The cost of hospital care for management of invasive group A streptococcal infections in England.

The objective of this study was to estimate the direct financial costs of hospital care for management of invasive group A streptococcal (GAS) infections using hospital records for cases diagnosed in England. We linked laboratory-confirmed cases (n = 3696) identified through national surveillance to hospital episode statistics and reimbursement codes. From these codes we estimated the direct hospital costs of admissions. Almost all notified invasive GAS cases (92% of 3696) were successfully matched to a primary hospital admission. Of these, secondary admissions (within 30 days of primary admission) were further identified for 593 (17%). After exclusion of nosocomial cases (12%), the median costs of primary and secondary hospital admissions were estimated by subgroup analysis as £1984-£2212 per case, totalling £4·43-£6·34 million per year in England. With adjustment for unmatched cases this equated to £4·84-£6·93 million per year. Adults aged 16-64 years accounted for 48% of costs but only 40% of cases, largely due to an increased number of surgical procedures. The direct costs of hospital admissions for invasive GAS infection are substantial. These estimated costs will contribute to a full assessment of the total economic burden of invasive GAS infection as a means to assess potential savings through prevention measures.

Evaluation of the Economic Impact of Streptococcus suis-Associated Disease.

The economic impact of Streptococcus suis-associated disease at farm level is well known by the producers, but the cost in a region or a country is more difficult to evaluate due to the lack of a centralized data system, the different incidences, and the control measures applied by each producer. In this chapter, we describe a method based on the information gathered through interviews with veterinary practitioners. A comprehensive questionnaire created specifically for the disease can help to conduct the interviews. The questions include information about the proportions of farms, batches and animals clinically affected, mortality, metaphylactic and therapeutic treatments, use of vaccines, and proportion of cases that are diagnosed at the laboratory. As the questionnaire is quite complex, the best option to obtain the data is send the questionnaire to the selected veterinarians to allow them to collect some data and make an interview with them some days later. The information allows to estimate the costs due to mortality, antimicrobial treatments, the use of autogenous vaccines, and analyses performed. Initially they are calculated per animal in each affected production phase, and later it can be extrapolated to estimate the annual cost per affected production unit and per country. The model does not consider indirect costs such as the cost as a zoonosis, the revenues forgone, or an increase of labor.

Long-term healthcare utilisation, costs and quality of life after invasive group B Streptococcus disease: a cohort study in five low-income and middle-income countries.

INTRODUCTION: There are no published data on the long-term impact of invasive group B Streptococcus disease (iGBS) on economic costs or health-related quality of life (HRQoL) in low-income and middle-income countries. We assessed the impact of iGBS on healthcare utilisation, costs and HRQoL in Argentina, India, Kenya, Mozambique and South Africa. METHODS: Inpatient and outpatient visits, out-of-pocket (OOP) healthcare payments in the 12 months before study enrolment, and health-state utility of children and caregivers (using the EuroQol 5-Dimensions-3-Level) were collected from iGBS survivors and an unexposed cohort matched on site, age at recruitment and sex. We used logistic or Poisson regression for analysing healthcare utilisation and zero-inflated gamma regression models for family and health system costs. For HRQoL, we used a zero-inflated beta model of disutility pooled data. RESULTS: 161 iGBS-exposed and 439 unexposed children and young adults (age 1-20) were included in the analysis. Compared with unexposed participants, iGBS was associated with increased odds of any healthcare utilisation in India (adjusted OR 11.2, 95% CI 2.9 to 43.1) and Mozambique (6.8, 95% CI 2.2 to 21.1) and more frequent healthcare visits (adjusted incidence rate ratio (IRR) for India 1.7 (95% CI 1.4 to 2.2) and for Mozambique 6.0 (95% CI 3.2 to 11.2)). iGBS was also associated with more frequent days in inpatient care in India (adjusted IRR 4.0 (95% CI 2.3 to 6.8) and Kenya 6.4 (95% CI 2.9 to 14.3)). OOP payments were higher in the iGBS cohort in India (adjusted mean: Int$682.22 (95% CI Int$364.28 to Int$1000.16) vs Int$133.95 (95% CI Int$72.83 to Int$195.06)) and Argentina (Int$244.86 (95% CI Int$47.38 to Int$442.33) vs Int$52.38 (95% CI Int$-1.39 to Int$106.1)). For all remaining sites, differences were in the same direction but not statistically significant for almost all outcomes. Health-state disutility was higher in iGBS survivors (0.08, 0.04-0.13 vs 0.06, 0.02-0.10). CONCLUSION: The iGBS health and economic burden may persist for years after acute disease. Larger studies are needed for more robust estimates to inform the cost-effectiveness of iGBS prevention.

Reduction of the use of antimicrobial drugs following the rapid detection of Streptococcus agalactiae in the vagina at delivery by real-time PCR assay.

OBJECTIVE: To assess whether the determination of the presence of group B streptococci (GBS) in the vagina using a rapid polymerase chain reaction (PCR) assay at delivery was able to spare useless antimicrobial treatments, as compared with conventional culture at 34-38 weeks of gestation. DESIGN: Practical evaluation and prospective cost-effectiveness analysis. SETTING: A university hospital in France. POPULATION: A cohort of 225 women in labour at the University-Hospital of Saint-Etienne. METHODS: Each woman had a conventional culture performed at 34-38 weeks of gestation. At the beginning of labour, two vaginal swabs were sampled for rapid PCR testing and culture. The decision to prescribe a prophylactic antimicrobial treatment or not was taken according to the result of the PCR test. A comparative cost-effectiveness analysis of the two diagnostic strategies was carried out. MAIN OUTCOME MEASURES: Number of women receiving inadequate prophylactic antimicrobial drugs following each testing strategy, costs of PCR testing and culture, frequency of vaginal GBS, and diagnostic performance of the PCR test at delivery. RESULTS: The percentage of unnecessarily treated women was significantly reduced using the rapid test versus conventional culture (4.5 and 13.6%, respectively; P < 0.001). The rate of vaginal GBS at delivery was 12.5%. The incremental cost-effectiveness ratio (ICER) for each inadequate management avoided was €36 and €173 from the point of view of the healthcare system and hospital, respectively. CONCLUSIONS: The PCR assay reduced the number of inadequate antimicrobial treatments aimed to prevent the early onset of GBS disease. However, this strategy generates extra costs that must be put into balance with its clinical benefits.

Early hospital discharge of infants born to group B streptococci-positive mothers: a decision analysis.

OBJECTIVE: To compare the cost-effectiveness of an additional 24-hour inpatient observation for asymptomatic term neonates born to group B streptococcus (GBS)-colonised mothers with adequate intrapartum antibiotic prophylaxis (IAP) after an initial 24-hour in-hospital observation. DESIGN: Cost-effectiveness analysis from a societal perspective. SETTING: United States. POPULATION: Asymptomatic term neonates born to GBS-colonised mothers with IAP after an initial 24-hour in-hospital observation. METHODS: Monte Carlo simulation for a decision tree model incorporating the following chance events: development of GBS sepsis during the second 24 hours of life, development of GBS sepsis between 48 hours and 7 days of life, prompt versus delayed treatment for sepsis, neonatal mortality and long-term health sequelae. MAIN OUTCOME MEASURES: Expected cost and quality-adjusted life years (QALYs), Incremental cost-effectiveness ratio (ICER). RESULTS: Delayed, versus early, hospital discharge results in similar mean expected QALYs, but substantially higher expected cost. The mean difference in QALY is 0.00016 (95% CI 0.00005-0.00040), whereas the mean difference in cost is $1170.96 (95% CI $750.13-1584.32). The ICER is estimated to be $9,771,520.87 per QALY (95% CI $2,573,139.89-24,407,017.82). The proportion of early-onset GBS that develops during the second 24 hours of life, the cost of 24 hours of inpatient observation, and the probability of long-term sequelae following prompt versus delayed treatment play important roles in determining the cost-effectiveness of delayed hospital discharge. CONCLUSION: Cost-effectiveness analysis suggests that with adequate IAP, discharging asymptomatic term neonates to home after 24 hours is the preferred approach compared with 48 hours inpatient observation.

Bioeconomic modeling of intervention against clinical mastitis caused by contagious pathogens.

The objective of this study was to assess the epidemiologic and economic consequences of intervention against contagious clinical mastitis during lactation. A bioeconomic model of intramammary infections (IMI) was used to simulate contagious spread of Staphylococcus aureus, Streptococcus uberis, and Streptococcus dysgalactiae, and an environmental spread of Escherichia coli IMI in a 100-cow dairy herd during 1 quota year. The costs of clinical IMI, subclinical IMI, and intervention were calculated into the total annual net costs of IMI during lactation per scenario and compared with a default scenario. Input parameter values were based on the scientific literature. The scenarios were 3-d intramammary lactational treatment (default), 5-d intramammary treatment, 5-d intramammary treatment and 3-d systemic treatment, 3-d intramammary treatment and culling bacteriologically unrecovered clinical IMI cows, and 5-d intramammary treatment and culling bacteriologically unrecovered clinical IMI cows. Sensitivity analysis was conducted on parameter input values. The results showed that interventions including antibiotic treatment combined with culling unrecovered clinical IMI cows resulted in the lowest transmission, number of IMI cases, and persistent subclinical IMI cases. Nonetheless, the high associated costs of culling bacteriologically unrecovered clinical IMI cows made the other scenarios with a long and intensive antibiotic treatment, but without culling, the most cost effective. The model was sensitive to changes to the cure rate of clinical IMI following treatment, but the ranking of the intervention scenarios did not change. The model was most sensitive to the changes to the transmission rate of Staph. aureus. The ranking of the intervention scenarios changed at low transmission rate of this pathogen, in which the default scenario became the most cost-effective scenario. In case of high transmission of contagious IMI pathogens, long and intensive treatment of clinical IMI should be preceded by strategies that lower the transmission.

Diagnosis and management of acute pharyngitis in a paediatric population: a cost-effectiveness analysis.

Acute pharyngitis is one of the most frequent causes of primary care physician visits; however, there is no agreement about which is the best strategy to diagnose and manage acute pharyngitis in children. The aim of the current study was to evaluate the cost-effectiveness of the recommended strategies to diagnose and manage acute pharyngitis in a paediatric population. A decision tree analysis was performed to compare the following six strategies: "treat all", "clinical scoring", "rapid test", "culture", "rapid test + culture" and "clinical scoring + rapid test". The cost data came from the Spanish National Health Service sources. Cost-effectiveness was calculated from the payer's perspective. Effectiveness was measured as the proportion of patients cured without complications from the disease and did not have any reaction to penicillin therapy; a sensitivity analysis was performed. The findings revealed that the "clinical scoring + rapid test" strategy is the most cost-effective, with a cost-effectiveness ratio of 50.72 . This strategy dominated all others except "culture", which was the most effective but also the most costly. The sensitivity analysis showed that "rapid test" became the most cost-effective strategy when the clinical scoring sensitivity was <91% and its specificity was ≤9%. In conclusion, the use of a clinical scoring system to triage the diagnoses and performing a rapid antigen test for those with a high score is the most cost-effective strategy for the diagnosis and management of acute pharyngitis in children. When the clinical scoring system has a low diagnostic accuracy, testing all patients with rapid test becomes the most cost-effective strategy.

Burden of disease and productivity impact of Streptococcus suis infection in Thailand.

BACKGROUND: Streptoccocus suis (S.suis) infection is a neglected zoonosis disease in humans mainly affects men of working age. We estimated the health and economic burden of S.suis infection in Thailand in terms of years of life lost, quality-adjusted life years (QALYs) lost, and productivity-adjusted life years (PALYs) lost which is a novel measure that adjusts years of life lived for productivity loss attributable to disease. METHODS: A decision-analytic Markov model was developed to simulate the impact of S. suis infection and its major complications: death, meningitis and infective endocarditis among Thai people in 2019 with starting age of 51 years. Transition probabilities, and inputs pertaining to costs, utilities and productivity impairment associated with long-term complications were derived from published sources. A lifetime time horizon with follow-up until death or age 100 years was adopted. The simulation was repeated assuming that the cohort had not been infected with S.suis. The differences between the two set of model outputs in years of life, QALYs, and PALYs lived reflected the impact of S.suis infection. An annual discount rate of 3% was applied to both costs and outcomes. One-way sensitivity analyses and Monte Carlo simulation modeling technique using 10,000 iterations were performed to assess the impact of uncertainty in the model. KEY RESULTS: This cohort incurred 769 (95% uncertainty interval [UI]: 695 to 841) years of life lost (14% of predicted years of life lived if infection had not occurred), 826 (95% UI: 588 to 1,098) QALYs lost (21%) and 793 (95%UI: 717 to 867) PALYs (15%) lost. These equated to an average of 2.46 years of life, 2.64 QALYs and 2.54 PALYs lost per person. The loss in PALYs was associated with a loss of 346 (95% UI: 240 to 461) million Thai baht (US$11.3 million) in GDP, which equated to 1.1 million Thai baht (US$ 36,033) lost per person. CONCLUSIONS: S.suis infection imposes a significant economic burden both in terms of health and productivity. Further research to investigate the effectiveness of public health awareness programs and disease control interventions should be mandated to provide a clearer picture for decision making in public health strategies and resource allocations.

The economic and health burdens of diseases caused by group A Streptococcus in New Zealand.

OBJECTIVES: In preparation for the future arrival of a group A Streptococcus (GAS) vaccine, this study estimated the economic and health burdens of GAS diseases in New Zealand (NZ). METHODS: The annual incidence of GAS diseases was based on extrapolation of the average number of primary healthcare episodes managed each year in general practices (2014-2016) and on the average number of hospitalizations occurring each year (2005-2014). Disease incidence was multiplied by the average cost of diagnosing and managing an episode of disease at each level of care to estimate the annual economic burden. RESULTS: GAS affected 1.5% of the population each year, resulting in an economic burden of 29.2 million NZ dollars (2015 prices) and inflicting a health burden of 2373 disability-adjusted life years (DALYs). Children <5 years of age were the most likely age group to present for GAS-related healthcare. Presentations for superficial throat and skin infections (predominantly pharyngitis and impetigo) were more common than other GAS diseases. Cellulitis contributed the most to the total economic and health burdens. Invasive and immune-mediated diseases disproportionately contributed to the total economic and health burdens relative to their frequency of occurrence. CONCLUSION: Preventing GAS diseases would have substantial economic and health benefits in NZ and globally.

Cost-effectiveness of rapid tests and other existing strategies for screening and management of early-onset group B streptococcus during labour.

OBJECTIVE: To determine the cost-effectiveness of alternative screening and prevention strategies, including rapid intrapartum testing, for prevention of early-onset neonatal group B streptococcus (GBS) infection in the UK. DESIGN: A decision model was developed to investigate the cost-effectiveness of screening and prevention strategies for GBS. A strategy of doing nothing was also considered. Deterministic and probabilistic sensitivity analyses were carried out. SETTING: Two large UK based obstetric units. PARTICIPANTS: Test accuracy data were obtained from a primary study of rapid tests at the onset of labour and risk factors from 1400 women. MAIN OUTCOME MEASURES: Incremental health sector costs per case of early-onset GBS death avoided. RESULTS: Compared with a strategy of do nothing, the incremental cost-effectiveness ratio was £32,000 per Early-Onset GBS Disease avoided and £427,000 per Early-Onset GBS Death avoided for the strategy of providing routine intrapartum antibiotic prophylaxis to all women without prior screening; Based on their current sensitivity, specificity and cost, screening using rapid tests was dominated by other more cost-effective strategies. CONCLUSIONS: The most cost-effective strategy was shown to be the provision of routine intrapartum antibiotic prophylaxis to all women without prior screening but, given broader concerns relating to antibiotic use, this is unlikely to be acceptable. In its absence, intrapartum antibiotic prophylaxis directed by screening with enriched culture becomes cost-effective. The current strategy of risk-factor-based screening is not cost-effective compared with screening based on culture.

Preferences for health outcomes associated with Group A Streptococcal disease and vaccination.

BACKGROUND: A 26-valent Group A Streptococcus (GAS) vaccine candidate has been developed that may provide protection against pharyngitis, invasive disease and rheumatic fever. However, recommendations for the use of a new vaccine must be informed by a range of considerations, including parents' preferences for different relevant health outcomes. Our objectives were to: (1) describe parent preferences for GAS disease and vaccination using willingness-to-pay (WTP) and time trade-off (TTO) methods; and (2) understand how parents' implied WTP for a quality-adjusted life year (QALY) gained might vary depending on the particular health outcome considered (e.g. averted GAS disease vs. vaccine adverse events). METHODS: Telephone interviews were conducted with parents of children diagnosed with GAS pharyngitis at 2 pediatric practice sites in the Boston metropolitan area. WTP and TTO (trading parental longevity for child's health) questions for 2 vaccine and 4 disease-associated health states were asked using a randomly selected opening bid, followed by a 2nd bid and a final open-ended question about the amount willing to pay or trade. Descriptive analyses included medians and interquartile ranges for WTP and TTO estimates. The Wilcoxon signed-rank test was used to assess differences in WTP/QALY values for vaccine adverse events vs. disease states. RESULTS: Of 119 respondents, 100 (84%) and 96 (81%) provided a complete set of responses for WTP and TTO questions, respectively. The median WTP and discounted (at 3% per year) TTO values to avoid each health state were as follows: local reaction, $30, 0.12 days; systemic reaction, $50, 0.22 days; impetigo, $75, 1.25 days; strep throat, $75, 2.5 days; septic arthritis, $1,000, 6.6 days; and toxic shock syndrome, $3,000, 31.0 days. The median WTP/QALY was significantly higher for vaccine adverse events (approximately $60,000/QALY) compared to disease states ($18,000 to $36,000/QALY). CONCLUSIONS: Parents strongly prefer to prevent GAS disease in children compared to vaccine adverse events. However, implied WTP/QALY ratios were higher for the prevention of vaccine adverse events. Regret for errors of commission vs. omission may differ and should be considered by vaccine policymakers.

Cost Effectiveness of Latest Recommendations for Group B Streptococci Screening in the United States.

OBJECTIVE: To evaluate whether group B streptococci (GBS) screening using the 2010 guideline (screening at 35 0/7-37 6/7 weeks of gestation) compared with the 2019 guideline (screening at 36 0/7-37 6/7 weeks of gestation with re-screening of women with GBS-negative results 5 weeks later) was more cost effective. METHODS: We constructed a decision-analysis model to compare the outcome of GBS early-onset disease in a hypothetical cohort of 3,614,049 women at 35 0/7 weeks of gestation or greater (the number of live births in 2017 excluding births based on population frequency from 23 to 34 weeks of gestation, women with GBS bacteriuria during the current pregnancy, and those with a history of a previous neonate with GBS disease). We took both a health care and societal perspective and all costs were expressed in 2017 U.S. dollars. Effectiveness was based on neonatal quality-adjusted life years (QALYs) gained. An incremental cost-effectiveness ratio was estimated with a willingness to pay threshold set at $100,000/QALY. All model inputs were derived from the literature. One-way probability and cost sensitivity analysis were performed to investigate model assumptions. RESULTS: Screening at 36 0/7-37 6/7 weeks of gestation with re-screening of women with GBS-negative results if 5 weeks passed from culture to delivery resulted in a 6% increase in neonatal QALYs gained (2,162 vs 2,037), 12% fewer cases of neonatal death (30 vs 34), and a 10% estimated reduction in total societal health care expenditures related to GBS early-onset disease ($639 million vs $707 million) when compared with the 2010 strategy of only screening at 35 0/7-37 6/7 weeks of gestation. The 2019 approach was cost effective, with an incremental cost-effectiveness ratio of $43,205 per neonatal QALY gained. CONCLUSION: Screening at 36 0/7-37 6/7 weeks of gestation with a 5-week re-screening for women with GBS-negative results is more cost effective than past strategies used in the United States.

Intravenous immunoglobulin in children with streptococcal toxic shock syndrome.

BACKGROUND: Streptococcal toxic shock syndrome (TSS) is a rare and severe manifestation of group A streptococcal infection. The role of intravenous immunoglobulin (IVIG) for streptococcal TSS in children is controversial. This study aims to describe the epidemiology of streptococcal TSS in children and to determine whether adjunctive therapy with IVIG is associated with improved outcomes. METHODS: A multicenter, retrospective cohort study of children with streptococcal TSS from 1 January 2003 through 31 December 2007 was conducted. Propensity scores were used to determine each child's likelihood of receiving IVIG. Differences in the primary outcomes of death, hospital length of stay, and total hospital costs were compared after matching IVIG recipients and nonrecipients on propensity score. RESULTS: The median patient age was 8.2 years. IVIG was administered to 84 (44%) of 192 patients. The overall mortality rate was 4.2% (95% confidence interval, 1.8%-8.0%). Differences in mortality between IVIG recipients (n = 3; 4.5%) and nonrecipients (n = 3; 4.5%) were not statistically significant (p > .99). Although patients receiving IVIG had higher total hospital and drug costs than nonrecipients, differences in hospital costs were not significant once drug costs were removed (median difference between matched patients, $6139; interquartile range, -$8316 to $25,993; P = .06). No differences were found in length of hospital stay between matched IVIG recipients and nonrecipients. CONCLUSION: This multicenter study is, to our knowledge, the largest to describe the epidemiology and outcomes of children with streptococcal TSS and the first to explore the association between IVIG use and clinical outcomes. IVIG use was associated with increased costs of caring for children with streptococcal TSS but was not associated with improved outcomes.

Cost-effectiveness of universal prophylaxis in pregnancy with prior group B streptococci colonization.

OBJECTIVE: To estimate the costs and outcomes of rescreening for group B streptococci (GBS) compared to universal treatment of term women with history of GBS colonization in a previous pregnancy. STUDY DESIGN: A decision analysis model was used to compare costs and outcomes. Total cost included the costs of screening, intrapartum antibiotic prophylaxis (IAP), treatment for maternal anaphylaxis and death, evaluation of well infants whose mothers received IAP, and total costs for treatment of term neonatal early onset GBS sepsis. RESULTS: When compared to screening and treating, universal treatment results in more women treated per GBS case prevented (155 versus 67) and prevents more cases of early onset GBS (1732 versus 1700) and neonatal deaths (52 versus 51) at a lower cost per case prevented ($8,805 versus $12,710). CONCLUSION: Universal treatment of term pregnancies with a history of previous GBS colonization is more cost-effective than the strategy of screening and treating based on positive culture results.

The economic costs of Group B Streptococcus (GBS) disease: prospective cohort study of infants with GBS disease in England.

The objective of this study was to estimate the economic costs over the first 2 years of life of Group B Streptococcus (GBS) disease occurring in infants less than 90 days of age. A cost analysis was conducted using a prospective cohort of children born between 2000 and 2003 in the Greater London, Oxford, Portsmouth and Bristol areas of England. Unit costs were applied to estimates of the health and social resource use made by 138 infants diagnosed with GBS disease and 305 non-GBS controls matched for birth weight and hospital stay and time of birth. The health and social care costs for infants exposed to GBS disease were analysed in a multiple linear regression model. The mean health and social care cost over the first 2 years of life was estimated at pound11,968.9 for infants with GBS, compared to pound6,260.7 for the non-GBS controls; a mean cost difference of pound5,708.1 (bootstrap 95% CI pound2,977.1, pound8,391.2, P=0.03). After adjusting for gestational age and other potential confounders in a multiple linear regression, mean societal costs was pound6,144.7 higher among GBS cases than among non-GBS controls (P<0.001). This study shows that the health and social care costs for infants with GBS disease is, on average, two-fold higher during the first 2 years of life than for infants without GBS disease. These data should be used to inform policy decisions regarding the cost-effectiveness of prevention and treatment strategies for GBS disease during early childhood.

Economic appraisal of vaccination against Streptoccocus agalactiae in Nile tilapia farms in Brazil.

Infection with Streptococcus agalactiae causes mortality and major economic losses in Nile tilapia (Oreochromis niloticus) farming worldwide. In Brazil, serotype strains Ia, Ib and III have been isolated in streptococcosis outbreaks, but serotype Ib is the most prevalent. Vaccination is considered an effective method to prevent economically-important diseases in aquaculture and has been associated with decreased use of antibiotics and improvements in fish survival. We developed a flexible partial-budget model to undertake an economic appraisal of vaccination against Streptococcus agalactiae in Nile tilapia farmed in net cages in large reservoirs. The model considers the benefits and costs that are likely to be associated with vaccination at the farm-level, in one production cycle. We built three epidemiological scenarios of cumulative mortality attributable to S. agalactiae (5%, 10%, and 20%, per production cycle) in a non-vaccinated farm. For each scenario, we applied a stochastic model to simulate the net return of vaccination, given a combination of values of "vaccine efficacy", "gain in feed conversion ratio", "feed price", "fish market price ", and "cost of vaccine dose". In the 20% cumulative mortality scenario, the net return would break-even (benefits ≥ costs) in at least 97.9% of interactions. Should cumulative mortality be lower than 10%, the profitability of vaccination would be more dependent on better feed conversion ratio. The inputs "feed price" and "cost of vaccine" had minor effects on the output, in all pre-vaccination mortality scenarios. Although our simulations are based on conservative values and consider uncertainty about the modeled parameters, we conclude that vaccination against S. agalactiae is likely to be profitable in Nile tilapia farms, under similar production conditions.

The burden of infant group B streptococcal infections in Ontario: Analysis of administrative data to estimate the potential benefits of new vaccines.

Group B streptococcus (GBS) is a leading bacterial cause of neonatal sepsis and meningitis in many countries as well as an important cause of disease in pregnant women. Currently, serotype-specific conjugate vaccines are being developed. We conducted an epidemiological analysis of health administrative data to estimate the burden of infant GBS disease in Ontario, Canada and combined these estimates with literature on serotype distribution to estimate the burden of disease likely to be vaccine-preventable. Between 1st January 2005 and 31st December 2015, 907 of 64320 health care encounters in Ontario in patients under 1 year old had codes specifically identifying GBS as the cause of the disease, of which 717 were under one month of age. In addition, application of epidemiological data to the remaining patients allowed us to estimate a further 2322 cases and among them 1822 were under one month of age. In the same period, 579 confirmed neonatal invasive GBS cases in patients up to one month of age were reported to public health. Depending on serotype distribution, vaccination coverage and early versus late onset disease (0-6 days and 7-90 days of age respectively), the preventable fraction ranged widely. With a vaccine that is 90% effective and 60% immunization coverage, up to 52% of early and late onset disease could be prevented by forthcoming vaccines. GBS is under-reported in Ontario. Uncertainty about the potential impact of vaccine indicates that further analysis and research may be needed to prepare for policy-decision making, including clinical validation studies and an economic evaluation of GBS vaccination in Ontario.

Point-of-Care Intrapartum Group B Streptococcus Molecular Screening: Effectiveness and Costs.

OBJECTIVE: To assess outcomes and costs associated with around-the-clock point-of-care intrapartum group B streptococcus (GBS) polymerase chain reaction (PCR) screening. METHODS: Intrapartum PCR screening was implemented in 2010. Intrapartum PCR was compared with antenatal culture screening in an uncontrolled, single institution, preintervention and postintervention study. The study periods included 4 years before and 6 years after the intervention, commencing in 2006 and concluding in 2015. The primary outcome measure was rate of early-onset neonatal GBS disease. Secondary outcomes included length of stay, days of antibiotics, and costs. RESULTS: During the 4 years of antenatal culture screening, 11,226 deliveries were recorded compared with 18,835 in the 6 years of intrapartum GBS PCR screening, corresponding to 11,818 and 18,980 live births, respectively. During the antenatal culture period, 3.8% of term deliveries did not undergo GBS testing compared with 0.1% during the intrapartum PCR period (P<.001). Between the two periods, the rate of proven early-onset GBS disease cases decreased from 1.01/1,000 to 0.21/1,000 (P=.026) and probable early-onset GBS disease cases from 2.8/1,000 to 0.73/1,000 (P<.001); the risk ratio for both was 0.25, 95% CI (0.14-0.43). Total days of hospital and antibiotic therapy for early-onset GBS disease declined by 64% and 60%, respectively, with no significant difference for average length of stay or antibiotic duration preintervention and postintervention. The yearly cost of delivery and treatment of newborns with GBS infection was reduced from $41,875±6,823 to $11,945±10,303 (P<.001). The estimated extra cost to avoid one early-onset GBS disease was $5,819. CONCLUSION: Point-of-care intrapartum GBS PCR screening was associated with a significant decrease in the rate of early-onset GBS disease and antibiotic use in newborns. The additional PCR costs were offset in part by the reduction in early-onset GBS disease treatment costs.

Burden of disease and economic impact of human Streptococcus suis infection in Viet Nam.

BACKGROUND: Streptococcus suis is a zoonotic disease mainly affecting men of working age and can result in death or long-term sequelae, including severe hearing loss and vestibular dysfunction. We aimed to quantify the burden of disease and economic impact of this infection in Viet Nam. METHODS: The annual disease incidence for the period 2011-2014 was estimated based on surveillance data using a multiple imputation approach. We calculated disease burden in disability-adjusted life years (DALYs) and economic costs using an incidence-based approach from a patient's perspective and including direct and indirect impacts of S. suis infection and its long-term sequelae. RESULTS: The estimated annual incidence rate was 0.318, 0.324, 0.255 and 0.249 cases per 100 000 population in 2011, 2012, 2013 and 2014, respectively. The corresponding DALYs lost were 1832, 1866, 1467 and 1437. The mean direct cost per episode was US$1635 (95% confidence interval 1352-1923). The annual direct cost was US$370 000-500 000 and the indirect cost was US$2.27-2.88 million in this time period. CONCLUSIONS: This study showed a large disease burden and high economic impact of S. suis infection and provides important data for disease monitoring and control.

Economic and epidemiological impact of different intervention strategies for subclinical and clinical mastitis.

The objective of this study was to evaluate and compare different combinations of intervention strategies for contagious or opportunistic subclinical and clinical intramammary infections (IMI). We simulated two different Danish dairy cattle herds with ten different intervention strategies focusing on cow-specific treatment or culling, including three baseline strategies without subclinical interventions. In one herd, the main causative pathogen of IMI was Staphylococcus (S.) aureus. In the other herd, Streptococcus (St.) agalactiae was the main causative agent. For both herds, we investigated costs and effectiveness of all ten intervention strategies. Intervention strategies consisted of measures against clinical and subclinical IMI, with baselines given by purely clinical intervention strategies. Our results showed that strategies including subclinical interventions were more cost-effective than the respective baseline strategies. Increase in income and reduction of IMI cases came at the cost of increased antibiotic usage and an increased culling rate in relation to IMI. However, there were differences between the herds. In the St. agalactiae herd, the clinical intervention strategy did not seem to have a big impact on income and number of cases. However, intervention strategies which included cow-specific clinical interventions led to a higher income and lower number of cases in the S. aureus herd. The results show that intervention strategies including interventions against contagious or opportunistic clinical and subclinical IMI can be highly cost-effective, but should be herd-specific.