Epidemiologic patterns of influenza outbreaks in institutional settings.

OBJECTIVES: Congregate environments facilitate spread of influenza viruses and could result in serious outcomes among residents. METHODS: We reviewed the epidemiology and identified factors that affect outbreak outcomes, using descriptive statistics and generalized estimating equations (GEE) regression. Outbreak duration, attack rate, hospitalization rate, case fatality rate, and the proportion of laboratory tests performed among infected residents were calculated by viral etiology, time to notification, and facility type and size. RESULTS: Between January 2011 and May 2015, the median attack rate for the 41 influenza outbreaks was highest among children in kindergarten (34%) and lowest among patients, who acquired influenza during hospitalization (17%). The median number of cases in each outbreak was 37 (range: 6-158) and a median of 199 individuals (range: 25-574) was exposed to influenza. The outbreaks lasted 2-49 days (median: 13 days). The average case fatality rate among residents for outbreaks attributed to influenza A or B was 3.1/1000 and for outbreaks attributed to influenza B 6.7/1000. Median time to notification was 10 days after the index case. In multivariate analysis, influenza outbreaks reported sooner after onset in the primary case ended sooner (P = 0.027) and had lower case fatality rates (P < 0.001). Residing in larger facilities was associated with lower proportion of laboratory tests performed (P = 0.024). CONCLUSIONS: Understanding whether earlier notification is a measure of a better functioning and therefore safer facility is a potentially important measure of the quality of care.

An outbreak of Microsporum canis in two elementary schools in a rural area around the capital city of Slovenia, 2012.

An outbreak of Microsporum canis infection affected 12 persons in two elementary schools over a period of 48 days in 2012 in Slovenia. Epidemiological, microbiological, and animal investigations were conducted. We defined cases as pupils or employees with skin lesions and confirmed or probable M. canis infection, attending one of the implicated elementary schools. Two clusters of six primary and six secondary cases were included in an unmatched case-control study. Contact with an adopted stray kitten at a birthday party was identified as the most probable source of infection. Secondary cases were more likely to have participated in gymnastic classes with a primary case than controls and were also more likely to have touched an infected child. Prompt communication and implementation of adequate control measures after the primary cases occurred would have prevented the secondary cases in another school.

Experimental design of an optimal phase duration control strategy used in batch biological wastewater treatment.

The paper presents the design of an algorithm used in control of a sequencing batch reactor (SBR) for wastewater treatment. The algorithm is used for the on-line optimization of the batch phases duration which should be applied due to the variable input wastewater. Compared to an operation with fixed times of batch phases, this kind of a control strategy improves the treatment quality and reduces energy consumption. The designed control algorithm is based on following the course of some simple indirect process variables (i.e. redox potential, dissolved oxygen concentration and pH), and automatic recognition of the characteristic patterns in their time profile. The algorithm acts on filtered on-line signals and is based on heuristic rules. The control strategy was developed and tested on a laboratory pilot plant. To facilitate the experimentation, the pilot plant was superimposed by a computer-supported experimental environment that enabled: (i) easy access to all data (on-line signals, laboratory measurements, batch parameters) needed for the design of the algorithm, (ii) the immediate application of the algorithm designed off-line in the Matlab package also in real-time control. When testing on the pilot plant, the control strategy demonstrated good agreement between the proposed completion times and actual terminations of the desired biodegradation processes.