Safety and immunogenicity of a trivalent virus-like particle vaccine against western, eastern, and Venezuelan equine encephalitis viruses: a phase 1, open-label, dose-escalation, randomised clinical trial

BACKGROUND

Western (WEEV), eastern (EEEV), and Venezuelan (VEEV) equine encephalitis viruses are mosquito-borne pathogens classified as potential biological warfare agents for which there are currently no approved human vaccines or therapies. We aimed to evaluate the safety, tolerability, and immunogenicity of an investigational trivalent virus-like particle (VLP) vaccine, western, eastern, and Venezuelan equine encephalitis (WEVEE) VLP, composed of WEEV, EEEV, and VEEV VLPs.

METHODS

The WEVEE VLP vaccine was evaluated in a phase 1, randomised, open-label, dose-escalation trial at the Hope Clinic of the Emory Vaccine Center at Emory University, Atlanta, GA, USA. Eligible participants were healthy adults aged 18-50 years with no previous vaccination history with an investigational alphavirus vaccine. Participants were assigned to a dose group of 6 μg, 30 μg, or 60 μg vaccine product and were randomly assigned (1:1) to receive the WEVEE VLP vaccine with or without aluminium hydroxide suspension (alum) adjuvant by intramuscular injection at study day 0 and at week 8. The primary outcomes were the safety and tolerability of the vaccine (assessed in all participants who received at least one administration of study product) and the secondary outcome was immune response measured as neutralising titres by plaque reduction neutralisation test (PRNT) 4 weeks after the second vaccination. This trial is registered at ClinicalTrials.gov, NCT03879603.

FINDINGS

Between April 2, 2019, and June 13, 2019, 30 trial participants were enrolled (mean age 32 years, range 21-48; 16 [53%] female participants and 14 [47%] male participants). Six groups of five participants each received 6 μg, 30 μg, or 60 μg vaccine doses with or without adjuvant, and all 30 participants completed study follow-up. Vaccinations were safe and well tolerated. The most frequently reported symptoms were mild injection-site pain and tenderness (22 [73%] of 30) and malaise (15 [50%] of 30). Dose-dependent differences in the frequency of pain and tenderness were found between the 6 μg, 30 μg, and 60 μg groups (p=0·0217). No significant differences were observed between dosing groups for any other reactogenicity symptom. Two adverse events (mild elevated blood pressure and moderate asymptomatic neutropenia) were assessed as possibly related to the study product in one trial participant (60 μg dose with alum); both resolved without clinical sequelae. 4 weeks after second vaccine administration, neutralising antibodies were induced in all study groups with the highest response seen against all three vaccine antigens in the 30 μg plus alum group (PRNT₈₀ geometric mean titre for EEEV 60·8, 95% CI 29·9-124·0; for VEEV 111·5, 49·8-249·8; and for WEEV 187·9, 90·0-392·2). Finally, 4 weeks after second vaccine administration, for all doses, the majority of trial participants developed an immune response to all three vaccine components (24 [83%] of 29 for EEEV; 26 [90%] of 29 for VEEV; 27 [93%] of 29 for WEEV; and 22 [76%] of 29 for EEEV, VEEV, and WEEV combined).

INTERPRETATION

The favourable safety profile and neutralising antibody responses, along with pressing public health need, support further evaluation of the WEVEE VLP vaccine in advanced-phase clinical trials.

FUNDING

The Vaccine Research Center of the National Institute of Allergy and Infectious Diseases, National Institutes of Health funded the clinical trial. The US Department of Defense contributed funding for manufacturing of the study product.

Methods for estimating the direct and indirect effect of 10 valent pneumococcal vaccine on nasopharyngeal carriage in children under 2 years in Matiari, Pakistan

Pneumonia is the leading cause of morbidity and mortality in children worldwide. The ten valent pneumococcal vaccine (PCV10) was introduced in Pakistan's Expanded Program on Immunization (EPI) in 2012 as a 3 + 0 schedule without catchup immunization. Nasopharyngeal carriage is taken as a surrogate marker to measure the impact of pneumococcal vaccine on populations. Carriage surveys are necessary to monitor the persistence of Vaccine Type (VT) serotypes, the emergence of Non-Vaccine Type (NVT) serotypes, and their role in both transmission and disease. This article describes various troubleshooting measures which we undertook to adopt the protocol to our setting. We also used an innovative approach to describe various epidemiological parameters of vaccine effectiveness against carriage. It is important to publish these methods to allow for valid regional and temporal comparisons of results in different settings. Thus, in this article, we describe the following methods for isolating upper airway pneumococcal carriage:•Methods for the collection, transport, and storage of nasopharyngeal samples.•Methods for identification and serotyping of pneumococci.•Methods for estimation of the direct and indirect effects of pneumococcal vaccines on nasopharyngeal carriage.

'Drip-and-ship' intravenous thrombolysis and outcomes for large vessel occlusion thrombectomy candidates in a hub-and-spoke telestroke model

BACKGROUND

Randomized trials have not demonstrated benefit from intravenous thrombolysis among patients undergoing endovascular thrombectomy (EVT). However, these trials included primarily patients presenting directly to an EVT capable hub center. We sought to study outcomes for EVT candidates who presented to spoke hospitals and were subsequently transferred for EVT consideration, comparing those administered alteplase at spokes (i.e., 'drip-and-ship' model) versus those not.

METHODS

Consecutive EVT candidates presenting to 25 spokes from 2018 to 2020 with pre-transfer CT angiography defined emergent large vessel occlusion and Alberta Stroke Program CT score ≥6 were identified from a prospectively maintained Telestroke database. Outcomes of interest included adequate reperfusion (Thrombolysis in Cerebral Infarction (TICI) 2b-3), intracerebral hemorrhage (ICH), discharge functional independence (modified Rankin Scale (mRS) ≤2), and 90 day functional independence.

RESULTS

Among 258 patients, median age was 70 years (IQR 60-81), median National Institutes of Health Stroke Scale (NIHSS) score was 13 (6-19), and 50% were women. Ninety-eight (38%) were treated with alteplase at spokes and 113 (44%) underwent EVT at the hub. Spoke alteplase use independently increased the odds of discharge mRS ≤2 (adjusted OR 2.43, 95% CI 1.08 to 5.46, p=0.03) and 90 day mRS ≤2 (adjusted OR 3.45, 95% CI 1.65 to 7.22, p=0.001), even when controlling for last known well, NIHSS, and EVT; it was not associated with an increased risk of ICH (OR 1.04, 95% CI 0.39 to 2.78, p=0.94), and there was a trend toward association with greater TICI 2b-3 (OR 3.59, 95% CI 0.94 to 13.70, p=0.06).

CONCLUSIONS

Intravenous alteplase at spoke hospitals may improve discharge and 90 day mRS and should not be withheld from EVT eligible patients who first present at alteplase capable spoke hospitals that do not perform EVT. Additional studies are warranted to confirm and further explore these benefits.

Population impact and effectiveness of sequential 13-valent pneumococcal conjugate and monovalent rotavirus vaccine introduction on infant mortality: prospective birth cohort studies from Malawi

Background

Pneumococcal conjugate vaccine (PCV) and rotavirus vaccine (RV) are key tools for reducing common causes of infant mortality. However, measurement of population-level mortality impact is lacking from sub-Saharan Africa. We evaluated mortality impact and vaccine effectiveness (VE) of PCV13 introduced in November 2011, with subsequent RV1 roll-out in October 2012, in Malawi.

Methods

We conducted two independent community-based birth cohort studies. Study 1, in northern Malawi (40000population), evaluated population impact using change-point analysis and negative-binomial regression of non-traumatic 14–51-week infant mortality preintroduction (1 January 2004 to 31 September 2011) and postintroduction (1 October 2011 to 1 July 2019), and against three-dose coverage. Study 2, in central Malawi (465 000 population), was recruited from 24 November 2011 to 1 June 2015. In the absence of preintroduction data, individual three-dose versus zero-dose VE was estimated using individual-level Cox survival models. In both cohorts, infants were followed with household visits to ascertain vaccination, socioeconomic and survival status. Verbal autopsies were conducted for deaths.

Results

Study 1 included 20 291 live births and 216 infant deaths. Mortality decreased by 28.6% (95% CI: 15.3 to 39.8) post-PCV13 introduction. A change point was identified in November 2012. Study 2 registered 50 731 live births, with 454 deaths. Infant mortality decreased from 17 to 10/1000 live births during the study period. Adjusted VE was 44.6% overall (95% CI: 23.0 to 59.1) and 48.3% (95% CI: −5.9 to 74.1) against combined acute respiratory infection, meningitis and sepsis-associated mortality.

Conclusion

These data provide population-level evidence of infant mortality reduction following sequential PCV13 and RV1 introduction into an established immunisation programme in Malawi. These data support increasing coverage of vaccine programmes in high-burden settings.

Teleneurology Comprehensive Inpatient Consultations Expedite Access to Care and Decreases Hospital Length of Stay

Background and Purpose

While the successful provision of telestroke care has been well documented in the literature, studies on the impact of comprehensive teleneurology service (TN) to hospital measures are lacking. We evaluated 3 traditional health services metrics of hospital performance: time from consult request to consult completion, inpatient length of stay (LOS), and the rate of patients transferred for tertiary care.

Methods

Medical records (n = 899) from 3 community hospitals and our TN consultation database were retrospectively reviewed during the 2 years before (n = 703, 3 hospitals) and 4 months (n = 2 hospitals) to 2 years (n = 1 hospital) after implementation (n = 196) of a TN program for routine and urgent consult requests. Consult order time, consult completion time, total length of stay and discharge disposition were compared across the pre-TN implementation group, which consisted of in-person consultations and the post-TN implementation group, which consisted of TN consultations only.

Results

After TN implementation, median length of stay decreased 28% (3.9 vs. 2.8 days, p < 0.0001) and median time from consult order to consult completion decreased by 74% across all diagnoses (5.8 vs. 1.5 hours, p < 0.0001). There were no significant differences in the percentage of patients discharged home (52.3% vs. 56.1%, p = 0.10) or transferred to tertiary care (6.1% to 9.2%, p = 0.10).

Conclusions

Implementation of TN program was associated with significant reductions in LOS and time to consultation completion without an increase in shunting of patients to more advanced facilities. Further research is warranted to confirm these findings in independent cohorts and other models of teleneurology delivery.

CTA Protocols in a Telestroke Network Improve Efficiency for Both Spoke and Hub Hospitals

BACKGROUND AND PURPOSE

Telestroke networks support screening for patients with emergent large-vessel occlusions who are eligible for endovascular thrombectomy. Ideal triage processes within telestroke networks remain uncertain. We characterize the impact of implementing a routine spoke hospital CTA protocol in our integrated telestroke network on transfer and thrombectomy patterns.

MATERIALS AND METHODS

A protocol-driven CTA process was introduced at 22 spoke hospitals in November 2017. We retrospectively identified prospectively collected patients who presented to a spoke hospital with National Institutes of Health Stroke Scale scores ≥6 between March 1, 2016 and March 1, 2017 (pre-CTA), and March 1, 2018 and March 1, 2019 (post-CTA). We describe the demographics, CTA utilization, spoke hospital retention rates, emergent large-vessel occlusion identification, and rates of endovascular thrombectomy.

RESULTS

There were 167 patients pre-CTA and 207 post-CTA. The rate of CTA at spoke hospitals increased from 15% to 70% (P < .001). Despite increased endovascular thrombectomy screening in the extended window, the overall rates of transfer out of spoke hospitals remained similar (56% versus 54%; P = .83). There was a nonsignificant increase in transfers to our hub hospital for endovascular thrombectomy (26% versus 35%; P = .12), but patients transferred >4.5 hours from last known well increased nearly 5-fold (7% versus 34%; P < .001). The rate of endovascular thrombectomy performed on patients transferred for possible endovascular thrombectomy more than doubled (22% versus 47%; P = .011).

CONCLUSIONS

Implementation of CTA at spoke hospitals in our telestroke network was feasible and improved the efficiency of stroke triage. Rates of patients retained at spoke hospitals remained stable despite higher numbers of patients screened. Emergent large-vessel occlusion confirmation at the spoke hospital lead to a more than 2-fold increase in thrombectomy rates among transferred patients at the hub.

Direct and indirect effect of 10 valent pneumococcal vaccine on nasopharyngeal carriage in children under 2 years of age in Matiari, Pakistan

Background

Pakistan introduced Ten-valent pneumococcal-conjugate-vaccine PCV10 in 2012 as a 3 + 0 schedule without catch-up.

Methods

Children <2 years old in Matiari, Sindh provided nasopharyngeal swabs between 2014 and 2018, which were cultured for pneumococcus and serotyped through multiplex PCR at the Aga Khan University Hospital. Carriage rates over time for Vaccine-Type (VT) and Non-VT (NVT) serotypes were used to estimate direct, indirect, total and overall effects of vaccination. Regression analysis was used to determine factors associated with VT carriage.

Results

Pneumococcus was detected in 2370/3140 (75%). VT carriage decreased overall, 16.1–9.6% (p-trend <0.001); vaccinated (all 3 doses of PCV10 received) 11.3–8.1% (p-trend 0.031) and unvaccinated (no PCV10 dose received) 17.4–10.3% (p-trend 0.003) with a decline in serotypes 6B, 9V/9A and 19F. Immunization increased from 41.0% to 68.4% (p-trend 0.001). Direct effect of vaccine was 32.8% (95% CI 14.7–47.0%) and indirect effect 44.6%(95% CI 40.6–48.6%). Factors associated with decreased VT colonization were education 1–5 years (aOR 0.7, 95%CI 0.6–1.0), history of difficulty breathing (aOR 0.7, 95%CI 0.5–1.0), exposure to smoke (aOR 0.8, 95% CI 0.6–1.0), child fully immunized (aOR 0.7, 95%CI 0.5–1.0) and enrolled in 3rd (aOR 0.6, 95%CI 0.4–0.8) and 4th (aOR 0.6, 95%CI 0.5–0.9) year of the study whereas history of runny nose (aOR 1.5, 95% CI 1.2–1.9) was positively associated.

Conclusions

Decrease in VT pneumococcal carriage in vaccinated and unvaccinated children indicates herd immunity. Sustained increase in vaccine coverage and close long-term surveillance is warranted.

A lay provider delivered behavioral intervention for Syrian refugees and their children in Jordan

Background

Refugees and their children are exposed to many distressing events, including detention in refugee camps. Not surprisingly, refugees are at high risk for common mental disorders. A major barrier to addressing mental health problems in refugees is that most host countries lack sufficient mental health specialists to provide high-intensity treatments.

A recent trend has focused on training non-specialists to deliver simple psychosocial programs to those with distress. One such program is Problem Management Plus (PM+) which was developed by the World Health Organization; it comprises 5 small-group sessions that teach behavioural skills to reduce distress. This study reports the first evaluation of group PM+ in a refugee camp. We investigated the extent to which PM+ provided to adult Syrian refugees can benefit their children.

Methods

480 Adult Syrian refugees in the Azraq Refugee Camp were randomized to either PM+ or Treatment as Usual (TAU). Participants were independently assessed prior to the program, immediately following the program, and 3 months later. Outcome variables included anxiety, depression, functioning, posttraumatic stress, and grief and parenting behaviours. Children's psychological wellbeing was assessed in one child of each participant.

Results

Of the 650 adult refugees were screened in the camp, 96% met the cut-off for psychological distress and 76% met criteria for functional impairment. 480 participants were randomized to PM+ or TAU. The baseline assessment indicated 85% of refugees met criteria for depression, 84% met criteria for anxiety, and 84% met criteria for posttraumatic stress disorder. The 3-month assessment will be presented following linear mixed modelling to determine the relative gains made by refugees and their children in PM+ and TAU.

Conclusions

These findings will be discussed in terms of implementation of scalable programs in refugee settings, and specifically how these can benefit participants and their children.

Abstract WP294: In Search of Greater Efficiencies: Implementation of Computed Tomography Angiography in a Telestroke Network Improves Triage for Both Primary and Comprehensive Stroke Centers

Introduction: Telestroke (TS) networks provide an important function in community hospitals by supporting thrombolytic use and screening for patients with large vessel occlusion (LVO) who may be eligible for endovascular thrombectomy (EVT). The expansion of treatment to 24 hours from last known well has dramatically increased the pool of patients to screen. Idealized triage processes within TS networks remain uncertain. We sought to characterize the impact of the implementation of a routine spoke hospital (SH) CTA protocol in our integrated TS network.

Methods: We introduced protocol-driven CTA process at 25 SH in November 2017. We retrospectively identified patients who presented to a SH with an NIHSS ≥ 6 between 3/1/2016-3/1/2017 (pre-CTA) and 3/1/2018-3/1/2019 (post-CTA). We characterized baseline demographics, transfer patterns, and rates of CTA utilization, LVO, and EVT. Differences were assessed using Wilcoxon rank-sum for continuous variables and χ2 tests for categorical variables.

Results: There were 167 patients pre-CTA and 207 post-CTA. The rate of CTA at SHs increased from 13% to 70% (p<0.001). Despite increased screening of patients >4.5 hr from last known well time, the rates of transfer out of SHs did not increase (56% vs 54%, p=0.83). The rate of transfer to our CSC for EVT increased non-significantly (26% vs 35%, p=0.12) but the proportion of patients transferred >4.5 hr increased ~5-fold (7% vs 34%, p<0.001) with a decrease in need for repeat imaging at our CSC (94% vs 66%, p<0.001). The overall rate of EVT performed on patients transferred for possible EVT more than doubled (22% to 47%, p=0.011).

Conclusions: Implementation of a CTA protocol at SHs in our TS network was feasible, and effective in improving the efficiency of interhospital triage of candidates for EVT. In the era of late-window EVT, introducing CTA into PSC enhances the stroke system of care and keeps care local whenever possible. Replication of these findings in other TS networks is needed.

Abstract WP482: Pragmatic Times: A Telestroke Response to the Need for Increased Large Vessel Occlusion Stroke Triage

Introduction: Identification of patients with stroke from large vessel occlusion (LVO), including into extended time windows, is a current medical imperative. Capacity challenges limit transfer of all patients with clinical deficit to receiving hospitals, while referring hospitals desire patient retention if transfer is not indicated. The use of CT angiography (CTA) provides the most reliable option for LVO screening at the referring hospital. We evaluate the utilization of CTA within our Telestroke network.

Methods: A CTA protocol was developed for Telestroke referring hospitals and disseminated through the network (25 centers) in a staggered fashion. CTA was encouraged for all patients with NIHSS of ≥6 and presentation <24 hours from last known well. Patients were included in this analysis if they had NIHSS of ≥6 and either Telestroke video consultation, or Telestroke telephone consultation after local Neurology evaluation.

Results: Prior to the protocol implementation CTA was utilized at none of the Telestroke referring hospitals. The CTA protocol was disseminated by March 2018. Between March and August 2018 there were a total of 623 Telestroke consults (185 video); 75 patients met inclusion criteria. CTA was obtained by the referring hospital in 65 cases (86%). Reasons for not obtaining a referring hospital CTA were vascular anatomical complexities (aortic dissection, multiple systemic emboli) in 2 patients, medical comorbid concerns (anaphylaxis with prior contrast, endocarditis, hemodynamic instability) in 3 patients, transfer to a different facility (2 patients), declined by family, and not indicated based on Telestroke video evaluation due to lacunar syndrome (1 patient each). Of patients with CTAs, 34 remained at the referring hospital (52%) based on CTA findings.

Conclusions: We demonstrate a pragmatic approach to the challenge of LVO triage up to 24 hours within the tele-stroke network. Our approach demonstrated high rates of CTA adoption within a short timeframe (5 months), and may provide a model to be replicated in other Telestroke environments. While retention rates of over 52% at the referring hospital are encouraging, subsequent data will provide information regarding further triage implications for these patients.

Nasopharyngeal carriage of Streptococcus pneumoniae in children under 5 years of age before introduction of pneumococcal vaccine (PCV10) in urban and rural districts in Pakistan

Background

Benefits of pneumococcal conjugate vaccine programs have been linked to the vaccine’s ability to disrupt nasopharyngeal carriage and transmission. The 10-valent pneumococcal vaccine (PCV10) was included in the Expanded Program on Immunization (EPI) in Sindh, Pakistan in February 2013. This study was carried out immediately before PCV10 introduction to establish baseline pneumococcal carriage and prevalent serotypes in young children and to determine if carriage differed in urban and rural communities.

Methods

Nasopharyngeal specimens were collected from a random sample of children 3-11 and 12-59 months of age in an urban community (Karachi) and children 3-11 months of age in a rural community (Matiari). Samples were processed in a research laboratory in Karachi. Samples were transported in STGG media, enriched in Todd Hewitt broth, rabbit serum and yeast extract, cultured on 5% sheep blood agar, and serotyped using the CDC standardized sequential multiplex PCR assay. Serotypes were categorized into PCV10-type and non-vaccine types.

Results

We enrolled 670 children. Pneumococci were detected in 73.6% and 79.5 % of children in the infant group in Karachi and Matiari, respectively, and 78.2% of children 12 to 59 months of age in Karachi. In infants, 38.9% and 33.5% of those carrying pneumococci in Karachi and Matiari, respectively, had PCV10 types. In the older age group in Karachi, the proportion was 30.7%, not significantly different from infants. The most common serotypes were 6A, 23F, 19A, 6B and 19F.

Conclusion

We found that about 3 of 4 children carried pneumococci, and this figure did not vary with age group or urban or rural residence. Planned annual surveys in the same communities will inform change in carriage of PCV10 serotype pneumococci after the introduction and uptake of PCV10 in these communities

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3608-5) contains supplementary material, which is available to authorized users.

151. Evaluation of Pneumococcal Vaccine Effectiveness Against Invasive Pneumococcal Disease Among US Medicare Beneficiaries ≥65 Years Old

Background

Pneumococcal conjugate vaccine (PCV13) was recommended in series with PPSV23 for all US adults ≥65 years in late 2014. We evaluated effectiveness of PCV13 against invasive pneumococcal disease (IPD) among Medicare beneficiaries ≥65 years old to assess this new policy.

Methods

We linked records for IPD cases (pneumococcus isolated from sterile sites) in persons ≥65 years old identified through Active Bacterial Core surveillance with those of Medicare beneficiaries. Isolates were serotyped and classified as PCV13 (with or without cross-reacting type 6C), and nonvaccine types. We selected Medicare beneficiaries with no record of IPD or pneumonia as controls, and matched to cases on age, residence census tract, and length of Medicare enrollment; we included all eligible controls. Vaccination and medical histories were obtained through Medicare. We estimated vaccine effectiveness (VE) as 1 minus the IPD odds ratio for vaccinated (PCV13) vs. unvaccinated (no PCV13 or PPSV23) persons using conditional logistic regression, adjusted for sex and underlying conditions.

Results

From 2,246 IPD cases identified in 2015–2016, 1,017 (45%) were matched to Medicare beneficiaries. After excluding cases in persons residing in long-term care facilities or with <1 year of Medicare enrollment, we included 699 eligible cases and 10,152 controls in our analysis. PCV13-types (+6C) accounted for 164 (23%) cases, and serotype 3 was the most common PCV13-type. Case patients were more likely than controls to have one or more chronic (88% vs. 58%) or immunocompromising (54% vs. 32%) conditions present. Fourteen percent, 22%, and 8% of case patients, and 18%, 21%, and 8% of controls received PCV13 only, PPSV23 only, or both vaccines, respectively. PCV13-only VE against PCV13-types was 36% (95% CI −18, 65%). When we included type 6C with PCV13-types, VE was 67% (95% CI 11, 88%). PCV13 showed similar effectiveness against PCV13 type (+6C) IPD among adults >75 years of age (VE 61%, 95% CI 14, 82). VE was 26% (95% CI −58, 65%) against serotype 3 and 67% (95% CI 11, 88%) against other PCV13-types (+6C). PCV13 was not effective against nonvaccine types.

Conclusion

PCV13 was effective in preventing IPD caused by PCV13 types when excluding type 3; no effectiveness was demonstrated against serotype 3.

Disclosures

W. Schaffner, Merck: Member, Data Safety Monitoring Board, Consulting fee. Pfizer: Member, Data Safety Monitoring Board, Consulting fee. Dynavax: Consultant, Consulting fee. Seqirus: Consultant, Consulting fee. SutroVax: Consultant, Consulting fee. Shionogi: Consultant, Consulting fee.

1445. Impact of 10-Valent Pneumococcal Conjugate Vaccine Introduction on Pneumococcal Carriage and Antibiotic Susceptibility Patterns Among Children Aged <5 Years and Adults with HIV Infection, Kenya 2009–2013

Background

Kenya introduced 10-valent pneumococcal conjugate vaccine (PCV10) in 2011 (three doses at ages 6, 10, and 14 weeks). Impact of PCV10 on pneumococcal carriage was unknown in this setting. We assessed changes in pneumococcal carriage and antibiotic susceptibility in children aged <5 years (U5) and HIV-infected adults (HIV+ adults) post-PCV10 introduction.

Methods

During 2009–2013, we performed annual cross-sectional pneumococcal carriage surveys in two sites with ongoing population-based surveillance: Kibera (U5 only) and Lwak (U5 and HIV+ adults, catch-up vaccination for children 1–4 years offered in 2011). Nasopharyngeal swabs (and oropharyngeal swabs in adults) were obtained for culture. Pneumococcal isolates were serotyped by multiplex PCR and Quellung. Antibiotic susceptibility was determined (2009 and 2013). We calculated changes in penicillin nonsusceptible (intermediate or resistant) pneumococci (PNSP) carriage by chi-squared test. Changes in PCV10-type (VT) pneumococcal carriage in 2013 compared with baseline (U5: 2009–10, adults: 2009 only) were calculated by modified Poisson regression by age and site.

Results

Overall, 2,962 U5 (2,073 in Kibera, 889 in Lwak) and 2,028 HIV+ adults were enrolled. VT carriage declined by 52–60% in children 1–4 years, by 60% in children <1 year in Kibera, and by 76% in HIV+ adults (table). PNSP carriage declined from 32.8% to 22.3% (P < 0.01) in HIV+ adults but did not change in U5 (Kibera: 77.0% vs. 75.5%, P =0.10; Lwak: 74.3% vs. 74.6%, P = 0.94).

Conclusion

The infant PCV10 program was associated with declines in VT carriage among U5 and HIV+ adults, and declines in PNSP carriage among HIV+ adults; however, VT carriage remained >10% among U5 2 years post-PCV10 introduction.

Disclosures

All authors: No reported disclosures.

1436. Risk Factors for Invasive Pneumococcal Disease in Adults ≥65 Years Old Following Pneumococcal Conjugate Vaccine Recommendation

Background

In 2014, pneumococcal conjugate (PCV13) and polysaccharide (PPSV23) vaccines were recommended in series for all US adults ≥65 years. We conducted a case–control study to evaluate risk factors for invasive pneumococcal disease (IPD) among adults ≥65 years old.

Methods

IPD cases (isolation of pneumococcus from sterile sites) were identified through Active Bacterial Core surveillance during 2015–2018. Isolates were serotyped using whole genome sequencing. Four controls, identified through a commercial database, were matched per case by age and zip code. We obtained vaccination and medical histories from providers, vaccine registries and participant interviews. A functional status score was calculated based on participant interview. We calculated IPD odds ratios using multivariable conditional logistic regression.

Results

We enrolled 328 IPD cases and 1,280 matched controls. Fifty percent of case-patients and 55% of controls received a dose of PCV13. Case-patients were more likely than controls to have a chronic condition (heart, liver, or lung disease, diabetes, cochlear implant, alcohol abuse, smoking; 82% vs. 59%), immunosuppression (60% vs. 32%), poor functional status (score of ≥ 3; 71% vs. 50%), annual household income <$30,000 (38% vs. 25%) and education level of high school or less (36% vs. 25%). In a multivariable model, case-patients were more likely than controls to have a chronic condition (OR 2.48, 95% CI 1.72, 3.58), immunosuppression (OR 2.56, 95% CI 1.92,3.42), poor functional status (OR 3.66, 95% CI 2.42, 5.54), and primary or secondary smoking exposure (OR 3.09, 95% CI 1.32, 7.2). In analysis limited to PCV13-type cases and matched controls, adjusting for PCV13 receipt, measures of association were no longer significant for chronic conditions (OR 1.45, 95% 0.71, 2.95), immunosuppression (OR 1.51, 95% CI 0.83, 2.74), or poor functional status (OR 1.98, 95% CI 0.91, 4.3).

Conclusion

Chronic and immunosuppressive conditions remain IPD risk factors for adults in the era of PCV13 use; poor functional status was also identified as a risk factor. Targeted evaluation of adults with poor functional status could inform IPD prevention strategies. PCV13 may reduce the risk of PCV13-type IPD associated with chronic conditions and poor functional status.

Disclosures

W. Schaffner, Merck: Member, Data Safety Monitoring Board, Consulting fee; Pfizer: Member, Data Safety Monitoring Board, Consulting fee

Dynavax: Consultant, Consulting fee; Seqirus: Consultant, Consulting fee; SutroVax: Consultant, Consulting fee; Shionogi: Consultant, Consulting fee.

Evaluation of the Experience of Spoke Hospitals in an Academic Telestroke Network

Background/Introduction: Implementation of telestroke has been associated with improved thrombolysis rates and clinical outcomes in remote or neurologically underserved spoke hospitals. Yet, the experience of spoke hospitals using telestroke has not been well described. We sought to characterize spoke hospitals' perceptions of telestroke to understand perceived advantages, challenges, and barriers to use. Design/Methods: Within our northeastern US telestroke network, we conducted scripted interviews with representatives (stroke coordinators, nurse managers, and emergency physicians) from each of the 15 spoke hospitals connected to a single academic hub hospital. Interview questions included both open-ended and Likert scale responses. We used descriptive and nonparametric analyses (e.g., logit) to present the results. Results: Of the 15 spoke hospitals interviewed, the majority felt that telestroke enabled them to treat more patients with the tissue plasminogen activator (tPA; 93.3%, n = 14) and to achieve faster door-to-needle times for tPA treatment (80%, n = 12). Higher Likert scores were not correlated with hospitals' consult volume or tPA volume. The most commonly reported barriers to using telestroke were providers who were not familiar or comfortable using the technology (66%, n = 10). Few hospitals had concerns that telestroke led to overtreatment with tPA (13.3%, n = 2) or led to unnecessary transfers (20%, n = 3). None of the hospitals felt that the physician-patient relationship was compromised, nor was there a concern that patients would have a negative perception of the spoke hospital with utilization of services. Conclusions: Within this single hub-spoke telestroke system in the northeast, we found that spoke hospitals perceive the advantages of telestroke to be in enabling improved rates and efficiency of tPA administration. Barriers to use were most often related to technological challenges rather than concerns about patient care or patients' perceptions. Future work should further explore how to better meet the needs of spoke hospitals in caring for stroke patients.

Frequent Hub-Spoke Contact Is Associated with Improved Spoke Hospital Performance: Results from the Massachusetts General Hospital Telestroke Network

BACKGROUND

For acute ischemic stroke patients, shorter time to thrombolytic (tissue plasminogen activator [tPA]) is associated with improved outcomes.

INTRODUCTION

Telestroke increases tPA use at spoke hospitals, yet its effect on door-to-needle (DTN) times for tPA administration is unknown. We hypothesize that spoke hospitals with more frequent contact to a hub hospital will have shorter DTN times than those with less frequent contact.

MATERIALS AND METHODS

We identified 375 patients treated with tPA by conventional or telestroke methods in an academic hub-and-spoke telestroke network for whom date and time data were available. Strength of the spoke-hub connection was the primary predictor variable, defined as the number of all telestroke consults (tPA and non-tPA) done at each spoke hospital during the year of the patient's presentation. Patient-level regression analyses examined the relationship between DTN time and spoke-hub connection during the year of the patient's presentation, controlling for temporal trends and clustering within hospitals.

RESULTS

Sixteen spoke hospitals contributed data on 375 tPA-treated patients from 2006-2015. Hospitals treated a median of 13.5 patients with tPA per year; median hospital-level DTN was 78.8 min (interquartile range [IQR] 71.3-85). Median number of telestroke consults per year was 34 (range 3-137). Among all 375 patients, median DTN was 76 min (IQR 60-97). Strength of spoke-hub connection was significantly associated with faster DTN time for patients (1.3 min gain per 10 additional consults, p = 0.048).

CONCLUSIONS

More frequent contact between a telestroke spoke and its hub was associated with faster tPA delivery for patients, even after accounting for secular trends in DTN improvements.

Direct and Indirect Impact of 13-valent Pneumococcal Conjugate Vaccine (PCV13) on Invasive Pneumococcal Disease (IPD) Among Children and Adults in the U.S

Background

In February 2010, PCV13 was introduced for routine use among children aged < 5 years. In June 2012, PCV13 was recommended for use in series with 23-valent polysaccharide vaccine (PPSV23) for adults ≥19 years with select medical conditions, and in August 2014, for all adults ≥65 years. We evaluated the direct and indirect effects of PCV13 6 years post-introduction on invasive pneumococcal disease (IPD).

Methods

IPD cases (isolation of pneumococcus from sterile sites) were identified among residents of Active Bacterial Core surveillance (ABCs) sites during July 2007–June 2016. Isolates were serotyped by Quellung, PCR, or whole genome sequencing and classified as PCV13 or non-vaccine type (NVT). Incidence changes were estimated as percent changes (one minus rate ratio) and 95% confidence intervals (95% CI) between pre-PCV13 (2007–2009) and two post-PCV13 periods (July 2014–June 2015 and July 2015–June 2016).

Results

ABCs identified 31,190 IPD cases between 2007 and 2015, with 2,750 cases among children <5 years and 10,930 among those ≥65 years. During the two post-PCV13 periods, overall IPD rates were 33%-62% lower relative to 2007–2009 among all age groups, including <5 years and ≥65 years (Figure). Significant reductions in PCV13-type IPD incidence were observed for all age groups during both post-PCV13 periods, with incidence 84% (q95% CI 78, 88%) and 68% (95% CI 63, 73%) lower in 2015–2016 among children < 5 years and adults ≥65 years, respectively. PCV13-type IPD reductions were driven by serotypes 19A and 7F. IPD due to non-vaccine types also declined significantly among children < 5 years (−27%, 95% CI –42, –9%) and adults ≥65 years (-24%, 95% CI –34, –14%). PCV13-type IPD incidence did not differ significantly between the two post-PCV13 periods.

Conclusion

IPD incidence declined among children and adults in the U.S. following PCV13 introduction among children. The lack of difference in PCV13 rates between 2014–2015 and 2015–2016 suggests no measurable early impact of PCV13 introduction among adults ≥65 years. To date, we found no evidence of significant replacement disease with non-PCV13 types. Further work is needed to explain reductions in non-vaccine type disease observed in the post-PCV13 era.

Disclosures

W. Schaffner, Pfizer: Scientific Advisor, Consulting fee; Merck: Scientific Advisor, Consulting fee; Novavax: Consultant, Consulting fee; Dynavax: Consultant, Consulting fee; Sanofi-pasteur: Consultant, Consulting fee; GSK: Consultant, Consulting fee; Seqirus: Consultant, Consulting fee; L. Harrison, GSK: Scientific Advisor, Consulting fee

Abstract TMP65: Depth of Hospital Participation in Telestroke is Associated with Faster Door-to-Needle Time for Stroke Patients

Background: Telestroke increases tPA use at spoke hospitals, yet its effect on door-to-needle (DTN) times is unknown. More frequent use of telestroke may introduce delays in DTN time or may improve it as practice leads to streamlined processes.

Hypothesis: We hypothesize that spoke hospitals with more frequent contact to a hub hospital will have shorter DTN times than those with less frequent contact.

Methods: We identified 367 patients treated with tPA by conventional or telestroke methods in the MGH Telestroke network for whom date and time data were available. Strength of the spoke-MGH connection was the primary predictor variable, defined as the number of all telestroke consults (tPA and non-tPA) done at each spoke hospital during the year of the patient’s presentation. Patient-level regression analyses examined the relationship between DTN time and spoke-MGH connection. We controlled for hospitals’ tPA volume, temporal trends, and clustering within hospitals.

Results: Sixteen spoke hospitals contributed data on 367 tPA-treated patients from 2006-2016. Hospitals treated a median of 12.5 patients with tPA (IQR 7-33.5). Median hospital-level DTN was 78.8 minutes (IQR 71.3-85). Median number of telestroke consults per year was 37 (IQR 15-60). Among all 367 patients, median DTN was 76 minutes (IQR 61-98), and 24.8% of patients were treated within 60 minutes (n=91). Strength of connection between the spoke and hub hospital was significantly associated with faster DTN time for patients (1.8 minute gain per 10 additional consults, p<0.001) and increased likelihood of tPA delivery within 60 minutes (OR 1.01, p<0.001).

Conclusion: More frequent contact between a telestroke spoke and its hub was associated with faster tPA delivery for patients, even after accounting for hospitals’ tPA volume and secular trends in DTN improvements. This highlights added benefits of increased utilization of telestroke.

Use of surveillance data to estimate the effectiveness of the 7-valent conjugate pneumococcal vaccine in children less than 5 years of age over a 9 year period

BACKGROUND

Case-control studies evaluating post-licensure effectiveness of conjugate vaccines can be laborious and costly. We applied an indirect cohort method to evaluate the effectiveness of seven-valent pneumococcal conjugate vaccine (PCV7) against invasive pneumococcal disease (IPD) and compared the results to the effectiveness measured using a standard case-control study conducted during the same time period.

METHODS

IPD cases among children 2-59 months old were identified through the Active Bacterial Core surveillance system during 2001-2009. We used logistic regression to calculate the odds ratio of vaccination (versus no vaccination) among cases (PCV7-type IPD cases) and non-cases (non-PCV7-type IPD cases), controlling for the presence of underlying conditions. Vaccine effectiveness (VE) was calculated as one minus the adjusted odds ratio.

RESULTS

Among 4225 IPD cases reported during 2001-2009, 2680 (63%) had serotype information and vaccine history. Effectiveness of ≥ 1 dose of PCV7 against PCV7-types was 88% (95% confidence interval (CI) 78-94%) among children with comorbid conditions and 97% (95% CI 92-98%) among healthy children. Among healthy children, VE was higher in 2001-2003 (97%, 95% CI 95-98%) compared to 2004-2009 (81%, 95% CI 64-90%). The annual estimates of VE in 2004-2009 showed great variability and wide confidence intervals due to the small number of PCV7-type cases.

CONCLUSIONS

An indirect cohort design using IPD surveillance data confirms the findings of the case-control study and, therefore, appears suitable for estimating PCV7 effectiveness. This method would be most useful shortly after vaccine introduction, and less useful in a setting of very high vaccine coverage and fewer vaccine-type cases.

Hemisphere-specific effects in word recognition do not require hemisphere-specific modes of access

Consistent with converging experimental evidence, we assume that foveal information is initially split across the two cerebral hemispheres. We have previously presented the SERIOL model of letter-position coding, which specifies how the resulting two halves of a letter string are integrated into an abstract representation of letter order. This representation is based on ordered pairs of two letters (bigrams); such a representation is created for input occurring at any location in the visual field. Various studies have shown hemisphere-specific effects in lexical access by using unilateral presentation of stimuli. While the hemisphere-independent means of lexical access in the SERIOL model (via bigrams) may seem inconsistent with these findings, we propose that such effects arise from the hemisphere-specific transformations necessary to create the bigram representation. We provide a theoretical account of the finding that high N (lexical neighborhood size) evokes facilitation in the RH, but not the LH (Lavidor & Ellis, 2002a, 2002b); an experiment discussed elsewhere (Whitney & Lavidor, 2003) has verified key predictions of this account. We also discuss the differing effects of word length across visual fields.

Chronic lymphocytic leukemia presenting with symptomatic central nervous system involvement

Leukemic infiltration of the central nervous system (CNS) resulting in neurological manifestations is a rare complication of chronic lymphocytic leukemia (CLL). Furthermore, symptomatic CNS involvement as the initial presentation of previously undiagnosed CLL is extremely rare. In the present report, the authors describe a case of an 89-year-old female previously diagnosed with Alzheimer's disease who suddenly developed rapidly worsening mental changes. Cytological and immunocytological examinations of the lymphoid cells present on the cerebrospinal fluid (CSF) revealed CNS involvement by a clonal B-cell lymphoproliferative disorder, most consistent with de novo B-CLL expressing kappa light chain restriction. Subsequently, flow cytometric analysis done on the peripheral blood lymphocytes confirmed the diagnosis of B-CLL in this patient. Thus, this study shows the potential usefulness of immunocytological evaluation in detecting monoclonal lymphoid populations on CSF samples in adult patients presenting with altered mental status and CSF pleocytosis of lymphocytes.

Pulmonary eosinophilia in a murine model of allergic inflammation is attenuated by small molecule alpha4beta1 antagonists

Inhibition of alpha4beta1/vascular cell adhesion molecule-1 (VCAM-1) interactions have therapeutic potential in treating allergic airway disease because of the importance of these adhesion molecules in the trafficking of eosinophils, lymphocytes, and monocytes. We examined several small molecule inhibitors of alpha4beta1/VCAM-1 interactions with in vitro potencies (IC(50) values) ranging from 0.52 nM (CP-664511; 3-[3-(1-[2-[3-methoxy-4-(3-O-tolyl-ureido)phenyl]-acetylamino]-3-methyl-butyl)isoxazol-5-yl]-propionic acid) to 38.5 nM (CP-609643; 3-[3-methyl-1-[2-[4-(3-O-tolyl-ureido)-phenyl]-acetylamino]-butyl)-isoxazol-5-yl]-propionic acid). The same compounds were evaluated in vivo using a murine model of ovalbumin-induced pulmonary eosinophilia. In this model, systemic administration of antibodies against alpha4 reduced bronchoalveolar lavage (BAL) eosinophilia approximately 60%. Small molecule alpha4beta1 antagonists were administered by intratracheal instillation and demonstrated dose-dependent inhibition of BAL eosinophil numbers and achieved a maximum inhibition of approximately 60%. In general, the rank order of potency for these compounds in vitro was consistent with that observed in vivo, which confirms that their efficacy is likely via blockade of alpha4beta1/VCAM-1 interactions. The most potent compound, CP-664511, also inhibited BAL eosinophilia following s.c. administration (1-10 mg/kg, s.c.). These data support the utility of small molecule alpha4beta1 antagonists in the treatment of relevant diseases, such as asthma.

Simultaneously detected endometrial and ovarian carcinomas--a prospective clinicopathologic study of 74 cases: a gynecologic oncology group study

OBJECTIVES

The coexistence of carcinomas of the endometrium and ovary occurs in about 10% of women with ovarian carcinoma. It is often unclear whether this represents synchronous primary tumors or metastasis from endometrium to ovary, or from ovary to endometrium; consequently, staging, therapy, and expected outcome are uncertain. The Gynecologic Oncology Group sought to study patients with simultaneously detected adenocarcinomas in the endometrium and ovary with disease grossly confined to the pelvis to explore the possible correlation among discrete tumor subsets, natural history, and survival.

METHODS

Between 1985 and 1991, 85 patients were prospectively enrolled, of whom 74 were eligible. All were initially treated with total abdominal hysterectomy, bilateral salpingo-oophorectomy, and staging laparotomy, with radiation and chemotherapy left to the discretion of the treating physician and patient. Fifteen pathologic variables were examined to identify differences in tumor behavior.

RESULTS

Of the 74 patients, 23 (31%) had microscopic spread of tumor in the pelvis or abdomen. Sixty-four (86%) patients had endometrioid carcinomas in both the endometrium and the ovary, and endometriosis was found in the ovary of 23 (31%) patients. There was concordance between the histologic grade of the tumor in the ovary and the uterus in 51 (69%) patients. The estimated probability of recurrence 5 years following staging surgery is 15.1% (95% confidence interval (CI): 8.7-25.2%). The presence of metastasis discriminated two groups of patients that experienced different probabilities of recurrence within 5 years: 10.0% (95% CI: 4.32-21.3%) for those with tumors confined to the uterus and ovary and 27.1% (95% CI: 13.0-48.5%) for those with metastasis (hazard ratio = 4.6, P = 0.006). The histologic grades of ovarian and uterine tumors also distinguished groups of patients with different probabilities of recurrence at 5 years: 8.0% (95% CI: 2.8-21.3%) for those patients with no more than grade 1 disease at either site and 22.4% (95% CI: 11.8-38.4%) for those with a higher grade in either the ovary or the endometrium (hazard ratio = 3.1, P = 0.047). The estimated overall probability of surviving 5 years is 85.9% and that of surviving 10 years is 80.3%.

CONCLUSION

The prognosis for women with simultaneously detected carcinomas in the uterus and ovary with gross disease confined to the pelvis is surprisingly good, particularly for those with disease microscopically limited to the uterus and ovary or of low histologic grade.

How the brain encodes the order of letters in a printed word: the SERIOL model and selective literature review

This paper describes a novel theoretical framework of how the position of a letter within a string is encoded, the SERIOL model (sequential encoding regulated by inputs to oscillations within letter units). Letter order is represented by a temporal activation pattern across letter units, as is consistent with current theories of information coding based on the precise timing of neural spikes. The framework specifies how this pattern is invoked via an activation gradient that interacts with subthreshold oscillations and how it is decoded via contextual units that activate word units. Using mathematical modeling, this theoretical framework is shown to account for the experimental data from a wide variety of string-processing studies, including hemispheric asymmetries, the optimal viewing position, and positional priming effects.

Impact of penicillin susceptibility on medical outcomes for adult patients with bacteremic pneumococcal pneumonia

The impact of penicillin susceptibility on medical outcomes for adult patients with bacteremic pneumococcal pneumonia was evaluated in a retrospective cohort study conducted during population-based surveillance for invasive pneumococcal disease in the greater Atlanta region during 1994. Of the 192 study patients, 44 (23%) were infected with pneumococcal strains that demonstrated some degree of penicillin nonsusceptibility. Compared with patients infected with penicillin-susceptible pneumococcal strains, patients whose isolates were nonsusceptible had a significantly greater risk of in-hospital death due to pneumonia (relative risk [RR], 2.1; 95% confidence interval [CI], 1-4.3) and suppurative complications of infection (RR, 4.5; 95% CI, 1-19.3), although only risk of suppurative complications remained statistically significant after adjustment for baseline differences in severity of illness. Among adults with bacteremic pneumococcal pneumonia, infection with penicillin-nonsusceptible pneumococci is associated with an increased risk of adverse outcome.

Dexamethasone but not indomethacin inhibits human phagocyte nicotinamide adenine dinucleotide phosphate oxidase activity by down-regulating expression of genes encoding oxidase components

We investigated the effects of dexamethasone or indomethacin on the NADPH oxidase activity, cytochrome b558 content, and expression of genes encoding the components gp91-phox and p47-phox of the NADPH oxidase system in the human monocytic THP-1 cell line, differentiated with IFN-gamma and TNF-alpha, alone or in combination, for up to 7 days. IFN-gamma and TNF-alpha, alone or in combination, caused a significant up-regulation of the NADPH oxidase system as reflected by an enhancement of the PMA-stimulated superoxide release, cytochrome b558 content, and expression of gp91-phox and p47-phox genes on both days 2 and 7 of cell culture. Noteworthy was the tremendous synergism between IFN-gamma and TNF-alpha for all studied parameters. Dexamethasone down-regulated the NADPH oxidase system of cytokine-differentiated THP-1 cells as assessed by an inhibition on the PMA-stimulated superoxide release, cytochrome b558 content, and expression of the gp91-phox and p47-phox genes. The nuclear run-on assays indicated that dexamethasone down-regulated the NADPH oxidase system at least in part by inhibiting the transcription of gp91-phox and p47-phox genes. Indomethacin inhibited only the PMA-stimulated superoxide release of THP-1 cells differentiated with IFN-gamma and TNF-alpha during 7 days. None of the other parameters was affected by indomethacin. We conclude that dexamethasone down-regulates the NADPH oxidase system at least in part by inhibiting the expression of genes encoding the gp91-phox and p47-phox components of the NADPH oxidase system.

The incentive effects of malpractice liability rules on dental practice behavior

OBJECTIVES

The impact of malpractice liability rules on dental practice behavior was estimated using data from a 1992 nationwide survey of US general dentists. The study examined the premise that malpractice liability rules can affect quality of care and related resource allocation decisions by dentists, but that market features, such as relatively complete and "non-experience rated" malpractice insurance, are likely to weaken the incentive effects of malpractice liability.

METHODS

General practice dentists in the United States were selected randomly, and 3,048 dentists were studied by mail survey. Secondary data on county-level characteristics were used to measure market area factors. Quality-of-care measures were derived from the survey about self-reported practice policies and behavior and participation in continuing education. Legal measures were assembled from state statutes and appellate court decisions. Ordinary least squares was used to assess the relation between legal variables and dependent variables of quality of care, continuing education, and the rate of dental output.

RESULTS

Hypotheses about the effects of malpractice law on practice quality and participation in continuing education were not supported. The relation between pro-dentist law and output was supported. A number of legal provisions related to differences in practice behavior, but often in ways opposite to the expected direction.

CONCLUSIONS

The direct effects of specific malpractice liability rules on dentist practice behavior often failed to point in the direction predicted by theory and were economically insignificant. It is possible that relatively complete malpractice liability insurance, coupled with "noisy" liability rules, substantially dulls the deterrent effect of malpractice liability. Other forces, such as the dentist's past malpractice claims experience, were more significant in shaping dentist behavior.

A computational model of acute focal cortical lesions

BACKGROUND AND PURPOSE

Determining how cerebral cortex adapts to sudden focal damage is important for gaining a better understanding of stroke. In this study we used a computational model to examine the hypothesis that cortical map reorganization after a simulated infarct is critically dependent on perilesion excitability and to identify factors that influence the extent of poststroke reorganization.

METHODS

A previously reported artificial neural network model of primary sensorimotor cortex, controlling a simulated arm, was subjected to acute focal damage. The perilesion excitability and cortical map reorganization were measured over time and compared.

RESULTS

Simulated lesions to cortical regions with increased perilesion excitability were associated with a remapping of the lesioned area into the immediate perilesion cortex, where responsiveness increased with time. In contrast, when lesions caused a perilesion zone of decreased activity to appear, this zone enlarged and intensified with time, with loss of the perilesion map. Increasing the assumed extent of intracortical connections produced a wider perilesion zone of inactivity. These effects were independent of lesion size.

CONCLUSIONS

These simulation results suggest that functional cortical reorganization after an ischemic stroke is a two-phase process in which perilesion excitability plays a critical role.

Refusal of food and water by a man with end stage Parkinson's disease

In the future, we need to consider the social and financial implications of allowing someone to remain in an acute care hospital for comfort care until death. Other acceptable options for the non-terminal but, severely disabled patients must be identified so that we are able to respect and honor our patients' autonomous decisions without using the increasingly scarce health care resources. While not all ethical dilemmas of this nature will be resolved in such a relatively uncomplicated manner, this situation does provide us with a foundation from which to approach future cases. We have learned to listen closely to our patients; we have learned the importance of understanding who our patients were and who they are now; we have learned from Mr. K's strength to express his convictions.

Frustrating patient visits

OBJECTIVES

This study, part of a national mail survey of dentist malpractice liability claims, reports the reliability and validity of a new 22-item instrument measuring frustrating patient visits.

METHODS

The items were subjected to factor analysis and subscales constructed. Reliability was assessed using Cronbach's alpha. Validity was assessed by comparing subscale scores to self-reports of satisfaction and liability claims.

RESULTS

Factor analysis revealed four subscales representing unpleasant feelings, lack of communication, compliance, and practice organization (alpha = 0.60-0.86). Compliance was the most important factor. Subscale scores were related to satisfaction with practice and the proportion of patient visits in the practice that were frustrating to the dentist. Dentists who reported frustrating patient visits as quite typical of their practices were more likely to have had a malpractice liability claim within the last five years.

CONCLUSION

This instrument may be of value in detecting patient-dentist communication difficulties that are the precursor to liability claims.

Do changes in patient beliefs and coping strategies predict temporomandibular disorder treatment outcomes?

OBJECTIVE

This study examined the applicability of the cognitive-behavioral model for temporomandibular disorders (TMD) by determining whether changes in TMD patient pain-related beliefs and coping over the course of treatment related to improvement in symptoms and disability and whether patients' posttreatment beliefs and coping predicted future pain and functioning.

PATIENTS/SETTING

We studied 139 TMD patients at a health maintenance organization or a university dental school who completed a clinical trial comparing usual treatment with or without a brief cognitive-behavioral intervention. OUTCOME MEASURES/DESIGN: Pain, disability, depression, objective physical impairment, and pain beliefs and coping strategies were assessed pretreatment and at 3- and 12-month follow-ups.

RESULTS

Increased ability to control pain and decreased Disease Conviction and Passive Coping scores were associated with improved pain, jaw opening, and depression from pretreatment to 3-month follow-up. Patient beliefs and coping at 3-month follow-up did not contribute much to the prediction of pain or physical and psychological functioning at 12-month follow-up after controlling for 3-month pain and functioning scores. However, passive coping and low ability to control pain at 3 months predicted greater activity interference at 12 months.

CONCLUSIONS

Pretreatment to 3-month follow-up changes in beliefs and coping are associated modestly with TMD patient improvement after conservative dental treatment with and without a brief cognitive-behavioral intervention. Research is needed to develop interventions that produce greater decreases in disease conviction, passive coping, and perceived inability to control pain and to determine whether these changes mediate symptom and disability improvement.

Tort reform and malpractice liability insurance

Legal factors related to the malpractice liability insurance purchased by general dentists in the United States were investigated using a comprehensive multivariate model that assessed the contribution of legal provisions affecting the probability of a malpractice claim, the probability of a payment, and the average size of the payment. General practice dentists in the United States were selected randomly, and 3,048 dentists were studied by mail survey. A number of legal statutes (periodic payment allowed, percentage fault liability informed consent limits, limits on res ipsa loquitor, attorney fee control, some statute of limitations provisions) had the intended effect of reducing the malpractice insurance sought by dentists. Other provisions, such as binding arbitration, may have unintended cost-raising effects. Previous malpractice claims were associated with purchasing greater amounts of insurance. These findings have implications for future changes in the legal system as part of health care reform.

Malpractice premiums in 1992: results of a national survey of dentists

According to a 1992 national survey, more than 95 percent of general dentists in the United States purchased malpractice insurance. The authors evaluated the survey findings to identify factors that had the greatest effect on dentists' insurance premium costs. Premiums were higher for dentists who had been the subject of previous complaints or claims, as well as for those who owned their practices. States with fewer lawyers had lower premiums. Finally, state limits on use of dental hygienists, number of offices and the extent of water fluoridation also affected premium levels.

Survival after retinoblastoma: long-term consequences and family history of cancer

Retinoblastoma (Rb) is a rare childhood tumor of the eye. In the heritable form, tumors are often bilateral and survivors have a greatly increased risk both for a second malignancy and for having children with Rb. Familial patterns of both cancer and birth defects are poorly understood in families with a heritable cancer, and little is known of the ways that a heritable cancer affects the lives of long-term survivors. To find out more about these and other issues in the lives of long-term survivors of childhood and adolescent cancer, we interviewed 56 adult survivors of retinoblastoma (15 with the heritable form) and 84 brothers and sisters as controls, who formed part of a large retrospective cohort study. Rb survivors were interviewed between 1980 and 1983, when they were 30 years old on average. Types of employment and health problems did not differ between survivors and controls, regardless of sight, but the income of blind survivors was considerably less than that of partially sighted survivors. Despite similar marriage rates, fewer survivors than controls reported a pregnancy (RR = 0.45; 95% CI; 0.24-0.83 for both sexes combined). Parents of children with heritable Rb seemed more likely to have had cancer than parents in families with nonheritable Rb (P = 0.06), and mothers were more likely than fathers to be affected (P = 0.01). This small series suggests that having retinoblastoma may have many long-term consequences, reaching beyond genetic and physical effects to touch family life and income attainment and the health of other family members. Follow-up of more modern cohorts and the use of molecular tools will clarify the long-term consequences of more recent therapies, and patterns of familiar cancer.