Increased diagnostic yield from negative whole genome-slice panels using automated reanalysis

We evaluated the diagnostic yield using genome-slice panel reanalysis in the clinical setting using an automated phenotype/gene ranking system. We analyzed whole genome sequencing (WGS) data produced from clinically ordered panels built as bioinformatic slices for 16 clinically diverse, undiagnosed cases referred to the Pediatric Mendelian Genomics Research Center, an NHGRI-funded GREGoR Consortium site. Genome-wide reanalysis was performed using Moon™, a machine-learning-based tool for variant prioritization. In five out of 16 cases, we discovered a potentially clinically significant variant. In four of these cases, the variant was found in a gene not included in the original panel due to phenotypic expansion of a disorder or incomplete initial phenotyping of the patient. In the fifth case, the gene containing the variant was included in the original panel, but being a complex structural rearrangement with intronic breakpoints outside the clinically analyzed regions, it was not initially identified. Automated genome-wide reanalysis of clinical WGS data generated during targeted panels testing yielded a 25% increase in diagnostic findings and a possibly clinically relevant finding in one additional case, underscoring the added value of analyses versus those routinely performed in the clinical setting.

Work-related injuries and attendance at a Canadian regional emergency department

BACKGROUND

Monitoring trends in the burden of illness and injury attributable to work is key in assessing occupational health hazards; however, New Brunswick does not participate in the Canadian National Ambulatory Care Reporting System which itself does not collect details of occupation and industry.

AIMS

We set out to determine the proportion of emergency department attendances that were attributable to a work-related cause. We also wanted to evaluate the recording of occupation in the electronic health record system, and to describe the characteristics of patients with a work-related presentation.

METHODS

A retrospective observational study over a 1-year period was conducted using an administrative database obtained from Canadian Emergency Department Information System. Descriptive statistics are used to present the analysis of categorical and continuous data.

RESULTS

A total of 49 365 patients were included for analysis. Two per cent of patients presented with a self-reported work-related condition. Health care and social assistance, construction, retail trade and manufacturing were the most common industries reported by patients.

CONCLUSIONS

This study found the rate of work-related medical conditions to be substantially less than expected, and that occupation was not captured for any patients presenting to the emergency department with a work-related condition, despite a field being available in the electronic health record registration system. We were able to analyse the industry sectors for work-related presentations. The recording and coding of occupation and industry would significantly benefit occupational epidemiology in emergency medicine as well as potentially improving patient outcomes and health system efficiencies.

Does point-of-care ultrasonography improve diagnostic accuracy in emergency department patients with undifferentiated hypotension? An international randomized controlled trial from the SHOC-ED investigators

PURPOSE

Point-of-care ultrasonography (POCUS) is an established tool in the management of hypotensive patients in the emergency department (ED). We compared the diagnostic accuracy of a POCUS protocol versus standard assessment without POCUS in patients with undifferentiated hypotension.

METHODS

This was an international, multicenter randomized controlled trial included three EDs in North America and three in South Africa from September 2012 to December 2016. Hypotensive patients were randomized to early POCUS protocol plus standard care (POCUS group) or standard care without POCUS (control group). Initial and secondary diagnoses were recorded at 0 and 60 min. The main outcome was measures of diagnostic accuracy of a POCUS protocol in differentiating between cardiogenic and non-cardiogenic shock. Secondary outcomes were diagnostic performance for shock sub-types, as well as changes in perceived category of shock and overall diagnosis.

RESULTS

Follow-up was completed for 270 of 273 patients. For cardiogenic shock, the POCUS-based diagnostic approach (POCUS) performed similarly to the non-POCUS approach (control) for specificity [95.5% (89.9-98.5) vs.93.8% (87.7-97.5)]; positive likelihood ratio (17.92 vs 14.80); negative likelihood ratio (0.21 vs 0.09) and diagnostic odds ratio (85.6 vs 166.57), with a similar overall diagnostic accuracy between the two approaches [93.7% (88-97.2) vs 93.6% (87.8-97.2)]. Diagnostic performance measures were similar across sub-categories of shock.

CONCLUSION

This is the first randomized controlled trial to compare diagnostic performance of a POCUS protocol to standard care without POCUS in undifferentiated hypotensive ED patients. POCUS performed well diagnostically in undifferentiated hypotensive patients, especially as a rule-in test; however, performance did not differ meaningfully from standard assessment.

5 Rifaximin prophylaxis against travellers’ diarrhoea does nor increase acquisition of extended-spectrum ß – lactamase producing enterobacteriaceae (ESBL-E) in a UK military population travelling to Kenya

Background

Travellers’ Diarrhoea (TD) is a significant issue for deployed troops. Antibiotic prophylaxis can be effective but raises antimicrobial resistance (AMR) concerns. PREVENT TD study, was a double-blind, randomised, placebo-controlled trial comparing once- and twice-daily rifaximin 550mg against placebo (ClinicalTrials.gov: NCT02498301). Rifaximin showed a protective effect (0.05 vs 0.36/100 person days, p= 0.025 vs placebo) against incident TD. Here we present our results on the acquisition of ESBL-E in PREVENT TD participants.

Methods

Enrolled UK subjects deployed to Kenya for 6-week periods. 121 participants provided stool samples upon arrival and prior to departure.

Approximately 100mg of stool was incubated in Luria Broth with cefotaxime (10 μg/ml) at 37°C overnight. Cultures were then spread onto ESBL Chromoselect agar and incubated again overnight. Growth was taken as positive for ESBL-E bacteria. The two rifaximin intervention arms were compared to placebo using Fisher’s exact test.

Bioinformatic analysis has been performed using Parsnp, MLST and Abricate programs.

Results

84/121 (69.4%) subjects had no ESBL-E present on arrival in Kenya. The highest incidence of ESBL acquisition was observed in subjects randomised to the placebo arm; however, the differences were not statistically significant (table in presentation).

In the cohorts colonised with ESBL-E at the start of the study, there was a non-statistically significant reduction in the ESBL-E rates with those taking rifaximin prophylaxis.

Genome sequencing showed a number of ESBL-E E. coli are genetically very similar suggesting a source in Kenya.

Conclusions

While ESBL acquisition rate was relatively high (26.5%), rifaximin was not associated with an increase in ESBL acquisition. Further work will be performed to investigate acquisition of rifaximin resistance among commensal Enterobacteriaceae during the trial.

Further Bioinformatic work is ongoing looking at acquisition of resistance genes.

Psychometric outcome measures in beta-propeller protein-associated neurodegeneration (BPAN)

BACKGROUND

Beta-propeller protein-associated neurodegeneration (BPAN) is a rare neurodegenerative disorder characterized by iron accumulation in the brain with spectrum of neurodevelopmental and movement phenotypes. In anticipation of future clinical trials and to inform clinical care, there is an unmet need to capture the phenotypic diversity of this rare disorder and better define disease subtypes.

METHODS

A total of 27 individuals with BPAN were included in our natural history study, from which traditional outcome measures were obtained in 18 subjects. Demographic and diagnostic information, along with acquisition of basic developmental skills and overall neurologic severity were extracted from the medical records. Functional outcome measures were administered at the time of the evaluation or applied retrospectively at the last clinical encounter for patients who were not able to travel for in person. Based on age and functional level, the following assessments were administered: Leiter-3, Gross Motor Function Measure (GMFM)-66 Item Sets, Vineland-3, and Peabody-2.

RESULTS

Overall, cognitive function was more impaired compared to gross motor function. Onset of symptoms of BPAN within the first 6 months of life was associated with decreased gain of ambulation and gain of spoken language (ambulation: log-rank test p = 0.0015; gain of first word: p = 0.0015). There was no difference in age at seizure onset by age at initial symptom onset (p = 0.8823). Collection of prospective outcome measures was limited by attention and behavior in our patient population, reinforcing the complexity of phenotype assessment and inadequacy of available standardized tests. Overall, gross motor and adaptive behavior assessments were better able to capture the dynamic range of function across the BPAN population than the fine motor and non-verbal cognitive tests. Floor effects were noted across outcome measures in a subset of individuals for cognitive and adaptive behavior tests.

CONCLUSION

Our data suggest the distinct phenotypes of BPAN: a severe, early onset form and an attenuated form with higher cognitive capabilities. Early age at onset was a key factor in predicting future neurologic impairment.

Extracorporeal membrane oxygenation during pregnancy and peripartal. An international retrospective multicenter study

INTRODUCTION

Extracorporeal Membrane Oxygenation (ECMO) may be used in the setting of pregnancy or the peripartal period, however its utility has not been well-characterized. This study aims to give an overview on the prevalence of peripartel ECMO cases and further assess the indications and outcomes of ECMO in this setting across multiple centers and countries.

METHODS

A retrospective, multicenter, international cohort study of pregnant and peripartum ECMO cases was performed. Data were collected from six ECMO centers across three continents over a 10-year period.

RESULTS

A total of 60 pregnany/peripartal ECMO cases have been identified. Most frequent indications are acute respiratory distress syndrome (n = 30) and pulmonary embolism (n = 5). Veno-venous ECMO mode was applied more often (77%). ECMO treatment during pregnancy was performed in 17 cases. Maternal and fetal survival was high with 87% (n = 52), respectively 73% (n = 44).

CONCLUSIONS

Various emergency scenarios during pregnancy and at time of delivery may require ECMO treatment. Peripartal mortality in a well-resourced setting is rare, however emergencies in the labor room occur and knowledge of available rescue therapy is essential to improve outcome. Obstetricians and obstetric anesthesiologists should be aware of the availability of ECMO resource at their hospital or region to ensure immediate contact when needed.

Delayed diagnosis and racial bias in children with genetic conditions

As more therapeutics for genetic conditions become available, the need for timely and equitable genetic diagnosis has become urgent. Using clinical cases, we consider the health system-, provider-, and patient-level factors that contribute to the delayed diagnosis of genetic conditions in pediatric patients from minority populations, leading to health disparities between racial groups. We then provide suggestions to address these factors, with the aim of improving minority health and access to genetic care for all children.

726. Operational Impact of Infectious Disease Threats During Military Travel

Background

We evaluated the incidence and operational impact of travelers’ diarrhea (TD), influenza-like illness (ILI) and undifferentiated febrile illness (FI) in US active duty (AD) personnel traveling outside the continental U.S for deployment (DEP), joint military training exercises (EXR) or other military travel (e.g. Temporary Duty Travel) (TDY).

Methods

AD personnel traveling for ≤ 6.5 months were prospectively enrolled between 2010-2019. Participants completed a post-travel survey regarding risk behaviors, illnesses and impact on daily activities. Trip purpose was categorized into DEP, EXR, TDY and syndromic definitions were used to identify cases of TD, ILI and FI based on symptoms. A multivariate logistic regression model with backward selection was used to determine the odds ratio associated with partial or complete incapacitation due to infections (a composite endpoint of either TD, ILI or FI).

Results

1822 servicemembers were enrolled: 36.2% traveled on DEP, 36.2% for EXR and 27.7% for TDY (Table 1). 83.5% of personnel traveling for DEP were Special Operations and Marine units, and 82% of the EXR group participated in Pacific Pathways. Overall, 19% of US personnel experienced infections associated with partial or complete incapacitation (median duration of incapacitation- TD: 1 day; ILI: 4 days; FI: 3 days). DEP personnel had a longer travel duration and the highest rate of partial or complete incapacitation due to TD, ILI or FI (Figure 1 and 2). Risk factors associated with partial or complete incapacitation due to infections were non-adherence with malaria chemoprophylaxis (OR: 1.7 [95%CI:1.2-2.4]), close contact with locals (OR:1.7 [95%CI:1.3-2.2]), inability to clean hands regularly before meals (OR: 1.7 [95%CI: 1.3-2.3]), fresh water or rodent exposure OR: 1.4 (95%CI:1.1-1.9) and consuming street vendor food (OR:1.8 [95%CI:1.3-2.4]).

Table 1. Demographic and travel characteristics of AD personnel traveling outside the continental US.

Proportion of AD servicemembers that experienced TD, ILI or undifferentiated febrile illness during DEP, EXR, TDY (p<0.05 for the comparison of each illness between DEP, EXR and TDY).

Figure 2.

Proportion of AD personnel with partial or complete incapacitation due to TD, ILI or FI during DEP, EXR or TDY (p < 0.05 for the comparison of each illness between DEP, EXR and TDY).

Conclusion

Infectious disease syndromes are common during overseas military travel. TD had the highest negative impact on military travel especially among DEP personnel. We identified several modifiable risk factors associated with incapacitating infections which can be used to inform preventive and treatment strategies.

Disclosures

All Authors: No reported disclosures

1342. TOSCANA: The Observational Seroepidemiologic Study of COVID-19 at the United States Naval Academy

Background

University students, including those at military service academies, are at increased risk of acute respiratory infection (ARI), including SAR-CoV-2, due to crowded living conditions, frequent social interaction and other factors that facilitate pathogen transmission. Unlike many universities, the United States Naval Academy (USNA) continued in-person instruction in Fall 2020 in the midst of the COVID-19 pandemic. The Observational Seroepidemiologic Study of COVID-19 at the United States Naval Academy (TOSCANA,) a longitudinal cohort characterizes the burden and risk factors of SARS-CoV-2 in USNA midshipmen.

Methods

Midshipmen were enrolled August- October 2020. Participants were queried about their ARI risk factors, COVID-19 history, and recent receipt of medical care for any ARI at enrollment, in December 2020 and again in May 2021. Subjects were also asked to provide blood and saliva samples to assess their SARS-CoV-2 serostatus at the same three timepoints. A saliva sample was collected by a subset of subjects in February 2021. Presence of anti-SARS-CoV-2 serum IgG in dried blood spots and saliva was measured by multiplex magnetic microparticle-based immunoassays.

Results

181 midshipmen consented to the study and completed the baseline survey (Table 1). 17 (17.5%) of the 97 subjects who submitted baseline blood sample were SARS-CoV-2 seropositive. Only 4 (24%) positive individuals reported having been tested for or diagnosed with COVID-19 prior to arrival at USNA. 121 participants completed the midyear survey, of whom 61 (50%) submitted a blood sample. 16 (26%) of the midyear specimens were SARS-CoV-2 positive. Of these, 3 were new infections. 73 subjects completed the May survey, and 63 (100%) of the submitted blood samples were positive. 83 subjects provided baseline saliva samples, and ~55 submitted saliva at each successive time point. 1 (5%) was positive at enrollment, 9 (17%) were positive at midyear and 47 (96%) were positive in May.

Conclusion

SAR-CoV-2 prevalence in a sample of USNA midshipmen was &lt; 20% at enrollment. A small proportion of subjects seroconverted between the September and December visits. SARS-CoV-2 positivity rose in May, following a COVID-19 outbreak in February and COVID-19 vaccination efforts in March at USNA.

Disclosures

Jitu Modi, MD, GSK (Speaker’s Bureau)

735. Malaria Chemoprophylaxis Adherence Among U.S. Active Duty Service Members during Deployment to Endemic Regions

Background

Military members frequently deploy to malaria-endemic regions. Most cases of travel-related malaria occur due to prophylaxis non-adherence, impacting mission readiness. Factors assessing adherence are described in outbreak settings; we prospectively assess adherence in military travelers.

Methods

TravMil is a prospective, observational cohort study of US military beneficiaries traveling outside the US (2010-2019). Our analysis includes only active-duty service members traveling with a military purpose to malaria-endemic regions, who were prescribed malaria prophylaxis, and who completed a pre- and post-deployment survey; they could also enroll after return from deployment. All travelers received pre-travel counseling. Survey responses were assessed using descriptive statistics and multivariate regression to determine risk factors for adherence.

Results

1504 travelers were included (85% male; median age 28 years; 73% white). Median duration of travel was 77 days (12% traveled ≤ 14 days). Africa was the most common destination (33%). Primary prophylaxis included doxycycline (54%) and atovaquone/proguanil (43%). 969 (64%) were fully adherent to their regimen. The frequency of prophylaxis did not match expected values, as 3.6% of subjects reported taking prophylaxis weekly, and 2.9% did not know how often they took it. 103 (6.9%) did not take any of the prescribed regimen. On multivariate analysis, deployers were more likely to adhere if they traveled for ≤ 14 days or to Africa or practiced other mosquito-avoidance behaviors. Study enrollment post-deployment was associated with decreased odds of adherence, as was use of a tent. The use of daily versus weekly prophylaxis was not associated with a difference in adherence, though we had limited subjects prescribed weekly regimens.

Figure 1. Reasons for not taking any of the prescribed chemoprophylaxis (n = 103)

Table 1. Odds of full adherence to malaria chemoprophylaxis on multivariate logistic analysis

Conclusion

Short-duration travel, travel to highly endemic regions, and mosquito-avoidance behaviors were associated with increased adherence to prophylaxis. The lower rate of adherence in post-deployment enrollees may be a surrogate for inadequate counseling or recall bias. Our study highlights potential holes in counseling regarding malaria prophylaxis and the importance of ongoing provider and patient education on malaria.

Disclosures

Heather Yun, MD, American Board of Internal Medicine (Individual(s) Involved: Self): Board Member

Helminth infections in the US military: from strongyloidiasis to schistosomiasis

BACKGROUND

Helminth infections caused by parasitic worms, including nematodes (roundworms), cestodes (tapeworms) and trematodes (flukes), can cause chronic symptoms and serious clinical outcomes if left untreated. The US military frequently conducts activities in helminth-endemic regions, particularly Africa, the Middle East and Southeast Asia. However, the military does not currently screen for these infections, and to date, no comprehensive surveillance studies have been completed to assess the frequency of helminth diagnoses in the military personnel and their families.

METHODS

To determine the burden of helminth infections in the US Military Health System (MHS), we conducted a retrospective analysis of International Classification of Diseases (ICD)-9/10 diagnosis codes from all medical encounters in the MHS Data Repository (MDR) from fiscal years (FY) 2012 to 2018. Chart reviews were conducted to assign ICD diagnoses as incorrect, suspected, probable or confirmed based on the laboratory results and symptoms.

RESULTS

Abstraction of MHS data revealed over 50 000 helminth diagnoses between FY 2012 and FY 2018. Of these, 38 445 of diagnoses were amongst unique subjects. After chart review, we found there were 34 425 validated helminth infections diagnosed amongst the unique subjects of US military personnel, retirees and dependents. Nearly 4000 of these cases represented infections other than enterobiasis. There were 351 validated strongyloidiasis diagnoses, 317 schistosomiasis diagnoses and 191 diagnoses of cysticercosis during the study period. Incidence of intestinal nematode infection diagnoses showed an upward trend, whilst the incidence of cestode infection diagnoses decreased.

CONCLUSIONS

The results of this study demonstrate that helminth infections capable of causing severe morbidity are often diagnosed in the US military. As helminth infections are often asymptomatic or go undiagnosed, the true burden of helminth infections in US military personnel and dependents may be higher than observed here. Prospective studies of US military personnel deployed to helminth-endemic areas may be indicated to determine if post-deployment screening and/or empirical treatment are warranted.

Travel-Related Risk Behaviors and Antibiotic Use Among Older Travelers

Background

Antibiotic stewardship in the pretravel care of older adults is important to effectively treat infections while minimizing harm from side effects and unnecessary antibiotic use. The objective of this study was to compare the characteristics, risk behaviors, infectious diseases, and antibiotic use between older (≥60 years) and younger (18-59 years) travelers.

Methods

TravMil is a prospective, observational cohort of United States (US) Department of Defense beneficiaries traveling outside the continental US for ≤6.5 months. For this analysis, we included adults enrolled pretravel between January 2010 and August 2018 and excluded active duty personnel on deployment. Pre and post-travel surveys captured trip characteristics, exposures, illnesses, and antibiotic use.

Results

A total of 1742 travelers were analyzed: 747 (42.9%) were aged ≥60 years and 995 (57.1%) were aged 18-59 years. Older travelers were less likely to engage in high-risk dietary behaviors and experience travelers' diarrhea than younger travelers (18.2% vs 22.9%; P < .05). Influenza-like illness (12.5%) and febrile illness (3.4%) occurred less frequently in the older cohort. Antibiotic use for self-treatment was common in both age groups (25.7% vs 26.7%) and often inappropriate, for example, for treatment of occasional loose stool or mild travelers' diarrhea (67.0% [67/100] in older adults vs 57.6% [83/144] in younger adults; P < .05), and influenza-like illness (63.4% [64/101] vs 58.6% [68/116], respectively; P < .05).

Conclusions

Older travelers were less likely to engage in high-risk behaviors and experience travelers' diarrhea, and both age groups experienced mild, self-limited infections. Inappropriate use of antibiotics was common, suggesting that antimicrobial stewardship should be emphasized at pretravel counseling with international travelers.

Fecal Microbiota Functional Gene Effects Related to Single-Dose Antibiotic Treatment of Travelers' Diarrhea

Background

Travelers' diarrhea (TD) is common among military personnel deployed to tropical and subtropical regions. It remains unclear how TD and subsequent antibiotic treatment impact the resident microflora within the gut, especially given increased prevalence of antibiotic resistance among enteric pathogens and acquisition of multidrug-resistant organisms. We examined functional properties of the fecal microflora in response to TD, along with subsequent antibiotic treatment.

Methods

Fecal samples from US and UK military service members deployed to Djibouti, Kenya, and Honduras who presented with acute watery diarrhea were collected. A sample was collected at acute presentation to the clinic (day 0, before antibiotics), as well as 7 and/or 21 days following a single dose of antibiotics (azithromycin [500 mg], levofloxacin [500 mg], or rifaximin [1650 mg], all with loperamide). Each stool sample underwent culture and TaqMan reverse transcription polymerase chain reaction analyses for pathogen and antibiotic resistance gene detection. Purified DNA from each sample was analyzed using the HumiChip3.1 functional gene array.

Results

In total, 108 day 1 samples, 50 day 7 samples, and 94 day 21 samples were available for analysis from 119 subjects. Geographic location and disease severity were associated with distinct functional compositions of fecal samples. There were no overt functional differences between pre- and postantibiotic treatment samples, nor was there increased acquisition of antibiotic resistance determinants for any of the antibiotic regimens.

Conclusions

These results indicate that single-dose antibiotic regimens may not drastically alter the functional or antibiotic resistance composition of fecal microflora, which should inform clinical practice guidelines and antimicrobial stewardship.

Clinical Trials Registration Number

NCT01618591.

Travel-associated multidrug-resistant organism acquisition and risk factors among US military personnel

BACKGROUND

International travel is a risk factor for incident colonization with extended spectrum beta-lactamase (ESBL)-producing organisms. These and other multidrug-resistant (MDR) bacteria are major pathogens in combat casualties. We evaluated risk factors for colonization with MDR bacteria in US military personnel travelling internationally for official duty.

METHODS

TravMil is a prospective observational study enrolling subjects presenting to military travel clinics. We analysed surveys, antimicrobial use data, and pre- and post-travel perirectal swabs in military travellers to regions outside the continental USA, Canada, Western or Northern Europe, or New Zealand, presenting to one clinic from 12/2015 to 12/2017. Recovered Gram-negative isolates underwent identification and susceptibility testing (BD Phoenix). Characteristics of trip and traveller were analysed to determine risk factors for MDR organism colonization.

RESULTS

110 trips were planned by 99 travellers (74% male, median age 38 years [IQR 31, 47.25]); 72 trips with returned pre- and post-travel swabs were completed by 64 travellers. Median duration was 21 days (IQR 12.75, 79.5). 17% travelled to Mexico/Caribbean/Central America, 15% to Asia, 57% to Africa and 10% to South America; 56% stayed in hotels and 50% in dormitories/barracks. Travellers used doxycycline (15%) for malaria prophylaxis, 11% took an antibiotic for travellers' diarrhoea (TD) treatment (fluoroquinolone 7%, azithromycin 4%). Incident MDR organism colonization occurred in 8 travellers (incidence density 3.5/1000 travel days; cumulative incidence 11% of trips [95% CI: 4-19%]), all ESBL-producing Escherichia coli. A higher incidence of ESBL-producing E. coli acquisition was associated with travel to Asia (36% vs 7%, P = 0.02) but not with travel to other regions, TD or use of antimicrobials. No relationship was seen between fluoroquinolone or doxycycline exposure and resistance to those antimicrobials.

CONCLUSIONS

Incident colonization with MDR organisms occurs at a lower rate in this military population compared with civilian travellers, with no identified modifiable risk factors, with highest incidence of ESBL acquisition observed after South Asia travel.

632. A Randomized, Placebo-Controlled, Double-Blind, Clinical Trial Evaluating Two Dose Regimens of Rifaximin (550mg daily or twice-daily) for Chemoprophylaxis Against Travelers’ Diarrhea Among Deployed U.S. and U.K. Military Personnel (PREVENT TD)

Background

Travelers’ diarrhea (TD) is a leading threat to military readiness. Most trials of rifaximin chemoprophylaxis involve civilians or short-duration travel, whereas military travelers are exposed for longer periods at austere locations and are often physically taxed. We sought to assess efficacy of two regimens among military personnel deployed overseas.

Methods

This was a multi-site, double-blind, placebo-controlled trial of deployed military, randomized to placebo, rifaximin 550 mg daily, or rifaximin 550 mg twice-daily, for up to 42 days (1:1:1; 6 randomizations/block). Diaries were reviewed with subjects on return. Primary endpoint was time to first unformed stool (TFUS) in a TD episode. Other endpoints were assessed by intention to treat (ITT) and subgroups included incidence of any loose stool, meeting criteria for TD, safety, efficacy, adherence and impact to activity endpoints.

Results

343 subjects were included in the ITT population. All UK travelers deployed to a single-site in Kenya; US travelers mostly deployed to various Asia-Pacific locations. Of 73 (21.2%) subjects reporting diarrhea, 42 (57.5%) met TD criteria. Among rifaximin-treated subjects, 15.9% (n=17) reported diarrhea in the twice-daily arm, 20.7% (n=25) in the daily arm, vs. 27.0% (n=31) of placebo recipients; p=.04 and 0.26 respectively. TD was reported by 10.3% (n=11) and 10.7% (n=13) in the daily and twice-daily arms, vs. 15.7% (n=18) among placebo recipients; p=0.24 vs. 0.26 respectively. Among UK personnel, a twice-daily regimen vs. placebo resulted in significantly fewer TD episodes (1.6% vs. 11.9%; p=0.03). Adverse events were similar between groups.

Table 1: Demographics, endpoints, and adverse events (Comparisons are across placebo vs. each dosing regimen. Intent-to-treat [ITT] population defined as subjects enrolled into the study, randomized, travelled and had follow-up. p-values calculated from chi-square or Fisher’s exact test [categorical variables] and Wilcoxon-Mann-Whitney test [continuous variables]. Analyses performed on SAS v9.4. BID: twice-daily)

Conclusion

This is the first trial comparing two high-dose regimens of rifaximin prophylaxis in deployed personnel. Unlike prior reports, neither regimen was associated with an overall significant decrease in TD, potentially due to low overall TD incidence. However, the twice-daily regimen was associated with a numerically lower incidence of diarrheal stool, and in the UK subject group, there was a significant decrease of both TD and diarrheal stool. The impact of variability in regional TD risk, pathogen distribution and adherence in austere deployment environments on efficacy will be reviewed.

Disclosures

All Authors: No reported disclosures

775. The Burden of Arboviral Infection in the Military Health System, 2011-2019

Background

Travel-related arboviral infections are important preventable, emerging infectious diseases, with an estimated annual global toll of US$950 million. We investigated the burden of arboviral infections in the military health system (MHS).

Methods

KAPOS (Deployment and Travel Health: Knowledge, Attitudes, Practices, and Outcomes Study) is a multi-cohort study evaluating the burden of travel-associated diseases in the MHS. The MHS Data Repository was searched for International Classification of Diseases (ICD)-9/10 codes for arboviral infection in military beneficiaries receiving care in military treatment facilities (direct care) or civilian centers (purchased care) for fiscal years 2011-2019. Diagnostic codes were classified as Dengue, Chikungunya, Zika, or other arboviral infection. 755 outpatient charts in the direct-care system were randomly selected for diagnostic validation using Armed Forces Health Surveillance Center case definitions, and review of travel history, medical comorbidities, and pre-travel counseling.

Results

11,066 unique-patient ICD codes for arboviral infections were identified; 6356 (57.4%) were direct care; 4710 (42.6%) were purchased care; 889 (8.0%) were inpatient. Median age was 31 years; 5110 (46.2%) were active duty. The most frequent ICD codes for arboviral infection were Japanese encephalitis virus (JEV) (n=4483), dengue (DENV) (n=1786), yellow fever (YF) (n=230), Zika virus (ZIKV) (n=217), West Nile virus (WNV) (n=171), and chikungunya virus (CHIKV) (n=91). DENV codes were confirmed in 166/249 (66.7%) charts; CHIKV in 23/41 (56.1%), and ZIKV in 15/129 (11.6%). No cases of JEV were confirmed in 171 encounters; all codes referred to JEV vaccine administration. 173/204 (84.8%) of confirmed arboviral cases did not undergo pre-travel counseling.

Conclusion

Arboviral infections constitute a substantial burden of preventable infections within the MHS. Dengue contributed the largest burden of arboviral infection when corrected for accuracy. Coding for ZIKV and JEV likely overestimated the burden of these diseases in the MHS. Low rates of pre-travel counseling among patients with confirmed, non-endemic arboviral infections represent an opportunity for increased emphasis on travel counseling and insect-avoidance precautions.

Disclosures

All Authors: No reported disclosures

207. Travel Related Risk Behaviors and Antibiotic Use among Older Travelers

Background

Older travelers (≥ 60 years) are a unique risk population for travel related infections and adverse events from antibiotics. We evaluated the differences in travel characteristics, exposures, illnesses and antibiotic use among older travelers and those between 18 – 59 y using a prospective, observational cohort of US Department of Defense (DoD) beneficiaries traveling outside the US for ≤ 6.5 months (TravMil).

Methods

Adult DoD beneficiaries were enrolled pre-travel. Itineraries limited to Western/Northern Europe, Canada, or New Zealand and active duty personnel on military travel were excluded. Demographics, itineraries and prescriptions were abstracted. A post-travel survey collected information on exposures and illnesses (travelers’ diarrhea (TD), influenza-like illness (ILI) or febrile illness). Categorical variables were analyzed using chi-square or Fishers exact test and the Mann-U Whitney test was used for continuous variables.

Results

Of the 1468 travelers, 755 were ≥ 60y and 719 were < 60y. Asia (35%) and South/Central America (28%) were the most common travel regions. Older travelers were more likely to be Caucasian (80% vs. 67%), male (52% vs. 39%) and travel for tourism (84% vs. 51%) (p< 0.05). Younger travelers were more likely engage in risk behaviors (e.g. consume poorly cooked meat or seafood (16% vs 9%) or street vendor food (26% vs 8.6%), wade in fresh water (24% vs. 18%), and non-compliance with malaria prophylaxis (22% vs 12%) (p< 0.05). Older travelers had a lower incidence of TD (18% vs 24%), and a higher proportion of cases with loose stool or mild TD that did not interfere with daily activities (63% vs. 51%) (p< 0.05). Inappropriate antibiotic use for loose stool or mild TD were similar among the two age groups (67% vs 59%). Non-significant trends of lower incidence and mild infections were observed for ILI and febrile illness in older travelers.

Conclusion

Older travelers were less likely to engage in risk behaviors, had a lower TD incidence and reported mild diarrheal symptoms. Inappropriate antibiotic use for loose stool or mild TD was common in both age groups. Enhancing antibiotic stewardship is important for older travelers to prevent potential side effects, drug interactions and antibiotic resistance.

Disclosures

All Authors: No reported disclosures

Doxycycline Malaria Prophylaxis Impact on Risk of Travelers' Diarrhea among International Travelers

International travelers are frequently at risk for travelers' diarrhea (TD) and malaria. Doxycycline was one of the earliest antibiotics shown to have efficacy in TD prevention. With increasing resistance and recommendations against antibiotic chemoprophylaxis, doxycycline fell out of use. We evaluated TD incidence and risk factors in a prospective cohort of travelers, specifically in regard to malaria prophylaxis. Travelers' diarrhea was defined as ≥ 3 loose stools in 24 hours or two loose stools in 24 hours associated with other gastrointestinal symptoms. The Poisson regression model with robust error variance was used to estimate the RR of TD. Three thousand two hundred twenty-seven trips were enrolled: 62.1% of participants were male, with a median age of 39 years (interquartile range [IQR] 27,59) and a median travel duration of 19 days (IQR 12,49); 17.4% developed TD; 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean and Latin America; and 20% took doxycycline for malaria chemoprophylaxis, 50% took other antimalarials, and 30% took none. Decreased RR of TD was associated with doxycycline (RR 0.62 [0.47-0.82], P < 0.01) and military travel (RR 0.57 [0.47-0.70], P < 0.01). Increased risk of TD was associated with female gender (RR 1.28 [1.09-1.50], P < 0.01), hotel accommodations (RR 1.30 [1.10-1.53], P < 0.01), travel to tropical South America (RR 1.34 [1.09-1.64], P < 0.01), and duration of travel (RR 1.00 [1.00-1.01], P < 0.01). The use of doxycycline for malaria prophylaxis is associated with lower TD risk, suggesting increasing bacterial enteropathogen susceptibility similar to previous observations. Doxycycline selection for antimalarial chemoprophylaxis may provide additional traveler benefit in infection prevention.

Deployment Infectious Disease Threats: IDCRP Initiatives and Vision Forward

BACKGROUND

Infectious diseases pose a significant threat to health and readiness of military personnel deployed globally during wartime and peacekeeping activities. Surveillance and improvement in mitigation through research of infectious disease threats remain an integral part of Force Health Protection. Herein, we review research efforts of the Infectious Disease Clinical Research Program related to deployment and travel-related infections.

METHODS

The objectives of the Deployment and Travel-Related Infections Research Area are to (1) provide epidemiologic and clinical data, including pathogen-specific estimates of disease incidence among deployed troops, (2) execute clinical trials and effectiveness studies to improve recommendations regarding prevention and treatment of infections during deployment, and (3) evaluate the knowledge and practice patterns of health care providers engaged in deployment/travel medicine and the impact on outcomes. The centerpiece protocol of the research area is the Deployment and Travel-Related Infectious Disease Risk Assessment, Outcomes, and Prevention Strategies cohort study (TravMil), which was initiated in 2010 and collects data on a broad range of deployment-related infections.

RESULTS

To date, 4,154 deployed military personnel and traveling Department of Defense (DoD) beneficiaries have been enrolled in TravMil. Surveillance data collected through the TravMil study provide assessment of deployment and travel-related infectious disease threats, and the effectiveness of mitigation strategies. The incidence of travelers' diarrhea, influenza-like illness, and undifferentiated febrile illness is 20.48%, 9.34%, and 6.16%, respectively. The cohort study also provides necessary infrastructure to execute clinical trials. The TrEAT TD clinical trial evaluated the effectiveness of single-dose antibiotic therapy for travelers' diarrhea in the deployed setting. When compared to levofloxacin, azithromycin was not inferior; however, inferiority was not demonstrated with use of single dose of rifaximin. The trial findings supported the development of a deployment-related health guideline for the management of acute diarrheal disease. A clinical trial evaluating the effectiveness of rifaximin for prevention for travelers' diarrhea (Prevent TD) is underway.

CONCLUSIONS

The research area has proven its ability to conduct impactful research, including the development of field-expedient diagnostics, the largest DoD multi-site travelers' diarrhea randomized control trial in peacetime and combat settings, and informed Force Health Protection guidance. The research area continues to provide surveillance data to military commands via an established collaborative network of military treatment facilities, DoD laboratories (both within and outside the continental United States), foreign militaries, and academia. The conduct of clinical and translational research in a deployment setting presents significant challenges, most notably in recruitment/enrollment and compliance with study-related procedures during deployment.

Impact of Doxycycline as Malaria Prophylaxis on Risk of Influenza-Like Illness among International Travelers

Travelers are often at risk for both influenza-like illness (ILI) and malaria. Doxycycline is active against pathogens causing ILI and is used for malaria prophylaxis. We evaluated the risk factors for ILI, and whether the choice of malaria prophylaxis was associated with ILI. TravMil is a prospective observational study enrolling subjects presenting to military travel clinics. Influenza-like illness was defined as subjective fever with either a sore throat or cough. Characteristics of trip and use of malaria prophylaxis were analyzed to determine association with development of ILI. Poisson regression models with robust error variance were used to estimate relative risk (RR) of ILI. A total of 3,227 trips were enrolled: 62.1% male, median age of 39 years (interquartile range [IQR] 27,59), median travel duration 19 days (IQR 12, 49); 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean and Latin America. Military travel (46%) and vacation (40%) were most common reasons for travel. Among them, 20% took doxycycline, 50% other prophylaxis, and 30% took none; 8.7% developed ILI. Decreased RR of ILI was associated with doxycycline (RR 0.65 [0.43–0.99], P = 0.046) and military travel (RR 0.30 [0.21–0.43], P < 0.01). Increased risk of ILI was associated with female gender (RR 1.57 [1.24–1.98], P < 0.01), travel to Asia (RR 1.37 [1.08–1.75], P = 0.01), and cruises (RR 2.21 [1.73–2.83], P < 0.01). Use of doxycycline malaria prophylaxis is associated with a decreased risk of ILI. Possible reasons include anti-inflammatory or antimicrobial effects, or other unmeasured factors. With few strategies for decreasing ILI in travelers, these findings bear further investigation.

Deployment and Travel Medicine Knowledge, Attitudes, Practices, and Outcomes Study (KAPOS): Malaria Chemoprophylaxis Prescription Patterns in the Military Health System

The Deployment and Travel Medicine Knowledge, Attitudes, Practices, and Outcomes Study (KAPOS) examines the integrated relationship between provider and patient inputs and health outcomes associated with travel and deployments. This study describes malaria chemoprophylaxis prescribing patterns by medical providers within the U.S. Department of Defense’s Military Health System and its network of civilian healthcare providers during a 5-year period. Chemoprophylaxis varied by practice setting, beneficiary status, and providers’ travel medicine expertise. Whereas both civilian and military facilities prescribe an increasing proportion of atovaquone–proguanil, doxycycline remains the most prevalent antimalarial at military facility based practices. Civilian providers dispense higher rates of mefloquine than their military counterparts. Within military treatment facilities, travel medicine specialists vary their prescribing pattern based on service member versus beneficiary status of the patient, both in regards to primary prophylaxis, and use of presumptive anti-relapse therapy (PQ-PART). By contrast, nonspecialists appear to carry over practice patterns developed under force health protection (FHP) policy for service members, into the care of beneficiaries, particularly in high rates of prescribing doxycycline and PQ-PART compared with both military travel medicine specialists and civilian comparators. Force health protection policy plays an important role in standardizing and improving the quality of care for deployed service members, but this may not be the perfect solution outside of the deployment context. Solutions that broaden both utilization of decision support tools and travel medicine specialty care are necessary.

High-Sensitivity Dry Rehydratable Film Method for Enumeration of Coliforms in Dairy Products: Collaborative Study

A dry-film coliform count plate that is inoculated with 5 mL sample was compared with the Violet Red Bile Agar plate method in a collaborative study by 18 laboratories. Products analyzed were 2% milk, chocolate milk, cream, vanilla ice cream, cottage cheese, and cheese. Collaborators tested blind duplicate uninoculated samples and samples inoculated at low, medium, and high level. Significantly (P&lt; 0.05) higher numbers of coliforms were recovered by the dry-film method from 2% milk samples at the 3 inoculum levels, the chocolate milk at the low- and high-inoculum levels, and the cream at the high-inoculum level. Significantly higher counts were obtained by the agar method for cottage cheese samples at the low-inoculum level. The repeatability standard deviation for the dry-film method was significantly higher for the high-inoculum level chocolate milk sample and the medium-inoculum level cottage cheese. The same statistic was significantly higher for the agar method at all 3 inoculum levels in the 2% milk and the medium-inoculum level cream. The high-sensitivity dry rehydratable film method for enumeration of coliforms in dairy products has been adopted first action by AOAC INTERNATIONAL.

RARS1-related hypomyelinating leukodystrophy: Expanding the spectrum

OBJECTIVE

Biallelic variants in RARS1, encoding the cytoplasmic tRNA synthetase for arginine (ArgRS), cause a hypomyelinating leukodystrophy. This study aimed to investigate clinical, neuroradiological and genetic features of patients with RARS1-related disease, and to identify possible genotype-phenotype relationships.

METHODS

We performed a multinational cross-sectional survey among 20 patients with biallelic RARS1 variants identified by next-generation sequencing techniques. Clinical data, brain MRI findings and genetic results were analyzed. Additionally, ArgRS activity was measured in fibroblasts of four patients, and translation of long and short ArgRS isoforms was quantified by western blot.

RESULTS

Clinical presentation ranged from severe (onset in the first 3 months, usually with refractory epilepsy and early brain atrophy), to intermediate (onset in the first year with nystagmus and spasticity), and mild (onset around or after 12 months with minimal cognitive impairment and preserved independent walking). The most frequent RARS1 variant, c.5A>G, led to mild or intermediate phenotypes, whereas truncating variants and variants affecting amino acids close to the ArgRS active centre led to severe phenotypes. ArgRS activity was significantly reduced in three patients with intermediate and severe phenotypes; in a fourth patient with intermediate to severe presentation, we measured normal ArgRS activity, but found translation mainly of the short instead of the long ArgRS isoform.

INTERPRETATION

Variants in RARS1 impair ArgRS activity and do not only lead to a classic hypomyelination presentation with nystagmus and spasticity, but to a wide spectrum, ranging from severe, early-onset epileptic encephalopathy with brain atrophy to mild disease with relatively preserved myelination.

741. TravMil Surveillance of Travel-Related Illness in a Prospective Cohort of US Military Beneficiaries, 2010–2018

Background

Increasing international travel places larger populations at risk for infections outside of their usual exposure. Deployed military personnel have unique risks for such infections. Our cohort’s rates of travelers’ diarrhea and influenza-like illness have been defined, but the rate of travelers with symptoms apart from a clinical syndrome has not. We present a survey of intra-travel symptoms of all travelers and confirmed diagnoses of ill-returned travelers in a cohort of military and civilian travelers.

Methods

TravMil is a prospective, multicenter observational study enrolling US military beneficiaries traveling outside the continental United States from 2010–2018; beneficiaries could also enroll after travel if they presented for a possible travel-related illness. Demographic information, intra-travel symptoms, and confirmed diagnoses were recorded.

Results

2671 travelers embarked on 3050 trips: 63.1% male; median age 38 years (IQR 27, 57); median trip duration 20 days (IQR 13, 46). Common purposes of travel: military deployment (45.9%), vacation (23.7%), and visiting friends/relatives (10.9%). Ninety-seven travelers (3.2%) enrolled post-travel. Top regions of travel: Africa (31.5%), South and Central America/Caribbean (25.5%), and Southeast and North Asia/Oceania (19.4%). During travel, 56.6% experienced gastrointestinal (GI) symptoms, 11.9% respiratory symptoms, and 3.0% fever; of those, 10.3% sought medical care. Eighty returned travelers sought medical care (21 prospective enrollees vs. 59 post-travel enrollees): 5 vs. 17 malaria cases, 3 vs. 16 arbovirus infections, and 6 vs. 14 GI syndromes. All malaria cases in prospective enrollees were in military subjects. Post-travel enrollees accounted for 1 acute human immunodeficiency virus and 3 rickettsial infections.

Conclusion

A majority of our travelers experienced symptoms during travel. Post-travel diagnoses, although uncommon, emphasize needed improvements in the application of known risk mitigation strategies. Our findings can help clinicians optimize their pretravel counseling by focusing education on self-treatment of common travel-related symptoms, prevention of GI, arthropod-borne, and respiratory illness, and emphasizing symptoms that should prompt medical care.

Disclosures

All authors: No reported disclosures.

Influenza-Like Illness in Travelers to the Developing World

Travelers to developing regions are at risk for development of influenza-like illness (ILI). Little is known of traveler and trip characteristics associated with the development of ILI. TravMil is a prospective observational study, enrolling subjects presenting to six military travel clinics or predeployment-screening sites. We analyzed pre- and post-travel surveys from travelers visiting regions outside of the continental United States, Western or Northern Europe, Canada, Australia, or New Zealand between January 2010 and March 2016. Influenza-like illness was defined as a self-reported fever associated with either sore throat or cough. Trip and traveler characteristics were analyzed to determine risk factors for the development of ILI. Two thousand nine hundred and thirty-two trips were recorded (55% male, median age 45 years, 69% white, 51% on vacation, median travel duration 17 days). The 2,337 trips included the number of self-reported influenza vaccinations in the preceding 5 years (median 5). Eleven percent of the trips were complicated by an ILI lasting a median of 5 days; 70% and 17% of these reported upper and lower respiratory tract infection, respectively, and 12% reported both. On multivariate analysis, increased risk of ILI was associated with female gender (odds ratio [OR]: 1.60 [confidence interval (CI): 1.25-2.05], P < 0.01), age (years) (OR: 1.01 [CI: 1.01-1.02], P < 0.01); and duration of travel (days) (OR: 1.01 [CI: 1.00-1.01], P < 0.01). Influenza-like illness is common in travelers, regardless of traveler characteristics, purpose of travel, destination, or season of year. Female gender, older age, and longer duration of travel were associated with an increased risk of ILI. Additional tools and strategies are needed to prevent ILI in international travelers.

A national survey of out-of-hours working and fatigue in consultants in anaesthesia and paediatric intensive care in the UK and Ireland

The tragic death of an anaesthetic trainee driving home after a series of night shifts prompted a national survey of fatigue in trainee anaesthetists. This indicated that fatigue was widespread, with significant impact on trainees' health and well-being. Consultants deliver an increasing proportion of patient care resulting in long periods of continuous daytime duty and overnight on-call work, so we wished to investigate their experience of out-of-hours working and the causes and impact of work-related fatigue. We conducted a national survey of consultant anaesthetists and paediatric intensivists in the UK and Ireland between 25 June and 6 August 2018. The response rate was 46% (94% of hospitals were represented): 84% of respondents (95%CI 83.1-84.9%) contribute to a night on-call rota with 32% (30.9-33.1%) working 1:8 or more frequently. Sleep disturbance on-call is common: 47% (45.6-48.4%) typically receive two to three phone calls overnight, and 48% (46.6-49.4%) take 30 min or more to fall back to sleep. Only 15% (14.0-16.0%) reported always achieving 11 h of rest between their on-call and their next clinical duty, as stipulated by the European Working Time Directive. Moreover, 24% (22.8-25.2%) stated that there is no departmental arrangement for covering scheduled clinical duties following a night on-call if they have been in the hospital overnight. Overall, 91% (90.3-91.7%) reported work-related fatigue with over half reporting a moderate or significantly negative impact on health, well-being and home life. We discuss potential explanations for these results and ways to mitigate the effects of fatigue among consultants.

Characterization of male breast cancer: results of the EORTC 10085/TBCRC/BIG/NABCG International Male Breast Cancer Program

Background

Male breast cancer (BC) is rare, managed by extrapolation from female BC. The International Male BC Program aims to better characterize and manage this disease. We report the results of part I, a retrospective joint analysis of cases diagnosed during a 20-year period.

Methods

Patients with follow-up and tumor samples, treated between 1990 and 2010, in 93 centers/9 countries. Samples were centrally analyzed in three laboratories (the United Kingdom, the Netherlands and the United States).

Results

Of 1822 patients enrolled, 1483 were analyzed; 63.5% were diagnosed between 2001 and 2010, 57 (5.1%) had metastatic disease (M1). Median age at diagnosis: 68.4 years. Of 1054 M0 cases, 56.2% were node-negative (N0) and 48.5% had T1 tumors; 4% had breast conserving surgery (BCS), 18% sentinel lymph-node biopsy; half received adjuvant radiotherapy; 29.8% (neo)adjuvant chemotherapy and 76.8% adjuvant endocrine therapy (ET), mostly tamoxifen (88.4%). Per central pathology, for M0 tumors: 84.8% ductal invasive carcinomas, 51.5% grade 2; 99.3% estrogen receptor (ER)-positive; 81.9% progesterone receptor (PR)-positive; 96.9% androgen receptor (AR)-positive [ER, PR or AR Allred score ≥3]; 61.1% Ki67 expression low (<14% positive cells); using immunohistochemistry (IHC) surrogates, 41.9% were Luminal-A-like, 48.6% Luminal-B-like/HER-2-negative, 8.7% HER-2-positive, 0.3% triple negative. Median follow-up: 8.2 years (0.0-23.8) for all, 7.2 years (0.0-23.2), for M0, 2.6 years (0.0-12.7) for M1 patients. A significant improvement over time was observed in age-corrected BC mortality. BC-specific-mortality was higher for men younger than 50 years. Better overall (OS) and recurrence-free survival (RFS) were observed for highly ER+ (P = 0.001), highly PR+ (P = 0.002), highly AR+ disease (P = 0.019). There was no association between OS/RFS and HER-2 status, Ki67, IHC subtypes nor grade.

Conclusions

Male BC is usually ER, PR and AR-positive, Luminal B-like/HER2-negative. Of note, 56% patients had T1 tumors but only 4% had BCS. ER was highly positive in >90% of cases but only 77% received adjuvant ET. ER, PR and AR were associated with OS and RFS, whereas grade, Ki67 and IHC surrogates were not. Significant improvement in survival over time was observed.

A Comparison of Pretravel Health Care, Travel-Related Exposures, and Illnesses among Pediatric and Adult U.S. Military Beneficiaries

We evaluated differences in pretravel care, exposures, and illnesses among pediatric and adult travelers, using a prospective, observational cohort. Eighty-one pediatric travelers were matched 1:1 with adult military dependents by travel region, destination's malaria risk, and travel duration. Pediatric travelers were more likely to have coverage for hepatitis A and B (90% versus 67% of adults; 85% versus 44%), visit friends and relatives (36% versus 16%), report mosquito bites (69% versus 44%), and have close contact with wild or domesticated animals (40% versus 20%) than adults (P < 0.05). Subjects < 10 years of age were less likely to be prescribed antibiotics (28% versus 95%; RR = 0.63; 95% CI: 0.46-0.85) and antidiarrheals (9% versus 100%; RR = 0.10; 95% CI: 0.03-0.29) for travelers' diarrhea (TD) self-treatment than adults. Travel medicine providers should emphasize strategies for vector avoidance, prevention of animal bites and scratches, and TD self-treatment in pediatric pretravel consultations.

Abstract P6-19-01: Evaluation of multiple transcriptomic gene risk signatures in male breast cancer

Introduction: Male breast cancer (MBC) is a rare disease accounting for less than 1% of all breast cancers (BC) and 1% of all cancers in males. The clinical management is largely extrapolated from female BC. Several multigene assays are increasingly used to guide clinical treatment decisions in female BC, however there is little data on the utility of these tests in MBC.

Methods: Here we present the gene expression results of 380 M0, ER+ve, HER2-ve MBCs enrolled in the Part 1 (retrospective joint analysis) International Male Breast Cancer Program of 1483 patients diagnosed between 1990-2010 (Cardoso et al. Annals of Oncology, 2018). Using a custom Nanostring™ panel comprised of the genes from the commercial risk tests Prosigna®, OncotypeDx® and Mammaprint®, risk scores and intrinsic subtyping data were generated to recapitulate the commercial tests as described by Bayani and Yao et al (npjBreast Cancer, 2017). Survival outcomes by risk classification were analyzed using Cox models with time-dependent covariates when the proportional hazard assumption was not met and adjusted for clinical and treatment variables.

Results: Prosigna-like risk scores identified 99 (26.1%) as low-risk, 159 (41.8%) as intermediate-risk, and 122 (32.1%) as high-risk. Using the TAILORx cut-off (25) for OncotypeDx-like risk of recurrence scoring, 158 (41.6%) were identified as low-risk, while 222 (58.4%) were identified as high-risk. MammaPrint-like results identified 175 (46.1%) as low-risk and 205 (53.9%) as high-risk. Overall, patients classified as high-risk had higher grade, more nodal involvement, larger tumors, and more frequently treated with chemotherapy than low-risk patients. Survival analyses demonstrated clear clinical utility for each test, showing patients at high-risk with poor relapse-free survival (RFS) as compared to patients classified as low-risk: Prosigna-like RFS at 3-years (HR=2.20, 95% CI, 1.28-3.80); Oncotype-like RFS at 3-years (HR=1.92, 95% CI, 1.17-3.17); MammaPrint-like RFS (HR=1.51, 95% CI, 1.00-2.27); with similar findings for distant relapse-free survival (DRFS) and overall survival (OS). Across outcomes and all gene signatures, patients with concordant Low/Low risk classification had better prognosis than those with concordant High/High risk classification. PAM50 intrinsic subtyping identified 147 (38.7%) as Luminal A, 57 (15.0%) as Luminal B, 80 (21.1%) as Her2-enriched and 96 (25.3%) as Basal-like; showing overall 34.5% concordance to clinic-pathological subtyping by central pathology (95% CI, 29.7%-39.5%). Comparison between the tests in the MBC cohort and a comparable cohort of female BC from the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial processed in the same way will be presented.

Conclusion: Common transcriptomic assays designed to assess residual risk, validated in female BC, provide similar information in male BC patients. Not surprisingly, disagreement between test results at the individual patient level was observed. To our knowledge, this is the largest study of MBC assayed to generate risk scores of the current commercial BC tests to demonstrate their clinical utility and their differences and similarity to female BC.

This work has been funded by the Breast Cancer Research Foundation (BCRF).

Citation Format: Bayani J, Poncet C, Yao CQ, Crozier C, Anouk N, Piper T, Cunningham C, Sobol M, Aebi S, Benstead K, Bogler O, Dal Lago L, Fraser J, Hilbers FH, Hedenfalk I, Korde L, Linderholm B, Martens J, Middleton L, Murray M, Kelly C, Nilsson C, Nowaczyk M, Peeters S, Peric A, Porter P, Schröder C, Rubio IT, Ruddy KJ, van Asperen C, Van Den Weyngaert D, van Deurzen C, van Leeuwen-Stok E, Vermeij J, Winer E, Boutros PC, Giordano SH, Cardoso F, Bartlett JM. Evaluation of multiple transcriptomic gene risk signatures in male breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-19-01.

964. Impact of Doxycycline as Malaria Prophylaxis on Risk of Influenza Like Illness Among International Travelers

Background

International travelers are often at risk for both influenza like illness (ILI) and malaria. Doxycycline is active against many pathogens causing ILI and is routinely used for malaria prophylaxis. We evaluated the incidence of and risk factors for ILI, and whether the choice of malaria prophylaxis was associated with ILI.

Methods

TravMil is a prospective observational study enrolling subjects presenting to 6 military travel clinics. We analyzed pre- and post-travel surveys from travelers to regions outside of the continental United States, Western or Northern Europe, Canada, or New Zealand between July 2010 and August 2018. ILI was defined as subjective fever associated with either a sore throat or cough. Characteristics of trip and traveler and the use of malaria prophylaxis were analyzed to determine association with development of ILI. Poisson regression models with robust error variance were used to estimate relative risk of ILI.

Results

A total of 3,227 travelers were enrolled: 62.1% male, median age of 39 (IQR 27, 59), median travel duration 19 days (IQR 12, 49). 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean, Mexico, and Central or South America. Military travel (46%) and vacation (40%) were most common reasons for travel. Twenty percent took doxycycline for malaria prophylaxis, 50% other prophylaxis (89% atovaquone–proguanil), and 30% took none. 8.7% developed ILI. Compared with those on no or other prophylaxis, doxycycline was associated with decreased risk of ILI [RR 0.65 (0.43–0.99), P = 0.046], as was military travel [RR 0.30 (0.21–0.43), P &lt; 0.01]. Increased risk of ILI was associated with female gender [RR 1.57 (1.24–1.98), P &lt; 0.01], travel to Asia [RR 1.37 (1.08–1.75), P = 0.01], cruises [RR 2.21 (1.73–2.83), P &lt; 0.01], and longer duration of travel [RR 1.01 (1.00–1.01, P &lt; 0.01].

Conclusion

The use of doxycycline is associated with a decreased risk of ILI compared with taking no or other malaria prophylaxis. The reasons for this are unclear but may be related to anti-inflammatory effects, activity against bacterial respiratory pathogens, effects on disease transmission in closed populations (e.g., military deploying groups), or other unmeasured factors. With few proven strategies for decreasing ILI risk in travelers, these findings bear further investigation.

Disclosures

All authors: No reported disclosures.

1172. Travel-Associated Multidrug-Resistant Organism Acquisition and Risk Factors Among US Military Personnel

Background

International travel is a risk factor for incident colonization with extended spectrum β-lactamase (ESBL)-producing organisms. These and other multidrug-resistant (MDR) bacteria are major pathogens in combat casualties. We evaluated risk factors for colonization with MDR bacteria in US military personnel traveling internationally for official duty.

Methods

TravMil is a prospective observational study enrolling subjects presenting to military travel clinics. We analyzed surveys, antimicrobial use data, and pre- and post-travel self-collected perirectal swabs in military travelers to regions outside the continental United States, Canada, Western or Northern Europe, or New Zealand presenting to one clinic from December 2015 to December 2017. Gram-negative isolates recovered from swabs underwent real-time identification and susceptibility testing (BD Phoenix). Characteristics of trip and traveler were analyzed to determine risk factors for MDR organism colonization.

Results

One hundred ten trips were planned by 99 travelers (74% male, median age 38 years [IQR 31, 47.25]); 72 trips were completed by 64 travelers. Median trip duration was 21 days (IQR 12.75, 79.5). Of those with trips completed, 17% traveled to Mexico/Caribbean/Central America, 15% to Asia, 57% to Africa, and 10% to South America; 56% stayed in hotels and 50% in dormitories/barracks. Travelers used doxycycline (15%) for malaria prophylaxis, 11% took an antibiotic for travelers’ diarrhea (TD) treatment (fluoroquinolone 7%, azithromycin 4%). Incident MDR organism colonization occurred in eight travelers (incidence density 3.5/1,000 travel days; cumulative incidence 11% of trips [95% CI: 4%–19%]), all ESBL-producing E. coli. A higher incidence of ESBL-producing E. coli acquisition was associated with travel to Asia (36% vs. 7%, P = 0.02) but not with travel to other regions, TD, or use of antimicrobials. No relationship was seen between fluoroquinolone or doxycycline exposure and resistance to those antimicrobials.

Conclusion

Consistent with other studies of US military personnel travelers, incident colonization with MDR organisms following official travel occurs at a lower rate in this population compared with civilian travelers, with no identified modifiable risk factors. The highest incidence of ESBL acquisition was observed during travel to Asia.

Disclosures

All authors: No reported disclosures.

Using English National Cancer Registration and Linked Health Datasets to Assess Variation in Diagnostic Pathway Length for Colorectal and Lung Cancer Patients by Stage and Route to Diagnosis

Background: Understanding factors that contribute to longer diagnostic pathways is important to improve efficiency of these pathways and can provide evidence for the implementation of the forthcoming 28-day Faster Diagnostic Standard (FDS) in England. This analysis uses linked national cancer registrations and other health datasets to define diagnostic pathway length and examine variation by route to diagnosis (RtD), stage and patient characteristics for colorectal and lung cancer patients. Aim: To achieve a more in-depth understanding of the diagnostic pathway for colorectal and lung cancer patients and identify particular factors associated with longer diagnostic pathways. Methods: English cancer registrations (2014 & 2015) diagnosed with colorectal and lung cancers (C18-20, C33-34) were linked to the hospital episode statistics, diagnostic imaging dataset, cancer waiting times and RtD data. Patients with multiple diagnoses or unknown RtD were excluded. To construct the pathway length, a start date was derived by defining the earliest relevant event (referral into/appointment in secondary care or diagnostic procedure) from available datasets in the 6 months prediagnosis. The pathway length was determined for each cancer site separately, by stage, RtD and patient characteristic. Regression analysis produced odds ratios (OR) of having a longer diagnostic pathway while controlling for other factors, including age, sex, comorbidities and deprivation. The longer pathway was defined as longer than the median days per cancer site. Results: Of 64,320 colorectal and 71,526 lung patients included, 99.5% and 99.8% respectively had at least one relevant first event recorded. The median pathway length (days) was 26 (IQR 11-56) for colorectal and 35 for lung (15-83). Pathway length decreased significantly with later stage (stage 1-4 - colorectal: 35 to 20, lung: 75 to 25) with significant variation also by presentation route and comorbidity score. Regression analysis showed that, after adjustment for other factors (including stage), patients on a GP referral route had an increased odds of a long pathway compared with the two week wait route (an urgent GP referral with a suspicion of cancer) (colorectal aOR: 4.5, lung aOR: 2.5). Patients diagnosed via emergency presentation route, which are predominantly late stage, had the shortest pathway length and reduced ORs of having a longer diagnostic pathway (colorectal aOR: 0.2, lung aOR: 0.4). Certain patient characteristics are also associated with longer diagnostic pathway length. Conclusion: There is substantial variation in diagnostic pathway length by stage and route for both sites and in many cases these pathways exceeded 28-days (colorectal: 45.3%, lung: 56.4%). Vague symptoms, comorbidities and other patient characteristics may make cancer more difficult to diagnose. Factors associated with longer waits could support the creation of targeted initiatives to reduce the diagnostic pathway length.

Trial Evaluating Ambulatory Therapy of Travelers' Diarrhea (TrEAT TD) Study: A Randomized Controlled Trial Comparing 3 Single-Dose Antibiotic Regimens With Loperamide

Background

Recommended treatment for travelers' diarrhea includes the combination of an antibiotic, usually a fluoroquinolone or azithromycin, and loperamide for rapid resolution of symptoms. However, adverse events, postdose nausea with high-dose azithromycin, effectiveness of single-dose rifaximin, and emerging resistance to front-line agents are evidence gaps underlying current recommendations.

Methods

A randomized, double-blind trial was conducted in 4 countries (Afghanistan, Djibouti, Kenya, and Honduras) between September 2012 and July 2015. US and UK service members with acute watery diarrhea were randomized and received single-dose azithromycin (500 mg; 106 persons), levofloxacin (500 mg; 111 persons), or rifaximin (1650 mg; 107 persons), in combination with loperamide (labeled dosing). The efficacy outcomes included clinical cure at 24 hours and time to last unformed stool.

Results

Clinical cure at 24 hours occurred in 81.4%, 78.3%, and 74.8% of the levofloxacin, azithromycin, and rifaximin arms, respectively. Compared with levofloxacin, azithromycin was not inferior (P = .01). Noninferiority could not be shown with rifaximin (P = .07). At 48 and 72 hours, efficacy among regimens was equivalent (approximately 91% at 48 and 96% at 72 hours). The median time to last unformed stool did not differ between treatment arms (azithromycin, 3.8 hours; levofloxacin, 6.4 hours; rifaximin, 5.6 hours). Treatment failures were uncommon (3.8%, 4.4%, and 1.9% in azithromycin, levofloxacin, and rifaximin arms, respectively) (P = .55). There were no differences between treatment arms with postdose nausea, vomiting, or other adverse events.

Conclusions

Single-dose azithromycin, levofloxacin, and rifaximin with loperamide were comparable for treatment of acute watery diarrhea.

Clinical Trial Registration

NCT01618591.

Abstract PD7-12: Molecular subtyping of male breast cancer by the International male breast cancer program (IMBC): EORTC 10085/TBCRC 0-29/BIG 2-07/NABCG/BOOG 2009-04

Introduction. Male breast cancer (male BC) is a rare disease for which disease management is extrapolated from females. IMBC, an international consortium, which previously reported on clinico-pathological aspects, now reports on molecular subgroups revealed by RNA sequencing and their relation to patient outcome.

Methods. Tumor samples from the retrospective MALE BC registry diagnosed between 1990-2010 and with pathology and outcome data (relapse-free- (RFS) and overall survival (OS)) were included (n=699). To allow the discovery of prognostic features, we selected, stratified for known risk factors (TN stage, grade, age at diagnose and adjuvant endocrine treatment), from the cohort 152 cases with poor (RFS &lt;= 4 yrs) and good outcome (RFS &gt; 7yrs) evenly distributed. Here, we report RNA sequencing results of the first 73 cases, 38 with poor and 35 with good outcome. RNA sequencing reads were used to generate gene expression values and to report transcripts carrying driver mutations. Unsupervised clustering identified subgroups and within subgroups differentially expressed genes were identified. The reported prognostic male BC subgroups M1 and M2 (Johansson BCR 2012(14):R31) were also annotated. All identified subgroups were related to outcome using logistic regression (p-value using Wald test).

Results. Unsupervised clustering revealed 2 main subgroups of which group 1 was enriched for expression of ER target genes, WNT3 and genes from amplicons known for female BC, e.g. 19p13 (CCNE1), 8q24 (MYC), and 11q13 (CCND1). The biology of the smaller group 2 was less defined but TGFβ2 expression was high as were various kallikreins (KLK) including interestingly KLK3 (prostate specific antigen). Other known amplified regions [(8p11 (FGFR1), 20q13 (ZNF217) and 12q15 (MDM2)] and mutated transcripts [PIK3CA (H1047R/L/Q; E542K, E545K, N345K; 16% of cases), TP53 and SF3B1 (K700E) (2% of cases)] were identified. Profound tumor infiltrate gene expression was present in 5% of cases and one third of cases expressed proliferation markers. Except for TP53, none of these latter characteristics were unevenly distributed among the 2 main subgroups. ER and AR were highly correlated, particularly in group 1. The two main groups could be further subdivided. Group 1 comprised 3 subgroups of which subgroup 1a expressed TFF1/3 and NAT1, well-known ER targets, while subgroups 1b and 1c expressed other ER targets,respectively BEX1 and PITX1. HOXC cluster expression differentiated subgroup 1b from 1a and 1c. None of these intrinsic subgroups were, however, related to RFS. The previously reported M2 subgroup, which largely segregated with subclusters 1a and 1b, was associated with a better RFS than the M1 subgroup (OR=2.9; 95%CI 1.1-7.5; p-value=0.03).

Conclusions. 1) Intrinsic subtypes of male BC were revealed and their subgrouping is defined by ER associated subsets of genes. 2) The association of the reported M2 subgroup of male BC with longer RFS was validated; 3) Currently identified biological characteristics of male BC may improve future treatments. The full report on 152 cases including a comparison to female BC will be presented at the conference.

This research was funded by Breast Cancer Research Foundation

Citation Format: Martens JWM, Sieuwerts A, Ponchet C, Smid M, de Weerd V, Slaets L, Piper T, van Deurzen CHM, Schroder CP, Stangle C, Kloosterman W, van Leeuwen-Stok E, Nilsson C, Vermeij J, Peeters S, Goulioti T, Nowaczyk M, Aebi S, Rubio IT, Kelly C, Bayani J, Porter P, Murray M, Hudis C, Middleton L, Korde L, Ruddy K, Winer E, Bogler O, van den Weyngaert D, dal Lago L, Fraser J, Benstead K, van Asperen C, Linderholm B, Hedenfalk I, Tryfonidis K, Giordano S, Bartlett J, Cardoso F. Molecular subtyping of male breast cancer by the International male breast cancer program (IMBC): EORTC 10085/TBCRC 0-29/BIG 2-07/NABCG/BOOG 2009-04 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD7-12.

Prevalence of Staphylococcus aureus Colonization and Risk Factors for Infection Among Military Personnel in a Shipboard Setting

Staphylococcal skin and soft tissue infections (SSTIs), especially those due to methicillin-resistant Staphylococcus aureus (MRSA) are an important public health issue for the military. Limited data exist regarding the prevalence of S. aureus colonization in the shipboard setting. We conducted a cross-sectional, observational study to determine the point prevalence of S. aureus colonization among military personnel onboard a naval vessel. Asymptomatic active duty personnel completed a survey for risk factors associated with colonization and SSTIs. Culture specimens were obtained from the anterior nares, pharynx, groin, and perirectal regions. MRSA isolates underwent testing for antimicrobial resistance, virulence factors, and pulsed-field type. 400 individuals were enrolled, 198 (49.5%) of whom were colonized with S. aureus, with MRSA identified in 14 participants (3.5%). No significant risk factors were associated with MRSA colonization. USA800 was the most common colonizing MRSA strain in the cohort and was detected in 10 participants (71%). Two participants (14%) were colonized with USA300 MRSA. In this first report of S. aureus epidemiology in a shipboard setting, we observed high rates of S. aureus and MRSA colonization. Longitudinal studies are needed to document the incident rates of S. aureus colonization during shipboard deployment and its impact on SSTI risk.