[Effect of continuous probiotic fermented milk intake containing Lactobacillus casei strain Shirota on fever in mass infectious gastroenteritis rest home outbreak].

As part of medical risk management in a long-term stay facility for the elderly, we introduced probiotic fermented milk containing Lactobacillus casei strain Shirota (LcS-fermented milk) in an open case-control study of its effect of (1 bottle a day) on winter-time norovirus gastroenteritis. During the 1 month from December 1 to 31, 2006, norovirus gastroenteritis occurred in 21 (55%) of 38 cases in the nonmilk group, and in 27 (64%) of 39 cases in the milk group, showing no statistically significant difference. The mean duration of >37 degrees C fever after disease onset, however, was 2.9+/-2.3 days in the non-milk group and 1.5+/-1.7 days in the milk group, showing significant shortening (p<0.05). The duration of > 38 degrees C fever after disease onset also tended to be shorter. No significant differences were seen in age, gender, days of antipyretic use, or stool-free days. These results suggested that continuous intake of LcS-fermented milk could aggravate fever duration in elderly long-term rest home residents although it probably did not prevent noroviral gastroenteritis onset.