Influence of the COVID-19 pandemic on the incidence and exacerbation of childhood allergic diseases.

To explore the influence of changes in human lifestyle and the living environment caused by nonpharmaceutical interventions in coronavirus disease 2019 (COVID-19) on allergic diseases, the present study enrolled children who came to the Children's Hospital of Zhejiang University for allergen detection between January 2019 and December 2020. By comparing the positive rates and levels of various allergen-specific immunoglobulin E (IgE) before and during the COVID-19 pandemic, the influence of changes in human lifestyle and the living environment caused by prevention and control measures in COVID-19 on allergic diseases was evaluated. In 2019, 41 648 allergic children went to the hospital, but in 2020, due to the impact of the COVID-19 epidemic, the number decreased to 24 714. In 2020, the number of allergy visits was the lowest in February and gradually increased. There were 45 879 children with total IgE > 17.5 IU/ml in 2 years, accounting for 69.13% of the total samples, of which the proportion was 68.52% (28 536/41 648) in 2019 and 70.17% (17 343/24 714) in 2020. A total of 29 906 children were positive for one or more allergens in 2 years. It accounts for 45.06% of the total number of samples, of which the proportion is 41.53% (17 296/41 648) in 2019 and 51.02% (12 610/24 714) in 2020. Except for cashew nuts, the positive number of other allergens in 2020 was less than in 2019, especially after June and July 2020. Except for Artemisia argyi, the positive rates of other allergens in 2020 were significantly higher than those in 2019 (p < 0.05). Moreover, the changing trend of the positive allergen rate in each month in 2020 was different from that in 2019. In 2020, except for Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Crab, specific IgE levels of other allergens were not greater than those in 2019 (p < 0.05). Thus it can be seen, during the COVID-19 pandemic, nonpharmaceutical interventions played a protective role in reducing children's exposure to allergens and alleviating allergic reactions.

Assessment of global asymptomatic SARS-CoV-2 infection and management practices from China.

With ongoing research, it was found that asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was widespread in coronavirus disease 2019 (COVID-19) populations. Studies have confirmed asymptomatic patients with COVID-19 have potential infectivity, and most of the transmission occurred before symptoms appear. Asymptomatic infection rates varied widely in different countries and regions. Identifying the asymptomatic infected persons and cutting off the infection source is an effective way to prevent the spread of this disease. However, asymptomatic patients have hidden clinical symptoms, and screening based only on the clinical symptoms of COVID-19 can easily lead to a missed diagnosis. Therefore, determining asymptomatic infection patients by SARS-CoV-2 nucleic acid testing is the gold standard. A series of prevention and control measures adopted by the Chinese government, especially the "Four Early" policy, have achieved outstanding achievements, which are worth learning from by other countries.

The pathogenesis and treatment of the `Cytokine Storm' in COVID-19.

Cytokine storm is an excessive immune response to external stimuli. The pathogenesis of the cytokine storm is complex. The disease progresses rapidly, and the mortality is high. Certain evidence shows that, during the coronavirus disease 2019 (COVID-19) epidemic, the severe deterioration of some patients has been closely related to the cytokine storm in their bodies. This article reviews the occurrence mechanism and treatment strategies of the COVID-19 virus-induced inflammatory storm in attempt to provide valuable medication guidance for clinical treatment.

The mechanism and treatment of gastrointestinal symptoms in patients with COVID-19.

In addition to the typical respiratory response, new coronavirus disease 2019 (COVID-19) is also associated with very common gastrointestinal symptoms. Cases with gastrointestinal symptoms are more likely to be complicated by liver injury and acute respiratory distress syndrome (ARDS). If not treated in time, coma and circulatory failure may ensue. As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects the human body through the combination of angiotensin-converting enzyme 2 (ACE2) in the gastrointestinal tract, the mechanism underlying the gastrointestinal symptoms may involve damage to the intestinal mucosal barrier and promotion of the production of inflammatory factors. Indeed, after cells in the lungs become infected by SARS-CoV-2, effector CD4+ T cells reach the small intestine through the gut-lung axis, causing intestinal immune damage and diarrhea; early extensive use of antibacterial and antiviral drugs can also lead to diarrhea in patients. Thus, treatment options for COVID-19 patients should be promptly adjusted when they have gastrointestinal symptoms. As SARS-CoV-2 has been detected in the feces of COVID-19 patients, future prevention and control efforts must consider the possibility of fecal-oral transmission of the virus.

Epidemiological analysis of COVID-19 and practical experience from China.

The rapid spread of the epidemic has aroused widespread concern in the international community. Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) was first reported in China, with bats as the likely original hosts and pangolins as potential intermediate hosts. The current source of the disease is mainly patients infected with SARS-COV-2. Patients in the incubation period may also become sources of infection. The virus is mainly transmitted via respiratory droplets and contact, and the population is generally susceptible. The epidemic has progressed through the local outbreak stage and community transmission stage due to exposure at Wuhan's Huanan wholesale seafood market and is now in the stage of large-scale transmission due to the spread of the epidemic. The basic productive number (R0) at the beginning of the epidemic was 2.2, with an average incubation period of 5.2 days. The proportion of critically ill patients was 23.4%, the mortality rate was lower than those of SARS and Middle East respiratory syndrome, and 96.5% of deaths occurred in Hubei Province, where the outbreak occurred first. Among them, elderly men with underlying diseases had a higher mortality rate. Chinese medical staff have summarized a set of effective strategies and methods in the diagnosis and treatment of this disease that are worthy of reference for their international counterparts. With powerful government intervention and the efforts of Chinese medical staff, China's outbreak has gradually improved.