Adverse events associated with methicillin-resistant Staphylococcus aureus in a nursing home.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) generates concern in nursing homes. Restrictive isolation precautions may be applied for indefinite periods. Adverse events driving these concerns include transmission and infection. METHODS: The 721-bed Wisconsin Veterans Home in King performs approximately 645 cultures annually. The site, severity, and number of MRSA infections were determined for 69 months. Pulsed-field gel electrophoresis was performed on all initial isolates, followed by a statistical cluster analysis looking for evidence of transmission. RESULTS: Sixty-seven MRSA infections were identified (1.6 per 100 residents per year); many were polymicrobial, and it was difficult to determine the proportionate role of MRSA in morbidity or mortality. There was an episode of rapidly fatal MRSA septicemia in which empiric antibiotic therapy was ineffective. Twenty-one genetic strains were encountered. Statistical analysis identified 13 clusters of genetically identical strains clustered in time and space (P<.05). CONCLUSIONS: Infections with MRSA were identified at relatively low rates; however, the etiology of many serious nursing home infections is not determined, especially pneumonia. Statistical analysis revealed clustering and evidence of transmission. Nursing home practitioners should consider MRSA when applying empiric treatment to serious infections. We recommend a program including (1) judicious use of antibiotics, including topical agents, to reduce selection of resistant organisms; (2) obtaining and tracking cultures of infectious secretions to diagnose MRSA infections and focus antibiotic therapy; (3) universal standard secretion precautions because any resident could be a carrier; and (4) a detailed assessment and care plan for the carrier that maximizes containment of secretions and independence in activities. However, basic hygiene cannot be maintained in communal areas by some residents without restriction of activities of daily living.

Granzyme B: a marker of risk for influenza in institutionalized older adults.

Risk for influenza increases with age while cellular immune responses decline. This was a prospective study to determine the relationship between cytokine and granzyme B levels in peripheral blood mononuclear cells stimulated with live influenza virus, and subsequent influenza illness. Granzyme B levels were lower in the group who later developed symptomatic laboratory-confirmed influenza (n=10) compared to the group who did not (n=90) (ANOVA, P=0.024). In contrast, none of the cytokine levels were related to the development of influenza. Thus, granzyme B is a potential marker of influenza risk in older adults.

Sputum bacteriology in nursing home pneumonia: a retrospective study.

INTRODUCTION: Pneumonia is the most lethal infection in nursing homes. The Infectious Disease Society of America recommends that attempts be made to obtain quality sputum to focus antibiotic therapy. This is especially important within the enclosed space of a nursing home, where constant pressure from broad spectrum, empiric antibiotics sets the stage for the emergence of resistant organisms. METHODS: We reviewed all cases of radiographic pneumonia diagnosed on-site at the Wisconsin Veterans Home, a 721-bed facility, for the recording of sputum bacteriology and 30-day mortality. RESULTS: Ninety-nine cases of radiographic pneumonia diagnosed on-site were identified over 1 year. Mortality was 10% within 30 days. Fourteen quality sputum specimens were obtained and processed microbiologically. None of the individuals who had a sputum specimen died within 30 days, probably because the ability to obtain a sputum specimen is a marker of higher functional status. DISCUSSION: Even if empiric therapy continues in the majority of cases, cultures in individual cases may alert clinicians to noncovered, resistant pathogens, and allow focused antibiotic therapy with agents like amoxicillin that might extend the usefulness of empiric, broad spectrum antibiotics. Institutions may also sum the results of sputum bacteriology to assist in the choice of empiric antibiotic therapy. Sputum bacteriology may benefit both the individual resident and the entire population of the institution.

Reintroduction of influenza A to a nursing building.

We report an outbreak of influenza A from a four-building veterans' facility in King, Wisconsin. Influenza was isolated in 154 of 721 residents over a 121-day period. Building A had 2 cases, no isolates for 40 days, followed by 27 cases. Building B had 25 cases, no isolates for 75 days, followed by 4 cases. Building C had 23 cases, no isolates for 14 days, followed by 17 cases. Influenza A may be reintroduced to a nursing building. Surveillance with contingency plans for restarting of prophylaxis must continue for the duration of influenza in the community.

A serious outbreak of parainfluenza type 3 on a nursing unit.

OBJECTIVE: To report a serious outbreak of respiratory illness in a nursing home, with isolation of parainfluenza type 3 in four cases. DESIGN: Viral respiratory cultures from a sample of symptomatic residents, and retrospective chart review. SETTING: A 50-bed nursing unit/floor in a skilled nursing facility. PARTICIPANTS: All residents of the nursing unit. MEASUREMENTS: Respiratory viral cultures and clinical chart review. RESULTS: Twenty-five of 49 residents developed new respiratory symptoms between September 2 and September 25, 1999. Ten cases (40%) had a tympanic temperature of 100 degrees F or greater. Eighteen (72%) had a chest X-ray with 11 (44%) new infiltrates. Sixteen (64%) were treated with antibiotics. Three cases were hospitalized and four died (16%) within 1 to 9 days after onset of symptoms. Four of 10 viral cultures yielded parainfluenza type 3. CONCLUSIONS: Parainfluenza type 3 may cause outbreaks complicated by pneumonia and fatal outcome. Clinicians should consider uniform secretion precautions to contain all viral URIs in nursing homes.

Surveillance for respiratory illness in long-term care settings: detection of illness using a prospective research technique.

BACKGROUND: The overall frequency and severity of viral respiratory infections affecting residents of long-term care facilities (LTCFs) is not well described. This is due primarily to the cumbersome and expensive techniques required for adequate surveillance of respiratory illnesses and the associated costs and availability of a laboratory capable of the relevant and timely report of diagnostic tests. Here we describe our technique for surveillance of respiratory illness in the LTCF. Elements of it may serve as strategies for routine care. METHODS: Nurses were trained to record respiratory complaints and to track them using a histogram-based calendar charting system. For the research technique, all new illnesses during the winter months, no matter how minor, were sampled for viral culture. RESULTS: Influenza A and B, parainfluenza types 1 through 4, herpes simplex virus types 1 and 2, rhinovirus, and respiratory syncytial virus (RSV) were detected in the nursing homes studied. Outbreaks of influenza were documented annually by prospective surveillance. Outbreaks of parainfluenza type 1 and RSV indistinguishable clinically from influenza were detected. CONCLUSIONS: Intense surveillance for respiratory illness and viral pathogens using the described research technique identified viral activity reliably on an annual basis in several large LTCFs. Elements of the research protocol may be adapted for general use to create a cost-effective surveillance program for LTCFs that have limited resources. Such a technique is essential for implementing effective measures for outbreak prevention and control.

Mortality following isolation of various respiratory viruses in nursing home residents.

OBJECTIVE: To compare mortality following isolation of influenza A to mortality following isolation of other respiratory viruses in a nursing home. SETTING: The Wisconsin Veterans Home, a 688-bed skilled nursing facility for veterans and their spouses. PARTICIPANTS: All residents with respiratory viral isolates obtained between 1988 and 1999. DESIGN: Thirty-day mortality was determined following each culture-proven illness. RESULTS: Thirty-day mortality following isolation of viral respiratory pathogens was 4.7% (15/322) for influenza A; 5.4% (7/129) for influenza B; 6.1% (3/49) for parainfluenza type 1; 0% (0/26) for parainfluenza types 2, 3, and 4; 0% (0/26) for respiratory syncytial virus (RSV); and 1.6% (1/61) for rhinovirus. CONCLUSIONS: Mortality following isolation of certain other respiratory viruses may be comparable to that following influenza A (although influenza A mortality might be higher without vaccination and antiviral agents). The use of uniform secretion precautions for all viral respiratory illness deserves consideration in nursing homes.

Non-influenza respiratory viruses may overlap and obscure influenza activity.

OBJECTIVE: To report the number and timing of influenza A isolates, as well as overlapping respiratory viruses. Co-circulating respiratory viruses may obscure the determination of influenza activity. DESIGN: Prospective clinical surveillance for the new onset of respiratory illness followed by viral cultures during seven separate influenza seasons. SETTING: The Wisconsin Veterans Home, a skilled nursing facility for veterans and their spouses. RESULTS: Influenza A isolates were encountered in greater numbers than non-influenza A isolates during three seasons. Seasonal variability is striking. In December 1992, we identified a large outbreak of respiratory illness. Influenza type B was cultured from 102 residents. In December 1995, influenza A was cultured from 285 people in Wisconsin. At that time, we identified outbreaks of respiratory illness in two of our four buildings. Based on statewide data, we suspected an influenza outbreak; however, 26 isolates of parainfluenza virus type 1 were cultured with no influenza. The potential importance of culturing at the end of the season was demonstrated in 1991-1992 when an outbreak of respiratory syncytial virus (RSV) overlapped and extended beyond influenza A activity. CONCLUSIONS: When interpreting new clinical respiratory illnesses as a basis for declaring an outbreak of influenza A, clinicians should realize that co-circulating respiratory viruses can account for clinical illnesses. Clinicians might utilize healthcare dollars efficiently by performing cultures to focus the timing of influenza A chemoprophylaxis. Cultures could be performed when clinical outbreak criteria are approached to confirm an outbreak. Culturing of new respiratory illness could begin again before the anticipated discontinuation of prophylaxis (approximately 2 weeks).

Abnormal TSH: a rational approach to the older patient.

The clinician whose older patient exhibits an abnormal TSH value must first determine if the result is caused by nonthyroidal illness or a medication whose effect is reversible. Patients without a nonthyroidal cause for the TSH abnormality and corresponding abnormalities in levels of circulating thyroid hormones and/or significant reproducible TSH elevation are usually in need of therapy. Those with normal circulating concentrations of thyroid hormone and potentially reversible signs and symptoms may be considered for a monitored therapeutic trial of treatment. All others need to be followed biochemically regardless of treatment choices. Patients with subclinical thyroid dysfunction require follow-up.

Duration of antiviral prophylaxis during nursing home outbreaks of influenza A: a comparison of 2 protocols.

BACKGROUND: We performed a randomized trial of 2 protocols guiding the duration of antiviral chemoprophylaxis during outbreaks of influenza A in a rural, 700-bed nursing home for veterans and their spouses with 14 nursing units in 4 buildings. METHODS: Half of all residents volunteered to participate. Nursing units were randomized, and the effectiveness of short-term (minimum, 14 days and 7 days without the onset of a case in the building) vs long-term (minimum, 21 days and 7 days without the onset of a case in the 4-building facility) prophylaxis was compared using amantadine hydrochloride in the influenza seasons of 1991-1992 and 1993-1994 and rimantadine hydrochloride in the influenza season of 1994-1995. A "case" is defined as an incident of a respiratory tract illness and the isolation of an influenza virus organism. We compared the number of cases after the discontinuation of short- vs long-term chemoprophylaxis. Prospective surveillance identified residents with new respiratory tract symptoms, and specimens for viral cultures were obtained even in the absence of temperature elevation. RESULTS: We documented influenza A virus activity during 3 seasons (32, 68, and 12 patients, respectively). During the 1991-1992, 1993-1994, and 1994-1995 influenza seasons, the patients on 11 floors were assigned to receive short-term chemoprophylaxis and those on 10 floors were assigned to long-term chemoprophylaxis. Only in 1993-1994 did chemoprophylaxis extend beyond 14 or 21 days when new cases continued beyond 14 days. Amantadine-resistant strains were circulating at that time. None of the participants in the prospective, controlled study had influenza develop after the termination of short- or long-term chemoprophylaxis. CONCLUSION: Antiviral chemoprophylaxis can be administered for the longer duration of 14 days or, in the absence of new culture-confirmed illness in the nursing building, for 7 days.

Assessment of markers of the cell-mediated immune response after influenza virus infection in frail older adults.

The purpose of this study was to determine whether measures of the cell-mediated immune response to influenza virus could be used as markers of influenza virus infection. We studied 23 subjects who developed upper respiratory, lower respiratory, or systemic symptoms during a small outbreak of influenza in a nursing home population. Influenza virus culture from nasopharyngeal swabs yielded influenza virus isolates from 7 of the 23 subjects. Only three of the subjects had a fourfold rise in antibody titer to the influenza virus antigen positivity after the infection. Granzyme B and cytokine levels were measured in peripheral blood mononuclear cells (PBMC) obtained from all subjects and stimulated with live influenza virus. Elevated granzyme B levels in virus-stimulated PBMC in combination with lower respiratory tract or systemic symptoms in study subjects was a significant predictor of culture-confirmed influenza virus infection compared to those from whom influenza virus could not be identified. Cytokine levels did not distinguish between the two groups in a similar type of analysis. Granzyme B in combination with the clinical profile of symptoms may be a useful retrospective marker for influenza virus infection.

Efficacy of zanamivir for chemoprophylaxis of nursing home influenza outbreaks.

Despite vaccination, influenza remains a common of morbidity in nursing homes. Chemoprophylaxis of residents with currently available antivirals is not always effective and new agents effective against both influenza A and B are needed. In a randomized, unblinded pilot study, we compared 14 day chemoprophylaxis with zanamivir, an antiviral which inhibits influenza neuraminidase, to standard of care during sequential influenza A and influenza B outbreaks in a 735 bed nursing home. Influenza A outbreaks were declared on 6/14 epidemic units. Sixty-five volunteers on four epidemic units were randomized to zanamivir and on two epidemic units, 23 volunteers were randomized to rimantadine. During the 14 days of prophylaxis, only four new febrile respiratory illnesses were detected. One volunteer receiving rimantadine prophylaxis developed laboratory-confirmed influenza. Influenza B outbreaks were declared on 3/14 epidemic units. Thirty-five volunteers on two epidemic units were randomized to zanamivir and 18 volunteers on one epidemic unit were randomized to no drug. During the 14 days of prophylaxis, only one new febrile respiratory illness was detected. One volunteer randomized to receive no drug developed laboratory-confirmed influenza. Zanamivir appears comparably effective to standard of care in preventing influenza-like illness and laboratory-confirmed influenza in nursing homes, but requires further testing.

Position-related changes in voiding dynamics in men.

OBJECTIVES: To investigate by urodynamic study position-related changes in uroflowmetry and postvoid residual urine volume (PVR) in men because altered bladder function in the supine position may be a predisposing factor for urinary tract infections in the institutionalized elderly. METHODS: Two healthy men, 34 and 59 years of age and living at home, and 53 nursing home residents (mean age 71.8 years, range 46 to 92) were evaluated with uroflowmetry in the standing and recumbent positions (lying on the left or right side); corresponding PVRs were measured by transabdominal ultrasonic bladder scanning. The two healthy men were monitored longitudinally with multiple recordings in both voiding positions, and the nursing home residents were subjected to two observations: one measurement of the variable parameters in either position. Differences were considered to be significant at P < 0.05. RESULTS: The 34-year-old man performed 51 3 flows (368 standing and 145 recumbent). The mean of all the peak flow rates in the upright (28.2 +/- 4.2 mL/s) versus the recumbent (16.8 +/- 4.1 mL/s) position revealed a highly significant difference (P = 0.0001). Sixteen urinary flows and corresponding PVRs were completed by this subject in either voiding position. The difference between PVRs in the standing (13.1 +/- 14.7 mL) versus recumbent (15.3 +/- 17.5 mL) position was not statistically significant. The 59-year-old man completed 156 flows (128 standing and 28 recumbent). A highly significant difference was noted between the mean of all peak flows in the upright (18.9 +/- 4.1 mL/s) versus recumbent (12.6 +/- 2.0 mL/s) position (P = 0.0001). Thirty-seven urinary flows and corresponding PVRs were completed by this individual (10 PVRs were determined after voiding in the standing and 27 after voiding in the recumbent position). No significant difference was noted between PVRs in the standing (24.6 +/- 34.4 mL) versus recumbent (16.5 +/- 60.0 mL) position. In the nursing home residents, the difference between the mean peak flow rates in the standing (14.5 +/- 8.6 mL/s) versus recumbent (12.4 +/- 6.7 mL/s) position also reached statistical significance (P = 0.0084). The difference between PVRs in the standing (60.5 +/- 125.6 mL) versus recumbent (84.8 +/- 186.2 mL) position barely reached statistical significance (P = 0.0497). CONCLUSIONS: The urinary flow rate decreases in the recumbent position. Bedridden residents may be predisposed to urinary tract infections because of alterations in voiding dynamics in the supine position. This area needs further study.

Immune response to influenza vaccination in institutionalized elderly: effect on different T-cell subsets.

Humoral and cellular immunological responses to influenza vaccination were measured in volunteers in a long-term care facility. All participants were vaccinated with the commercially available 1994-95 trivalent influenza vaccine and blood samples were collected before and 6 and 12 weeks after vaccination. Cytokine and granzyme B in peripheral blood mononuclear cell (PBMC) cultures after virus stimulation, and serum antibody titres were measured for each of these time points. In general, the measures of the immunological response to vaccination were low and variably significant. The major finding was the difference with respect to post-vaccination measures for the two strains of influenza A contained in the vaccine. Geometric mean antibody titres were significantly higher for A/Texas/36/91 at all time points in the study when compared to A/Shangdong/09/93. There was a corresponding rise for interleukin-10 (IL-10) to the A/Texas/36/91 strain while no increase in IL-10 was observed in A/Shangdong/09/93-stimulated cultures after vaccination. In contrast, granzyme B rose after vaccination only in cultures stimulated with A/Shangdong/09/93. Interferon-gamma levels were also significantly higher in these PBMC cultures. There was a poor interleukin-2 (IL-2) response to both strains of influenza A. These data suggest that different strains or subtypes of influenza A may preferentially enhance T-helper type 1 versus type 2 responses through vaccination in institutionalized seniors.