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Background: While the role of contact tracing in the containment of the COVID-19 epidemic remains important until vaccines are widely available, literature on objectively measurable indicators for the effectiveness of contact tracing is scarce. We suggest the diagnostic serial interval, the time between the diagnosis of the infector and infectee, as a new indicator for the effectiveness of contact tracing. Methods: Using an agent-based simulation model, we demonstrate how the diagnostic serial interval correlates with the course of the epidemic. We consider four scenarios of how diagnosis and subsequent isolation are triggered: 1. never, 2. by symptoms, 3. by symptoms and loose contact tracing, 4. by symptoms and tight contact tracing. We further refine scenarios 3 and 4 with different lengths of target diagnostic serial intervals. Results: Scenarios 1 and 2 did not yield a notable difference. In scenarios 3 and 4, however, contact tracing led to a decrease of the height of the epidemic as well as the cumulative proportion of infected agents. Generally, the shorter the diagnostic serial interval was, the smaller the peak of the epidemic became, and the more proportion of the population remained susceptible at the end of the epidemic. Conclusion: A short target diagnosis interval is critical for contact tracing to be effective in the epidemic control. The diagnosis interval can be used to assess and guide the contact tracing strategy.

A 40-year-old female presented with rapid-onset generalized erythematous eruption with pustules agminated over the flexural areas and the flanks for 2 days. In skin histopathology, extensive subcorneal pustules, spongiosis and neutrophilic exocytosis, papillary dermal edema, and perivascular and interstitial mixed-cell infiltrates were observed. No psoriasis history but irregular intake of numerous kinds of Chinese herbal medications and the last-modified regimen including Radix Aucklandiae 14 days before the onset of pustular eruption were unveiled. Patch test showed positive result with only Radix Aucklandiae. Thus, acute generalized exanthematous pustulosis induced by Radix Aucklandiae was diagnosed.

We have investigated different properties (thickness, moisture loss, oil uptake, breaking force, color, puffing ratio during 0.5–5 min frying, microstructure, and sensory evaluation) of raw pork skins with varying thickness (2, 3, and 4 mm) after drying, intended as deep-fried snacks. We have found that the oil content, breaking force, and puffing ratio of fried pork skin with different raw skin thickness have no significant difference under similar water content (1.68–1.98 g/100 g wet weight basis, wb) after 3–5 min of deep-frying at 180 °C. Additionally, sensory score results have shown that fried pork skins with 4 mm raw skin thickness had lower flavor, texture, and overall acceptability than those with 2 mm and 3 mm raw skin thickness. Scanning electron micrographs (SEM) have revealed less holes and irregular and crack microstructure in fried pork skins with 4 mm raw skin thickness than in other groups. Different thickness of raw pork skins resulted in different effects in microstructure and influenced water evaporation and oil uptake of fried pork skin. Finally, we have proposed the kinetic equations of water loss and oil uptake of fried pork skins. Fried pork skin from raw skin thicker than 4 mm need frying at temperature higher than 180 °C to improve their puffing ratio and sensory acceptability.