Dogs on the move: Estimating the risk of rabies in imported dogs in the United States, 2015-2022.

BACKGROUND: Dog-mediated rabies virus variant (DMRVV), a zoonotic pathogen that causes a deadly disease in animals and humans, is present in more than 100 countries worldwide but has been eliminated from the United States since 2007. In the United States, the U.S. Centers for Disease Control and Prevention has recorded four instances of rabies in dogs imported from DMRVV-enzootic countries since 2015. However, it remains uncertain whether the incidence of DMRVV among imported dogs from these countries significantly surpasses that of domestically acquired variants among domestic U.S. dogs. AIM: This evaluation aimed to estimate the number of dogs imported from DMRVV-enzootic countries and compare the risk of rabies between imported dogs and the U.S. domestic dog population. MATERIALS AND METHODS: Data from the CDC's dog import permit system (implemented during 2021 under a temporary suspension of dog importation from DMRVV-enzootic countries) and U.S. Customs and Border Protection's Automated Commercial Environment system, each of which records a segment of dogs entering the U.S. from DMRVV-enzootic countries, was analysed. Additionally, we estimated the incidence rate of rabies in dogs imported from DMRVV-enzootic countries and compared it to the incidence rate within the general U.S. dog population, due to domestically acquired rabies variants, over the eight-year period (2015-2022). RESULTS: An estimated 72,589 (range, 62,660-86,258) dogs were imported into the United States annually between 2015 and 2022 from DMRVV-enzootic countries. The estimated incidence rate of rabies was 16 times higher (range, 13.2-19.4) in dogs imported from DMRVV-enzootic countries than that estimated for domestically acquired rabies in the general U.S. dog population. CONCLUSIONS: Preventing human exposure to dogs with DMRVV is a public health priority. The higher risk of rabies in dogs imported from DMRVV-enzootic countries supports the need for importation requirements aimed at preventing the reintroduction of DMRVV into the United States.

Cost effectiveness of preemptive school closures to mitigate pandemic influenza outbreaks of differing severity in the United States.

BACKGROUND: Nonpharmaceutical interventions (NPIs) may be considered as part of national pandemic preparedness as a first line defense against influenza pandemics. Preemptive school closures (PSCs) are an NPI reserved for severe pandemics and are highly effective in slowing influenza spread but have unintended consequences. METHODS: We used results of simulated PSC impacts for a 1957-like pandemic (i.e., an influenza pandemic with a high case fatality rate) to estimate population health impacts and quantify PSC costs at the national level using three geographical scales, four closure durations, and three dismissal decision criteria (i.e., the number of cases detected to trigger closures). At the Chicago regional level, we also used results from simulated 1957-like, 1968-like, and 2009-like pandemics. Our net estimated economic impacts resulted from educational productivity costs plus loss of income associated with providing childcare during closures after netting out productivity gains from averted influenza illness based on the number of cases and deaths for each mitigation strategy. RESULTS: For the 1957-like, national-level model, estimated net PSC costs and averted cases ranged from $7.5 billion (2016 USD) averting 14.5 million cases for two-week, community-level closures to $97 billion averting 47 million cases for 12-week, county-level closures. We found that 2-week school-by-school PSCs had the lowest cost per discounted life-year gained compared to county-wide or school district-wide closures for both the national and Chicago regional-level analyses of all pandemics. The feasibility of spatiotemporally precise triggering is questionable for most locales. Theoretically, this would be an attractive early option to allow more time to assess transmissibility and severity of a novel influenza virus. However, we also found that county-wide PSCs of longer durations (8 to 12 weeks) could avert the most cases (31-47 million) and deaths (105,000-156,000); however, the net cost would be considerably greater ($88-$103 billion net of averted illness costs) for the national-level, 1957-like analysis. CONCLUSIONS: We found that the net costs per death averted ($180,000-$4.2 million) for the national-level, 1957-like scenarios were generally less than the range of values recommended for regulatory impact analyses ($4.6 to 15.0 million). This suggests that the economic benefits of national-level PSC strategies could exceed the costs of these interventions during future pandemics with highly transmissible strains with high case fatality rates. In contrast, the PSC outcomes for regional models of the 1968-like and 2009-like pandemics were less likely to be cost effective; more targeted and shorter duration closures would be recommended for these pandemics.

Productivity costs associated with reactive school closures related to influenza or influenza-like illness in the United States from 2011 to 2019.

INTRODUCTION: Schools close in reaction to seasonal influenza outbreaks and, on occasion, pandemic influenza. The unintended costs of reactive school closures associated with influenza or influenza-like illness (ILI) has not been studied previously. We estimated the costs of ILI-related reactive school closures in the United States over eight academic years. METHODS: We used prospectively collected data on ILI-related reactive school closures from August 1, 2011 to June 30, 2019 to estimate the costs of the closures, which included productivity costs for parents, teachers, and non-teaching school staff. Productivity cost estimates were evaluated by multiplying the number of days for each closure by the state- and year-specific average hourly or daily wage rates for parents, teachers, and school staff. We subdivided total cost and cost per student estimates by school year, state, and urbanicity of school location. RESULTS: The estimated productivity cost of the closures was $476 million in total during the eight years, with most (90%) of the costs occurring between 2016-2017 and 2018-2019, and in Tennessee (55%) and Kentucky (21%). Among all U.S. public schools, the annual cost per student was much higher in Tennessee ($33) and Kentucky ($19) than any other state ($2.4 in the third highest state) or the national average ($1.2). The cost per student was higher in rural areas ($2.9) or towns ($2.5) than cities ($0.6) or suburbs ($0.5). Locations with higher costs tended to have both more closures and closures with longer durations. CONCLUSIONS: In recent years, we found significant heterogeneity in year-to-year costs of ILI-associated reactive school closures. These costs have been greatest in Tennessee and Kentucky and been elevated in rural or town areas relative to cities or suburbs. Our findings might provide evidence to support efforts to reduce the burden of seasonal influenza in these disproportionately impacted states or communities.

Cost-effectiveness of treatment strategies for populations from strongyloidiasis high-risk areas globally who will initiate corticosteroid treatment in the United States.

BACKGROUND: The risk of developing strongyloidiasis hyperinfection syndrome appears to be elevated among individuals who initiate corticosteroid treatment. Presumptive treatment or treatment after screening for populations from Strongyloides stercoralis-endemic areas has been suggested before initiating corticosteroids. However, potential clinical and economic impacts of preventative strategies have not been evaluated. METHODS: Using a decision tree model for a hypothetical cohort of 1000 individuals from S. stercoralis-endemic areas globally initiating corticosteroid treatment, we evaluated clinical and economic impacts of two interventions, 'Screen and Treat' (i.e. screening and ivermectin treatment after a positive test), and 'Presumptively Treat,' compared to current practice (i.e. 'No Intervention'). We evaluated the cost-effectiveness (net cost per death averted) of each strategy using broad ranges of pre-intervention prevalence and hospitalization rates for chronic strongyloidiasis patients initiating corticosteroid treatment. RESULTS: For the baseline parameter estimates, 'Presumptively Treat' was cost-effective (i.e. clinically superior with cost per death averted less than a threshold of $10.6 million per life) compared to 'No Intervention' ($532 000 per death averted) or 'Screen and Treat' ($39 000 per death averted). The two parameters contributing the most uncertainty to the analysis were the hospitalization rate for individuals with chronic strongyloidiasis who initiate corticosteroids (baseline 0.166%) and prevalence of chronic strongyloidiasis (baseline 17.3%) according to a series of one-way sensitivity analyses. For hospitalization rates greater than 0.022%, 'Presumptively Treat' would remain cost-effective. Similarly, 'Presumptively Treat' remained preferred at prevalence rates of 4% or above; 'Screen and Treat' was preferred for prevalence between 2% and 4%, and 'No Intervention' was preferred for prevalence less than 2%. CONCLUSIONS: The findings support decision-making for interventions for populations from S. stercoralis endemic areas before initiating corticosteroid treatment. Although some input parameters are highly uncertain and prevalence varies across endemic countries, 'Presumptively Treat' would likely be preferred across a range for many populations given plausible parameters.

Costs of malaria treatment in the United States.

We estimated inpatient and outpatient payments for malaria treatment in the USA. The mean cost per hospitalized patient was significantly higher than for non-hospitalized patients (e.g. $27 642 vs $1177 among patients with private insurance). Patients with severe malaria payed two to four times more than those hospitalized with uncomplicated malaria.

Low Treatment Rates of Parasitic Diseases with Standard-of-Care Prescription Drugs in the United States, 2013-2019.

To assess appropriate drug treatment of parasitic diseases in the United States, we examined the treatment rates of 11 selected parasitic infections with standard-of-care prescription drugs and compared them to the treatment rates of two more common bacterial infections (Clostridioides difficile and streptococcal pharyngitis). We used the 2013 to 2019 IBM® MarketScan® Commercial Claims and Encounters and MarketScan® Multi-State Medicaid databases, which included up to 7 years of data for approximately 88 million and 17 million individuals, respectively, to estimate treatment rates of each infection. The number of patients diagnosed with each parasitic infection varied from 57 to 5,266, and from 12 to 2,018, respectively, across the two databases. Treatment rates of 10 of 11 selected parasitic infections (range, 0-56%) were significantly less than those for streptococcal pharyngitis and Clostridioides difficile (range, 65-85%); giardiasis treatment (64%) was comparable to Clostridioides difficile (65%) in patients using Medicaid. Treatment rates for patients with opisthorchiasis, clonorchiasis, and taeniasis were less than 10%. Although we could not verify that patients had active infections because of limitations inherent to claims data, including coding errors and the inability to review patients' charts, these data suggest a need for improved treatment of parasitic infections. Further research is needed to verify the results and identify potential clinical and public health consequences.

Low Use of Standard-of-Care Antiparasitic Drugs and Increased Estimated Outpatient Payments for Treating Schistosomiasis in the United States, 2013-19.

Drug utilization and payment estimates for standard-of-care treatment of schistosomiasis have not been reported previously in the United States. This study estimates the utilization of praziquantel (standard-of-care drug) among patients with schistosomiasis and outpatient payments among those who were treated with praziquantel, and investigates the factors associated with praziquantel use from 2013-19 using IBM's MarketScan® Commercial Claims and Encounters database. Claims data showed that only 21% of patients with schistosomiasis diagnoses were treated with praziquantel. The mean total drug payments per patient treated with praziquantel increased from $110 in 2013-14 to $612 in 2015-18 (P < 0.01), and use decreased. These factors, including residing in a rural area, having a documented Schistosoma haematobium infection, or having a first schistosomiasis diagnosis in 2015-16, were associated with a decreased likelihood of patients receiving standard-of-care treatment. Policy solutions to exorbitant drug pricing, and better awareness and education among healthcare providers about schistosomiasis-especially those practicing in rural areas with high immigrant populations-are needed.

Trends in Percentages of the US Population Covered by State-Issued COVID-19 Nonpharmaceutical Interventions, March 1, 2020-August 15, 2021.

Trends in the percentages of the US population covered by state-issued nonpharmaceutical interventions (NPIs), including restaurant and bar restrictions, stay-at-home orders, gathering limits, and mask mandates, were examined by using county-specific data sets on state-issued orders for NPIs from March 1, 2020, to August 15, 2021. Most of the population was covered by multiple NPIs early in the pandemic. Most state-issued orders were lifted or relaxed as COVID-19 cases decreased during summer 2020. Few states reimplemented strict NPIs during later surges in US COVID-19 cases over the winter of 2020-2021. The exceptions were mask mandates, which covered about 80% of the population between August 2020 and February 2021, and the most restrictive gathering limits, which covered a maximum of 66% of the population in early 2020 and 68% of the population in winter 2020-2021. Most NPIs were lifted by the end of the analysis period.

Risk factors for death and illness in dogs imported into the United States, 2010-2018.

CDC estimates 1 million dogs are imported into the United States annually. With the movement of large numbers of animals into the United States the risk of disease importation, especially emerging diseases, and animal welfare issues are of concern. Dogs that arrive to the United States ill or dead are investigated by public health authorities to ensure dogs are not infected with diseases of concern (such as rabies). We identified factors associated with illness and death in imported dogs and estimated the initial investigation cost to public health authorities. Dog importation data from the CDC's Quarantine Activity Reporting System were reviewed from 2010 to 2018. The date of entry, country of origin, port of entry, transportation method and breed were extracted to examine factors associated with illness and death in dogs during international travel. Costs for public health investigations were estimated from data collected by the Bureau of Labor Statistics and Office of Personal Management. Death or illness was more likely to occur in brachycephalic breeds (aOR = 3.88, 95%CI 2.74-5.51). Transportation of dogs via cargo (aOR = 2.41, 95%CI 1.57-3.70) or as checked baggage (aOR = 5.74, 95%CI 3.65-9.03) were also associated with death or illness. On average, 19 dog illnesses or deaths were reported annually from 2010 to 2018. The estimated annual cost to public health authorities to conduct initial public health assessments ranged from $2,071 to $104,648. Current regulations do not provide adequate resources or mechanisms to monitor the rates of morbidity and mortality of imported dogs. There are growing attempts to assess animal welfare and communicable disease importation risks. However, because the responsibility for dogs' health and wellbeing is overseen by multiple agencies it is challenging to coordinate implementation and enforcement measures. A joint federal agency approach to identify interventions that reduce dog morbidity and mortality during flights while continuing to protect US borders from public health and foreign animal disease threats could be beneficial.

The Effect of Drug Pricing on Outpatient Payments and Treatment for Three Soil-Transmitted Helminth Infections in the United States, 2010-2017.

The price of certain antiparasitic drugs (e.g., albendazole and mebendazole) has dramatically increased since 2010. The effect of these rising prices on treatment costs and use of standard of care (SOC) drugs is unknown. To measure the impact of drug prices on overall outpatient cost and quality of care, we identified outpatient visits associated with ascariasis, hookworm, and trichuriasis infections from the 2010 to 2017 MarketScan Commercial Claims and Encounters and Multi-state Medicaid databases using Truven Health MarketScan Treatment Pathways. Evaluation was limited to members with continuous enrollment in non-capitated plans 30 days prior, and 90 days following, the first diagnosis. The utilization of SOC prescriptions was considered a marker for quality of care. The impact of drug price on the outpatient expenses was measured by comparing the changes in drug and nondrug outpatient payments per patient through Welch's two sample t-tests. The total outpatient payments per patient (drug and nondrug), for the three parasitic infections, increased between 2010 and 2017. The increase was driven primarily by prescription drug payments, which increased 20.6-137.0 times, as compared with nondrug outpatient payments, which increased 0.3-2.2 times. As prices of mebendazole and albendazole increased, a shift to alternative SOC and non-SOC drug utilization was observed. Using parasitic infection treatment as a model, increases in prescription drug prices can act as the primary driver of increasing outpatient care costs. Simultaneously, there was a shift to alternative SOC, but also to non-SOC drug treatment, suggesting a decrease in quality of care.

Cost effectiveness analysis of implementing tuberculosis screening among applicants for non-immigrant U.S. work visas.

BACKGROUND: While persons who receive immigrant and refugee visas are screened for active tuberculosis before admission into the United States, nonimmigrant visa applicants (NIVs) are not routinely screened and may enter the United States with infectious tuberculosis. OBJECTIVES: We evaluated the costs and benefits of expanding pre-departure tuberculosis screening requirements to a subset of NIVs who arrive from a moderate (Mexico) or high (India) incidence tuberculosis country with temporary work visas. METHODS: We developed a decision tree model to evaluate the program costs and estimate the numbers of active tuberculosis cases that may be diagnosed in the United States in two scenarios: 1) "Screening": screening and treatment for tuberculosis among NIVs in their home country with recommended U.S. follow-up for NIVs at elevated risk of active tuberculosis; and, 2) "No Screening" in their home country so that cases would be diagnosed passively and treatment occurs after entry into the United States. Costs were assessed from multiple perspectives, including multinational and U.S.-only perspectives. RESULTS: Under "Screening" versus "No Screening", an estimated 179 active tuberculosis cases and 119 hospitalizations would be averted in the United States annually via predeparture treatment. From the U.S.-only perspective, this program would result in annual net cost savings of about $3.75 million. However, rom the multinational perspective, the screening program would cost $151,388 per U.S. case averted for Indian NIVs and $221,088 per U.S. case averted for Mexican NIVs. CONCLUSION: From the U.S.-only perspective, the screening program would result in substantial cost savings in the form of reduced treatment and hospitalization costs. NIVs would incur increased pre-departure screening and treatment costs.

The effects of past SARS experience and proximity on declines in numbers of travelers to the Republic of Korea during the 2015 MERS outbreak: A retrospective study.

BACKGROUND: The experience of previous sizable outbreaks may affect travelers' decisions to travel to an area with an ongoing outbreak. METHODS: We estimated changes in monthly numbers of visitors to the Republic of Korea (ROK) in 2015 compared to projected values by selected areas. We tested whether areas' experience of a previous SARS outbreak of ≥100 cases or distance to the ROK had a significant effect on travel to the ROK during the MERS outbreak using t-tests and regression models. RESULTS: The percentage changes in visitors from areas with a previous SARS outbreak of ≥100 cases decreased more than the percentage changes in visitors from their counterparts in June (52.4% vs. 23.3%) and July (60.0% vs. 31.4%) during the 2015 MERS outbreak. The percentage changes in visitors from the close and intermediate categories decreased more than the far category. The results from regression models and sensitivity analyses demonstrated that areas with ≥100 SARS cases and closer proximity to the ROK had significantly larger percentage decreases in traveler volumes during the outbreak. CONCLUSIONS: During the 2015 MERS outbreak, areas with a previous sizable SARS outbreak and areas near the ROK showed greater decreases in percentage changes in visitors to the ROK.

Economic Impact of the 2015 MERS Outbreak on the Republic of Korea's Tourism-Related Industries.

The 2015 Middle East respiratory syndrome (MERS) outbreak in the Republic of Korea (ROK) is an example of an infectious disease outbreak initiated by international travelers to a high-income country. This study was conducted to determine the economic impact of the MERS outbreak on the tourism and travel-related service sectors, including accommodation, food and beverage, and transportation, in the ROK. We projected monthly numbers of noncitizen arrivals and indices of services for 3 travel-related service sectors during and after the MERS outbreak (June 2015 to June 2016) using seasonal autoregressive integrated moving average models. Tourism losses were estimated by multiplying the monthly differences between projected and actual numbers of noncitizen arrivals by average tourism expenditure per capita. Estimated tourism losses were allocated to travel-related service sectors to understand the distribution of losses across service sectors. The MERS outbreak was correlated with a reduction of 2.1 million noncitizen visitors corresponding with US$2.6 billion in tourism loss for the ROK. Estimated losses in the accommodation, food and beverage service, and transportation sectors associated with the decrease of noncitizen visitors were US$542 million, US$359 million, and US$106 million, respectively. The losses were demonstrated by lower than expected indices of services for the accommodation and food and beverage service sectors in June and July 2015 and for the transportation sector in June 2015. The results support previous findings that public health emergencies due to traveler-associated outbreaks of infectious diseases can cause significant losses to the broader economies of affected countries.

Vaccine delivery to newly arrived refugees and estimated costs in selected U.S. clinics, 2015.

BACKGROUND: Newly arrived refugees are offered vaccinations during domestic medical examinations. Vaccination practices and costs for refugees have not been described with recent implementation of the overseas Vaccination Program for U.S.-bound Refugees (VPR). We describe refugee vaccination during the domestic medical examination and the estimated vaccination costs from the US government perspective in selected U.S. clinics. METHODS: Site-specific vaccination processes and costs were collected from 16 clinics by refugee health partners in three states and one private academic institution. Vaccination costs were estimated from the U.S. Vaccines for Children Program and Medicaid reimbursement rates during fiscal year 2015. RESULTS: All clinics reviewed overseas vaccination records before vaccinating, but all records were not transferred into state immunization systems. Average vaccination costs per refugee varied from $120 to $211 by site. The total average cost of domestic vaccination was 15% less among refugees arriving from VPR- vs. nonVPR-participating countries during a single domestic visit. CONCLUSION: Our findings indicate that immunization practices and costs vary between clinics, and that clinics adapted their vaccination practices to accommodate VPR doses, yielding potential cost savings.

A comparative cost analysis of the Vaccination Program for US-bound Refugees.

BACKGROUND: Vaccination Program for US-bound Refugees (VPR) currently provides one or two doses of some age-specific Advisory Committee on Immunization Practices (ACIP)-recommended vaccines to US-bound refugees prior to departure. METHODS: We quantified and compared the full vaccination costs for refugees using two scenarios: (1) the baseline of no VPR and (2) the current situation with VPR. Under the first scenario, refugees would be fully vaccinated after arrival in the United States. For the second scenario, refugees would receive one or two doses of selected vaccines before departure and complete the recommended vaccination schedule after arrival in the United States. We evaluated costs for the full vaccination schedule and for the subset of vaccines provided by VPR by four age-stratified groups; all costs were reported in 2015 US dollars. We performed one-way and probabilistic sensitivity analyses and break-even analyses to evaluate the robustness of results. RESULTS: Vaccination costs with the VPR scenario were lower than costs of the scenario without the VPR for refugees in all examined age groups. Net cost savings per person associated with the VPR were ranged from $225.93 with estimated Refugee Medical Assistance (RMA) or Medicaid payments for domestic costs to $498.42 with estimated private sector payments. Limiting the analyses to only the vaccines included in VPR, the average costs per person were 56% less for the VPR scenario with RMA/Medicaid payments. Net cost savings with the VPR scenario were sensitive to inputs for vaccination costs, domestic vaccine coverage rates, and revaccination rates, but the VPR scenario was cost savings across a range of plausible parameter estimates. CONCLUSIONS: VPR is a cost-saving program that would also reduce the risk of refugees arriving while infected with a vaccine preventable disease.

A multi-country study of the economic burden of dengue fever: Vietnam, Thailand, and Colombia.

BACKGROUND: Dengue fever is a major public health concern in many parts of the tropics and subtropics. The first dengue vaccine has already been licensed in six countries. Given the growing interests in the effective use of the vaccine, it is critical to understand the economic burden of dengue fever to guide decision-makers in setting health policy priorities. METHODS/PRINCIPAL FINDINGS: A standardized cost-of-illness study was conducted in three dengue endemic countries: Vietnam, Thailand, and Colombia. In order to capture all costs during the entire period of illness, patients were tested with rapid diagnostic tests on the first day of their clinical visits, and multiple interviews were scheduled until the patients recovered from the current illness. Various cost items were collected such as direct medical and non-medical costs, indirect costs, and non-out-of-pocket costs. In addition, socio-economic factors affecting disease severity were also identified by adopting a logit model. We found that total cost per episode ranges from $141 to $385 for inpatient and from $40 to $158 outpatient, with Colombia having the highest and Thailand having the lowest. The percentage of the private economic burden of dengue fever was highest in the low-income group and lowest in the high-income group. The logit analyses showed that early treatment, higher education, and better knowledge of dengue disease would reduce the probability of developing more severe illness. CONCLUSIONS/SIGNIFICANCE: The cost of dengue fever is substantial in the three dengue endemic countries. Our study findings can be used to consider accelerated introduction of vaccines into the public and private sector programs and prioritize alternative health interventions among competing health problems. In addition, a community would be better off by propagating the socio-economic factors identified in this study, which may prevent its members from developing severe illness in the long run.

Cost analysis of measles in refugees arriving at Los Angeles International Airport from Malaysia.

Background On August 24, 2011, 31 US-bound refugees from Kuala Lumpur, Malaysia (KL) arrived in Los Angeles. One of them was diagnosed with measles post-arrival. He exposed others during a flight, and persons in the community while disembarking and seeking medical care. As a result, 9 cases of measles were identified. Methods We estimated costs of response to this outbreak and conducted a comparative cost analysis examining what might have happened had all US-bound refugees been vaccinated before leaving Malaysia. Results State-by-state costs differed and variously included vaccination, hospitalization, medical visits, and contact tracing with costs ranging from $621 to $35,115. The total of domestic and IOM Malaysia reported costs for US-bound refugees were $137,505 [range: $134,531 - $142,777 from a sensitivity analysis]. Had all US-bound refugees been vaccinated while in Malaysia, it would have cost approximately $19,646 and could have prevented 8 measles cases. Conclusion A vaccination program for US-bound refugees, supporting a complete vaccination for US-bound refugees, could improve refugees' health, reduce importations of vaccine-preventable diseases in the United States, and avert measles response activities and costs.

Economic Analysis of the Impact of Overseas and Domestic Treatment and Screening Options for Intestinal Helminth Infection among US-Bound Refugees from Asia.

BACKGROUND: Many U.S.-bound refugees travel from countries where intestinal parasites (hookworm, Trichuris trichuria, Ascaris lumbricoides, and Strongyloides stercoralis) are endemic. These infections are rare in the United States and may be underdiagnosed or misdiagnosed, leading to potentially serious consequences. This evaluation examined the costs and benefits of combinations of overseas presumptive treatment of parasitic diseases vs. domestic screening/treating vs. no program. METHODS: An economic decision tree model terminating in Markov processes was developed to estimate the cost and health impacts of four interventions on an annual cohort of 27,700 U.S.-bound Asian refugees: 1) "No Program," 2) U.S. "Domestic Screening and Treatment," 3) "Overseas Albendazole and Ivermectin" presumptive treatment, and 4) "Overseas Albendazole and Domestic Screening for Strongyloides". Markov transition state models were used to estimate long-term effects of parasitic infections. Health outcome measures (four parasites) included outpatient cases, hospitalizations, deaths, life years, and quality-adjusted life years (QALYs). RESULTS: The "No Program" option is the least expensive ($165,923 per cohort) and least effective option (145 outpatient cases, 4.0 hospitalizations, and 0.67 deaths discounted over a 60-year period for a one-year cohort). The "Overseas Albendazole and Ivermectin" option ($418,824) is less expensive than "Domestic Screening and Treatment" ($3,832,572) or "Overseas Albendazole and Domestic Screening for Strongyloides" ($2,182,483). According to the model outcomes, the most effective treatment option is "Overseas Albendazole and Ivermectin," which reduces outpatient cases, deaths and hospitalization by around 80% at an estimated net cost of $458,718 per death averted, or $2,219/$24,036 per QALY/life year gained relative to "No Program". DISCUSSION: Overseas presumptive treatment for U.S.-bound refugees is a cost-effective intervention that is less expensive and at least as effective as domestic screening and treatment programs. The addition of ivermectin to albendazole reduces the prevalence of chronic strongyloidiasis and the probability of rare, but potentially fatal, disseminated strongyloidiasis.