Dynamic Zero-Covid strategy curtails mutagenesis and emergence of new variants of the SARS-CoV-2 (preprint)

Within the local outbreak period of SARS-CoV-2 Delta variant in Nanjing and Yangzhou, China, we analyzed the mutation process of the Delta variants in 520 cases, as well as the production, spread and elimination of new mutant strains under the non-pharmaceutical interventions (NPI) strategy. The investigation on distribution of COVID-19 cases and phylogenetic analysis of SARS-CoV-2 genome sequences attributed to tracking the transmission chains, transmission chains were terminated by the isolation of the COVID-19 patients and quarantine of close-contracts, suggesting the importance of NPI in prompting some mutations to disappear and stopping the transmission of new variants. Dynamic zero-Covid strategy has been implemented successfully to against the second-largest local epidemic caused by an imported COVID-19 case in China.

The impact of intervention to the incidence of natural focus diseases during the outbreak of COVID-19 in Jiangsu Province, China (preprint)

Doxorubicin (DOX) is a well-known chemotherapeutic drug for most malgnencies including breast cancer and leukemia whilst the usage of DOX is limited owing to its cardiotoxicity. The present study analyzed the effects of crocin on doxorubicin’s cardiotoxic efect in rat myocardium and searched their mechanistic interaction in the pathogenesis of DOX-induced myocardial toxicity. Forty rats were divided into four groups; (a) control (received normal saline as a dose of 1 ml/kg by ip for 15 days), (b) Crocin (received crocin as a dose of 40 mg/kg/24h by ip for 15 days), (c) DOX (received DOX as a dose of 2 mg/kg/48h by ip in six injection, cumulative dose 12 mg/kg), and (d) DOX+Crocin (received DOX as a dose of 2 mg/kg/48h by ip in six injection and crocin as a dose of 40 mg/kg/24h ip for 15 days). According to the present study, DOX administration caused significant increases in lipid indices (triglyseride, low-dencity lipoproteins and very low-dencity lipoproteins) as well as cardiac markers (Creatine kinase-muscle/brain and Cardiac Troponin I). Morever, DOX caused significant increases in oxidative stress parameters (malondialdehyde and total oxidant status) as well as decreases in antioxidant defense systems (glutathione, superoxide dismutase, catalase and total antioxidant status). The present study also demonstrated that co-administration of crocin with DOX significantly ameliorated the lipid profile and biochemical parameters in rats receiving DOX. The results were supported by histopathological and immunohistochemical evaluations. Taken together, our results reveal that crocin might be a cardioprotective agent in DOX treated patients for cancer.

The Impact of Intervention to Routine Surveillance of Natural Focal Diseases During the Outbreak of COVID-19 in Jiangsu Province, China (preprint)

Background: With the strength intervention of China, the outbreak of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) had a great control effect. The measures may influence the development and progression of others infectious diseases.Method: The data of daily coronavirus virus disease 2019 (COVID-19) confirmed cases from January 3, 2020 to April 30, 2020 and natural focal disease cases from January, 2005 to April, 2020 were collected from Jiangsu Provincial Center for Disease Control and Prevention (Jiangsu Provincial CDC). We describe and compare the data of natural focal diseases from January to April, 2020 with the same months from 2015 to 2019 in the four aspects: trend of incidence, regional, age and sex distribution. Nonparametric tests were used to analyzed to the difference between the duration from onset of illness to date of diagnosis of natural focal diseases and the same period of the previous year. Results: The incidence of malaria in February (0.9 per 10,000,000 people), March (0.3 per 10,000,000 people) and April (0.1 per 10,000,000 people) 2020 less than the lower limit for range of February (1.6-4.5 per 10,000,000 people), March (0.8-3.3 per 10,000,000 people) and April (1.0-2.9 per 10,000,000 people) from 2015 to 2019 respectively. The incidence of brucellosis in February was 0.9 (per 10,000,000 people), less than the lower limit for the range from 2015 to 2019 (1.6-4.5 per 10,000,000 people). The incidence of hemorrhagic fever (HF) in March was 1.0 (per 10,000,000 people), less than the lower limit for the range from 2015 to 2019 (1.4-2.6 per 10,000,000 people). However, the incidence of Severe Fever with Thrombocytopenia Syndrome (SEFT) in March was 0.3 (per 10,000,000 people), higher than the upper limit for the range from 2015 to 2019 (0.0-0.1 per 10,000,000 people). Furthermore, we respectively observed the incidence with various degree of reduction in male, 20-60 years old and both rural and urban areas. Conclusions: In Jiangsu province, the incidence of natural focal diseases decreased during the outbreak of COVID-19 in 2020, especially malaria, HF and SEFT. The impact of interventions were felt most by male individuals within the age group of 20-50 years. The interventions for COVID-19 may control the epidemics of natural focal diseases.

Early warning signs for severe patients with Coronavirus Disease 2019 and its epidemical significance (preprint)

Background Since December 2019 coronavirus disease 2019 (COVID-19) emerged in Wuhan city and rapidly spread throughout China. However, early warning signs for severe patients with COVID-19 were not fully known.Methods Information on admission was collected through a standard questionnaire. We described the epidemiological characteristics of the patients with COVID-19, analyzed the risk factors associated with severe illness, and estimated the key epidemiologic time-delay distributions.Results A total of 631 patients with laboratory-confirmed COVID-19 were identified. The proportion of severe cases was 8.4%. The epidemic of COVID-19 experienced four stages: sporadic phase, exponential growth phase, peak plateau phase, and declining phase. The proportion of severe cases was significantly different in four stages and 13 municipal prefectures (P < 0.001). Factors including elderly more than 65years(yrs) old, underlying medical conditions, fever patient whose highest temperature beyond 39.0℃, dyspnea, and lymphocytopenia(< 1.0 × 109/L) could possibly become the early warning signs for severe patients of COVID-19. In contrast, earlier visit to the clinic could reduce the severe risk. Besides, the viral load may be a potentially useful marker associated with disease severity of COVID-19 infection.Conclusions The epidemic experienced four stages with obviously areas difference. People aged beyond 65 yrs or underlying medical conditions once appear symptoms like fever beyond 39.0℃ and/or dyspnea should immediately visit health care.