Prospective study of respiratory infections at the U.S. Naval Academy.

Midshipmen at the U.S. Naval Academy have recently suffered epidemics of upper respiratory tract infections. Seeking to determine cause, in June 1998 we enrolled 1,243 (99.5%) of 1,249 new midshipmen (plebes) and followed them during their first 11 months of training. Eighty-five plebes sought medical attention for acute respiratory disease. Using culture, serologic studies, and polymerase chain reaction, considerable evidence for respiratory pathogen infection was found among the ill subjects: Chlamydia pneumoniae in 41 (52.6%), Mycoplasma pneumoniae in 19 (25.3%), influenza in 11 (14.2%), Streptococcus pneumoniae in 6 (7.3%), and adenovirus in 1 (1.2%). Additionally, 873 (81%) the 1,077 plebes who completed an end-of-year questionnaire complained of having one or more respiratory symptoms (> 12 hours) during their first year of school. Of these, 132 (15%) reported that the symptoms significantly affected their performance. Study results suggest that respiratory infections were frequent, had a significant adverse impact on training, and were often attributable to bacterial pathogens.

Simplified microneutralization test for serotyping adenovirus isolates.

A simplified microneutralization procedure is described that uses an empirically determined virus challenge dose, a single dilution of antiserum, and observation of cytopathic effect to determine the adenovirus serotype. The simplified test has faster turnaround time and was 96% concordant with a confirmatory test using serial dilutions of type-specific sera. This method will find utility in high-volume serotyping work.

Adult adenovirus infections: loss of orphaned vaccines precipitates military respiratory disease epidemics. For the Adenovirus Surveillance Group.

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.

The Naval Health Research Center Respiratory Disease Laboratory.

Concern about emerging and reemerging respiratory pathogens prompted the development of a respiratory disease reference laboratory at the Naval Health Research Center. Professionals working in this laboratory have instituted population-based surveillance for pathogens that affect military trainees and responded to threats of increased respiratory disease among high-risk military groups. Capabilities of this laboratory that are unique within the Department of Defense include adenovirus testing by viral shell culture and microneutralization serotyping, influenza culture and hemagglutination inhibition serotyping, and other special testing for Streptococcus pneumoniae, Streptococcus pyogenes, Mycoplasma pneumonia, and Chlamydia pneumoniae. Projected capabilities of this laboratory include more advanced testing for these pathogens and testing for other emerging pathogens, including Bordetella pertussis, Legionella pneumoniae, and Haemophilus influenzae type B. Such capabilities make the laboratory a valuable resource for military public health.