Outbreak of pneumonia in a long-term care facility: antecedent human parainfluenza virus 1 infection may predispose to bacterial pneumonia

OBJECTIVES: To determine the causes of an outbreak of lobar pneumonia. DESIGN: Matched (1:2) case-control study. SETTING: A 70-bed chronic care facility for older people. PARTICIPANTS: Residents of the facility. RESULTS: Ten residents developed pneumonia over a 10-day period. Two residents died. One case-patient had Streptococcus pneumoniae bacteremia; another had polymerase chain reaction evidence of S. pneumoniae infection. No other etiologic agent was identified. Only four of 10 case-patients had received routine diagnostic cultures of blood or sputum before the administration of antibiotics. Symptoms of upper respiratory illness (URI) among residents before the pneumonia outbreak corresponded with elevation of antibodies to human parainfluenza virus 1 (HPIV1). In a matched case-control study, six of 10 case-patients, compared with five of 20 controls, had symptoms of URI during the preceding month (matched odds ratio (MOR) = 4.5, 95% CI = 0.8-33). Nine case-patients had serum available, and five of these had both serologic evidence of recent HPIV1 infection and recent URI, compared with two of 18 controls (MOR = 9.0, 95% CI = 1.2-208). Only three residents had documentation of pneumococcal vaccination. CONCLUSIONS: Noninfluenza viral infections may play a role in the pathogenesis of some bacterial pneumonias. S. pneumoniae was the cause of at least two pneumonias; lack of preantibiotic cultures may have interfered with isolation of S. pneumoniae in others. Recent HPIV1 infection was epidemiologically linked to subsequently developing pneumonia. Spread of HPIV1 in the facility may have contributed to increased susceptibility to S. pneumoniae and, potentially, to other bacterial pathogens.     

Multiple cases of life-threatening adenovirus pneumonia in a mental health care center

Eighteen cases of pneumonia developed during an outbreak of adenovirus infection in a chronic psychiatric care facility. The six patients most severely affected were admitted to the intensive care unit (ICU) at our institution. Four of these patients developed septic shock. We report the presentation, disease progression, and response to treatment of these patients. Clinical features consisted of high fever, nonproductive cough, and dense lower lobe infiltrates. Laboratory abnormalities included transient fall in white blood cell and platelet counts, and elevations of transaminases, lactate dehydrogenase (LDH), and creatinine phosphokinase (CPK). Five patients were intubated for hypoxemia and four developed the acute respiratory distress syndrome (ARDS) and septic shock (mean cardiac output, 14.1 +/- 1.3 L/min; cardiac index, 6.4 +/- 0.4 L/min/min2; systemic vascular resistance, 326 +/- 107 dyne cm/s2). All patients recovered and were discharged back to the chronic care facility except for one patient with chronic renal failure who died 2 mo after admission. Adenovirus (serotype 35) was isolated from the respiratory secretions of five patients and antibody titers increased 6-fold in the other. These patients constitute the largest series of patients with ARDS and septic shock caused by adenovirus pneumonia and the first outbreak of multiple cases of adenovirus pneumonia in immunocompetent civilian adults occurring from a single source.     

Seroprevalence of hepatitis B virus markers and risk factors in patients and staff of an Italian residential institution for the mentally disabled

We conducted a cross-sectional study to evaluate the prevalence rate and risk factors for hepatitis B virus (HBV) infection among residents and staff at the Fatebenefratelli Institute in San Colombano in the province of Milan. We tested serum from 510 patients and 165 staff members. In addition, a medical record and a completed questionnaire were obtained from each patient. A total of 338 (66.5%) residents were found to have markers of HBV infection, including 29 (5.7%) who were identified as carriers. Thirty-nine members of staff (24.1%) showed evidence of HBV infection but only 1 (0.6%) was identified as a carrier. Among patients the prevalence rate of HBV was significantly associated with length of stay and age at admission, as it was with length of employment among staff members. The hepatitis B vaccine was offered to all patients and staff in the institution during 1994. A total of 143 (84%) patients and 111 (90%) members of the staff were vaccinated in the same year. To prevent the further spread of HBV infection in this institution, all current and future residents and staff members should be screened for serological markers for HBV and subjects identified as being susceptible should be vaccinated according to a compulsory routine policy.     

An outbreak of multidrug-resistant pneumococcal pneumonia and bacteremia among unvaccinated nursing home residents

BACKGROUND: Outbreaks of pneumococcal disease are uncommon and have occurred mainly in institutional settings. Epidemic, invasive, drug-resistant pneumococcal disease has not been seen among adults in the United States. In February 1996, there was an outbreak of multidrug-resistant pneumococcal pneumonia among the residents of a nursing home in rural Oklahoma. METHODS: We obtained nasopharyngeal swabs for culture from residents and employees. Streptococcus pneumoniae isolates were serotyped and compared by pulsed-field gel electrophoresis. A retrospective cohort study was conducted to identify factors associated with colonization and disease. RESULTS: Pneumonia developed in 11 of 84 residents (13 percent), 3 of whom died. Multidrug-resistant S. pneumoniae, serotype 23F, was isolated from blood and sputum from 7 of the 11 residents with pneumonia (64 percent) and from nasopharygeal specimens from 17 of the 74 residents tested (23 percent) and 2 of the 69 employees tested (3 percent). All the serotype 23F isolates were identical according to pulsed-field gel electrophoresis. Recent use of antibiotics was associated with both colonization (relative risk, 2.3; 95 percent confidence interval, 1.3 to 4.2) and disease (relative risk, 3.6; 95 percent confidence interval, 1.2 to 10.8). Only three residents (4 percent) had undergone pneumococcal vaccination. After residents received pneumococcal vaccine and prophylactic antibiotics, there were no additional cases of pneumonia, and the rates of carriage decreased substantially. CONCLUSIONS: In this outbreak a single pneumococcal strain was disseminated among the residents and employees of a nursing home. The high prevalence of colonization with a virulent organism in an unvaccinated population contributed to the high attack rate. Clusters of pneumococcal disease may be underrecognized in nursing homes, and wider use of pneumococcal vaccine is important to prevent institutional outbreaks of drug-resistant S. pneumoniae infection.     

Interobserver variability in the interpretation of chest roentgenograms of patients with possible pneumonia

BACKGROUND: Previous studies have found considerable interobserver variability in the roentgenographic diagnosis of pneumonia. In this study we determined the impact of experience on interobserver variability in the interpretation of chest roentgenograms of patients with pneumonia and defined the characteristics of chest roentgenograms interpreted as pneumonia by all groups. METHODS: The chest roentgenograms of 15 consecutive patients with a clinical and roentgenographic diagnosis of pneumonia were read by a convenience sample of 10 first-year and 20 fourth-year medical students, 21 medical residents, and 21 staff physicians from the department of medicine. Three board-certified radiologists served as the gold standard. The majority rule decision and logistic regression analysis were used to analyze agreement among the various groups of observers. RESULTS: Agreement with the majority decisions of the gold-standard radiologists on the presence or absence of pneumonia for all observations of the various groups were as follows: original radiologist, 87%; first-year medical students, 59%; fourth-year medical students, 54%; medical residents, 66%; and attending staff, 72%. Chest roentgenograms with dense lobar or segmental opacities were generally interpreted as pneumonia by all observers. Patchy opacities caused major disagreements and were usually read as not being due to pneumonia. Bronchopneumonia was not diagnosed by any of the observers. Air bronchograms, atelectasis, and chronic obstructive lung disease were usually not recognized by the nonradiologists. CONCLUSIONS: There is considerable interobserver variability in the roentgenographic diagnosis of pneumonia. This variability does not improve with increasing experience. Dense lobar or segmental opacities are uniformly recognized as pneumonia while patchy opacities result in a variety of interpretations.     

Nurses helping nurses. Development of internal specialists in long-term care

The prevalence of psychiatric disorders and behavioral disturbances among nursing home residents, combined with observed deficits in geriatric mental health/illness expertise among LTC staff, supports the need for creative approaches to improve the knowledge, understanding, and management of such problems among LTC providers. The train-the-trainer model described in this article proved to be a viable method to providing geriatric mental health consultation and training that targets both improved quality of life for residents and quality of work life for the staff in charge of residents' care. More collaborative efforts among nursing specialists, subspecialists, and generalists are needed to empower those who work in LTC to utilize strengths and abilities inherent to their positions. Nursing homes nurses, who are all too familiar with the problems and challenges of their patient population, may act not only as mental health trainers but also as resource persons, role models, liaisons with geropsychiatric specialists, and leaders in the application of geropsychiatric care principles to residents within their facility, thus promoting improved resident and staff care alike.     

A tuberculin screening and isoniazid preventive therapy program in an inner-city population

As tuberculosis transmission decreases, case rates decline and an increasing proportion of cases arises from the pool of persons with latent infection. Elimination of tuberculosis will require preventing disease from developing in infected persons. From 1994 to 1996 the Atlanta TB Prevention Coalition conducted a community-based tuberculin screening and isoniazid preventive therapy project among high-risk inner-city residents of Atlanta, Georgia. We established screening centers in outpatient waiting areas of the public hospital serving inner-city residents, the city jail, clinics serving the homeless, and with outreach teams in neighborhoods frequented by drug users. All services were provided free. A total of 7,246 persons participated in tuberculin testing; 4,701 (65%) adhered with skin test reading, 809 (17%) had a positive test, 409 (50%) fit current guidelines for isoniazid preventive therapy, 84 (20%) we intended to treat completed therapy. The major limitations of this community-based tuberculin screening and preventive therapy project were the low proportion of infected individuals who were eligible for isoniazid preventive therapy and the poor adherence with a complete regimen among those we intended to treat. For community-based programs to be efficacious, preventive therapy regimens that are of shorter duration and safe for older persons will need to be implemented.     

Establishing albumin levels in sheep serum by a specific fluoroimmunoassay

The study determined the policies and procedures for the control and prevention of methicillin-resistant Staphylococcus aureus (MRSA) and its prevalence among nursing and residential homes, and evaluated whether certain home characteristics such as bed size, staffing level, and type of home are related to the prevalence of MRSA. A 21-questionnaire survey, with primarily categorical responses, was mailed to the home managers of all the 121 nursing and residential homes in the district, following which a simple, stratified random sample of 28 (23.14%) homes was taken and all agreeing residents screened from multiple sites for MRSA. Seventy-seven (63.6%) homes returned a completed questionnaire, 13 (46.4%) of whom agreed to participate in the microbiological study. The response rates for returning questionnaires and agreeing to participate in the microbiological study were similar for nursing and residential homes (65% vs. 60%; 67% vs. 40%; P = 0.12; P = 0.62), respectively. Nursing homes had a mean bed size of 30 (95% Confidence Interval (CI) 17-43), not significantly different from residential homes of 23 (95% CI 18-27; P = 0.26). The nursing homes employed a mean of 8.6 (95% CI 4.7-12.5) staff nurses per home; significantly higher than residential homes with a mean of 1.6 (95% CI 0.3-2.8; P = 0.006). No significant differences in mean number of home care assistants employed per home (22.8; 95% CI 12.4-33.13; and 14.4; 95% CI 11.83-16.90; P = 0.098, for nursing and residential homes, respectively) were observed. None of the homes had employed infection control practitioners. Only four (6.8%) of the responding homes stated that MRSA was a problem. Nursing homes were not significantly more likely to have admission policies for colonized person than residential homes (10/13 vs. 40/55, P = 1.00). Of the fifty-five (71.4%) homes who had admission policies, 40 (72.7%) stated that persons colonized/infected with MRSA would not be accepted, while 12 (21.8%) would accept such persons in single-room isolation and/or barrier nursing. Greater proportions of residential homes than nursing homes would not accept admission of persons with documented MRSA colonization (30/35 vs. 4/10, P = 0.007). Four (9.1%) homes (three nursing) had identified a total of five residents colonized/infected with MRSA in 5 years prior to the survey. Two hundred and forty-six residents were screened (552 sites), two (0.81%) of whom were found to be colonized in the nose (one resident) and in the groin (two residents) with MRSA, giving a 2-month weighted point prevalence rate of 0.14% (95% CI 0.01-0.26%). We conclude that in our district the nursing staffing levels and control measures vary widely within these homes, while the prevalence of residents who are colonized/infected with MRSA is lower than in other areas. We suggest that the exclusion admission policy for MRSA positive patients should be abandoned and targeted infection control programmes be instituted.     

The etiology of pneumonia in malnourished and well-nourished Gambian children

During a 2-year period 159 malnourished children ages 3 months to 5 years with radiologic evidence of pneumonia were investigated to determine the cause of their pneumonia. In addition 119 malnourished children without pneumonia, 119 well-nourished children with pneumonia and 52 well-nourished children without pneumonia were studied as controls. Percutaneous lung aspiration was performed on 35 malnourished and 59 well-nourished children with pneumonia. Bacteria were isolated from the blood, lung or pleural fluid of 28 (18%) malnourished children with pneumonia, 42 (35%) well-nourished children with pneumonia and from the blood of 5 (4%) malnourished children without pneumonia. Streptococcus pneumoniae and Haemophilus influenzae, which were the two organisms isolated most frequently in both groups of children with pneumonia, were found in 17 (11%) malnourished and 39 (33%) well-nourished children with pneumonia. Mycobacterium tuberculosis was detected in 5 malnourished children with pneumonia. A potentially pathogenic virus was identified in 35% of malnourished children with pneumonia and 40% of well-nourished children with pneumonia, and from 25% of children without pneumonia. The viruses identified most frequently were adenovirus and respiratory syncytial virus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnosis of avian adenovirus infections using DNA in situ hybridization

Three DNA oligonucleotide probes designated FN-23, FN-48, and FN-96 were evaluated for the diagnosis of aviadenovirus infections by DNA in situ hybridization. Paraffin-embedded tissues were obtained from birds with confirmed adenovirus infection, birds with putative adenovirus infections, and birds with intranuclear inclusions caused by herpesvirus and polyomavirus. In birds with confirmed adenovirus infection, probes FN-23 and FN-96 identified 78% and 72% of diseased individuals, respectively. Only probe FN-48 detected chickens with group II adenovirus infection. In birds with putative adenovirus infection, the DNA probes confirmed aviadenovirus infections in 76% of the population. Probes FN-23, FN-96, and FN-48 detected 85%, 74%, and 18% of adenovirus-infected birds, respectively. None of the DNA probes cross-hybridized with tissues from polyomavirus-infected psittaciform birds or with tissues from a chicken with infectious laryngotracheitis. In contrast, probe FN-23 did cross-hybridize to herpesvirus-infected tissues from two of eight psittaciform birds with Pacheco's parrot disease. Probes FN-48 and FN-96 did not react with these tissues.     

Infection due to Clostridium difficile among elderly residents of a long-term-care facility

In a study of the epidemiology of infection due to Clostridium difficile at long-term-care facilities, we conducted point-prevalence surveys and obtained stool samples from residents receiving antibiotics and from those developing diarrhea during 1 year at a 350-bed nursing home and an adjoining 280-bed chronic-care hospital. C. difficile and/or its cytotoxin was detected in 236 specimens from 94 residents. Only 16 (17%) of these 94 individuals had diarrhea at the time C. difficile was detected. The prevalence of C. difficile infection ranged from 2.1% to 8.1% in the nursing home and from 7.1% to 14.7% in the hospital. The organism was recovered from six (8.8%) of 68 residents receiving antibiotics, and four of the six developed antibiotic-associated diarrhea. The receipt of antibiotic treatment within the previous 8 weeks (odds ratio [OR], 7.9), the presence of a nasogastric or gastrostomy feeding tube (OR, 6.5), urinary and fecal incontinence (OR, 2.5), and the presence of more than three underlying diseases (OR, 2.0) were statistically significant independent variables associated with C. difficile infection. Typing of isolates by restriction-endonuclease analysis indicated that most C. difficile infections at this long-term-care facility were associated with endogenous enteric carriage of the organism, with little evidence of cross-infection.     

Protection from Mycobacterium avium complex disease in human immunodeficiency virus-infected persons with a history of tuberculosis

Risk of Mycobacterium avium complex disease was examined in human immunodeficiency virus (HIV)-infected patients with and without a history of tuberculosis. Information was obtained by retrospective review of charts of patients in HIV clinics in 10 US cities. Among 1363 patients with <200 CD4 cells/mm3 seen at Grady Memorial Hospital (GMH), 11 (17%) of 66 with a history of a positive purified protein derivative (PPD) skin test acquired M. avium infection, while 29 (16%) of 185 who were PPD-negative (but not anergic) did not (P = .85). Only 4 (8%) of 49 GMH patients with a history of tuberculosis acquired M. avium infection compared with 252 (19%) of 1314 GMH patients without a history of tuberculosis (P = .05). Proportional hazards analysis of risk factors for M. avium infection among 441 persons with and 8702 persons without a history of tuberculosis in 9 other cities confirmed protection from M. avium infection in persons with a history of tuberculosis (relative risk, 0.52; 95% confidence interval, 0.36-0.76; P < .001). Prior tuberculosis provides protection against M. avium infection in HIV-infected persons, possibly by stimulation of antimycobacterial immunity.     

Overcoming the mind/body dichotomy in drug abuse treatment

OBJECTIVE: To estimate the prevalence of asthma in urban residents of Shanghai in 1990 and evaluate the risk factors of asthma. METHODS: A cluster uneven random survey of asthma was conducted among 36,872 urban residents, 5/1000 of the population of the city. The asthmatics were suspected based upon case history, and then confirmed by home visit and further investigation. Single factor and unconditional logistic regression analysis were employed to evaluate the risk factors of asthma. RESULTS: The accumulative prevalence of asthma was 1.53% for age group 0-35 and it was higher in male (1.74%) than in female (1.31%). Sex, age and type of living house were possible risk factors. The prevalences were much higher among people with history of TB and pneumonia of which the values of relative risks were 2.53 and 4.95, respectively. Histories of food, drug and other kinds of hypersensitivity were significantly related to the history of asthma. CONCLUSION: Several risk factors possibly associated with asthma were identified in Shanghai area.     

Fever among outpatients with advanced human immunodeficiency virus infection

BACKGROUND: Fever is common among persons with human immunodeficiency virus (HIV) infection. However, the clinical implications of fever in this population have not been evaluated. We therefore undertook a prospective study of fever in persons with advanced HIV infection to determine the incidence and etiology of fever in this patient group. METHODS: Prospective natural history study of 176 patients with advanced HIV infection followed up at Memorial Sloan-Kettering Cancer Center, New York, NY, from April 1, 1990, through December 31, 1990. RESULTS: Fever occurred in 46% of patients. A diagnosis was made in 83% of episodes, with acquired immunodeficiency virus-defining illnesses accounting for half of the diagnosed cases. Patients whose conditions required more than 2 weeks to diagnose most often had lymphoma, Mycobacterium avium-intracellulare bacteremia, or Pneumocystis carinii pneumonia. Four patients had persistent unexplained fever without a clear source. Only one patient had fever that clearly responded to antiretroviral therapy. CONCLUSIONS: Fever is common among outpatients with advanced HIV infection. Human immunodeficiency virus itself is rarely the cause of fever in such patients; the cause of the fever should be thoroughly evaluated.     

The spectrum of adult adenovirus pneumonia

Adenovirus pneumonia is endemic among infants and children. We report an adult case of adenovirus pneumonia causing respiratory failure and infection in the patient's spouse. The case in the spouse presented as an exacerbation of COPD.     

Cold preservation of the porcine pancreas with histidine-tryptophan-ketoglutarate solution

OBJECTIVES: To describe the prescribing and use of antiepileptic drug (AED) therapy in nursing facility residents. DESIGN: A retrospective, multicenter drug use evaluation. SETTING: A total of 85 nursing facilities (average size, 119 beds) in five states. PARTICIPANTS: 1132 residents of the total 10,168 residents screened were prescribed at least one AED. MEASURES: Demographic information, primary indication for AED, comorbid conditions, prescribing physician's specialty, concomitant medications, and AED dosage regimen information were collected. Laboratory tests obtained in the most recent 6 months and seizure occurrence and seizure-related diagnostic assessments made in the most recent 3 months were also recorded. RESULTS: Of 1132 residents receiving AED therapy, 892 (78.8%) were prescribed AED therapy for a seizure-related diagnosis although 86% of seizure types were unspecified. Another 215 residents (19.0%) were prescribed AEDs for nonseizure diagnoses, and 25 (2.2%) had no indication for AED therapy. AEDs most frequently prescribed were phenytoin (56.8%), carbamazepine (23.0%), phenobarbital (15.6%), and valproic acid (13.1%). For residents with a seizure diagnosis, the most frequently prescribed monotherapy agents were phenytoin (52.0%), carbamazepine (12.2%), and phenobarbitol (7.1%). Almost 25% of residents with a seizure diagnosis took a combination of AEDs; more than 50% of all combinations included phenobarbital. About 9% of residents with a seizure diagnosis had one or more documented seizures during a 3-month review period. CONCLUSION: Among the substantial percentage of residents treated with AEDs, the lack of diagnosis of seizure type has serious implications for the choice of AED therapy. Opportunities exist for prescribing physicians, consultant pharmacists, and nursing staff to improve the medical management of nursing facility residents with seizures and of others receiving AEDs.     

First recorded outbreak of yellow fever in Kenya, 1992-1993. I. Epidemiologic investigations

Outbreaks of yellow fever (YF) have never been recorded in Kenya. However, in September 1992, cases of hemorrhagic fever (HF) were reported in the Kerio Valley to the Kenya Ministry of Health. Early in 1993, the disease was confirmed as YF and a mass vaccination campaign was initiated. Cases of suspected YF were identified through medical record review and hospital-based disease surveillance by using a clinical case definition. Case-patients were confirmed serologically and virologically. We documented 55 persons with HF from three districts of the Rift Valley Province in the period of September 10, 1992 through March 11, 1993 (attack rate = 27.4/100,000 population). Twenty-six (47%) of the 55 persons had serologic evidence of recent YF infection, and three of these persons were also confirmed by YF virus isolation. No serum was available from the other 29 HF cases. In addition, YF virus was isolated from a person from the epidemic area who had a nonspecific febrile illness but did not meet the case definition. Five patients with confirmed cases of YF died, a case-fatality rate of 19%. Women with confirmed cases of YF were 10.9 times more likely to die than men (P = 0.010, by Fisher's exact test). Of the 26 patients with serologic or virologic evidence of YF, and for whom definite age was known, 21 (81%) were between 10 and 39 years of age, and 19 (73%) were males. All patients with confirmed YF infection lived in rural areas. There was only one instance of multiple cases within a single family, and this was associated with bush-clearing activity. This was the first documented outbreak of YF in Kenya, a classic example of a sylvatic transmission cycle. Surveillance in rural and urban areas outside the vaccination area should be intensified.     

Seroepidemiology of emerging tickborne infectious diseases in a Northern California community

A seroprevalence and risk factor study of emerging tickborne infectious diseases (Lyme disease, ehrlichiosis, and babesiosis) was conducted among 230 residents of a semirural community in Sonoma County, California. Over 50% of residents reported finding a tick on themselves in the preceding 12 months. Samples from 51(23%) residents were seroreactive to antigens from one or more tickborne disease agents: 1.4% to Borrelia burgdorferi, 0.4% to Ehrlichia equi, 4.6% to Ehrlichia chaffeensis, and 17.8% to the Babesia-like piroplasm WA1. Only 14 (27%) of these seroreactive residents reported one or more symptoms compatible with these diseases. Seroreactivity was significantly associated with younger age (<16 years), longer residence in the community (11-20 years), and having had a physician's diagnosis of Lyme disease. In northern California, the risk of infection with these emerging tickborne diseases, particularly in children, may be greater than previously recognized.     

Observed sleep/wakefulness and severity of dementia in an Alzheimer's disease special care unit

BACKGROUND: This study tested the hypothesis that behaviorally defined sleep disturbance among residents in a Special Care Unit (SCU) for Alzheimer's disease (AD) was related to the severity of their dementia. Previously, sleep laboratory studies have reported such relationships when sleep has been recorded polysomnographically over several nights. Observational studies of sleep have not shown such relationships, presumably because of the impression involved in determining sleep/wake state behaviorally. METHODS: Nightly sleep data based on observations made every two hours by nursing staff for a period of 13 to 18 months were examined for 47 AD residents with a mean age of 80.7 +/- 6.5 years. Level of dementia and functional capacity were assessed with the Mattis Dementia Rating Scale (DRS) and the Katz Activities of Daily Living Scale (ADL). RESULTS: Data indicated that these SCU residents experienced a moderately disturbed night of sleep an average of 24% +/- 10% of their nights in the facility and a severely disturbed night of sleep on 7% +/- 6% of those nights. More profound dementia was associated with more sleep disturbance; however, incapacity in ADLs, age, gender, and psychoactive medications were unrelated to such disturbances. CONCLUSIONS: The results indicate that patterns of relationships noted between laboratory-based measures of sleep and variables such as severity of dementia can be detected using behavioral observations of sleep, provided that the number of nights of observation are sufficiently large to offset the measurement error involved in their use.     

A 1957 outbreak of Legionnaires' disease associated with a meat packing plant

Retrospective study shows that a 1957 outbreak of pneumonia in Austin, Minnesota, was Legionnaires' disease. Between June 7 and August 9, 1957, 78 persons were hospitalized with acute respiratory disease of unknown cause. Most had fever, headache, cough, and pneumonitis; two died. Ages ranged from 14-83 years; half of the patients were aged 55 years or older. Eighty-seven per cent were men. There were no secondary cases. Forty-six (59%) of the 78 patients were employees at a local meat packing plant, in distinction to the area's total working population (32%). Serosurvey of 15 of the 1957 outbreak cases and 30 controls matched for age, sex, and either occupation or residence was carried out in 1979. Antibody titers were determined for Legionella pneumophila serogroups 1-4 by means of indirect immunofluorescence. Twelve (80%) of the 15 cases and 13 (43%) of the 30 controls had antibody titers of 1:64 or greater to one or more of the L. pneumophila serogroups. Significant differences in L. pneumophila antibody titers (prevalence and level) were found between cases and control groups matched for residence (serogroups 1-3) or occupation (serogroups 2 and 3). Only three of 20 Austin residents with pneumonia diagnosed between 1978 and 1980 had L. pneumophila antibody titers of 1:128 or greater (p less than 0.001), in comparison to cases. These serologic data and the 1957 clinical and epidemiologic observations support the contention that this is the earliest documented outbreak of Legionnaires' disease.