Ava Marie S. Conlin

Halting a pneumococcal pneumonia outbreak among United States Marine Corps trainees

BACKGROUND Streptococcus pneumoniae is the leading cause of bacterial pneumonia in all age groups. Identifying outbreaks of pneumococcal disease and key risk factors may lead to improvements in vaccination and prevention strategies for high-risk groups. A significant outbreak of S. pneumoniae pneumonia that occurred among Marine recruits is reported here. METHODS An outbreak was investigated using standard microbiologic procedures and epidemiologic evaluation to define the extent of the outbreak, determine the microbiologic causative agent(s), identify risk factors for the development of disease, and institute preventive measures against further cases of pneumonia among recruits. RESULTS Fifty-two cases of radiographically confirmed pneumonia occurred among 3367 Marine recruits over a 2-week period in November 2000. Twenty-five of these cases occurred in a single company of 481 men, with an attack rate of 5.2%. Twelve of the 25 cases were caused by S. pneumoniae, serotypes 4 and 9v. The outbreak rapidly ended following isolation of cases, prophylaxis with oral azithromycin, and administration of the 23-valent pneumococcal vaccine. CONCLUSIONS This outbreak of pneumococcal disease occurred in the setting of intense military training and a crowded environment. The use of the pneumococcal vaccine year-round in military trainees and other high-risk populations to reduce pneumococcal disease should be considered.

Safety of the pandemic H1N1 influenza vaccine among pregnant U.S. military women and their newborns.

OBJECTIVES: To assess adverse pregnancy outcomes among active-duty U.S. military women who received pandemic H1N1 vaccine during pregnancy as well as adverse health outcomes among the newborns resulting from these pregnancies. METHODS: The primary study population was a retrospective cohort of active-duty U.S. military women vaccinated during pregnancy with either the pandemic H1N1 vaccine between October 2009 and June 2010 or with seasonal influenza vaccine between October 2008 and June 2009. Rates of pregnancy loss, preeclampsia or eclampsia, and preterm labor were compared between pandemic H1N1 vaccine-exposed (n=10,376) and seasonal influenza vaccine-exposed pregnancies (n=7,560). A secondary study population consisted of newborns resulting from these pregnancies. Rates of preterm birth, birth defects, fetal growth problems, and the male-to-female sex ratio were compared between newborns exposed to pandemic H1N1 vaccine and newborns exposed to seasonal influenza vaccine in utero. RESULTS: No significant differences were observed in rates of pregnancy loss (6.4% compared with 6.5%), preeclampsia or eclampsia (5.8% compared with 5.2%), or preterm labor (6.5% compared with 6.2%) between pandemic H1N1 vaccine-exposed and seasonal influenza vaccine-exposed pregnancies. Furthermore, no significant differences were observed in rates of preterm birth (6.2% compared with 6.3%), birth defects (2.1% compared with 2.0%), fetal growth problems (2.6% compared with 2.4%), or the male-to-female sex ratio (1.05 compared with 1.07) between newborns exposed in utero to pandemic H1N1 vaccine compared with seasonal influenza vaccine. Rates of all outcomes were lower or similar to overall general population rates. This study had at least 80% power to detect hazard ratios of 1.18–1.21 or odds ratios of 1.10–1.36, depending on outcome prevalence. CONCLUSION: No adverse pregnancy or newborn health outcomes associated with pandemic H1N1 vaccination during pregnancy were noted among our cohort. These findings should be used to encourage increased vaccine coverage among pregnant women. LEVEL OF EVIDENCE: II

Does acute maternal stress in pregnancy affect infant health outcomes? Examination of a large cohort of infants born after the terrorist attacks of September 11, 2001

BackgroundInfants in utero during the terrorist attacks of September 11, 2001 may have been negatively affected by maternal stress. Studies to date have produced contradictory results.MethodsData for this retrospective cohort study were obtained from the Department of Defense Birth and Infant Health Registry and included up to 164,743 infants born to active-duty military families. Infants were considered exposed if they were in utero on September 11, 2001, while the referent group included infants gestating in the same period in the preceding and following year (2000 and 2002). We investigated the association of this acute stress during pregnancy with the infant health outcomes of male:female sex ratio, birth defects, preterm birth, and growth deficiencies in utero and in infancy.ResultsNo difference in sex ratio was observed between infants in utero in the first trimester of pregnancy on September 11, 2001 and infants in the referent population. Examination of the relationship between first-trimester exposure and birth defects also revealed no significant associations. In adjusted multivariable models, neither preterm birth nor growth deficiencies were significantly associated with the maternal exposure to the stress of September 11 during pregnancy.ConclusionThe findings from this large population-based study suggest that women who were pregnant during the terrorist attacks of September 11, 2001 had no increased risk of adverse infant health outcomes.

Evaluation of preterm births and birth defects in liveborn infants of US military women who received smallpox vaccine.

BACKGROUND Women serving in the US military have some unique occupational exposures, including exposure to vaccinations that are rarely required in civilian professions. When vaccinations are inadvertently given during pregnancy, such exposures raise special concerns. These analyses address health outcomes, particularly preterm births and birth defects, among infants who appear to have been exposed to maternal smallpox vaccination in pregnancy. METHODS This retrospective cohort study included 31,420 infants born to active-duty military women during 2003-2004. We used Department of Defense databases to define maternal vaccination and infant health outcomes. Multivariable regression models were developed to describe associations between maternal smallpox vaccination and preterm births and birth defects in liveborn infants. RESULTS There were 7,735 infants identified as born to women ever vaccinated against smallpox, and 672 infants born to women vaccinated in the first trimester of pregnancy. In multivariable modeling, maternal smallpox vaccination in pregnancy was not associated with preterm or extreme preterm delivery. Maternal smallpox vaccination in the first trimester of pregnancy was not significantly associated with overall birth defects (OR 1.40; 95% CI: 0.94, 2.07), or any of seven specific defects individually modeled. CONCLUSIONS Results may be reassuring that smallpox vaccine, when inadvertently administered to pregnant women, is not associated with preterm delivery or birth defects in liveborn infants.

Infant Abusive Head Trauma in a Military Cohort

OBJECTIVE: Evaluate the rate of, and risk factors for, abusive head trauma (AHT) among infants born to military families and compare with civilian population rates. METHODS: Electronic International Classification of Diseases data from the US Department of Defense (DoD) Birth and Infant Health Registry were used to identify infants born to military families from 1998 through 2005 (N = 676 827) who met the study definition for AHT. DoD Family Advocacy Program data were used to identify infants with substantiated reports of abuse. Rates within the military were compared with civilian population rates by applying an alternate AHT case definition used in a civilian study. RESULTS: Applying the study definition, the estimated rate of substantiated military AHT was 34.0 cases in the first year of life per 100 000 live births. Using the alternate case definition, the estimated AHT rate was 25.6 cases per 100 000 live births. Infant risk factors for AHT included male sex, premature birth, and a diagnosed major birth defect. Parental risk factors included young maternal age (<21 years), lower sponsor rank or pay grade, and current maternal military service. CONCLUSIONS: This is the first large database study of AHT with the ability to link investigative results to cases. Overall rates of AHT were consistent with civilian populations when using the same case definition codes. Infants most at risk, warranting special attention from military family support programs, include infants with parents in lower military pay grades, infants with military mothers, and infants born premature or with birth defects.

Birth outcomes among military personnel after exposure to documented open-air burn pits before and during pregnancy.

Objective: To examine birth outcomes in military women and men with potential exposure to documented open-air burn pits before and during pregnancy. Methods: Electronic data from the Department of Defense Birth and Infant Health Registry and the Defense Manpower Data Center were used to examine the prevalence of birth defects and preterm birth among infants of active-duty women and men who were deployed within a 3-mile radius of a documented open-air burn pit before or during pregnancy. Results: In general, burn pit exposure at various times in relation to pregnancy and for differing durations was not consistently associated with an increase in birth defects or preterm birth in infants of active-duty military personnel. Conclusions: These analyses offer reassurance to service members that burn pit exposure is not consistently associated with these select adverse infant health outcomes.

Analysis of pregnancy and infant health outcomes among women in the National Smallpox Vaccine in Pregnancy Registry who received Anthrax Vaccine Adsorbed.

The National Smallpox Vaccine in Pregnancy Registry (NSVIPR) actively follows women inadvertently vaccinated with smallpox vaccine during or shortly before pregnancy to evaluate their reproductive health outcomes. Approximately 65% of NSVIPR participants also inadvertently received Anthrax Vaccine Adsorbed (AVA) while pregnant, providing a ready opportunity to evaluate pregnancy and infant health outcomes among these women. AVA-exposed pregnancies were ascertained using NSVIPR and electronic healthcare data. Rates of pregnancy loss and infant health outcomes, including major birth defects, were compared between AVA-exposed and AVA-unexposed pregnancies. Analyses included AVA-exposed and AVA-unexposed pregnant women who also received smallpox vaccine 28 days prior to or during pregnancy. Rates of adverse outcomes among the AVA-exposed group were similar to or lower than expected when compared with published reference rates and the AVA-unexposed population. The findings provide reassurance of the safety of AVA when inadvertently received by a relatively young and healthy population during pregnancy.

Is Military Deployment a Risk Factor for Maternal Depression

BACKGROUND Maternal depression is a common condition among new mothers that can be associated with poor maternal health and negative consequences on infant health. Little research has been conducted to examine maternal depression, especially among military mothers, where unique conditions often exist. Using data from a large military cohort, this study prospectively examined the relationship between deployment experience before and after childbirth and maternal depression among U.S. service women. METHODS The study included 1,660 female Millennium Cohort participants who gave birth during active duty service and completed baseline and follow-up questionnaires between 2001 and 2008. Maternal depression was assessed at follow-up using Primary Care Evaluation of Mental Disorders Patient Health Questionnaire criteria. RESULTS Deployment before childbirth, regardless of combat experience, and deployment without combat experience after childbirth did not increase the risk of maternal depression. Women who deployed and reported combat experience after childbirth were at increased risk for maternal depression compared with nondeployed women who gave birth (adjusted odds ratio [OR] 2.01, 95% confidence interval [CI] 1.17-3.43). Among the subgroup of female combat deployers, however, women who gave birth did not have a significantly increased risk for depression compared with those who did not give birth. CONCLUSIONS Military women who deployed with combatlike experiences after childbirth were at increased risk for postdeployment maternal depression. The risk, however, appeared primarily related to combat rather than childbirth-related experiences.

Health outcomes among infants born to women deployed to United States military operations during pregnancy

BACKGROUND Military professionals who deploy to combat operations may encounter hazards that could adversely affect reproductive health. Pregnant women are generally exempt from deployment to military operations; however, exposures to such environments may inadvertently occur. We investigated whether maternal deployment during pregnancy was associated with adverse health outcomes in infants. METHODS The United States Department of Defense Birth and Infant Health Registry identified infants born to military service women between 2002 and 2005, and defined their health outcomes at birth and in the first year of life. Multivariable modeling was applied to investigate preterm birth and birth defects among infants, based on maternal deployment experience during pregnancy. RESULTS Among 63,056 infants born to military women from 2002 to 2005, 22,596 were born to women with deployment experience in support of the current military operations before, during, or after their pregnancy. These included 2941 infants born to women who appeared to have been deployed some time during their first trimester of pregnancy. Compared to infants born to women who deployed at other times, or never deployed, exposed infants were not more likely to be born preterm, diagnosed with a major birth defect, or diagnosed with a malignancy. CONCLUSIONS In this exploratory analysis, infants born to women who inadvertently deployed to military operations during their pregnancy were not at increased risk of adverse birth or infant health outcomes. Future analyses should examine outcomes related to specific maternal exposures during deployment, and outcomes among the growing number of infants conceived after deployment.