Pulmonary Medicine and Critical Care

Review of Boivin G, De Serres G, Hamelin ME, et al. An outbreak of severe respiratory tract infection due to human metapneumovirus in a long-term care facility. Clin Infect Dis 2007;44:1152–1158. Objectives: To describe the epidemiological features of a large outbreak of human metapneumovirus infection in a long-term care facility (LTCF). Summary: The etiological agent responsible for acute respiratory infections remains unidentified in 40% to 60% of cases. Human metapneumovirus (hMPV) is a recently identified paramyxovirus that has been shown to account for 5% to 10% of hospitalizations for acute respiratory tract infections in children younger than age 3, but the role of this agent as a cause of respiratory infections in older adults has not been well characterized. From January 1 to February 15, 2006, 96 of 364 residents (26.4%) of a LTCF in Quebec City, Canada, developed unexplained respiratory or constitutional symptoms. Of these, six had confirmed hMPV infection based on viral cultures or polymerase chain reaction. An additional 31 cases had probable hMPV infection based on symptoms, signs, residence on the same ward as a confirmed case, and absence of an identifiable alternative pathogen. Among confirmed cases, all patients exhibited fever of 381C or higher, 67% developed cough, and 33% experienced respiratory distress. The mean duration of symptoms was 14.5 days (range 7–22 days). Mortality was 50% in confirmed cases, accounting for 33% of all deaths due to respiratory infection during the study period. Among probable cases, symptoms were generally less severe, the mean duration was 8.2 days, and mortality was 9.7%. In one ward, which housed four of the confirmed cases, the overall attack rate was 72%. Epidemiological investigation suggested two separate generations of infection propagation despite implementation of contact and droplet precautions. Conclusion: Human MPV infection may be an important and previously unrecognized cause of serious acute respiratory infections in LTCF residents. Comment: Influenza virus and respiratory syncitial virus (RSV) are established causes of major morbidity and mortality in the geriatric population. In the midst of the current swine influenza outbreak, the findings of this studyFespecially the high mortality rate in laboratoryconfirmed casesFsuggest that hMPV infection may be an equally important concern for institutionalized older adults. Although no specific therapy for hMPV is available, these data highlight the need for a reliable rapid screening tool, because prompt diagnosis during an outbreak could reduce the use of antibiotics or corticosteroids and facilitate the timely implementation of precautionary measures. Although additional study is needed, this report should stimulate discussion regarding possible development of an effective hMPV vaccine. Submitted by: Lee Morrow, MD, MSc, Associate Professor of Medicine, Creighton University, Omaha, NE, 2004 Williams Scholar. Review of Barrett-Connor E, Dam TT, Stone K, Harrison SL, Redline S, Orwoll E. The association of testosterone levels with overall sleep quality, sleep architecture, and sleep-disordered breathing. J Clin Endocrinol Metab 2008;93(7):2602–2609. Objectives: To examine the association between serum testosterone levels and sleep characteristics in older men. Summary: Sleep disturbances increase with age, and the prevalence and severity of sleep disorders tend to be greater in men than in women, but the relationship between testosterone levels and sleep disturbances has not been delineated. In this study, 1,312 men (mean age 72.6) participating in the Osteoporotic Fractures in Older Men Study had total serum testosterone levels measured at the baseline examination and then underwent actigraphy (to assess total sleep time, sleep efficiency, sleep latency, and wakefulness after sleep onset) and in-home polysomnography (to determine percentage time in slow-wave and rapid eye movement (REM) sleep, percentage time with oxygen saturation less than 90%, and apnea–hypopnea index) a mean of 3.4 years later. After adjusting for age, race, and clinical site, statistically significant associations were noted between lower testosterone quartile and poorer sleep efficiency, greater wakefulness, higher apnea–hypopnea index, and more hypoxemia (P-values for linear trend o.001, o.001, .02, and o.001, respectively). After further adjusting for body mass index (BMI), these associations were no longer significant, although men in the lowest testosterone quartile had greater wakefulness and lower sleep efficiency than Address correspondence to Michael W. Rich, Cardiovascular Division, Washington University, 660 S. Euclid Avenue, Campus Box 8086, St. Louis, MO 63110. E-mail: mrich@wustl.edu