Cost Of Outbreak Research Articles

Cost of a measles outbreak in a remote island economy: 2014 Federated States of Micronesia measles outbreak.

After 20years with no reported measles cases, on May 15, 2014 the Centers for Disease Control and Prevention (CDC) was notified of two cases testing positive for measles-specific immunoglobulin M (IgM) antibodies in the Federated States of Micronesia (FSM). Under the Compact of Free Association, FSM receives immunization funding and technical support from the United States (US) domestic vaccination program managed by the Centers for Disease Control and Prevention (CDC). In a collaborative effort, public health officials and volunteers from FSM and the US government worked to respond and contain the measles outbreak through an emergency mass vaccination campaign, contact tracing, and other outbreak investigation activities. Contributions were also made by United Nations Children's Emergency Fund (UNICEF) and World Health Organization (WHO). Total costs incurred as a result of the outbreak were nearly $4,000,000; approximately $10,000 per case. Direct medical costs (≈$141,000) were incurred in the treatment of those individuals infected, as well as lost productivity of the infected and informal caregivers (≈$250,000) and costs to contain the outbreak (≈$3.5 million). We assessed the economic burden of the 2014 measles outbreak to FSM, as well as the economic responsibilities of the US. Although the US paid the majority of total costs of the outbreak (≈67%), examining each country's costs relative to their respective economy illustrates a far greater burden to FSM. We demonstrate that while FSM was heavily assisted by the US in responding to the 2014 Measles Outbreak, the outbreak significantly impacted their economy. FSM's economic burden from the outbreak is approximately equivalent to their entire 2016 Fiscal Year budget dedicated to education.

Cost of Nosocomial Outbreak Caused by NDM-1–Containing Klebsiella pneumoniae in the Netherlands, October 2015–January 2016

During October–December 2015, 29 patients in a hospital in the Netherlands acquired nosocomial infection with a multidrug-resistant, New Delhi-metallo-β-lactamase–positive Klebsiella pneumoniae strain. Extensive infection control measures were needed to stop this outbreak. The estimated economic impact of the outbreak was $804,263; highest costs were associated with hospital bed closures.

Caprine brucellosis: A historically neglected disease with significant impact on public health.

Caprine brucellosis is a chronic infectious disease caused by the gram-negative cocci-bacillus Brucella melitensis. Middle- to late-term abortion, stillbirths, and the delivery of weak offspring are the characteristic clinical signs of the disease that is associated with an extensive negative impact in a flock’s productivity. B. melitensis is also the most virulent Brucella species for humans, responsible for a severely debilitating and disabling illness that results in high morbidity with intermittent fever, chills, sweats, weakness, myalgia, abortion, osteoarticular complications, endocarditis, depression, anorexia, and low mortality. Historical observations indicate that goats have been the hosts of B. melitensis for centuries; but around 1905, the Greek physician Themistokles Zammit was able to build the epidemiological link between “Malta fever” and the consumption of goat milk. While the disease has been successfully managed in most industrialized countries, it remains a significant burden on goat and human health in the Mediterranean region, the Middle East, Central and Southeast Asia (including India and China), sub-Saharan Africa, and certain areas in Latin America, where approximately 3.5 billion people live at risk. In this review, we describe a historical evolution of the disease, highlight the current worldwide distribution, and estimate (by simple formula) the approximate costs of brucellosis outbreaks to meat- and milk-producing farms and the economic losses associated with the disease in humans. Successful control leading to eradication of caprine brucellosis in the developing world will require a coordinated Global One Health approach involving active involvement of human and animal health efforts to enhance public health and improve livestock productivity.

Carbapenemase-producing Acinetobacter baumannii: An outbreak report with special highlights on economic burden

ObjectiveWe aimed to describe the management of a carbapenemase-producing Acinetobacter baumannii (CP-AB) outbreak using the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) statement. We also aimed to evaluate the cost of the outbreak and simulate costs if a dedicated unit to manage such outbreak had been set-up. MethodsWe performed a prospective epidemiological study. Multiple interventions were implemented including cohorting measures and limitation of admissions. Cost estimation was performed using administrative local data. ResultsFive patients were colonized with CP-AB and hospitalized in the neurosurgery ward. The index case was a patient who had been previously hospitalized in Portugal. Four secondary colonized patients were further observed within the unit. The strains of A. baumannii were shown to belong to the same clone and all of them produced an OXA-23 carbapenemase. The closure of the ward associated with the discharge of the five patients in a cohorting area of the Infectious Diseases Unit with dedicated staff put a stop to the outbreak. The estimated cost of this 17-week outbreak was $474,474. If patients had been managed in a dedicated unit — including specific area for cohorting of patients and dedicated staff — at the beginning of the outbreak, the estimated cost would have been $189,046. ConclusionControlling hospital outbreaks involving multidrug-resistant bacteria requires a rapid cohorting of patients. Using simulation, we highlighted cost gain when using a dedicated cohorting unit strategy for such an outbreak.

Impact of Nonmedical Vaccine Exemption Policies on the Health and Economic Burden of Measles

ObjectiveDespite relatively high national vaccination coverage for measles, geographic vaccination variation exists resulting in clusters of susceptibility. A portion of this geographic variation can be explained by differences in state policies related to nonmedical vaccine exemptions. The objective of this analysis was to determine the magnitude, likelihood, and cost of a measles outbreak under different nonmedical vaccine exemption policies. MethodsAn agent-based transmission model simulated the likelihood and magnitude of a measles outbreak under different nonmedical vaccine exemption policies, previously categorized as easy, medium, or difficult. The model accounted for measles herd immunity, infectiousness of the pathogen, vaccine efficacy, duration of incubation and communicable periods, acquired natural immunity, and the rate of recovery. Public health contact tracing was also modeled. Model outcomes, including the number of secondary cases, hospitalizations, and deaths, were monetized to determine the economic burden of the simulated outbreaks. ResultsA state with easy nonmedical vaccine exemption policies is 140% and 190% more likely to experience a measles outbreak compared with states with medium or difficult policies, respectively. The magnitude of these outbreaks can be reduced by half by strengthening exemption policies. These declines are associated with significant cost reductions to public health, the health care system, and the individual. ConclusionsStrengthening nonmedical vaccine exemption policies is 1 mechanism to increase vaccination coverage to reduce the health and economic effect of a measles outbreak. States exploring options for decreasing their vulnerability to outbreaks of vaccine-preventable diseases should consider more stringent requirements for nonmedical vaccine exemptions.

Quantifying the Value of Perfect Information in Emergency Vaccination Campaigns

Foot-and-mouth disease outbreaks in non-endemic countries can lead to large economic costs and livestock losses but the use of vaccination has been contentious, partly due to uncertainty about emergency FMD vaccination. Value of information methods can be applied to disease outbreak problems such as FMD in order to investigate the performance improvement from resolving uncertainties. Here we calculate the expected value of resolving uncertainty about vaccine efficacy, time delay to immunity after vaccination and daily vaccination capacity for a hypothetical FMD outbreak in the UK. If it were possible to resolve all uncertainty prior to the introduction of control, we could expect savings of £55 million in outbreak cost, 221,900 livestock culled and 4.3 days of outbreak duration. All vaccination strategies were found to be preferable to a culling only strategy. However, the optimal vaccination radius was found to be highly dependent upon vaccination capacity for all management objectives. We calculate that by resolving the uncertainty surrounding vaccination capacity we would expect to return over 85% of the above savings, regardless of management objective. It may be possible to resolve uncertainty about daily vaccination capacity before an outbreak, and this would enable decision makers to select the optimal control action via careful contingency planning.

Evaluation of fixed and variable hospital costs due to Clostridium difficile infection: institutional incentives and directions for future research

Economic analysis of Clostridium difficile infection (CDI) should consider the incentives facing institutional decision-makers. To avoid overstating the financial benefits of infection prevention, fixed and variable costs should be distinguished. To quantify CDI fixed and variable costs in a tertiary referral hospital during August 2015. A micro-costing analysis estimated CDI costs per patient, including the additional costs of a CDI outbreak. Resource use was quantified after review of patient charts, pharmacy data, administrative resource input, and records of salary and cleaning/decontamination expenditure. The incremental cost of CDI was €75,680 (mean: €5,820 per patient) with key cost drivers being cleaning, pharmaceuticals, and length of stay (LOS). Additional LOS ranged from 1.75 to 22.55 days. For seven patients involved in a CDI outbreak, excluding the value of the 58 lost bed-days (€34,585); costs were 30% higher (€7,589 per patient). Therefore, total spending on CDI was €88,062 (mean: €6,773 across all patients). Potential savings from variable costs were €1,026 (17%) or €1,768 (26%) if outbreak costs were included. Investment in an antimicrobial pharmacist would require 47 CDI cases to be prevented annually. Prevention of 5%, 10% and 20% CDI would reduce attributable costs by €4,403, €8,806 and €17,612. Increasing the incremental LOS attributable to CDI to seven days per patient would have increased costs to €7,478 or €8,431 (if outbreak costs were included). As much CDI costs are fixed, potential savings from infection prevention are limited. Future analysis must consider more effectively this distinction and its impact on institutional decision-making.

Ensemble modelling and structured decision-making to support Emergency Disease Management

Epidemiological models in animal health are commonly used as decision-support tools to understand the impact of various control actions on infection spread in susceptible populations. Different models contain different assumptions and parameterizations, and policy decisions might be improved by considering outputs from multiple models. However, a transparent decision-support framework to integrate outputs from multiple models is nascent in epidemiology. Ensemble modelling and structured decision-making integrate the outputs of multiple models, compare policy actions and support policy decision-making. We briefly review the epidemiological application of ensemble modelling and structured decision-making and illustrate the potential of these methods using foot and mouth disease (FMD) models. In case study one, we apply structured decision-making to compare five possible control actions across three FMD models and show which control actions and outbreak costs are robustly supported and which are impacted by model uncertainty. In case study two, we develop a methodology for weighting the outputs of different models and show how different weighting schemes may impact the choice of control action. Using these case studies, we broadly illustrate the potential of ensemble modelling and structured decision-making in epidemiology to provide better information for decision-making and outline necessary development of these methods for their further application.

Cost analysis of an outbreak of Clostridium difficile infection ribotype 027 in a Dutch tertiary care centre

The economic impact of Clostridium difficile infection (CDI) on the healthcare system is significant. From May 2013 to May 2014, an outbreak of C.difficile ribotype 027 occurred in a Dutch tertiary care hospital, involving 72 patients. The primary aim of this study was to provide insight into the financial burden that this CDI outbreak brought upon this hospital. A retrospective analysis was performed to estimate the costs of a one-year-long C.difficile ribotype 027 outbreak. Medical charts were reviewed for patient data. In addition, all costs associated with the outbreak control measures were collected. The attributable costs of the whole outbreak were estimated to be €1,222,376. The main contributing factor was missed revenue due to increased length of stay of CDI patients and closure of beds to enable contact isolation of CDI patients (36%). A second important cost component was extra surveillance and activities of the Department of Medical Microbiology and Infection Control (25%). To the authors' knowledge, this is the first study to provide insight into the attributable costs of CDI in an outbreak setting, and to delineate the major cost items. It is clear that the economic consequences of CDI are significant. The high costs associated with a CDI outbreak should help to justify the use of additional resources for CDI prevention and control.

The economic burden of a Salmonella Thompson outbreak caused by smoked salmon in the Netherlands, 2012-2013.

In 2012, the Netherlands experienced the most extensive food-related outbreak of Salmonella ever recorded. It was caused by smoked salmon contaminated with Salmonella Thompson during processing. In total, 1149 cases of salmonellosis were laboratory confirmed and reported to RIVM. Twenty percent of cases was hospitalised and four cases were reported to be fatal. The purpose of this study was to estimate total costs of the Salmonella Thompson outbreak. Data from a case-control study were used to estimate the cost-of-illness of reported cases (i.e. healthcare costs, patient costs and production losses). Outbreak control costs were estimated based on interviews with staff from health authorities. Using the Dutch foodborne disease burden and cost-of-illness model, we estimated the number of underestimated cases and the associated cost-of-illness. The estimated number of cases, including reported and underestimated cases was 21 123. Adjusted for underestimation, the total cost-of-illness would be €6.8 million (95% CI €2.5-€16.7 million) with productivity losses being the main cost driver. Adding outbreak control costs, the total outbreak costs are estimated at €7.5 million. In the Netherlands, measures are taken to reduce salmonella concentrations in food, but detection of contamination during food processing remains difficult. As shown, Salmonella outbreaks have the potential for a relatively high disease and economic burden for society. Early warning and close cooperation between the industry, health authorities and laboratories is essential for rapid detection, control of outbreaks, and to reduce disease and economic burden.

Emergency fire response in Ghana: the case of fire stations in Kumasi

Recently, Ghana has been plagued by increasing and disastrous fire emergencies, yet little research exists on Ghana’s fire response system. This paper examines the emergency fire response system in Kumasi, Ghana’s second largest city. We use spatial analysis to evaluate the geographic distribution of existing fire stations and their service areas, and identify coverage gaps based on specified response times. Our results show that large portions of the Kumasi Metropolitan Area are underserved, a situation that partly explains the huge losses in property and lives during recent fire outbreaks. Efficient location of fire stations using simple location–allocation models can help to improve response to fire emergencies and reduce the cost of fire outbreaks in African cities.

Counting the cost of an outbreak of carbapenemase-producing Enterobacteriaceae: an economic evaluation from a hospital perspective

ObjectiveTo perform an economic evaluation on the cost associated with an outbreak of carbapenemase-producing Enterobacteriaceae (CPE). MethodsWe performed an observational economic evaluation of an outbreak of CPE (NDM-producing Klebsiella pneumoniae) affecting 40 patients in a group of five hospitals across three sites in West London. Costs were split into actual expenditure (including anti-infective costs, enhanced CPE screening, contact precautions, temporary ward-based monitors of hand and environmental practice, and environmental decontamination), and ‘opportunity cost’ (staff time, bed closures and elective surgical missed revenue). Costs are estimated from the hospital perspective over the 10-month duration of the outbreak. ResultsThe outbreak cost €1.1m over 10 months (range €0.9–1.4m), comprising €312 000 actual expenditure, and €822 000 (range €631 000–€1.1m) in opportunity cost. An additional €153 000 was spent on Estates renovations prompted by the outbreak. Actual expenditure comprised: €54 000 on anti-infectives for 18 patients treated, €94 000 on laboratory costs for screening, €73 000 on contact precautions for 1831 contact precautions patient-days, €42 000 for hydrogen peroxide vapour decontamination of 24 single rooms, €43 000 on 2592 hours of ward-based monitors, and €6000 of expenditure related to ward and bay closures. Opportunity costs comprised: €244 000 related to 1206 lost bed-days (range 366–2562 bed-days, €77 000–€512 000), €349 000 in missed revenue from 72 elective surgical procedures, and €228 000 in staff time (range €205 000–€251 000). Reduced capacity to perform elective surgical procedures related to bed closures (€349 000) represented the greatest cost. ConclusionsThe cost estimates that we present suggest that CPE outbreaks are highly costly.

An economic evaluation of intervention strategies for Porcine Epidemic Diarrhea (PED)

The economic losses of Porcine Epidemic Diarrhea (PED) and the net benefits of strategies to control the virus are calculated for individual farrow-to-finish herds. A production simulation model that estimates the number of pigs by population cohorts on a weekly basis for a farrow-to-finish farm depending on production parameters is simulated under normal operating conditions and then with an outbreak of PED. The estimated annual costs of a PED outbreak with the closure of the breeding herd as the only intervention is approximately $300,000 for a 700-sow farrow-to-finishing herd. The net returns per sow (hog) fall from $255 ($11.54) to a loss of $174 ($10.68). These losses can be significantly reduced with any of the 16 intervention strategies considered in this study. The most profitable strategy involving front loading of gilts with average feedback of infected material to improve herd immunity, intensive biosecurity protocols and no vaccination costs $27,000 to implement but reduces losses by 10 times this amount. Even the implementation of the least comprehensive strategy, which involves back-loading gilts after the herd reopens and an average feedback practice at a cost of $1000 reduces the losses caused by a PED outbreak by $130,000. Front-loading gilts in combination with herd closure is more cost-effective than back-loading. Despite the extra spending on intensive biosecurity protocols, the overall loss reductions achieved by the intensive biosecurity effort can be significant. Vaccination is the least cost-effective of the intervention practices considered. Even with significant increases in cost or effectiveness in the practices, intervention is justified across all strategies. The spreadsheet model of a farrow-finish hog farm developed in this study can be used to examine changes to the production parameters or to consider other swine disease outbreaks.

Emergence of ebola virus disease and its devastating impact in poor-resourced areas of sub-Saharan Africa

Ebola virus disease (EVD) is an unusual infection, and one of the most virulent emerging viral diseases known causing severe morbidity and significant mortality. In recent epidemic outbreak of EVD in West African countries of Guinea, Sierra Leone and Liberia (the 3 nations epi-centre of the epidemic), the disease has affected over 25,000 people resulting in more than 10,000 deaths, (Case Fatality Rate, CFR>40%; i.e. from December, 2013-March, 2015). Following the first outbreak of EVD in Sudan and Democratic Republic of Congo (DRC) in 1976, several epidemics (>20 outbreaks) of the disease have been recorded particularly in poor-resourced areas of the East, Central and West-Africa resulting in significant mortality. CFR of EVD is 25-90 percent. Ebola virus is transmitted to humans by wild animals (mainly non-human primates) and spreads in human population via close contact with blood, body fluids and secretions of infected patients. EVD can also be acquired through direct contact with infected corpses. It is characterized (at initial stage) by non-specific flu-like symptoms including headache, fever, myalgia and malaise following incubation period of 2-21 days. This may terminate into severe systemic manifestations including diffuse internal and external bleeding, shock and death if untreated early. Non recognition of the specific natural host of Ebola virus and rapid progression of infection including slow mounting of acquired immunity against EVD by infected host complicate control measures. The socio-economic cost of EVD epidemic outbreak is colossal. Despite notable advances in healthcare-related technology enhancing the diagnosis, treatment / management and prevention / control of infectious or viral diseases, the response of the stakeholders over the years geared toward controlling the spread of the disease left much to be desired. No clinically certified drugs or vaccines against EVD are yet available. There is the urgent need by stakeholders to device appropriate preventive / control measures including development of effective drugs and vaccines to checkmate the spread of EVD and associated severe morbidity, high mortality and devastating socio-economic impact. Key Words : Ebola virus disease, severe morbidity, mortality, socio-economic impact, checkmate.

Behind certification and regulatory processes: Contributions to a political history of the Chilean salmon farming

Abstract This text follows the public regulatory and the private certificatory paths undergone in the last decade by the widely criticized salmon industry in Chile, with the purpose of exploring the political process that underlies this path. The discussion focuses on the several instances in which both industrial actors and oppositional groups have stabilized those conflicts by sitting down at formally established dialogue tables, which, as we will see, have conducted public and private processes of regulation. In particular, we follow two paths: one promoted and overseen by the public sector and the other a process of self-organization and self-control of the industry at the national and global levels, which initially led to processes of self-certification and third-party certification. We argue that it cannot be reduced to an industrial learning due to the economic cost of disease outbreaks but rather that it is the outcome of a contested political process with interplay between global and local actors. This argument challenges the learning narratives espoused by the industry, contributing to a political ecology of certification processes. It analyzes the outcome of this process showing its contested political and social legitimacy, and the interplay between labor and environment within this regulatory path.

Norovirus in a United States virgin islands resort: outbreak investigation, response, and costs.

During 8-20 April 2012, an outbreak of gastrointestinal illness occurred among guests and employees of a resort hotel in St. Thomas, US Virgin Islands. We describe outbreak characteristics, and estimate indirect (non-medical) costs to travellers. Employees who met the case definition were interviewed and provided stool samples. Samples were tested for norovirus by real-time reverse-transcription polymerase chain reaction. Guests were asked to complete a survey aimed to identify and characterize cases, and to estimate quality adjusted vacation days (QAVD) lost. Overall, 66 persons (20 employees and 46 guests) met the probable case definition. The first reported illness onset occurred in a hotel employee on 8 April, while the first reported onset in a guest occurred on 13 April. An employee suffered a public diarrhoea incident on 13 April in the central kitchen, followed by illness onset in the next day among employees that assisted with the clean-up. On 15 April, after 10 guests reported ill, the hotel implemented an outbreak response protocol instructing ill employees to take a 3-day leave, and obtain medical clearance prior to resuming work. Ill guests were advised to self-isolate, and rapid cleaning of public areas and guest rooms where suspected contamination occurred was implemented. We estimated that 65 QAVDs were lost by 43 guests (1.5 days/guest). Using an approximate cost of $450 per vacation day, we estimated indirect illness cost at $675 per guest case. Seven (64%) of 11 cases' stool specimens were positive for norovirus genotype GII.4 Den Haag. A norovirus outbreak in a resort hotel resulted in substantial indirect costs and loss of vacation days to ill travellers. We recommend outbreak control measures including exclusion of ill employees, until ≥48-72 h after resolution of symptoms, self-isolation of ill guests and appropriate cleaning in hotel-associated norovirus outbreaks.

The economic cost of measles: Healthcare, public health and societal costs of the 2012–13 outbreak in Merseyside, UK

BackgroundMeasles is a highly contagious vaccine-preventable infection that caused large outbreaks in England in 2012 and 2013 in areas which failed to achieve herd protection levels (95%) consistently. We sought to quantify the economic costs associated with the 2012–13 Merseyside measles outbreak, relative to the cost of extending preventative vaccination to secure herd protection. MethodsA costing model based on a critical literature review was developed. A workshop and interviews were held with key stakeholders in the Merseyside outbreak to understand the pathway of a measles case and then quantify healthcare activity and costs for the main NHS providers and public health team incurred during the initial four month period to May 2012. These data were used to model the total costs of the full outbreak to August 2013, comprising those to healthcare providers for patient treatment, public health and societal productivity losses. The modelled total cost of the full outbreak was compared to the cost of extending the preventative vaccination programme to achieve herd protection. FindingsThe Merseyside outbreak included 2458 reported cases. The estimated cost of the outbreak was £4.4m (sensitivity analysis £3.9m to £5.2m) comprising 15% (£0.7m) NHS patient treatment costs, 40% (£1.8m) public health costs and 44% (£2.0m) for societal productivity losses. In comparison, over the previous five years in Cheshire and Merseyside a further 11,793 MMR vaccinations would have been needed to achieve herd protection at an estimated cost of £182,909 (4% of the total cost of the measles outbreak). InterpretationFailure to consistently reach MMR uptake levels of 95% across all localities and sectors (achieve herd protection) risks comparatively higher economic costs associated with the containment (including healthcare costs) and implementation of effective public health management of outbreaks. FundingCommissioned by the Cheshire and Merseyside Public Health England Centre.

Counting the cost of a measles outbreak in the UK

Counting the cost of a measles outbreak in the UK

Cost-Analysis of Seven Nosocomial Outbreaks in an Academic Hospital.

ObjectivesNosocomial outbreaks, especially with (multi-)resistant microorganisms, are a major problem for health care institutions. They can cause morbidity and mortality for patients and controlling these costs substantial amounts of funds and resources. However, how much is unclear. This study sets out to provide a comparable overview of the costs of multiple outbreaks in a single academic hospital in the Netherlands.MethodsBased on interviews with the involved staff, multiple databases and stored records from the Infection Prevention Division all actions undertaken, extra staff employment, use of resources, bed-occupancy rates, and other miscellaneous cost drivers during different outbreaks were scored and quantified into Euros. This led to total costs per outbreak and an estimated average cost per positive patient per outbreak day.ResultsSeven outbreaks that occurred between 2012 and 2014 in the hospital were evaluated. Total costs for the hospital ranged between €10,778 and €356,754. Costs per positive patient per outbreak day, ranged between €10 and €1,369 (95% CI: €49-€1,042), with a mean of €546 and a median of €519. Majority of the costs (50%) were made because of closed beds.ConclusionsThis analysis is the first to give a comparable overview of various outbreaks, caused by different microorganisms, in the same hospital and all analyzed with the same method. It shows a large variation within the average costs due to different factors (e.g. closure of wards, type of ward). All outbreaks however cost considerable amounts of efforts and money (up to €356,754), including missed revenue and control measures.

Comparative Performance of a Parallel Implementation of an Internet-Scale Zero-Day Worm Epidemiology Simulator

The threat posed by fast-spreading malware is significant, particularly given the fact that network operator/administrator intervention is not likely to take effect within the typical epidemiological timescale of such infections. The cost of zero-day network worm outbreaks has been estimated to be up to US $2.6 billion for a single worm outbreak. Zero-day network worm outbreaks have been observed that spread at a significant pace across the global Internet, with an observed rate of reaching more than 90 percent of vulnerable hosts within 10 minutes. An accepted technology that is used in addressing the security threat presented by zero-day worms is the use of simulation systems, and a common factor determining their efficacy is their performance. An empirical comparison of a sequential and parallel implementation of a novel simulator, the Internet Worm Simulator (IWS), is presented detailing the impact of a selection of parameters on its performance. Experimentation demonstrates that IWS has the capability to simulate up to 91.8 million packets transmitted per second (PTS) for an IPv4 address space simulation on a single workstation computer, comparing favourably to previously reported metrics. It is concluded that in addition to comparing PTS performance, simulation requirements should be taken into consideration when assessing the performance of such simulators.