Surveillance for Vector-borne Diseases Among Active and Reserve Component Service Members, U.S. Armed Forces, 2016-2020.

This report summarizes data from electronic reports of reportable medical events (RMEs) to examine the incidence of vector-borne infectious diseases among members of the U.S. Armed Forces during a recent 5-year period. Case reports of such diseases were characterized as confirmed, probable, or suspected by the senders of the RME reports. Records of inpatient and outpatient care were not searched to find additional cases. Lyme disease and malaria were the most common diagnoses among confirmed cases. The next most common diagnoses were Zika virus infection, Rocky Mountain spotted fever, and dengue. Those 5 diseases were responsible for 94% of all confirmed vectorborne diseases reported as RMEs. Among the 1,068 RMEs for vector-borne diseases (confirmed, probable, and suspected), there were only 105 such cases that could be linked to a record of hospitalization for the same diagnosis.

Re-evaluation of the MSMR Case Definition for Incident Cases of Malaria.

The MSMR has been publishing the results of surveillance studies of malaria since 1995. The standard MSMR case definition uses Medical Event Reports and records of hospitalizations in counting cases of malaria. This report summarizes the performance of the standard MSMR case definition in estimating incident cases of malaria from 2015 through 2017. Also explored was the potential surveillance value of including outpatient encounters with diagnoses of malaria or positive laboratory tests for malaria in the case definition. The study corroborated the relative accuracy of the MSMR case definition in estimating malaria incidence and provided the basis for updating the case definition in 2019 to include positive laboratory tests for malaria antigen within 30 days of an outpatient diagnosis.

Incidence rates of diagnoses of cardiovascular diseases and associated risk factors, active component, U.S. Armed Forces, 2007-2016.

During 2007-2016, 18.1% of all active component service members were diagnosed with at least one of the five risk factors for cardiovascular disease (CVD) studied in this analysis. In addition, 0.6% of service members were diagnosed with at least one of the four CVDs studied. The most frequently diagnosed risk factors were (in descending order of frequency) obesity, hyperlipidemia, essential hypertension, abnormal blood glucose level, and diabetes mellitus. Incidence rates of both risk factors and CVD were progressively higher with advancing age. Annual incidence rates during the 10-year period declined for the risk factors hyperlipidemia, hypertension, and diabetes, but rose for obesity and abnormal blood glucose level. Annual rates of the CVDs ischemic heart disease and cerebrovascular disease declined, but rates of hypertensive heart/kidney disease and atherosclerosis remained relatively stable. Noteworthy findings were the increase in incidence rates of obesity, the decline in incidence rates of ischemic heart disease, and the decline in rates of hypertension in non-Hispanic black service members. The identification of CVD risk factors, including others not studied in this analysis, offers the opportunity for preventive interventions that can reduce the rates of clinical CVD during, but especially after, military service.

Surveillance for vector-borne diseases among active and reserve component service members, U.S. Armed Forces, 2010-2016.

This report summarizes available health record information about the occurrence of vector-borne infectious diseases among members of the U.S. Armed Forces during a recent 7-year surveillance period. Information about confirmed, possible, and suspected cases was obtained from electronic reports of reportable medical events (RMEs) and records of diagnoses documented during hospitalizations and outpatient healthcare encounters. Lyme disease and malaria were the most common diagnoses among confirmed and possible cases. Diagnoses of chikungunya and Zika were elevated in the years following their respective entries into the Western Hemisphere. Large numbers of diagnoses of arboviral diseases were recorded in the category of suspected cases, but the overwhelming majority were associated with coding errors and tentative diagnoses not subsequently confirmed. For many confirmed cases, documentation could not be found in healthcare databases for positive laboratory tests that would be the basis for confirmation. Discussion covers the limitations of the available data and the importance to surveillance of RMEs, confirmatory laboratory tests, and accurate recording of diagnoses and their codes.

Update: Cold weather injuries, active and reserve components, U.S. Armed Forces, July 2012-June 2017.

From July 2016 through June 2017, a total of 387 members of the active (n=328) and reserve (n=59) components had at least one medical encounter with a primary diagnosis of cold injury. Among active component service members, the total number of cold injuries in the 2016-2017 cold season was the lowest since 1999 and the overall incidence rate was lower than in any of the previous four cold seasons. Frostbite was the most common type of cold injury. During the five cold seasons in the surveillance period (2012-2017), rates tended to be higher among service members who were in the youngest age groups, female, non-Hispanic black, or in the Army. The numbers of cold injuries associated with overseas deployments have fallen precipitously in the past three cold seasons and included just 10 cases in the most recent year.

Incidence of Campylobacter intestinal infections, active component, U.S. Armed Forces, 2007-2016.

During 2007-2016, there were 1,753 diagnosed cases of Campylobacter intestinal infection among active component service members. The overall rate for the period was 14.1 cases per 100,000 person-years (p-yrs), but the annual incidence rates steadily increased from 7.6 cases per 100,000 p-yrs in 2007 to 22.1 cases per 100,000 p-yrs in 2016. Overall rates were higher in females, those aged 45 years or older, members of the Air Force and Army, offi cers, and those in military healthcare occupations. Incidence rates were lowest among service members who were recruit trainees, younger than 20 years of age, non-Hispanic blacks, and Marines. For the entire 10-year surveillance period, more cases were diagnosed in the warmer months of the year. Only eight cases were diagnosed in deployment settings during the 10-year period. Discussion of the recognized risk factors for Campylobacter infections reviewed the hazards of undercooked meats (especially poultry), unpasteurized milk, and untreated surface water in the environment. The limitations of the study methodology were described.

Diagnoses of traumatic brain injury not clearly associated with deployment, active component, U.S. Armed Forces, 2001-2016.

From 2001 through 2016, a total of 276,858 active component service members received first-time diagnoses of traumatic brain injury (TBI). Person-time and incident cases of TBI were assigned to one of three groups. Group 1 included only service members' person-time before their first-ever deployments. Group 2 included service members' person-time during their overseas deployments and the 30 days after their return from deployment. Group 3 included only service members' person-time more than 30 days after return from deployment. The crude overall incidence rate of TBI among deployed service members (1,690.5 cases per 100,000 person-years [p-yrs]) was 1.5 times that of service members in group 1 (1,141.3 cases per 100,000 p-yrs), and 1.2 times that of service members in group 3 (1,451.2 cases per 100,000 p-yrs). The portion of the surveillance period during which the annual incidence rates of TBI in groups 3 and 2 exceeded the rates in group 1 likely represents, at least in part, the increased risk of service in an active combat zone. For group 2, this period extended from 2007 through 2013. For group 3, this period lasted from 2007 through 2016. Examination of the TBI case-defining encounters with recorded injury causes yielded leading causes similar to those of TBIs in same-aged civilians (land transport and slips, trips, and falls). Factors that may explain why the TBI incidence rates among the previously deployed were higher than those of the never-deployed group are discussed.

Update: Cold weather injuries, active and reserve components, U.S. Armed Forces, July 2011-June 2016.

From July 2015 through June 2016, a total of 447 members of the active (n=383) and reserve (n=64) components had at least one medical encounter with a primary diagnosis of cold injury. The numbers of affected individuals in both components were the lowest since the 2011-2012 cold season, when the total was 394. In the active component, the service-specific incidence rates for each of the four services were lower than the respective rates for the previous (2014-2015) cold season. Frostbite was the most common type of cold injury. During the five cold seasons in the surveillance period (2011-2016), rates tended to be higher among service members who were in the youngest age groups; female; black, non-Hispanic; or in the Army. The numbers of cold injuries associated with service in Iraq and Afghanistan have fallen precipitously in the past four cold seasons and included just 11 cases in the most recent year.

Incidence of abdominal hernias in service members, active component, U.S. Armed Forces, 2005-2014.

From 1 January 2005 through 31 December 2014, a total of 87,480 incident diagnoses of the five types of abdominal hernia (incidence rate 63.3 cases per 10,000 person-years) were documented in the health records of 72,404 active component service members. The overall incidence rate of inguinal hernias among males was six times the rate among females. However, incidence rates of femoral, ventral/incisional, and umbilical hernias were higher among females than males. During the 10-year interval, annual incidence rates for most of the five types of hernia trended downward, but rates increased for umbilical hernias in both males and females and for ventral/ incisional hernias among females. For most types of hernia, the incidence rates tended to be higher among the older age groups. Health records documented 35,624 surgical procedures whose descriptions corresponded to the types of hernia diagnoses in the service members. Most repair procedures were performed in outpatient settings. The proportion of surgical procedures performed via laparoscopy increased during the period, but the majority of operations were open procedures. The limitations to the generalizability of the findings in this study are discussed.

Incidence of hiatal hernia in service members, active component, U.S. Armed Forces, 2005-2014.

From 2005 through 2014, a total of 27,276 active component service members had incident diagnoses of hiatal hernia documented in their medical records. The overall incidence rate was 19.7 cases per 10,000 person-years (p-yrs); annual incidence rates ranged from 16.5 to 22.2 cases per 10,000 p-yrs. Rates overall increased monotonically with increasing age and were higher among Air Force and Army members, officers, and healthcare workers than their respective counterparts. During the surveillance period, the 27,276 service members who had incident diagnoses of hiatal hernia accounted for 44,092 hiatal hernia-related encounters overall (1.6 encounters per case). Among all incident cases, 235 (0.86%) had surgical repairs documented during the period. The frequency of surgical treatment of hiatal hernias among military members mirrored the low frequency in U.S. civilian practice. During 2010-2014, most surgical procedures (79%) were accomplished via laparoscopic approaches. The incidence rates of hiatal hernia diagnoses reported here likely greatly underestimate the true incidence in U.S. military populations. Reasons for the underestimates and comparisons with other populations are discussed.

Update: Urinary stones, active component, U.S. Armed Forces, 2011-2015.

Urinary stones can cause debilitating morbidity that impairs the operational effectiveness of affected members of the U.S. Armed Forces. This report documents that, during the past 5 years, rates of incident diagnoses of urinary stones decreased by about 17% in the active component of the U.S. military. During the period, annual rates of inpatient diagnosed cases were low and relatively stable, while rates of outpatient diagnosed cases slightly decreased. Incidence rates were slightly higher among females than males in 2011; however, rates were very similar among males and females from 2012 through 2015. Rates of incident diagnoses among white, non-Hispanic and Native American/Alaska Native service members were consistently 80%-100% higher than among black, non-Hispanic and Asian/Pacific Islander service members and 35%-45% higher than among Hispanic and "other race/ethnicity" service members. During the 5-year period, a total of 3,350 service members received more than one incident diagnosis of urinary stones ("recurrent cases"); one-tenth (10.2%) of all incident cases during the period were recurrent cases. Service members with histories of urinary stones should be counseled and closely supervised to avoid dehydration and to adhere to diets that reduce the risk of stone formation.

Incidence of gastroesophageal reflux disease (GERD), active component, U.S. Armed Forces, 2005-2014.

Gastroesophageal reflux disease (GERD) is a common condition among adults that can cause symptoms such as frequent heartburn, substernal chest pain, and regurgitation of food. During 2005-2014, a total of 137,081 active component service members had an incident (first-ever) diagnosis of GERD (incidence rate: 101.3 per 10,000 person-years). Incidence rates were higher than their respective counterparts among females, black and white non-Hispanics, service members in the Coast Guard and Air Force, officers, and those in healthcare occupations. Rates increased monotonically with increasing age groups. Most GERD cases (79.2%) were uncomplicated GERD; however, 20.8% were identified as having a symptom or complication linked to their GERD diagnosis. Lifestyle changes, medication, and prevention of serious complications should be emphasized among individuals diagnosed with GERD, particularly those at risk for severe disease.

Risk of Mental Health Disorders Following an Initial Diagnosis of Postpartum Depression, Active Component, U.S. Armed Forces, 1998-2010.

Postpartum depression (PPD) is one of the most common psychiatric conditions of the postpartum period. Several studies have found an association between PPD and other mental health disorders. The Defense Medical Surveillance System (DMSS) was used to identify a cohort of primiparous service women with PPD between 1998 and 2010 and match them by month of delivery to a cohort of women without PPD. During the surveillance period, there were 5,203 incident cases of PPD with a crude rate of 44.9 per 1,000 person-years. Individuals in the PPD cohort, when compared to their matched controls, were at higher risk for subsequent depressive disorders (adjusted hazard ratio [HR]: 7.3 [95% CI: 5.2-10.3]), anxiety disorders (adjusted HR: 3.2 [95% CI: 2.5-4.0]), and bipolar disorders (adjusted HR: 4.7 [95% CI: 1.9-11.9]). There were higher rates of these mental health diagnoses among individuals who eventually left service. Early screening, support, and treatment are essential during this vulnerable postpartum time frame to preserve the female fighting force.

Incidence and prevalence of diagnoses of eye disorders of refraction and accommodation, active component service members, U.S. Armed Forces, 2000-2014.

More than half of service members on duty in the active component of the U.S. Armed Forces in July 2014 had been previously diagnosed with at least one of the eye disorders of refraction and accommodation examined in this report. During 2000-2014, the most common diagnoses among service members, in descending order of frequency, were myopia, astigmatism, hyperopia, and presbyopia. The incidence rates for myopia were highest among those younger than 30 years and the rates for hyperopia and presbyopia were highest among those older than 39 years. Incidence rates and prevalence for all the disorders examined were higher among females than males. The methodological limitations of the analysis are discussed with respect to the generalizability of the results to the U.S population.

Measles and mumps among service members and other beneficiaries of the U.S. Military Health System, January 2007-December 2014.

Measles and mumps are highly communicable infectious diseases whose causative viruses are spread through airborne droplets and infected surfaces. Individuals at highest risk are infants and unvaccinated individuals. Despite effective vaccines, there have been recent increases in incidence in the U.S. of both infections. During the surveillance period, there were 14 confirmed measles cases and 99 confirmed mumps cases among U.S. military members and other beneficiaries of the U.S. Military Health System. Only one of the confirmed cases of measles was in a service member. Children aged 5 years and younger accounted for the greatest proportion of confirmed measles cases (50.0%); the greatest proportions of confirmed mumps cases were for children aged 1-5 years and adults aged 26-30 years (22.2% and 17.2%, respectively). California had more cases of both measles and mumps than any other state. Recent trends in measles and mumps in civilian populations in the U.S. highlight the importance of primary and booster vaccinations.

Incidence of Salmonella infections among service members of the active and reserve components of the U.S. Armed Forces and among other beneficiaries of the Military Health System, 2000-2013.

This report reviews the incidence of cases of typhoidal and non-typhoidal Salmonella infections based on diagnoses recorded in healthcare records and reported through the Armed Forces reportable medical event (RME) system. During 2000-2013, there were 1,815 incident cases of non-typhoidal Salmonella and 456 incident cases of typhoidal Salmonella diagnosed in the active component force. The crude incidence rate for non-typhoidal Salmonella was 0.91 cases per 10,000 person years (p-yrs) and the rate for typhoidal Salmonella was 0.23 cases per 10,000 p-yrs. Among retirees and family members, children under 5 years of age and those aged 75 years or older comprised the greatest number of non-typhoidal Salmonella cases. Preventive measures for reducing the risk of infection with Salmonella are discussed.

Follow-up analysis of the incidence of acute respiratory infections among enlisted service members during their first year of military service before and after the 2011 resumption of adenovirus vaccination of basic trainees.

This analysis estimated the incidence rates of acute respiratory infections (ARIs) during the first year of military service for service members in 16 cohorts (designated 1999 through 2014) based on the years in which they began their service. That first year of service was divided into two separate follow-up periods: the first 3 months of service (corresponding to the period of initial entry training) and the next 9 months of service (months 4-12). The surveillance period covered service members whose first years of service were before and after the 2011 resumption of the administration of adenovirus vaccines, types 4 and 7, to enlisted trainees at the beginning of their initial training periods. In general, the findings were that incidence rates of ARIs were relatively high for the cohorts who did not receive the vaccines, and that the rates were dramatically lower in the cohorts (2012-2014) who did receive the vaccines. These observations pertained to both the first 3 months of service and the next 9 months of service. Possible interpretations of these findings and the limitations of the study methods are discussed.