KRT are all important to explore.

Esthetic Evaluation of Anterior Implant-Supported Single Crowns: A Comparison Between Patients and Dentists.

PURPOSE: To compare the esthetic outcomes of anterior implant-supported single crowns as evaluated by patients and clinicians of different specialties. MATERIALS AND METHODS: A total of 133 patients with 138 implant-supported crowns were recalled from the National Dental Centre Singapore Implant Registry to rate the esthetic outcomes of their restorations using a visual analog scale (VAS) questionnaire. Patients with crowns in the maxillary or mandibular canine-to-canine region with a contralateral natural tooth and minimum time in function of 6 months were recruited. Three clinicians trained in prosthodontics rated each restoration using the modified Pink Esthetic Score/White Esthetic Score (PES/WES) index through photographs and models. Two periodontists, two orthodontists, and two general dentists each rated a randomized sample of 40 crowns using the same index for comparison. Statistical analysis was done using a linear mixed model, analysis of variance, intraclass correlation coefficient, kappa score, Spearman rank correlation, and Mann- Whitney U tests. RESULTS: Mean PES, WES, and PES/WES scores for the 138 implants were 4.7, 5.0, and 9.7, respectively. Based on modified PES/WES criteria, 22 (15.9%) of the 138 implants were deemed clinically acceptable. Mean patient VAS scores ranged from 79.3 to 84.4 out of 100. Prosthodontists had significantly lower mean PES, WES, and PES/WES scores (P < .05) than the other specialties. When orthodontists were excluded, papilla scores had the highest agreement of all the variables. CONCLUSION: Patients were less critical of esthetic outcomes than clinicians. A weak correlation was found between patients' subjective evaluations and the modified PES/WES index as rated by prosthodontists. Prosthodontists were the strictest assessors.

Prevalence and risk factors of erosive tooth wear among young adults in the Singapore military.

OBJECTIVES: Erosive tooth wear (ETW) is defined as the irreversible chemo-mechanical loss of dental hard tissues without plaque or bacteria and has been a growing phenomenon in the general population worldwide. The aim of this study was to determine the prevalence of ETW and the associated risk factors among young military personnel in Singapore. MATERIALS AND METHODS: This cross-sectional study consisted of a questionnaire and clinical examination of military personnel between 18 and 25 years. The questionnaire collected information on demographics, medical and dental history, lifestyle and dietary habits. Tooth wear was clinically evaluated using the Basic Erosive Wear Examination (BEWE) index. The participants were profiled into four risk categories (none, low, moderate, severe) based on the sum score. Multivariable logistic regression analysis was performed to determine the risk factors associated with the presence of ETW. RESULTS: Out of 1296 participants evaluated, 21.8% of them had ETW. The anterior sextants were more affected by erosion than posterior sextants for both arches. The risk factors significantly associated with ETW were GERD (OR = 2.83, p = 0.041), presence of self-reported TMD symptoms (OR = 2.51, p < 0.001), acidic food (OR = 2.03, p < 0.001) and drinks (OR = 3.07, p < 0.001), high caries risk (OR = 4.59, p < 0.001) and toothbrush stiffness (OR = 4.67, p < 0.001). CONCLUSION: ETW is prevalent among the young military population, with over half of the population at a risk of ETW. Gastric reflux disease, TMD, acidic diet, dental caries susceptibility and the use of stiff toothbrushes were identified as significant risk factors. CLINICAL RELEVANCE: A large proportion of young military personnel exhibited mild to moderate risk of ETW. Dental professionals can identify risk-susceptible individuals at a young age and educated them with preventive measures and dietary interventions to prevent the progression of the condition.

Strategies to Mitigate Establishment under the Wolbachia Incompatible Insect Technique.

The Incompatible Insect Technique (IIT) strategy involves the release of male mosquitoes infected with the bacterium Wolbachia. Regular releases of male Wolbachia-infected mosquitoes can lead to the suppression of mosquito populations, thereby reducing the risk of transmission of vector-borne diseases such as dengue. However, due to imperfect sex-sorting under IIT, fertile Wolbachia-infected female mosquitoes may potentially be unintentionally released into the environment, which may result in replacement and failure to suppress the mosquito populations. As such, mitigating Wolbachia establishment requires a combination of IIT with other strategies. We introduced a simple compartmental model to simulate ex-ante mosquito population dynamics subjected to a Wolbachia-IIT programme. In silico, we explored the risk of replacement, and strategies that could mitigate the establishment of the released Wolbachia strain in the mosquito population. Our results suggest that mitigation may be achieved through the application of a sterile insect technique. Our simulations indicate that these interventions do not override the intended wild type suppression of the IIT approach. These findings will inform policy makers of possible ways to mitigate the potential establishment of Wolbachia using the IIT population control strategy.

Modelling the Impact of Mass Testing to Transition from Pandemic Mitigation to Endemic COVID-19.

As countries transition from pandemic mitigation to endemic COVID-19, mass testing may blunt the impact on the healthcare system of the liminal wave. We used GeoDEMOS-R, an agent-based model of Singapore's population with demographic distributions and vaccination status. A 250-day COVID-19 Delta variant model was run at varying maximal rapid antigen test sensitivities and frequencies. Without testing, the number of infections reached 1,021,000 (899,400-1,147,000) at 250 days. When conducting fortnightly and weekly mass routine rapid antigen testing 30 days into the outbreak at a maximal test sensitivity of 0.6, this was reduced by 12.8% (11.3-14.5%) and 25.2% (22.5-28.5%). An increase in maximal test sensitivity of 0.2 results a corresponding reduction of 17.5% (15.5-20.2%) and 34.4% (30.5-39.1%). Within the maximal test sensitivity range of 0.6-0.8, test frequency has a greater impact than maximal test sensitivity with an average reduction of 2.2% in infections for each day removed between tests in comparison to a 0.43% average reduction per 1% increase in test frequency. Our findings highlight that mass testing using rapid diagnostic tests can be used as an effective intervention for countries transitioning from pandemic mitigation to endemic COVID-19.

Identification of giant hornet Vespa mandarinia queen sex pheromone components.

The Vespidae is a diverse family of wasps and hornets that are formidable predators of insects, including social bees1, and includes a number of invasive species2. Recently, the world's largest hornet, Vespa mandarinia Smith (Hymenoptera: Vespidae), which occurs naturally in the Indomalayan region, has been found in Canada and the United States2. Some simulations indicate that it could rapidly spread throughout Washington and Oregon in the western US, as well as some eastern parts of the country2,3, threaten native bees and honeybees, and harm bee-pollinated crop production worth over $100 million annually3. There is consequently an urgent need to learn more about V. mandarinia's reproductive biology and to develop trapping methods to locate its nests and to control its reproduction. We identified V. mandarinia queen-produced sex pheromone from the 5th and 6th intersegmental sternal glands of virgin queens. The major active compounds were hexanoic acid, octanoic acid, and decanoic acid. When placed in field traps, the synthetic compounds and a queen-equivalent mixture rapidly attracted hundreds of males but no females or other species.

Testing strategies to contain COVID-19 in migrant worker dormitories.

INTRODUCTION: COVID-19 transmission within overcrowded migrant worker dormitories is an ongoing global issue. Many countries have implemented extensive control measures to prevent the entire migrant worker population from becoming infected. Here, we explore case count outcomes when utilizing lockdown and testing under different testing measures and transmissibility settings. METHODS: We built a mathematical model which estimates transmission across 10 different blocks with 1000 individuals per block under different parameter combinations and testing conditions over the period of 1 month. We vary parameters including differences in block connectivity, underlying recovered proportions at the time of intervention, case importation rates and testing protocols using either PCR or rapid antigen testing. RESULTS: We estimate that a relatively transmissible environment with fortnightly PCR testing at a relatively low initial recovered proportion of 40%, low connectivity where 10% of contacts occurred outside of the infected individuals' block and a high importation rate of 1 100 000 per day, results in an average of 39 (95%Interval: 9-121) new COVID-19 cases after one month of observation. Similar results were observed for weekly rapid antigen testing at 33 (9-95) cases. INTERPRETATION: Our findings support the need for either fortnightly PCR testing or weekly rapid antigen testing in high population density environments such as migrant worker dormitories. Repeated mass testing is highly effective, preventing localized site outbreaks and reducing the need for site wide lockdowns or other extensive social distancing measures within and outside of dormitories.