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Objective We aimed to determine the burden of bacillary dysentery in China, its cross-regional variations, trends in morbidity and mortality, the causative bacterial species and antimicrobial resistance patterns. Methods We extracted and integrated governmental statistics and relevant medical literature published from 1991 to 2000. Data were also collected from one general hospital each for the six provinces and Jin-an district, Shanghai, representative of six geographical regions and a modern city. Findings In 2000, 0.8-1.7 million episodes of bacillary dysentery occurred of which 0.5 to 0.7 million were treated at health-care facilities and 0.15-0.20 million patients were hospitalized. The highest morbidity and mortality rates were among the youngest and oldest age groups. Bacillary dysentery peaked during the summer months. The major causative species was Shigella flexneri (86%) and the predominant S. flexneri serotype was 2a (80%). About 74-80% of Shigella isolates remained susceptible to fluorinated quinolones. Conclusion We conclude that while morbidity and mortality due to bacillary dysentery has decreased considerably in China in the past decade due to increasing access to affordable health care and antibiotics, a considerable burden exists among the youngest and oldest age groups and in regions with low economic development. We suggest that while a vaccine would be effective for short-and medium-term control of bacillary dysentery, improved water supply, sanitation, and hygiene are likely to be required for long-term control.Bulletin of the World Health Organization 2006;84:561-568.Voir page 567 le résumé en français. En la página 567 figura un resumen en español. IntroductionGlobally, morbidity and mortality due to diarrhoea has decreased from 4.6 million deaths in 1982 to 3.3 million in 1992 to 2.5 million in 2003.1-3 A review published in 1999 reported that bacillary dysentery caused by Shigella species (S. flexneri, S. sonnei, S. boydii, and S. dyse e enteriae) remains a major source of diarr r rhoea, especially in developing countries. It also reported that of the 164.7 million episodes of shigellosis (Shigellarrelated diarrhoea) occurring worldwide each year, 163.2 million were in developing countries; however, the review included sparse data from China. 5 Even so diarrhoeal diseases remain an important public health problem. A crossrsectional survey conducted in 1988 estimated that of the 84 million diarrhoeal episodes that ocr r curred in China annually, 25% affected children less than five years of age. The survey also found that Shigella is one of the principle etiologic organisms for diarrhoea.6 A live oral Shigella vaccine which was developed and produced in China in 1997 reportedly provides 60-70% protection against S. flexneri 2a and S. sonnei infections. 7A continuing analysis of the disease burden of bacillary dysentery would be required for effective treatment and prevention policies, health prioritization debates, and cost-benefit assessments to enable rational decisions on research, ...

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Microgrid (MG) is a cyber-physical system with coupled power and communication networks. The centralized secondary control of MGs with periodical communications restricts system efficiency and resilience. This paper proposes a distributed event-triggered secondary control scheme in islanded MGs with its cyber-physical implementation. The proposed control scheme operates with reduced frequency of communications depending on the MG states change 'events' (e.g. load variations and communication failures). Besides, the secondary control objectives, including frequency/voltage regulation and accurate real/reactive power sharing, are decoupled into two timescales. Instead of designing eventtriggering conditions (ETCs) for each secondary control functions, only ETCs for power sharing control in slower timescale are designed. Thus, the communication burden is significantly reduced since communications among neighbour controllers are only needed at the event-triggered time. The proposed controller has been tested on a hardware-in-the-loop (HIL) platform, where the physical system is modelled in OPAL-RT and the cyber system is realized in Raspberry Pis. The control effectiveness is validated by the HIL results. 1 Index Terms-distributed event-triggered control, cyberphysical systems, microgrids, hardware-in-the-loop, raspberry pi.