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Dive into the research topics where Margaret A. K. Ryan is active.

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Featured researches published by Margaret A. K. Ryan.


BMJ | 2008

New onset and persistent symptoms of post-traumatic stress disorder self reported after deployment and combat exposures: prospective population based US military cohort study

Tyler C. Smith; Margaret A. K. Ryan; Deborah L. Wingard; Donald J. Slymen; James F. Sallis; Donna Kritz-Silverstein

Objective To describe new onset and persistence of self reported post-traumatic stress disorder symptoms in a large population based military cohort, many of whom were deployed in support of the wars in Iraq and Afghanistan. Design Prospective cohort analysis. Setting and participants Survey enrolment data from the millennium cohort (July 2001 to June 2003) obtained before the wars in Iraq and Afghanistan. Follow-up (June 2004 to February 2006) data on health outcomes collected from 50 184 participants. Main outcome measures Self reported post-traumatic stress disorder as measured by the posttraumatic stress disorder checklist—civilian version using Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria. Results More than 40% of the cohort were deployed between 2001 and 2006; between baseline and follow-up, 24% deployed for the first time in support of the wars in Iraq and Afghanistan. New incidence rates of 10-13 cases of post-traumatic stress disorder per 1000 person years occurred in the millennium cohort. New onset self reported post-traumatic stress disorder symptoms or diagnosis were identified in 7.6-8.7% of deployers who reported combat exposures, 1.4-2.1% of deployers who did not report combat exposures, and 2.3-3.0% of non-deployers. Among those with self reported symptoms of post-traumatic stress disorder at baseline, deployment did not affect persistence of symptoms. Conclusions After adjustment for baseline characteristics, these prospective data indicate a threefold increase in new onset self reported post-traumatic stress disorder symptoms or diagnosis among deployed military personnel who reported combat exposures. The findings define the importance of post-traumatic stress disorder in this population and emphasise that specific combat exposures, rather than deployment itself, significantly affect the onset of symptoms of post-traumatic stress disorder after deployment.


JAMA | 2008

Alcohol Use and Alcohol-Related Problems Before and After Military Combat Deployment

Isabel G. Jacobson; Margaret A. K. Ryan; Tomoko I. Hooper; Tyler C. Smith; Paul J. Amoroso; Edward J. Boyko; Gary D. Gackstetter; Timothy S. Wells; Nicole S. Bell

CONTEXT High rates of alcohol misuse after deployment have been reported among personnel returning from past conflicts, yet investigations of alcohol misuse after return from the current wars in Iraq and Afghanistan are lacking. OBJECTIVES To determine whether deployment with combat exposures was associated with new-onset or continued alcohol consumption, binge drinking, and alcohol-related problems. DESIGN, SETTING, AND PARTICIPANTS Data were from Millennium Cohort Study participants who completed both a baseline (July 2001 to June 2003; n=77,047) and follow-up (June 2004 to February 2006; n=55,021) questionnaire (follow-up response rate = 71.4%). After we applied exclusion criteria, our analyses included 48,481 participants (active duty, n = 26,613; Reserve or National Guard, n = 21,868). Of these, 5510 deployed with combat exposures, 5661 deployed without combat exposures, and 37 310 did not deploy. MAIN OUTCOME MEASURES New-onset and continued heavy weekly drinking, binge drinking, and alcohol-related problems at follow-up. RESULTS Baseline prevalence of heavy weekly drinking, binge drinking, and alcohol-related problems among Reserve or National Guard personnel who deployed with combat exposures was 9.0%, 53.6%, and 15.2%, respectively; follow-up prevalence was 12.5%, 53.0%, and 11.9%, respectively; and new-onset rates were 8.8%, 25.6%, and 7.1%, respectively. Among active-duty personnel, new-onset rates were 6.0%, 26.6%, and 4.8%, respectively. Reserve and National Guard personnel who deployed and reported combat exposures were significantly more likely to experience new-onset heavy weekly drinking (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.36-1.96), binge drinking (OR, 1.46; 95% CI, 1.24-1.71), and alcohol-related problems (OR, 1.63; 95% CI, 1.33-2.01) compared with nondeployed personnel. The youngest members of the cohort were at highest risk for all alcohol-related outcomes. CONCLUSION Reserve and National Guard personnel and younger service members who deploy with reported combat exposures are at increased risk of new-onset heavy weekly drinking, binge drinking, and alcohol-related problems.


American Journal of Public Health | 2010

A Prospective Study of Depression Following Combat Deployment in Support of the Wars in Iraq and Afghanistan

Timothy S. Wells; Cynthia A. LeardMann; Sarah O. Fortuna; Besa Smith; Tyler C. Smith; Margaret A. K. Ryan; Edward J. Boyko; Dan G. Blazer

OBJECTIVE We investigated relations between deployment and new-onset depression among US service members recently deployed to the wars in Iraq and Afghanistan. METHODS We included 40 219 Millennium Cohort Study participants who completed baseline and follow-up questionnaires and met inclusion criteria. Participants were identified with depression if they met the Primary Care Evaluation of Mental Disorders Patient Health Questionnaire criteria for depression at follow-up, but not at baseline. RESULTS Deployed men and women with combat exposures had the highest onset of depression, followed by those not deployed and those deployed without combat exposures. Combat-deployed men and women were at increased risk for new-onset depression compared with nondeployed men and women (men: adjusted odds ratio [AOR]=1.32; 95% confidence interval [CI]=1.13, 1.54; women: AOR=2.13; 95% CI=1.70, 2.65). Conversely, deployment without combat exposures led to decreased risk for new-onset depression compared with those who did not deploy (men: AOR=0.66; 95% CI=0.53, 0.83; women: AOR=0.65; 95% CI=0.47, 0.89). CONCLUSIONS Deployment with combat exposures is a risk factor for new-onset depression among US service members. Post-deployment screening may be beneficial for US service members exposed to combat.


Clinical Infectious Diseases | 2000

Adult Adenovirus Infections: Loss of Orphaned Vaccines Precipitates Military Respiratory Disease Epidemics

Gregory C. Gray; Pulak R. Goswami; Marietta D. Malasig; Anthony W. Hawksworth; David H. Trump; Margaret A. K. Ryan; David P. Schnurr

Adenovirus vaccines have greatly reduced military respiratory disease morbidity since the 1970s. However, in 1995, for economic reasons, the sole manufacturer of these vaccines ceased production. A population-based adenovirus surveillance was established among trainees with acute respiratory illness at 4 US military training centers as the last stores of vaccines were depleted. From October 1996 to June 1998, 1814 (53.1%) of 3413 throat cultures for symptomatic trainees (78% men) yielded adenovirus. Adenovirus types 4, 7, 3, and 21 accounted for 57%, 25%, 9%, and 7% of the isolates, respectively. Unvaccinated trainees were much more likely than vaccinated trainees to be positive for types 4 or 7 (odds ratio [OR] = 28.1; 95% CI, 20.2-39.2). Two training centers experienced epidemics of respiratory disease affecting thousands of trainees when vaccines were not available. Until a new manufacturer is identified, the loss of orphaned adenovirus vaccines will result in thousands of additional preventable adenovirus infections.


American Journal of Preventive Medicine | 2001

Handwashing and respiratory illness among young adults in military training

Margaret A. K. Ryan; Rebecca S Christian; Julie Wohlrabe

OBJECTIVES In response to increasing concerns about respiratory illness in military recruits, a simple handwashing program was developed and evaluated at a large Navy training center. METHODS Clinical records from 1996 through 1998 were reviewed to determine weekly rates of respiratory illness before and after program implementation (1,089,800 person-weeks reviewed). A supplemental survey was given to a sample of recruits to assess self-reported respiratory illness and compliance with the handwashing program. RESULTS A 45% reduction in total outpatient visits for respiratory illness was observed after implementation of the handwashing program. No change was noted in hospitalization rates for respiratory illness, which remained low during the observation period. Survey data supported clinical observations, as frequent handwashers self-reported fewer respiratory illness episodes when compared to infrequent handwashers. Surveys also revealed challenges with handwashing compliance. CONCLUSIONS Implementation of a handwashing program in this population of healthy young adults was associated with a marked reduction in outpatient visits for respiratory illness. Despite its success, maintenance of the handwashing program has been challenging in the time-constrained setting of military training.


Journal of Clinical Microbiology | 2004

Risk Factors for Community-Associated Methicillin-Resistant Staphylococcus aureus Infections in an Outbreak of Disease among Military Trainees in San Diego, California, in 2002

Katherine M. Campbell; Andrew F. Vaughn; Kevin L. Russell; Besa Smith; Dinice L. Jimenez; Christopher P. Barrozo; John R. Minarcik; Nancy F. Crum; Margaret A. K. Ryan

ABSTRACT An outbreak of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) skin infections was observed in a population of U.S. military trainees in the summer of 2002. A questionnaire was developed and administered to 206 trainees, 22 of whom had MRSA infections. Factors associated with infection were described by multivariable logistic regression modeling and included having a roommate in training with a prior skin infection (odds ratio [OR] = 3.44) or having a family member or friend who worked in a health care setting (OR = 2.79). Previous antibiotic use, hospitalization, or health problems were not associated with MRSA infection. This outbreak of MRSA skin infections in an otherwise-healthy, well-defined, military population provided an opportunity to describe risk factors for CA-MRSA which may help focus prevention efforts in this and other communities.


The Journal of Infectious Diseases | 2006

Transmission Dynamics and Prospective Environmental Sampling of Adenovirus in a Military Recruit Setting

Kevin L. Russell; Michael P. Broderick; Suzanne E. Franklin; Lawrence B. Blyn; Nikki E. Freed; Emily Moradi; David J. Ecker; Peter Kammerer; Miguel Osuna; Adriana E. Kajon; Cassandra B. Morn; Margaret A. K. Ryan

Abstract BackgroundHigh levels of morbidity caused by adenovirus among US military recruits have returned since the loss of adenovirus vaccines in 1999. The transmission dynamics of adenovirus have never been well understood, which complicates prevention efforts MethodsEnrollment and end-of-study samples were obtained and active surveillance for febrile respiratory illnesses (FRIs) was performed for 341 recruits and support personnel. Environmental samples were collected simultaneously. Classic and advanced diagnostic techniques were used ResultsSeventy-nine percent (213/271) of new recruits were seronegative for either adenovirus serotype 4 (Ad-4) or adenovirus serotype 7 (Ad-7). FRI caused by Ad-4 was observed in 25% (67/271) of enrolled recruits, with 100% of them occurring in individuals with enrollment titers <1:4. The percentage of recruits seropositive for Ad-4 increased from 34% at enrollment to 97% by the end of the study. Adenovirus was most commonly detected in the environment on pillows, lockers, and rifles ConclusionsPotential sources of adenovirus transmission among US military recruits included the presence of adenovirus on surfaces in living quarters and extended pharyngeal viral shedding over the course of several days. The introduction of new recruits, who were still shedding adenovirus, into new training groups was documented. Serological screening could identify susceptible recruits for the optimal use of available vaccines. New high-throughput technologies show promise in providing valuable data for clinical and research applications


Journal of Clinical Microbiology | 2005

PCR analysis of egyptian respiratory adenovirus isolates, including identification of species, serotypes, and coinfections

David Metzgar; Miguel Osuna; Samuel L. Yingst; Magda Rakha; Kenneth C. Earhart; Diaa Elyan; Hala Esmat; Magdi D. Saad; Adriana E. Kajon; Jianguo Wu; Gregory C. Gray; Margaret A. K. Ryan; Kevin L. Russell

ABSTRACT Eighty-eight adenovirus (Ad) isolates and associated clinical data were collected from walk-in patients with influenza-like illness in Egypt during routine influenza surveillance from 1999 through 2002. Respiratory Ad distributions are geographically variable, and serotype prevalence has not been previously characterized in this region. Serotype identity is clinically relevant because it predicts vaccine efficacy and correlates strongly with both clinical presentation and epidemiological pattern. Species and serotype identities were determined using several well-validated multiplex PCR protocols culled from the literature and supplemented with a few novel primer sets designed to identify rare types. The isolates included common species B1 serotypes (Ad3 and Ad7), common species C serotypes (Ad1, Ad2, and Ad5), the less common species B2 serotype Ad11, and three isolates of the rare species B1 serotype Ad16. Two isolates that appear to be variant Ad16 were also identified. Fifteen coinfections of multiple adenoviral types, primarily AdB/AdC and Ad3/Ad7 dual infections, were detected. The majority of these were verified using redundant PCR tests targeted at multiple genes. PCR is able to resolve coinfections, in contrast to traditional serum neutralization tests. PCR is also comparatively rapid and requires very little equipment. Application of the method allowed an inclusive determination of the serotypes found in the Egyptian respiratory sample set and demonstrated that coinfections are common and may play a previously unrecognized role in adenovirus pathogenesis, evolution, and epidemiology. In particular, coinfections may influence adenoviral evolution, as interserotypic recombination has been identified as a source of emerging strains.


American Journal of Preventive Medicine | 2008

Cigarette Smoking and Military Deployment : A Prospective Evaluation

Besa Smith; Margaret A. K. Ryan; Deborah L. Wingard; Thomas L. Patterson; Donald J. Slymen; Caroline A. Macera

BACKGROUND The stress of military deployment may compound occupational stress experienced in the military and manifest in maladaptive coping behaviors such as cigarette smoking. The current study describes new smoking among never-smokers, smoking recidivism among past smokers, and change in daily smoking among smokers in relation to military deployment. METHODS The Millennium Cohort is a 21-year longitudinal study. The current analysis utilized participants (N=48,304) who submitted baseline data (July 2001-June 2003) before the current conflicts in Iraq and Afghanistan and follow-up data (June 2004-January 2006) on health measures. New smoking was identified among baseline never-smokers, smoking recidivism among baseline past smokers, and increased or decreased daily smoking among baseline smokers. Analyses were conducted March 2007-April 2007. RESULTS Among never-smokers, smoking initiation was identified in 1.3% of nondeployers and 2.3% of deployers. Among past smokers, smoking resumption occurred in 28.7% of nondeployers and 39.4% of those who deployed. Smoking increased 44% among nondeployers and 57% among deployers. Those who deployed and reported combat exposures were at 1.6 times greater odds of initiating smoking among baseline never-smokers (95% CI=1.2, 2.3) and at 1.3 times greater odds of resuming smoking among baseline past smokers when compared to those who did not report combat exposures. Other deployment factors independently associated with postdeployment smoking recidivism included deploying for >9 months and deploying multiple times. Among those who smoked at baseline, deployment was not associated with changes in daily amount smoked. CONCLUSIONS Military deployment is associated with smoking initiation and, more strongly, with smoking recidivism, particularly among those with prolonged deployments, multiple deployments, or combat exposures. Prevention programs should focus on the prevention of smoking relapse during or after deployment.


Clinical Infectious Diseases | 2002

Large Epidemic of Respiratory Illness Due to Adenovirus Types 7 and 3 in Healthy Young Adults

Margaret A. K. Ryan; Gregory C. Gray; Besa Smith; Jamie A. McKeehan; Anthony W. Hawksworth; Marietta D. Malasig

After 25 years of successful control through immunization, respiratory infections due to adenoviruses have reemerged to threaten the health of young adults in the military. Shortly after the loss of adenovirus vaccine supplies, a large outbreak of respiratory illness was observed at the United States Navys sole basic training center. Laboratory testing confirmed 541 cases of adenovirus infection, including 378 cases due to serotype 7 and 132 cases due to serotype 3. This outbreak was remarkable because of its unique serotype distribution and the large amount of data available to describe demographic factors associated with infection. This was the largest outbreak of respiratory illness due to adenovirus types 7 and 3 documented in recent history, and it portends even greater challenges for young adults in the military in the postvaccine era.

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Tyler C. Smith

Naval Medical Center San Diego

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Besa Smith

Naval Medical Center San Diego

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Margie L. Homer

California Institute of Technology

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Timothy S. Wells

Wright-Patterson Air Force Base

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Adam Kisor

California Institute of Technology

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Isabel G. Jacobson

Naval Medical Center San Diego

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R. M. Williams

California Institute of Technology

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Gary D. Gackstetter

Uniformed Services University of the Health Sciences

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