In the absence of valid medicines or vaccine, quarantine and isolation strategies are the most important and effective measures against the SARS outbreaks. This paper discusses the application of the optimal and sub-optimal control for SARS outbreak control via the Pontryagin’s Maximum Principle and genetic algorithm, respectively. To this end, a pair of control variables representing the quara...

We constructed a mathematical model to describe the spread of smallpox after a deliberate release of the virus. Assuming 100 persons initially infected and 3 persons infected per infectious person, quarantine alone could stop disease transmission but would require a minimum daily removal rate of 50% of those with overt symptoms. Vaccination would stop the outbreak within 365 days after release ...

Contact monitoring is an essential component of the public health response to a Middle East respiratory syndrome coronavirus outbreak, and is required for an effective quarantine to contain the epidemic. The timeliness of a quarantine is associated with its effectiveness. This paper provides a conceptual framework to describe the process of contact monitoring, and proposes a new measure called ...

An influenza pandemic--an outbreak of a novel influenza virus that spreads around the world--is a real threat. To predict the spread of an influenza pandemic across the whole of Japan, this study applies a real individual-based model (ribm) to the whole of Japan and simulates how a single case of influenza could spark pandemic influenza throughout Japan. We used Person-Trip (PT) data for nine r...

Infection commonly triggers nonspeciWc psychological and behavioral changes including fatigue and malaise, anhedonia, inability to concentrate, and disturbed sleep that collectively are termed “sickness behaviors”. Converging evidence from several lines of research implicate the activities of proinXammatory cytokines as a cause of sickness behaviors. Here we elaborate upon the Wndings of previo...

Several recent studies have tackled the issue of optimal network immunization by providing efficient criteria to identify key nodes to be removed in order to break apart a network, thus preventing the occurrence of extensive epidemic outbreaks. Yet, although the efficiency of those criteria has been demonstrated also in empirical networks, preventive immunization is rarely applied to real-world...

Iris yellow spot virus (IYSV) is a plant pathogenic virus which has been reported to continuously occur in onion bulbs, allium field crops, seed crops, lisianthus, and irises. In South Korea, IYSV is a "controlled" virus that has not been reported, and inspection is performed when crops of the genus Iris are imported into South Korea. In this study, reverse-transcription polymerase chain reacti...