Gastroenteritis and respiratory infection outbreaks in French nursing homes from 2007 to 2018: Morbidity and all-cause lethality according to the individual characteristics of residents.

BACKGROUND: Gastroenteritis (GE) and respiratory tract infection (RTI) outbreaks are a significant issue in nursing homes. This study aimed to describe GE and RTI outbreaks with infection and all-cause lethality rates according to the individual characteristics of nursing home residents. METHODS: Clinical and virological surveillance were conducted (2007 to 2018). Virus stratifications for the analysis were: outbreaks with positive norovirus or influenza identifications (respectively NoV+ or Flu+), episodes with no NoV or influenza identification or testing (respectively NoV- or Flu-). Associations between individual variables (sex, age, length of stay (LOS), autonomy status) and infection and lethality rates were tested with univariate and Mantel-Haenszel (MH) methods. RESULTS: 61 GE outbreaks and 76 RTI oubreaks (total 137 outbreaks) were recorded involving respectively 4309 and 5862 residents. In univariate analysis, higher infection rates and age were associated in NoV+, NoV-, and Flu+ contexts, and lower infection rates were associated with longer stays (NoV+ and NoV-). In MH stratified analysis (virus, sex (female/male)) adjusted for LOS (<4 or ≥4 years), the odds of being infected remained significant among older residents (≥86 years): NoV+/male (Odds ratio (ORMH): 1.64, 95% confidence interval (CI): 1.16-2.30) and Flu+/female and male (respectively ORMH: 1.50, CI: 1.27-1.79 and 1.73, CI: 1.28-2.33). In univariate analysis, lower autonomy status (NoV+, Flu+ and Flu-) and increased age (Flu+) were associated with higher lethality. In MH adjusted analysis, significant ORage adjusted for autonomy was: Flu+/ ≥86 years compared with <86 years, 1.97 (1.19-3.25) and ORautonomy adjusted for age for the more autonomous group (compared with the less autonomous group) was: Flu+, 0.41 (0.24-0.69); Flu-, 0.42 (0.20, 0.90). CONCLUSION: The residents of nursing homes are increasingly elderly and dependent. The specific infection and lethality risks according to these two factors indicate that surveillance and infection control measures are essential and of high priority.

Influenza prevention in nursing homes: Great significance of seasonal variability and spatio-temporal pattern.

OBJECTIVE: This work evaluated seasonal variations and spatio-temporal pattern of respiratory tract infections (RTI) in geriatric nursing homes in order to improve effective surveillance, prevention, control and management of RTI. METHODS: Prospective surveillance of RTI (Low Respiratory Tract infections and Influenza Like Illnesses) was conducted in 11 sites in Alsace over a 10-year period with clinical case definitions and rapid tests (Immunoassay) to identify influenza virus. RESULTS: Influenza national epidemic was a period at high risk of RTI in nursing homes with variable impacts depending on the seasonal period. 2004-2005, 2008-2009, 2011-2012 and 2012-2013 were the periods with the highest impacts. The higher risk was not well understood during these four influenza epidemics and outbreaks occurred in numerous nursing homes despite the alerts and surveillance. CONCLUSION: Information about seasonal variability and spatio-temporal patterns of the RTI during the national epidemic periods is essential for the nursing homes in order to help the health care workers and the visitors to understand the risk for the residents and then to improve the implementation of the control and prevention measures.

Influenza outbreaks management in a French psychiatric hospital from 2004 to 2012.

OBJECTIVE: Influenza epidemics can have consequences in terms of morbidity and mortality for the patients. This work assesses influenza outbreaks in order to validate and optimize alert and control measures in a psychiatric hospital. METHOD: The prospective monitoring of influenza episodes was conducted for 8 years in 19 units of a mental health hospital. Rapid influenza diagnostic tests were used. The study of the episodes with confirmed influenza cases was carried out. RESULTS: Influenza monitoring and alert were essential with information and laboratory-confirmed cases. Influenza was common with a total of 20 episodes for the studied period. A maximum of 25% (5/20) of the units were affected in 2008-2009. Rapid influenza diagnostic tests allowed a quick identification with an average time of 1.5 days. Mainly, control measures limited the spread of the influenza virus in units with patient not at high risk of complications. On the other hand, antiviral curative treatment and chemoprophylaxis are essential in units with patients at high risk of complications. CONCLUSION: In a psychiatric hospital, influenza management has to take into account the exposed patient's risks for influenza complications and to adapt the strategy according to the risks identified.