While antigenic drift of the circulating influenza virus was the major factor in the apparent vaccine failure, the observed poor staff immunization rate (10%) and absence of surveillance which precluded the use of amantadine chemoprophylaxis suggest that the use of these strategies may be of importance in controlling influenza outbreaks in nursing homes.

The largest recorded epidemic of sporotrichosis in the United States occurred in 1988 and involved a total of 84 cases in 15 states. All cases were associated with Wisconsin-grown sphagnum moss. Twenty-one clinical isolates of Sporothrir schenckii and 69 environmental isolates of Sporothrix spp. from the epidemic were characterized and compared. The environmental isolates were recovered from 102 samples of sphagnum moss and other material by using direct plating techniques. Characteristics examined included macroscopic and microscopic morphology, conversion to a yeast phase, exoantigen reactions, and virulence in mice. On the basis of these studies, eight environmental isolates were identified as S. schenckii, five were identified as Ophiostoma stenoceras, and the remainder were identified as Sporothrix species. The environmental isolates of S. schenckii were recovered from moss samples from one Pennsylvania nursery and from three New York State Soil and Water Conservation districts, but none were recovered from moss directly from the bogs in Wisconsin.

Institutional risk factors associated with the occurrence of nosocomial respiratory or gastrointestinal disease outbreaks in 1992 were examined in a case-cohort study of New York State nursing homes conducted in 1993. Facility size, staffing patterns, and employee sick leave policies were the principal effects found in an unconditional logistic regression model. The risk of having respiratory or gastrointestinal disease outbreaks was greater in larger nursing homes (adjusted risk ratio (RR) = 1.71 for each 100-bed increase in size, 95% confidence interval (CI) 1.20-2.42), for nursing homes with a single nursing unit (adjusted RR = 3.93, 95% CI 0.98-15.71), or those with multiple nursing units with shared staff (adjusted RR = 2.51, 95% CI 1.07-5.89). The risk was less for nursing homes with paid employee sick leave policies (adjusted RR = 0.38, 95% CI 0.15-0.99). Other potential risk factors examined in this study, such as the ratio of beds per unit, type of sponsorship, daily review of laboratory test results, and the proportion of private beds and patient-to-staff ratio, were not significantly associated with the risk of disease outbreaks. The results of this study have direct implications for control of nosocomial disease outbreaks in nursing homes.