Heat exhaustion and heat stroke among active component members of the U.S. Armed Forces, 2019-2023.

The most serious types of heat illnesses, heat exhaustion and heat stroke, are occupational hazards associated with many of the military's training and operational environments. These illnesses can typically be prevented by appropriate situational awareness, risk management strategies, along with effective countermeasures. In 2023, the crude incidence of heat stroke and heat exhaustion were 31.7 and 172.7 cases per 100,000 person-years, respectively. The rates of incident heat stroke declined during the 2019 to 2023 surveillance period, but rates of incident heat exhaustion increased over the same period. In 2023, higher rates of heat stroke were observed among male service members compared to their female counterparts, and female service members experienced higher rates of heat exhaustion compared to male personnel. Heat illness rates were also higher among those younger than age 20, Marine Corps and Army service members, non-Hispanic Black service members, and recruits. Leaders, training cadres, and supporting medical and safety personnel must inform their subordinate and supported service members of heat illness risks, preventive measures, early signs and symptoms of illness, and appropriate interventions.

Surveillance of spotted fever rickettsioses at Army installations in the U.S. Central and Atlantic regions, 2012-2018.

Spotted fever rickettsioses (SFR) are emerging in the Atlantic and Central regions of the U.S., though cases have been reported across the contiguous U.S. Military populations may be at increased risk for SFR because of residence in these regions and frequent field training in tick habitats. Surveillance for Rocky Mountain spotted fever in the Army began in 1998 and was expanded to include all SFR in 2017. Between 2016 and 2017, the rate of active component cases reported from Army installations in the Atlantic and Central regions of the U.S. increased nearly five-fold from 2016 (0.55 per 100,000 person-years [p-yrs]) to 2017 (2.65 per 100,000 p-yrs). The majority of SFR cases were reported from Fort Leonard Wood, MO, and Fort Bragg, NC. Most reported cases had no documented symptoms consistent with SFR and could not be confirmed as "cases" by standard case-defining methods. SFR surveillance and control efforts in military populations can be improved by better adherence to guidelines for SFR diagnosis and through the use of available advanced laboratory techniques.

Prevalence of selected underlying health conditions among active component Army service members with coronavirus disease 2019, 11 February-6 April 2020.

The novel coronavirus (severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) is exhibiting widespread community transmission throughout most of the world. Previous reports have evaluated the risk of serious illness in civilians diagnosed with COVID-19; however, similar reports have not been compiled for the Army active component (AC) population. COVID-19 has been a reportable condition for the Department of Defense since 5 February 2020, and, as of the morning of 6 April, a total of 873 cases were reported to the Disease Reporting System internet from Army installations. Of these cases, a total of 219 (25.1%) were identified as Army AC service members. The majority of these cases did not require hospitalization (n=207; 94.5%). The most common comorbidities present in nonhospitalized cases included other chronic illnesses (43.5%), neurologic disorders (24.6%), and obesity (21.7%). Overall, 12 cases (5.5%) required hospitalization. Hospitalized cases had a history of obesity (58.3%), neurologic disorder (50.0%), other chronic illnesses (41.7%), and hypertension (25.0%). No comorbidities were present among 27.1% (n=56) of nonhospitalized cases and 25.0% (n=3) of hospitalized cases.

Norovirus outbreak in Army service members, Camp Arifjan, Kuwait, May 2018.

In May 2018, an outbreak of gastrointestinal illnesses due to norovirus occurred at Camp Arifjan, Kuwait. The outbreak lasted 14 days, and a total of 91 cases, of which 8 were laboratory confirmed and 83 were suspected, were identified. Because the cases occurred among a population of several thousand service members transiting through a crowded, congregate setting of open bays of up to 250 beds, shared bathrooms and showers, and large dining facilities, the risk of hundreds or thousands of cases was significant. The responsible preventive medicine authorities promptly recognized the potential threat and organized and monitored the comprehensive response that limited the spread of the illness and the duration of the outbreak. This report summarizes findings of the field investigation and the preventive medicine response conducted from 18 May-3 June 2018 at Camp Arifjan.

Incidence, timing, and seasonal patterns of heat illnesses during U.S. Army basic combat training, 2014-2018.

Risk factors for heat illnesses (HIs) among new soldiers include exercise intensity, environmental conditions at the time of exercise, a high body mass index, and conducting initial entry training during hot and humid weather when recruits are not yet acclimated to physical exertion in heat. This study used data from the Defense Health Agency's-Weather-Related Injury Repository to calculate rates and to describe the incidence, timing, and geographic distribution of HIs among soldiers during U.S. Army basic combat training (BCT). From 2014 through 2018, HI events occurred in 1,210 trainees during BCT, resulting in an overall rate of 3.6 per 10,000 BCT person-weeks (p-wks) (95% CI: 3.4-3.8). HI rates (cases per 10,000 BCT p-wks) varied among the 4 Army BCT sites: Fort Benning, GA (6.8); Fort Jackson, SC (4.4); Fort Sill, OK (1.8); and Fort Leonard Wood, MO (1.7). Although the highest rates of HIs occurred at Fort Benning, recruits in all geographic areas were at risk. The highest rates of HI occurred during the peak training months of June through September, and over half of all HI cases affected soldiers during the first 3 weeks of BCT. Prevention of HI among BCT soldiers requires relevant training of both recruits and cadre as well as the implementation of effective preventive measures.

Outbreak of pneumonia in the setting of fatal pneumococcal meningitis among US Army trainees: potential role of Chlamydia pneumoniae infection.

BACKGROUND: Compared to the civilian population, military trainees are often at increased risk for respiratory infections. We investigated an outbreak of radiologically-confirmed pneumonia that was recognized after 2 fatal cases of serotype 7F pneumococcal meningitis were reported in a 303-person military trainee company (Alpha Company). METHODS: We reviewed surveillance data on pneumonia and febrile respiratory illness at the training facility; conducted chart reviews for cases of radiologically-confirmed pneumonia; and administered surveys and collected nasopharyngeal swabs from trainees in the outbreak battalion (Alpha and Hotel Companies), associated training staff, and trainees newly joining the battalion. RESULTS: Among Alpha and Hotel Company trainees, the average weekly attack rates of radiologically-confirmed pneumonia were 1.4% and 1.2% (most other companies at FLW: 0-0.4%). The pneumococcal carriage rate among all Alpha Company trainees was 15% with a predominance of serotypes 7F and 3. Chlamydia pneumoniae was identified from 31% of specimens collected from Alpha Company trainees with respiratory symptoms. CONCLUSION: Although the etiology of the outbreak remains unclear, the identification of both S. pneumoniae and C. pneumoniae among trainees suggests that both pathogens may have contributed either independently or as cofactors to the observed increased incidence of pneumonia in the outbreak battalion and should be considered as possible etiologies in outbreaks of pneumonia in the military population.

Gull-wing osteotomy for the treatment of the deficient patella in revision total knee arthroplasty.

Reconstruction of the deficient patella remains a challenge in revision total knee arthroplasty. Twelve consecutive patients who had a knee revision in which a nonresurfacable patella was treated with a gull-wing patellar osteotomy were followed using a computerized database. Radiographs revealed successful healing of the osteotomy in all patients with central tracking of the patella in the trochlear groove. There was a significant improvement in the range of motion and Knee Society scores. There were no patellar fractures or significant patellar malalignment in this series. This technique has shown promising results for the treatment of the nonresurfacable patella during revision total knee arthroplasty, and we conclude that it is a viable method of patellar salvage reserved for the most advanced cases of patellar bone stock compromise.