Trends and presentation patterns of acute rheumatic fever hospitalisations in the United States.

OBJECTIVE: Rheumatic fever, an immune sequela of untreated streptococcal infections, is an important contributor to global cardiovascular disease. The goal of this study was to describe trends, characteristics, and cost burden of children discharged from hospitals with a diagnosis of RF from 2000 to 2012 within the United States. METHODS: Using the Kids' Inpatient Database, we examined characteristics of children discharged from hospitals with the diagnosis of rheumatic fever over time including: overall hospitalisation rates, age, gender, race/ethnicity, regional differences, payer type, length of stay, and charges. RESULTS: The estimated national cumulative incidence of rheumatic fever in the United States between 2000 and 2012 was 0.61 cases per 100,000 children. The median age was 10 years, with hospitalisations significantly more common among children aged 6-11 years. Rheumatic fever hospitalisations among Asian/Pacific Islanders were significantly over-represented. The proportion of rheumatic fever hospitalisations was greater in the Northeast and less in the South, although the highest number of rheumatic fever admissions occurred in the South. Expected payer type was more likely to be private insurance, and the median total hospital charges (adjusted for inflation to 2012 dollars) were $16,000 (interquartile range: $8900-31,200). Median length of stay was 3 days, and the case fatality ratio for RF in the United States was 0.4%. CONCLUSIONS: Rheumatic fever persists in the United States with an overall downwards trend between 2003 and 2012. Rheumatic fever admissions varied considerably based on age group, region, and origin.

Community study to uncover the full spectrum of rheumatic heart disease in Uganda.

OBJECTIVE: Estimates of the prevalence of rheumatic heart disease (RHD) in many endemic countries are limited to samples of children attending schools, which generate an incomplete picture of disease burden in communities. The present study conducted household-based RHD screening in a representative community in Gulu district, Uganda. METHODS: Members of households identified through a two-stage cluster-sampling approach between the ages of 5 years and 50 years were invited to undergo limited cardiac testing with a handheld echocardiogram to assess for the presence of RHD. Suspicious cases underwent confirmatory echocardiogram with a fully functional machine. RESULTS: Of the 2453 community members screened, 2.45% (95% CI 1.87% to 3.14%) showed echocardiographic evidence of RHD with 1.26% (95% CI 0.860% to 1.79%) having definite RHD. The overall prevalence of RHD among participants <20 years was 2.52% (95% CI 1.78% to 3.45%), with a borderline prevalence of 1.97% (95% CI 1.33% to 2.82%) and a definite prevalence of 0.544% (95% CI 0.235% to 1.07%). Prevalence rates among youth increased with age and peaked in the age group of 16-20 years. The overall adult prevalence (>20 years) of RHD was 2.34% (95% CI 1.49% to 3.49%). The majority of definite cases were mild (81%) and marked by mitral regurgitation and associated morphological valve changes (71%). CONCLUSION: Our data reveal a high prevalence of undiagnosed RHD within an endemic community and fill a critical gap in RHD epidemiology in African adults.

Recurrent Cardiology Evaluation for Innocent Heart Murmur: Echocardiogram Utilization.

We conducted a retrospective study to identify electrocardiogram (ECG) and echocardiogram utilization among patients presenting for a follow-up cardiology evaluation with innocent heart murmur between 2012 and 2014. The 2014 echocardiogram Appropriate Use Criteria was applied. We observed high rates of ordering ECGs and echocardiograms on follow-up visits (79% and 36%); only 1 patient had an appropriate indication for echocardiogram while the rest had rarely appropriate indication. Having had an ECG done did not affect echocardiogram ordering behavior. Older patient age was the only factor associated with a higher likelihood for ordering echocardiograms on follow-up visit (odds ratio = 1.016, P = .021). In this small sample study, we noticed high rates of test utilization and low-probability utilization of echocardiogram in the recurrent evaluation of children with innocent heart murmur. A larger, multicenter prospective study to investigate patterns and drivers of test utilization in children with innocent heart murmur presenting for a follow-up cardiology visit is needed.

Child and teacher acceptability of school-based echocardiographic screening for rheumatic heart disease in Uganda.

Introduction Rheumatic heart disease causes substantial morbidity in children in low-income countries. School-based echocardiographic screening has been suggested as a means to identify children with latent disease; however, little is known about the experience of children and teachers participating in screenings. The aim of our study was to assess students' and teachers' experience of school-based echocardiographic screening and identify areas for improvement. Materials and methods A school-based echocardiographic screening programme was conducted in five schools in Northern Uganda in 2013. After 8 months, an age- and gender-stratified population that included 5% of the participating students and teachers completed a questionnaire via an in-person interview. Responses were reviewed by question and coded to identify key themes. RESULTS: A total of 255 students (mean 10.7 years; 48% male) and 35 teachers participated in our study. In total, 95% of the students and 100% of the teachers were happy to have participated in the screening; however, students reported feeling scared (35%) and nervous (48%) during the screening process. Programmatic strengths included the following: knowing one's health status, opportunity to receive treatment, and staff interactions. Although 43% of the patients did not suggest a change with open-ended questioning, concerns regarding privacy, fear of the screening process, and a desire to include others in the community were noted. Discussion School-based echocardiographic rheumatic heart disease screening was well received by students and teachers. Future programmes would likely benefit from improved pre-screening education regarding the screening process and diagnosis of rheumatic heart disease. Furthermore, education of teachers and students could improve screening perception and establish realistic expectations regarding the scope of screening.

The Impact of Echocardiographic Screening for Rheumatic Heart Disease on Patient Quality of Life.

OBJECTIVE: To assess the impact of rheumatic heart disease (RHD) on child-reported health-related quality of life (HRQOL) in the context of a Ugandan school-based echocardiographic screening program. Echocardiography-based screening has emerged as a tool for the early detection of RHD, but little is known about its impact on those screened. STUDY DESIGN: Participants included 358 children from Gulu and 28 children from Kampala Uganda. The Pediatric Quality of Life Inventory Version 4.0 was used to assess HRQOL in 4 groups of children: Gulu prescreen, Gulu postscreen, Gulu previously linked to care, and Kampala previously linked to care. Children in the pre- and postscreen groups were selected from a single school before and after screening occurred and matched by age and sex. Children previously linked to care were recruited from previous screening studies. RESULTS: When the echocardiogram was normal, there was no difference in HRQOL in the prescreen and postscreen groups. In the postscreen group, identification of latent RHD resulted in lower physical (75.3 vs 68.3, P = .03) and emotional (71.7 vs 63.4, P < .01) HRQOL, despite a lack of symptoms. The Kampala group had longer linkage to care (42 months vs 6 months, P < .01) and demonstrated greater HRQOL scores compared with the Gulu-linked group (70.7 vs 77.8, P < .01) and the combined Gulu cohort (77.8 vs 69.4, P = .02). CONCLUSIONS: Echocardiography-based screening for RHD does not diminish HRQOL in Ugandan children; rather, a diminished HRQOL score may be associated with being identified as RHD positive. Further investigation is needed to understand if longer linkage to care may ultimately normalize or improve HRQOL.

The utility of handheld echocardiography for early rheumatic heart disease diagnosis: a field study.

AIMS: The World Heart Federation (WHF) guidelines for rheumatic heart disease (RHD) are designed for a standard portable echocardiography (STAND) machine. A recent study in a tertiary care centre demonstrated that they also had good sensitivity and specificity when modified for use with handheld echocardiography (HAND). Our study aimed to evaluate the performance of HAND for early RHD diagnosis in the setting of a large-scale field screening. METHODS AND RESULTS: STAND was performed in 4773 children in Gulu, Uganda, with 10% randomly assigned to also undergo HAND. Additionally, any child with mitral or aortic regurgitation also underwent HAND. Studies were performed by experienced echocardiographers and blindly reviewed by cardiologists using 2012 WHF criteria, which were modified slightly for HAND--due to the lack of spectral Doppler capability. Paired echocardiograms were performed in 1420 children (mean age 10.8 and 53% female), resulting in 1234 children who were normal, 133 who met criteria for borderline RHD, 47 who met criteria for definite RHD, and 6 who had other diagnoses. HAND had good sensitivity and specificity for RHD detection (78.9 and 87.2%, respectively), but was most sensitive for definite RHD (97.9%). Inter- and intra-reviewer agreement ranged between 66-83 and 71.4-94.1%, respectively. CONCLUSIONS: HAND has good sensitivity and specificity for diagnosis of early RHD, performing best for definite RHD. Protocols for RHD detection utilizing HAND will need to include confirmation by STAND to avoid over-diagnosis. Strategies that evaluate simplified screening protocols and training of non-physicians hold promise for more wide spread deployment of HAND-based protocols.

Computational protein design using flexible backbone remodeling and resurfacing: case studies in structure-based antigen design.

Computational protein design has promise for vaccine design and other applications. We previously transplanted the HIV 4E10 epitope onto non-HIV protein scaffolds for structural stabilization and immune presentation. Here, we developed two methods to optimize the structure of an antigen, flexible backbone remodeling and resurfacing, and we applied these methods to a 4E10 scaffold. In flexible-backbone remodeling, an existing backbone segment is replaced by a de novo designed segment of prespecified length and secondary structure. With remodeling, we replaced a potentially immunodominant domain on the scaffold with a helix-loop segment that made intimate contact to the protein core. All three domain trim designs tested experimentally had improved thermal stability and similar binding affinity for the 4E10 antibody compared to the parent scaffold. A crystal structure of one design had a 0.8 Å backbone RMSD to the computational model in the rebuilt region. Comparison of parent and trimmed scaffold reactivity to anti-parent sera confirmed the deletion of an immunodominant domain. In resurfacing, the surface of an antigen outside a target epitope is redesigned to obtain variants that maintain only the target epitope. Resurfaced variants of two scaffolds were designed in which 50 positions amounting to 40% of the protein sequences were mutated. Surface-patch analyses indicated that most potential antibody footprints outside the 4E10 epitope were altered. The resurfaced variants maintained thermal stability and binding affinity. These results indicate that flexible-backbone remodeling and resurfacing are useful tools for antigen optimization and protein engineering generally.

Computational design of epitope-scaffolds allows induction of antibodies specific for a poorly immunogenic HIV vaccine epitope.

Broadly cross-reactive monoclonal antibodies define epitopes for vaccine development against HIV and other highly mutable viruses. Crystal structures are available for several such antibody-epitope complexes, but methods are needed to translate that structural information into immunogens that re-elicit similar antibodies. We describe a general computational method to design epitope-scaffolds in which contiguous structural epitopes are transplanted to scaffold proteins for conformational stabilization and immune presentation. Epitope-scaffolds designed for the poorly immunogenic but conserved HIV epitope 4E10 exhibited high epitope structural mimicry, bound with higher affinities to monoclonal antibody (mAb) 4E10 than the cognate peptide, and inhibited HIV neutralization by HIV+ sera. Rabbit immunization with an epitope-scaffold induced antibodies with structural specificity highly similar to mAb 4E10, an important advance toward elicitation of neutralizing activity. The results demonstrate that computationally designed epitope-scaffolds are valuable as structure-specific serological reagents and as immunogens to elicit antibodies with predetermined structural specificity.