Circulating viruses associated with severe complicated enterovirus infection in Taiwan: a multi-year analysis.

BACKGROUND: Few studies have investigated the viral isolation characteristics for severe complicated enterovirus infection (SCEI). This study evaluated the seasonality and contribution of circulated viruses to the chronologic trend and weekly reported SCEI epidemic. METHODS: Enterovirus infection surveillance and virology laboratory data in 2000 to 2008 obtained from the Centers for Disease Control in Taiwan were analyzed. We measured the monthly and weekly virology isolation rates by viral types. The virus-specific and the season-specific relative risks for SCEI and 95% confidence intervals (CI) associated with the isolated circulating viruses and weather status was evaluated. RESULTS: Among 1539 virology confirmed SCEI cases, the mean annual incidence rates ranged from 0.72/100,000 to 32.5/100,000 in children aged 5 years and less; rates were higher in warm months with cases peaking in June (12.6%). The untypeable nonpolio enterovirus was the most frequently isolated type among the monitored specimens (6.07%), followed by coxsackievirus A (3.99%), EV71 (1.77%), coxsackievirus B (1.56%), and echovirus (1.23%). However, these SCEI cases had very strong associations with the isolation of EV71 and coxsackievirus A and B. The corresponding relative risks were 1.14 (95% CI, 1.11-1.17), 1.03 (95% CI, 1.01-1.04), and 1.09 (95% CI, 1.07-1.12), respectively, for 1% increase in weekly isolation rate. CONCLUSIONS: Isolation rates for EV71 and coxsackieviruses A and B can predict the development of SCEI cases, particularly in warm months.

Development of linear irreversible thermodynamic model for oxidation reduction potential in environmental microbial system.

Nernst equation has been directly used to formulate the oxidation reduction potential (ORP) of reversible thermodynamic conditions but applied to irreversible conditions after several assumptions and/or modifications. However, the assumptions are sometimes inappropriate in the quantification of ORP in nonequilibrium system. We propose a linear nonequilibrium thermodynamic model, called microbial related reduction and oxidation reaction (MIRROR Model No. 1) for the interpretation of ORP in biological process. The ORP was related to the affinities of catabolism and anabolism. The energy expenditure of catabolism and anabolism was directly proportional to overpotential (eta), straight coefficient of electrode (L(EE)), and degree of coupling between catabolism and ORP electrode, respectively. Finally, the limitations of MIRROR Model No. 1 were discussed for expanding the applicability of the model.

Applying the Nernst equation to simulate redox potential variations for biological nitrification and denitrification processes.

In this paper, various forms of Nernst equations have been developed based on the real stoichiometric relationship of biological nitrification and denitrification reactions. Instead of using the Nernst equation based on a one-to-one stoichiometric relation for the oxidizing and the reducing species, the basic Nernst equation is modified into slightly different forms. Each is suitable for simulating the redox potential (ORP) variation of a specific biological nitrification or denitrification process. Using the data published in the literature, the validity of these developed Nernst equations has been verified by close fits of the measured ORP data with the calculated ORP curve. The simulation results also indicate that if the biological process is simulated using an incorrect form of Nernst equation, the calculated ORP curve will not fit the measured data. Using these Nernst equations, the ORP value that corresponds to a predetermined degree of completion for the biochemical reaction can be calculated. Thus, these Nernst equations will enable a more efficient on-line control of the biological process.