Lower socioeconomic status may help explain racial disparities in asthma and atopic dermatitis prevalence: A mediation analysis

BACKGROUND

Racial disparities in atopic disease (atopic dermatitis [AD], asthma, and allergies) prevalence are well documented. Despite strong associations between race and socioeconomic deprivation in the United States, and socioeconomic status (SES) and atopic diseases, the extent to which SES explains these disparities is not fully understood.

OBJECTIVE

We sought to identify racial disparities in childhood atopic disease prevalence and determine what proportion of those disparities is mediated by SES.

METHODS

This study used the National Health Interview Survey (2011-2018) to investigate AD, asthma, and respiratory allergy prevalence in Black and White children and the extent to which measures of SES explain any identified disparities.

RESULTS

By race, prevalences were as follows: AD, White 11.8% (95% CI: 11.4%, 12.2%) and Black 17.4% (95% CI: 16.6%, 18.3%); asthma prevalence, White 7.4% (95% CI: 7.0%, 7.7%) and Black 14.3% (95% CI: 13.5%, 15.0%); respiratory allergy, White 11.4% (95% CI: 11.0%, 11.9%) and Black 10.9% (95% CI: 10.3%, 11.6%). The percentage of the disparity between racial groups and disease prevalence explained by a multivariable measure of SES was 25% (95% CI: 15%, 36%) for Black versus White children with AD and 47% (95% CI: 40%, 54%) for Black versus White children with asthma.

CONCLUSIONS

In a nationally representative US population, Black children had higher prevalence of AD and asthma than White children did and similar prevalence of respiratory allergy; a multivariable SES measure explained a proportion of the association between Black versus White race and AD and a much larger proportion for asthma.

Racial and Ethnic Identity and Vulnerability to Upper Respiratory Viral Infections Among US Children

BACKGROUND

It is unclear whether there are racial/ethnic disparities in the risk of upper respiratory viral infection acquisition and/or lower respiratory manifestations.

METHODS

We studied all children and children with asthma aged 6 to 17 years in the National Health and Nutrition Examination Survey (2007-2012) to evaluate (1) the association between race/ethnicity and upper respiratory infection (URI) and (2) whether race/ethnicity is a risk factor for URI-associated pulmonary eosinophilic inflammation or decreased lung function.

RESULTS

Children who identified as Black (adjusted odds ratio [aOR], 1.38; 95% CI, 1.10-1.75) and Mexican American (aOR, 1.50; 95% CI, 1.16-1.94) were more likely to report a URI than those who identified as White. Among those with asthma, Black children were more than twice as likely to report a URI than White children (aOR, 2.28; 95% CI, 1.31-3.95). Associations between URI and pulmonary eosinophilic inflammation or lung function did not differ by race/ethnicity.

CONCLUSIONS

Findings suggest that there may be racial and ethnic disparities in acquiring a URI but not in the severity of infection. Given that upper respiratory viral infection is tightly linked to asthma exacerbations in children, differences in the risk of infection among children with asthma may contribute to disparities in asthma exacerbations.

Optimizing COVID-19 testing strategies on college campuses: Evaluation of the health and economic costs

Colleges and universities in the US struggled to provide safe in-person education throughout the COVID-19 pandemic. Testing coupled with isolation is a nimble intervention strategy that can be tailored to mitigate the changing health and economic risks associated with SARS-CoV-2. We developed a decision-support tool to aid in the design of university-based screening strategies using a mathematical model of SARS-CoV-2 transmission. Applying this framework to a large public university reopening in the fall of 2021 with a 60% student vaccination rate, we find that the optimal strategy, in terms of health and economic costs, is twice weekly antigen testing of all students. This strategy provides a 95% guarantee that, throughout the fall semester, case counts would not exceed twice the CDC's original high transmission threshold of 100 cases per 100k persons over 7 days. As the virus and our medical armament continue to evolve, testing will remain a flexible tool for managing risks and keeping campuses open. We have implemented this model as an online tool to facilitate the design of testing strategies that adjust for COVID-19 conditions as well as campus-specific populations, resources, and priorities.

Identifying barriers and facilitators along the hepatitis C care cascade to inform human-centered design of contextualized treatment protocols for vulnerable populations in Austin, Texas: a qualitative study

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of liver-related mortality and morbidity. Despite effective direct acting antivirals and a simplified treatment algorithm, limited access to HCV treatment in vulnerable populations, including people experiencing homelessness (PEH) and people who inject drugs (PWID), hinders global elimination. Adapting the evidence-based, simplified HCV treatment algorithm to the organizational and contextual realities of non-traditional clinic settings serving vulnerable populations can help overcome specific barriers to HCV care. The first phase of the Erase Hep C study aimed to identify barriers and facilitators specific to these vulnerable populations to design the site-specific, simplified treatment protocols.

METHODS

Forty-two semi-structured qualitative interviews, guided by the Practical, Robust Implementation and Sustainability Model (PRISM) framework, were conducted with clinic staff, community-based organizations providing screening and linkage to care, and patients diagnosed with HCV, to identify contextual barriers and facilitators to treatment at a local community health center's Health Care for the Homeless program in Austin, Texas. Audio-recorded interviews were systematically analyzed using thematic analysis informed by the PRISM framework and design thinking, to anchor barriers and facilitators along the HCV care cascade. Findings were fed into human-centered design workshops to co-design, with clinic staff, site-specific, simplified HCV treatment protocols.

RESULTS

The specific needs of PEH and PWID patient populations informed barriers and facilitators of HCV care. Barriers included tracking patients who miss critical appointments or labs, medication access and adherence, and patient HCV knowledge. Clinical teams leveraged existing facilitators and incorporated solutions to barriers into clinic workflows to improve care coordination and medication access. Actionable solutions included augmenting existing staff roles, employing HCV care navigation throughout the cascade, and standardizing medication adherence counseling.

CONCLUSIONS

Clinic staff identified HCV care facilitators to leverage, and designed actionable solutions to address barriers, to incorporate into site-specific treatment protocols to improve patient HCV outcomes. Methods used to incorporate staff and patient experiential knowledge into the design of contextualized treatment protocols in non-traditional clinic settings could serve as a model for future implementation research. The next phase of the study is protocol implementation and patient enrollment into a single-arm trial to achieve HCV cure.

Real time monitoring of COVID-19 intervention effectiveness through contact tracing data

Communities worldwide have used vaccines and facemasks to mitigate the COVID-19 pandemic. When an individual opts to vaccinate or wear a mask, they may lower their own risk of becoming infected as well as the risk that they pose to others while infected. The first benefit-reducing susceptibility-has been established across multiple studies, while the second-reducing infectivity-is less well understood. Using a new statistical method, we estimate the efficacy of vaccines and facemasks at reducing both types of risks from contact tracing data collected in an urban setting. We find that vaccination reduced the risk of onward transmission by 40.7% [95% CI 25.8-53.2%] during the Delta wave and 31.0% [95% CI 19.4-40.9%] during the Omicron wave and that mask wearing reduced the risk of infection by 64.2% [95% CI 5.8-77.3%] during the Omicron wave. By harnessing commonly-collected contact tracing data, the approach can broadly provide timely and actionable estimates of intervention efficacy against a rapidly evolving pathogen.

Development, implementation, and feasibility of site-specific hepatitis C virus treatment workflows for treating vulnerable, high-risk populations: protocol of the Erase Hep C study - a prospective single-arm intervention trial

BACKGROUND

Hepatitis C virus (HCV) is the leading indication for liver transplantation and liver-related mortality. The development of direct-acting antivirals (DAA) and a simplified treatment algorithm with a > 97% cure rate should make global elimination of HCV an achievable goal. Yet, vulnerable populations with high rates of HCV still have limited access to treatment. By designing locally contextualized site-specific HCV treatment workflows, we aim to cure HCV in vulnerable, high-risk populations, including people experiencing homelessness (PEH) and people who inject drugs (PWID), in Austin, TX, USA.

METHODS

Our implementation science study will utilize a qualitative and design thinking approach to characterize patient and systemic barriers and facilitators to HCV treatment in vulnerable, high-risk populations seeking care across seven diverse primary care clinics serving PEHs and PWIDs. Qualitative interviews guided by the Practical, Robust Implementation and Sustainability Model (PRISM) framework will identify barriers and facilitators by leveraging knowledge and experience from both clinic staff and patients. Data synthesized using thematic analysis and design thinking will feed into workshops with clinic stakeholders for idea generation to design site-specific HCV treatment workflows. Providers will be trained on the use of a simplified HCV treatment algorithm with DAAs and clinic staff on the new site-specific HCV treatment workflows. These workflows will be implemented by the seven diverse primary care clinics serving vulnerable, high-risk populations. Implementation and clinical outcomes will be measured using data collected through interviews with staff as well as through medical chart review.

DISCUSSION

Our study provides a model of how to contextualize and implement site-specific HCV treatment workflows targeting vulnerable, high-risk populations in other geographic locations. This model can be adopted for future implementation research programs aiming to develop and implement site-specific treatment workflows for vulnerable, high-risk populations and in primary care clinical settings for other disease states beyond just HCV.

TRIAL REGISTRATION

Registered on ClinicalTrials.gov on July, 14, 2022. Identifier: NCT05460130 .

Do upper respiratory viruses contribute to racial and ethnic disparities in emergency department visits for asthma?

BACKGROUND

There are marked disparities in asthma-related emergency department (ED) visit rates among children by race and ethnicity. Following the implementation of coronavirus disease 2019 (COVID-19) prevention measures, asthma-related ED visits rates declined substantially. The decline has been attributed to the reduced circulation of upper respiratory viruses, a common trigger of asthma exacerbations in children.

OBJECTIVES

To better understand the contribution of respiratory viruses to racial and ethnic disparities in ED visit rates, we investigated whether the reduction in ED visit rates affected Black, Latinx, and White children with asthma equally.

METHODS

Asthma-related ED visits were extracted from electronic medical records at Dell Children's Medical Center in Travis County, Texas. ED visit rates among children with asthma were derived by race/ethnicity. Incidence rate ratios (IRRs) and 95% CIs were estimated by year (2019-2021) and season.

RESULTS

In spring 2019, the ED visit IRRs comparing Black children with White children and Latinx children with White children were 6.67 (95% CI = 4.92-9.05) and 2.10 (95% CI = 1.57-2.80), respectively. In spring 2020, when infection prevention measures were implemented, the corresponding IRRs decreased to 1.73 (95% CI = 0.90-3.32) and 0.68 (95% CI = 0.38-1.23), respectively.

CONCLUSIONS

The striking reduction of disparities in ED visits suggests that during nonpandemic periods, respiratory viruses contribute to the excess burden of asthma-related ED visits among Black and Latinx children with asthma. Although further investigation is needed to test this hypothesis, our findings raise the question of whether Black and Latinx children with asthma are more vulnerable to upper respiratory viral infections.

Optimizing COVID-19 testing strategies on college campuses: evaluation of the health and economic costs

Colleges and universities in the US struggled to provide safe in-person education throughout the COVID-19 pandemic. Testing coupled with isolation is a nimble intervention strategy that can be tailored to mitigate health and economic costs, as the virus and our arsenal of medical countermeasures continue to evolve. We developed a decision-support tool to aid in the design of university-based testing strategies using a mathematical model of SARS-CoV-2 transmission. Applying this framework to a large public university reopening in the fall of 2021 with a 60% student vaccination rate, we find that the optimal strategy, in terms of health and economic costs, is twice weekly antigen testing of all students. This strategy provides a 95% guarantee that, throughout the fall semester, case counts would not exceed the CDC's original high transmission threshold of 100 cases per 100k persons over 7 days. As the virus and our medical armament continue to evolve, testing will remain a flexible tool for managing risks and keeping campuses open. We have implemented this model as an online tool to facilitate the design of testing strategies that adjust for COVID-19 conditions, university-specific parameters, and institutional goals.

Adoption of digital tools in the context of the COVID-19 pandemic in the Region of the Americas - the Go.Data experience

The COVID-19 pandemic has accelerated the growth of digital health tools. Although a number of different tools exist to support field data collection in the context of outbreak response, they have not been sufficient. This prompted the World Health Organization (WHO) to collaborate with the Global Outbreak Alert and Response Network (GOARN) and GOARN partners to develop a comprehensive system, Go.Data. Go.Data, a digital tool for outbreak response has simplified how countries operationalize and monitor case and contact data. Since the start of the pandemic, WHO and GOARN partners have provided support to Go.Data projects in 65 countries and territories, yet the demand by countries to have documented success cases of Go.Data implementations continues to grow. This viewpoint documents the successful Go.Data implementation frameworks in two countries, Argentina and Guatemala and an academic institution, the University of Texas at Austin.

Malaria surveillance and case management in remote and indigenous communities of Panama: results from a community-based health worker pilot

BACKGROUND

Panama is one of eight countries in Mesoamerica that aims to eliminate malaria by 2022. Malaria is concentrated in indigenous and remote regions like Guna Yala, a politically autonomous region where access to health services is limited and cases are predominately detected through intermittent active surveillance. To improve routine access to care, a joint effort was made by Guna Yala authorities and the Ministry of Health to pilot a network of community health workers (CHWs) equipped with rapid diagnostic tests and treatment. The impact of this pilot is described.

METHODS

Access to care was measured using the proportion of villages targeted by the effort with active CHWs. Epidemiological impact was evaluated through standard surveillance and case management measures. Tests for differences in proportions or rates were used to compare measures prior to (October 2014-September 2016) and during the pilot (October 2016-September 2018).

RESULTS

An active CHW was placed in 39 (95%) of 41 target communities. During the pilot, CHWs detected 61% of all reported cases from the region. Test positivity in the population tested by CHWs (22%) was higher than in those tested through active surveillance, both before (3.8%) and during the pilot (2.9%). From the pre-pilot to the pilot period, annual blood examination rates decreased (9.8 per 100 vs. 8.0 per 100), test positivity increased (4.2% to 8.5%, Χ2 = 126.3, p < 0.001) and reported incidence increased (4.1 cases per 1000 to 6.9 cases per 1000 [Incidence Rate Ratio = 1.83, 95% CI 1.52, 2.21]). The percent of cases tested on the day of symptom onset increased from 8 to 27% and those treated on the day of their test increased from 26 to 84%.

CONCLUSIONS

The CHW network allowed for replacement of routine active surveillance with strong passive case detection leading to more targeted and timely testing and treatment. The higher test positivity among those tested by CHWs compared to active surveillance suggests that they detected cases in a high-risk population that had not previously benefited from access to diagnosis and treatment. Surveillance data acquired through this CHW network can be used to better target active case detection to populations at highest risk.

The effectiveness of COVID-19 testing and contact tracing in a US city

Although testing, contact tracing, and case isolation programs can mitigate COVID-19 transmission and allow the relaxation of social distancing measures, few countries worldwide have succeeded in scaling such efforts to levels that suppress spread. The efficacy of test-trace-isolate likely depends on the speed and extent of follow-up and the prevalence of SARS-CoV-2 in the community. Here, we use a granular model of COVID-19 transmission to estimate the public health impacts of test-trace-isolate programs across a range of programmatic and epidemiological scenarios, based on testing and contact tracing data collected on a university campus and surrounding community in Austin, TX, between October 1, 2020, and January 1, 2021. The median time between specimen collection from a symptomatic case and quarantine of a traced contact was 2 days (interquartile range [IQR]: 2 to 3) on campus and 5 days (IQR: 3 to 8) in the community. Assuming a reproduction number of 1.2, we found that detection of 40% of all symptomatic cases followed by isolation is expected to avert 39% (IQR: 30% to 45%) of COVID-19 cases. Contact tracing is expected to increase the cases averted to 53% (IQR: 42% to 58%) or 40% (32% to 47%), assuming the 2- and 5-day delays estimated on campus and in the community, respectively. In a tracing-accelerated scenario, in which 75% of contacts are notified the day after specimen collection, cases averted increase to 68% (IQR: 55% to 72%). An accelerated contact tracing program leveraging rapid testing and electronic reporting of test results can significantly curtail local COVID-19 transmission.

Mapping the endemicity and seasonality of clinical malaria for intervention targeting in Haiti using routine case data

Towards the goal of malaria elimination on Hispaniola, the National Malaria Control Program of Haiti and its international partner organisations are conducting a campaign of interventions targeted to high-risk communities prioritised through evidence-based planning. Here we present a key piece of this planning: an up-to-date, fine-scale endemicity map and seasonality profile for Haiti informed by monthly case counts from 771 health facilities reporting from across the country throughout the 6-year period from January 2014 to December 2019. To this end, a novel hierarchical Bayesian modelling framework was developed in which a latent, pixel-level incidence surface with spatio-temporal innovations is linked to the observed case data via a flexible catchment sub-model designed to account for the absence of data on case household locations. These maps have focussed the delivery of indoor residual spraying and focal mass drug administration in the Grand’Anse Department in South-Western Haiti.

Global health on the front lines: an innovative medical student elective combining education and service during the COVID-19 pandemic

BACKGROUND

An innovative medical student elective combined student-directed, faculty-supported online learning with COVID-19 response field placements. This study evaluated students' experience in the course, the curriculum content and format, and its short-term impact on students' knowledge and attitudes around COVID-19.

METHODS

Students responded to discussion board prompts throughout the course and submitted pre-/post-course reflections. Pre-/post-course questionnaires assessed pandemic knowledge and attitudes using 4-point Likert scales. Authors collected aggregate data on enrollment, discussion posts, field placements, and scholarly work resulting from course activities. After the elective, authors conducted a focus group with a convenience sample of 6 participants. Institutional elective evaluation data was included in analysis. Authors analyzed questionnaire data with summary statistics and paired t-tests comparing knowledge and attitudes before and after the elective. Reflection pieces, discussion posts, and focus group data were analyzed using content analysis with a phenomenological approach.

RESULTS

Twenty-seven students enrolled. Each student posted an average of 2.4 original discussion posts and 3.1 responses. Mean knowledge score increased from 43.8 to 60.8% (p <  0.001) between pre- and post-course questionnaires. Knowledge self-assessment also increased (2.4 vs. 3.5 on Likert scale, p <  0.0001), and students reported increased engagement in the pandemic response (2.7 vs. 3.6, p <  0.0001). Students reported increased fluency in discussing the pandemic and increased appreciation for the field of public health. There was no difference in students' level of anxiety about the pandemic after course participation (3.0 vs. 3.1, p = 0.53). Twelve students (44.4%) completed the institutional evaluation. All rated the course "very good" or "excellent." Students favorably reviewed the field placements, suggested readings, self-directed research, and learning from peers. They suggested more clearly defined expectations and improved balance between volunteer and educational hours.

CONCLUSIONS

The elective was well-received by students, achieved stated objectives, and garnered public attention. Course leadership should monitor students' time commitment closely in service-learning settings to ensure appropriate balance of service and education. Student engagement in a disaster response is insufficient to address anxiety related to the disaster; future course iterations should include a focus on self-care during times of crisis. This educational innovation could serve as a model for medical schools globally.

Strengthening surveillance systems for malaria elimination: a global landscaping of system performance, 2015-2017

BACKGROUND

Surveillance is a core component of an effective system to support malaria elimination. Poor surveillance data will prevent countries from monitoring progress towards elimination and targeting interventions to the last remaining at-risk places. An evaluation of the performance of surveillance systems in 16 countries was conducted to identify key gaps which could be addressed to build effective systems for malaria elimination.

METHODS

A standardized surveillance system landscaping was conducted between 2015 and 2017 in collaboration with governmental malaria programmes. Malaria surveillance guidelines from the World Health Organization and other technical bodies were used to identify the characteristics of an optimal surveillance system, against which systems of study countries were compared. Data collection was conducted through review of existing material and datasets, and interviews with key stakeholders, and the outcomes were summarized descriptively. Additionally, the cumulative fraction of incident infections reported through surveillance systems was estimated using surveillance data, government records, survey data, and other scientific sources.

RESULTS

The landscaping identified common gaps across countries related to the lack of surveillance coverage in remote communities or in the private sector, the lack of adequate health information architecture to capture high quality case-based data, poor integration of data from other sources such as intervention information, poor visualization of generated information, and its lack of availability for making programmatic decisions. The median percentage of symptomatic cases captured by the surveillance systems in the 16 countries was estimated to be 37%, mostly driven by the lack of treatment-seeking in the public health sector (64%) or, in countries with large private sectors, the lack of integration of this sector within the surveillance system.

CONCLUSIONS

The landscaping analysis undertaken provides a clear framework through which to identify multiple gaps in current malaria surveillance systems. While perfect systems are not required to eliminate malaria, closing the gaps identified will allow countries to deploy resources more efficiently, track progress, and accelerate towards malaria elimination. Since the landscaping undertaken here, several countries have addressed some of the identified gaps by improving coverage of surveillance, integrating case data with other information, and strengthening visualization and use of data.

Unintended costs and consequences of school closures implemented in preparation for Hurricane Isaac in Harrison County School District, Mississippi, August-September 2012

INTRODUCTION

School closures, while an effective measure against the spread of disease during a pandemic, may carry unintended social and economic consequences for students and families. We evaluated these costs and consequences following a 4-day school closure in Mississippi's Harrison County School District (HCSD).

METHODS

In a survey of all households with students enrolled in HCSD, we collected information on difficulties related to the school closure, including interruption of employment and pay, loss of access to subsidized school meals, and arrangement of alternative childcare. We analyzed this information in the context of certain demographic characteristics of the survey respondents and households, such as race, level of education, and income. We also estimated the average number of lost work days and documented the childcare alternatives chosen by households affected by the school closure.

RESULTS

We received 2,229 (28.4%) completed surveys from an estimated 7,851 households eligible to participate. About half (1,082 [48.5%]) of the households experienced at least some difficulty during the closure, primarily in three areas: uncertainty about duration of the closure, lost income, and the effort of arranging alternate childcare. Adults working outside the home, particularly the major wage earner in the household, were more likely to suffer lost income while schools were closed, an effect mitigated by paid leave benefits. Difficulty arranging childcare was reported most frequently by respondents with lower levels of education and households with younger children. Beyond the top three concerns expressed by households in HCSD, the survey also shed light on the issue of food insecurity when subsidized school meals are not available. Reported by 17.9% of households participating in the subsidized school lunch program, difficulty providing meals during the closure was associated with higher numbers of dependent children, selection of "other" as the race of the household respondent, and lower levels of education.

CONCLUSION

To help prevent undue financial hardship in families of school children, public health authorities and school administrators should provide recommendations for childcare alternatives and paid leave or remote work options during prolonged school closures, particularly to households in which all adults work outside of the home.

Tuberculosis disease among Mexico-born individuals living in New York City, 2001-2014

SETTING

Tuberculosis (TB) has decreased substantially in New York City (NYC), but progress has slowed in recent years. Continued declines will require novel approaches tailored to foreign-born populations.

OBJECTIVE

To describe TB epidemiology among the Mexico-born population of NYC to inform interventions in this community.

DESIGN

The study included NYC patients with TB disease identified from 2001 to 2014. Incidence rates were compared by country of birth groupings. Demographic and patient characteristics were analyzed for all Mexico-born TB patients. Patients were compared by Mycobacterium bovis vs. non-M. bovis TB strain. Culture-confirmed patients were compared by genotype clustering status.

RESULTS

From 2001 to 2014, 621 Mexico-born TB patients were identified in NYC. TB rates were significantly higher among Mexico-born vs. US-born persons every year. Mexico-born patients had lived in the United States for a median 7 years at diagnosis. The geographic distribution of Mexico-born TB patients was similar to that of the total Mexico-born population. Overall, 71% of patients reported previous employment; 52% of non-M. bovis patients were clustered based on genotyping results.

CONCLUSIONS

Our results provide a foundation to inform future interventions in the Mexico-born population. Additional work is needed to explore possible local TB transmission and health care-seeking practices.

Census-derived migration data as a tool for informing malaria elimination policy

BACKGROUND

Numerous countries around the world are approaching malaria elimination. Until global eradication is achieved, countries that successfully eliminate the disease will contend with parasite reintroduction through international movement of infected people. Human-mediated parasite mobility is also important within countries near elimination, as it drives parasite flows that affect disease transmission on a subnational scale.

METHODS

Movement patterns exhibited in census-based migration data are compared with patterns exhibited in a mobile phone data set from Haiti to quantify how well migration data predict short-term movement patterns. Because short-term movement data were unavailable for Mesoamerica, a logistic regression model fit to migration data from three countries in Mesoamerica is used to predict flows of infected people between subnational administrative units throughout the region.

RESULTS

Population flows predicted using census-based migration data correlated strongly with mobile phone-derived movements when used as a measure of relative connectivity. Relative population flows are therefore predicted using census data across Mesoamerica, informing the areas that are likely exporters and importers of infected people. Relative population flows are used to identify community structure, useful for coordinating interventions and elimination efforts to minimize importation risk. Finally, the ability of census microdata inform future intervention planning is discussed in a country-specific setting using Costa Rica as an example.

CONCLUSIONS

These results show long-term migration data can effectively predict the relative flows of infected people to direct malaria elimination policy, a particularly relevant result because migration data are generally easier to obtain than short-term movement data such as mobile phone records. Further, predicted relative flows highlight policy-relevant population dynamics, such as major exporters across the region, and Nicaragua and Costa Rica's strong connection by movement of infected people, suggesting close coordination of their elimination efforts. Country-specific applications are discussed as well, such as predicting areas at relatively high risk of importation, which could inform surveillance and treatment strategies.

Distribution of Enteroinvasive and Enterotoxigenic Escherichia coli Across Space and Time in Northwestern Ecuador

Although Escherichia coli infections are common throughout the developing world, their prevalence patterns in space and over time are not well characterized. We used serial case control data collected from 16 communities in northwestern Ecuador between 2004 and 2010, to examine the prevalence of enteroinvasive E. coli (EIEC) and enterotoxigenic E. coli (ETEC). At its peak, the regional prevalence of EIEC was 8.3 infections/100 persons but this decreased to 1 infection/1,000 persons. The regional prevalence of ETEC ranged from 8 infections/1,000 persons to 3.7 infections/100 persons. The prevalence pattern of EIEC resembled that of a large epidemic whereas the prevalence of ETEC was more stable over time. Here, we provide community-based evidence for temporal shifts in the dominant E. coli pathotype from EIEC to ETEC over a multi-year time period. Furthermore, genotype analysis suggests that a given strain of EIEC and ETEC can persist in this region for long periods, up to 24 and 55 months, respectively.

Molecular identification of Giardia duodenalis in Ecuador by polymerase chain reaction-restriction fragment length polymorphism

The aim of this study was to determine the genetic diversity of Giardia duodenalis present in a human population living in a northern Ecuadorian rain forest. All Giardia positive samples (based on an ELISA assay) were analysed using a semi-nested polymerase chain reaction-restriction fragment length polymorphism assay that targets the glutamate dehydrogenase (gdh) gene; those amplified were subsequently genotyped using NlaIV and RsaI enzymes. The gdh gene was successfully amplified in 74 of 154 ELISA positive samples; 69 of the 74 samples were subsequently genotyped. Of these 69 samples, 42 (61%) were classified as assemblage B (26 as BIII and 16 as BIV), 22 (32%) as assemblage A (3 as AI and 19 as AII) and five (7%) as mixed AII and BIII types. In this study site we observe similar diversity in genotypes to other regions in Latin America, though in contrast to some previous studies, we found similar levels of diarrheal symptoms in those individuals infected with assemblage B compared with those infected with assemblage A.

Rabies death attributed to exposure in Central America with symptom onset in a U.S. detention facility - Texas, 2013

On June 7, 2013, a man was diagnosed in a Texas hospital with rabies. He had been detained in a U.S. detention facility during his infectious period. To identify persons exposed to rabies who might require rabies postexposure prophylaxis (PEP), CDC and the Texas Department of State Health Services (DSHS) conducted investigations at four detention facilities, one medical clinic, and two hospitals. In all, 25 of 742 persons assessed for rabies exposure were advised to receive PEP. Early diagnosis of rabies is essential for implementation of appropriate hospital infection control measures and for rapid assessment of potential contacts for PEP recommendations.

A space-time point process model for analyzing and predicting case patterns of diarrheal disease in northwestern Ecuador

We consider modeling case-patterns under a complex spatial and longitudinal sampling design as conducted via a serial case-control study of diarrheal disease in northwestern Ecuador. We build a two-stage space-time model to understand the role of spatially and temporally referenced covariates that reflect social and natural environments in the sampled region, after accounting for unmeasured residual heterogeneities. All diarrheal case events are collected from 21 sampled communities in Esmeraldes province in Ecuador, during seven sampling cycles from 2003 to 2008. The region of interest comprises 158 communities along a river basin. Prediction of case counts at unsampled communities at a future time is of interest along with estimation of risk-related parameters. We propose a computationally feasible two-stage Bayesian approach to estimate the risk-related parameters and conduct predictive inference. We first apply the log Gaussian Cox process (LGCP), commonly used to model spatial clustering of point patterns, to accommodate temporal variation within the sampled communities. Prediction of the number of cases at unsampled communities at a future time is obtained by a disease mapping model conditional on the expected case counts from Stage I.

Impact of rainfall on diarrheal disease risk associated with unimproved water and sanitation

Diarrheal disease remains a leading cause of morbidity in areas with limited access to safe water and sanitation. As water and sanitation interventions continue to be implemented, it will be important to understand the ecological context in which they can prevent diarrhea. We conducted six serial case control studies in Ecuador to estimate the risk of diarrhea from unimproved water and sanitation and the potential for effect modification by rainfall. Unimproved water source and unimproved sanitation increased the adjusted odds of diarrhea (odds ratio [OR] = 3.6, 95% confidence interval [95% CI] = 1.7-7.8 and OR = 1.7, 95% CI = 1.2-2.5, respectively). The OR associated with an unimproved water source was highest after maximum rainfall (OR = 6.8, 95% CI = 1.9-24.5), whereas the OR associated with unimproved sanitation was highest after minimal rainfall (OR = 2.9, 95% CI = 1.3-6.6). Our finding that use of safe water sources and improved sanitation facilities are most protective under opposing rainfall conditions highlights the need for integrated interventions to reduce the burden of diarrheal disease.

Molecular identification of Giardia duodenalis in Ecuador by polymerase chain reaction-restriction fragment length polymorphism

The aim of this study was to determine the genetic diversity of Giardia duodenalis present in a human population living in a northern Ecuadorian rain forest. All Giardia positive samples (based on an ELISA assay) were analysed using a semi-nested polymerase chain reaction-restriction fragment length polymorphism assay that targets the glutamate dehydrogenase (gdh) gene; those amplified were subsequently genotyped using NlaIV and RsaI enzymes. The gdh gene was successfully amplified in 74 of 154 ELISA positive samples; 69 of the 74 samples were subsequently genotyped. Of these 69 samples, 42 (61%) were classified as assemblage B (26 as BIII and 16 as BIV), 22 (32%) as assemblage A (3 as AI and 19 as AII) and five (7%) as mixed AII and BIII types. In this study site we observe similar diversity in genotypes to other regions in Latin America, though in contrast to some previous studies, we found similar levels of diarrheal symptoms in those individuals infected with assemblage B compared with those infected with assemblage A.

Synergistic effects between rotavirus and coinfecting pathogens on diarrheal disease: evidence from a community-based study in northwestern Ecuador

In developing countries where diarrheal disease is a leading cause of morbidity and mortality in children under 5 years of age, enteric coinfection is common. There is little understanding, however, of the biologic interaction between coinfecting pathogens. The authors investigated the potential for synergistic interaction between coinfecting pathogens on diarrhea pathogenesis using an epidemiologic framework. They conducted community-based, case-control studies in 22 communities in northwestern Ecuador between 2003 and 2008. Risk ratios of diarrhea associated with single infections and coinfections were estimated. Interaction between coinfecting pathogens was assessed through departure from risk ratio additivity and multiplicativity after adjustment for age. On the additive scale, the authors found departure from the null value of 0 for rotavirus-Giardia coinfections (interaction contrast ratio = 8.0, 95% confidence interval: 3.1, 18.9) and for rotavirus-Escherichia coli coinfections (interaction contrast ratio = 9.9, 95% confidence interval: 2.6, 28.4). On the multiplicative scale, they found departure from the value of 1 for rotavirus-Giardia coinfections (multiplicative interaction = 3.6, 95% confidence interval: 1.3, 8.7). This research provides epidemiologic evidence for synergism between rotavirus and other enteric pathogens. During coinfection, the pathogenic potential of each organism appears to be enhanced. The potential for pathogenesis to be more severe in the presence of a rotavirus coinfection amplifies the need for rotavirus vaccination.

Plesiomonas shigelloides infection, Ecuador, 2004-2008

Diarrheal risk associated with Plesiomonas shigelloides infection was assessed in rural communities in northwestern Ecuador during 2004–2008. We found little evidence that single infection with P. shigelloides is associated with diarrhea but stronger evidence that co-infection with rotavirus causes diarrhea.

The influence of rapid influenza diagnostic testing on antibiotic prescribing patterns in rural Thailand

OBJECTIVES

Rapid influenza diagnostic testing is potentially a useful means to decrease inappropriate prescription of antibiotics. We studied the impact of access to rapid influenza test results on antibiotic prescribing and other patient management practices for outpatients with influenza-like illness (ILI) in a rural province in Eastern Thailand.

METHODS

A medical record review was performed for 300 patients of all ages selected from five outpatient departments using a 1:2 ratio of ILI cases with and without influenza infection identified by the QuickVue rapid test. Chi-square analysis or Fisher's exact test was used to compare patient management practices (antibiotic prescriptions, individual treatments administered, additional tests ordered, and related hospitalization) between rapid test positive and negative patients. Logistic regression was used to evaluate the effect of rapid test results on patient management practices for ILI.

RESULTS

Eighty-two percent of all patients with ILI were prescribed antibiotics. Patients with a positive rapid test were less likely to be prescribed antibiotics than those with a negative result (73% vs. 87%, respectively, p=0.003). The likelihood of antibiotic prescription for influenza positive patients was 0.41 times the likelihood for influenza negative patients (95% CI 0.23-0.74, p=0.003). There was no significant difference in the frequency of other patient management practices between influenza positive and negative patients.

CONCLUSIONS

Thai outpatients with ILI are prescribed antibiotics at a frequency approximately twice that reported in the USA. Having access to a rapid influenza test result was associated with a significant decrease in antibiotic prescription. Improved access to rapid influenza testing and expanded physician education may reduce inappropriate antibiotic use and improve patient care.