Lori Nest

Report of an Outbreak: Nursing Home Architecture and Influenza-A Attack Rates

OBJECTIVE To determine factors that might account for a significantly lower attack rate in a newly constructed nursing building during an epidemic of type A influenza. SETTING A four-building, long-term care facility for veterans and their spouses, with an average daily census of 690. DESIGN Prospective surveillance with retrospective analysis. PARTICIPANTS Symptomatic residents submitting to viral culture. MEASUREMENTS Number of respiratory illnesses and influenza cultures in consenting symptomatic residents. Building characteristics. RESULTS An influenza A (H3N2) outbreak was culture-confirmed in 68 nursing home residents. Influenza A was isolated in 3/184 (2%) residents in Building A, 31/196 (16%) in Building B, 18/194 (9%) in Building C, and 16/116 (14%) in Building D. Denominators are average daily census during the outbreak. Building A had significantly fewer culture-confirmed cases than the other buildings (P < .001). Fewer residents in Building A, 47% compared with 61% in Buildings B, C, and D, were participants in a formal study of influenza. Eight of 15 respiratory illnesses identified during the outbreak that were not cultured occurred in Building A. These factors could not account for the difference in attack rates. Building A has a unique ventilation system, more square feet of public space per resident, and does not contain office space that serves the entire four-building facility. CONCLUSION Our retrospective observation suggests that architectural design may influence the attack rate of influenza A in nursing homes.

Between‐Meal Risedronate Does Not Alter Bone Turnover in Nursing Home Residents

OBJECTIVES: To assess the effect of between‐meal weekly risedronate and daily calcium 630 mg and vitamin D 400 IU on bone turnover markers.

Risk of acquiring influenza A in a nursing home from a culture-positive roommate

Influenza A was cultured in 62 double rooms. The roommate was infected in 12 (19.4%). During 3,294 resident-seasons, influenza was cultured in 208 single rooms (6.3%). Those who lived in double rooms with a culture-positive roommate had a 3.07 relative risk (CI95, 1.61-5.78) of acquiring influenza.

RISK OF ACQUIRING INFLUENZA B IN A NURSING HOME FROM A CULTURE-POSITIVE ROOMMATE

To the editor: It was recently reported that influenza A was cultured in 62 double rooms at the Wisconsin Veterans Home over six seasons. The roommate was infected in 12 (19.4%). During 3,294 resident-seasons, influenza was cultured in 208 single rooms (6.3%). Those who lived in double rooms with a culture-positive roommate had a 3.07 relative risk (95% confidence interval 5 1.61–5.78) of acquiring influenza A. Identical methodology was used to analyze the 1992/ 1993 influenza season, in which influenza B was encountered. Case finding was based on intense prospective surveillance by research staff and has been previously described. This study compared the relative risk of influenza B in residents whose roommate had a positive culture with that of those who resided in single rooms. It is possible that a second infected roommate became infected outside of the room. To control for this possibility, the number of single rooms and the number of cases in single rooms each year were determined for comparison. Influenza B was introduced to 29 double rooms. A second culture-confirmed case was noted in 10 (34%). The second cases occurred 0 to 11 days (mean 3.9 days) after the initial case. Seven of these second cases had been vaccinated (70%). Overall, 85% of residents were vaccinated. During 489 resident-seasons in single rooms, influenza was cultured in 65 rooms (13%). Those who lived in a double room with a culture-positive roommate had a relative risk of 2.6 (95% CI 5 1.2–5.6) of acquiring influenza B compared to those who resided in single rooms As expected, the data confirm a greater relative risk of acquiring influenza B in roommates of residents with influenza B than in residents who did not have roommates. The excess risk associated with having a culture-positive roommate is troublesome because it has been demonstrated that culture-confirmed influenza B was associated with an excess 30-day mortality of 3.9% over baseline mortality (1.5%/30 days) in nursing home residents. A private room is optimal, but this is not possible in most nursing homes. Other interventions might include using any curtain or barrier that may exist between roommates. The roommates should be counseled to maintain hand hygiene and 3-foot separation with extra environmental hygiene provided by staff. The unaffected roommate should probably be offered chemoprophylaxis with a neuraminidase inhibitor, even if the entire unit is not placed on chemoprophylaxis.

The Effect of Culture-Positive Influenza Type A on Resource Use and Adverse Events in Nursing Home Residents

OBJECTIVES: To determine adverse clinical events and resource utilization associated with culture‐positive influenza A in nursing home residents.

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.