The Role of "Hierarchical and Classified Prevention and Control Measures (HCPC)" Strategy for SARS-CoV-2 Delta Variant in Guangzhou: A Modeling Study.

BACKGROUND: The Delta variant of SARS-COV-2 has replaced previously circulating strains around the world in 2021. Sporadic outbreaks of the Delta variant in China have posed a concern about how to properly respond to the battle against evolving COVID-19. Here, we analyzed the "hierarchical and classified prevention and control (HCPC)" measures strategy deployed during the recent Guangzhou outbreak. METHODS: A modified susceptible-exposed-pre-symptomatic-infectious-recovered (SEPIR) model was developed and applied to study a range of different scenarios to evaluate the effectiveness of policy deployment. We simulated severe different scenarios to understand policy implementation and timing of implementation. Two outcomes were measured: magnitude of transmission and duration of transmission. The outcomes of scenario evaluations were presented relative to the reality case (i.e., 368 cases in 34 days) with 95% confidence interval (CI). RESULTS: Based on our simulation, the outbreak would become out of control with 7 million estimated infections under the assumption of the absence of any interventions than the 153 reported cases in reality in Guangzhou. The simulation on delayed implementation of interventions showed that the total case numbers would also increase by 166.67%-813.07% if the interventions were delayed by 3 days or 7 days. CONCLUSIONS: It may be concluded that timely and more precise interventions including mass testing and graded community management are effective measures for Delta variant containment in China.

Development and utility of a close contact information management system for the COVID-19 pandemic.

BACKGROUND: Since the outbreak started in 2019, COVID-19 pandemic has a significant global impact. Due to the highly infective nature of SARS-CoV-2, the COVID-19 close contacts are at significant risk of contracting COVID-19. China's experience in successfully controlling COVID-19 emphasized the importance of managing close contacts because this strategy helps to limit potential infection sources, prevent the unconscious spread of COVID-19 and thus control this pandemic. As a result, to understand and consider the management of close contacts may be beneficial to other countries. However, managing close contacts is challenging owing to the huge number of close contacts and a lack of appropriate management tools and literature references. METHODS: A new system called the COVID-19 Close Contact Information Management System was developed. Here we introduced the design, use, improvement and achievements of this system. RESULTS: This system was designed from the standpoint of the Centers for Disease Control and Prevention in charge of managing close contacts. Two main functions and eight modules/themes were ultimately formed after two development stages. The system introduces what information need to be collected in the close contact management. Since the system allows information flow across cities, the geographical distance and administrative regional boundaries are no longer obstacles for managing close contacts, which promotes the management of each close contact. Moreover, when this system is used in conjunction with other data tools, it provides data assistance for understanding the COVID-19 characteristics and formulating targeted COVID-19 control policies. To date, the system has been widely used in Guangdong Province for over 1 year and has recorded tens of thousands of pieces of data. There is sufficient practical experience to suggest that the system is capable of meeting the professional work requirements for close contact management. CONCLUSIONS: This system provides a new way to manage close contacts and restrict the spread of COVID-19 by combining information technology with disease prevention and control strategies in the realm of public health. We hope that this system will serve as an example and guide for those anticipating similar work in other countries in response to current and future public health incidents.

The impact of COVID-19 pandemic on headache symptoms and drug withdrawal among patients with medication overuse headache: a cross-sectional study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) bring about a range of psychological distress and symptom deterioration to headache patients especially to some migraineurs. Compared to migraineurs or normal control, medication overuse headache (MOH) patients are more likely to experience a worse psychological distress and poorer outcome in non-COVID-19 time. However, in COVID-19 pandemic, whether MOH patients would have greater physical and mental symptom deterioration or worse relief of headache symptoms and medications overuse remained unclear. We aim to investigate the impact of COVID-19 on MOH patients to guide for a better management in this study. METHODS: We enrolled MOH patients who were diagnosed and treated at headache clinic of West China Hospital. Information of the pre-pandemic 3 months period and COVID-19 pandemic period was collected. Univariate and multivariate logistic regression were performed to identify independent factors associated with changes in headache symptoms and drug withdrawal. RESULTS: Seventy-eight MOH patients were enrolled into the study ultimately. In comparison to pre-pandemic period, fewer MOH patients reported decreased headache days, intensity and days with acute medications per month during the pandemic. Available access to regular prophylactic medications was significantly associated with a reduction of at least 50% in headache days and decrease in headache intensity per month with respective odds ratios of 39.19 (95% CI 3.75-409.15, P = 0.002) and 10.13 (95% CI 2.33-44.12, P = 0.002). Following abrupt withdrawal and high educational level were both significant factors in decreasing headache intensity. Male sex was significantly associated with decrease in days with acute medication per month during the pandemic (odds ratios 4.78, 95%CI 1.44-15.87, P = 0.011). CONCLUSIONS: Our findings reflect that MOH patients experienced a worse relief of headache symptoms and drug withdrawal during the pandemic. Available access to regular prophylactic medications was the significant independent factor for improvement of headache symptoms. Male sex was significantly associated with decreased days with acute medications per month.

Impact of Headache Frequency and Sleep on Migraine Patients During the COVID-19 Pandemic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has spread worldwide and poses a great threat to global health. COVID-19 has also an unneglected effect on migraine patients. Migraine attack frequency is one of the migraine characteristics, and its impact during COVID-19 needs further research. We aimed to evaluate whether migraine attack frequency during the COVID-19 pandemic differed from pre-COVID-19 attack frequency and explore possible influencing factors during the pandemic. METHODS: This prospective cohort study enrolled 187 migraine patients from the Department of Neurology of West China Hospital from October 2019 to December 2019. After the inclusion and exclusion criteria, a total of 157 patients were included. We collected demographic data, clinical characteristics, and epidemiological contact information and followed up on March 2020. Then, paired-samples T-tests, logistic regression and interaction tests were used to analyze the data. RESULTS: We found that the migraine attack frequency was 2.47 ± 1.12 before and 3.54 ± 1.79 during COVID-19 (P<0.0001). Then, we divided patients into two groups based on the difference in migraine attack frequency between the COVID-19 and pre-COVID-19 periods and employed logistic regression analysis. In the logistic regression analysis, divorced status (OR = 6.53, P = 0.0453), good sleep pre-COVID-19 and poor sleep during COVID-19 (OR = 3.11, P = 0.0432) had independent effects on migraine attack frequency during the COVID-19 pandemic. We found no interaction in poor sleep during COVID-19 between various subgroups. CONCLUSION: We found that migraineurs' headache attacks were more frequent during COVID-19 than pre-COVID-19 and that increased migraine attack frequency was independently related to divorced status and poor sleep during COVID-19.

Mitigating the impact of coronavirus disease 2019 on emergency stroke care: an original study and meta-analysis.

The coronavirus disease 2019 is still continuing and may affect stroke emergency care. We aim to investigate the impact of pandemic on stroke treatment in tertiary stroke centers in western China, and to quantitatively evaluate the worldwide influence with a meta-analysis. The original part was conducted in three tertiary stroke centers in Sichuan province. We compared emergency visits and efficiency of stroke treatment pre-, early, peak and late pandemic. Single-center analysis was further conducted in the largest local hospital and one hospital located close to the epicenter respectively. Relevant studies were searched in PubMed, Ovid Embase and Cochrane Library for English publications from December 2019 to July 2020 for systematic review. Fixed-and random-effect meta-analysis was performed to calculate the overall rates. Totally current original study showed fewer time of hospital admission and significantly higher rates of mechanical thrombectomy during the early and peak epidemic periods, compared with pre-epidemic time. The largest local hospital had significantly higher mechanical thrombectomy rates during the whole crisis and less daily admission during early and peak epidemic periods. The hospital located close to the epicenter presented higher proportions of intravenous thrombolysis since outbreak, and more favorable outcomes after reperfusion therapies than later (all P values <0.05). In meta-analysis, studies reported differences in reperfusion therapies and stroke severity but pooled results were non-significant. Overall, comprehensive measures should be implemented to keep hospital's capacity to deliver high-quality stroke emergency care during the global pandemic. Some key messages were provided for medical practice in the crisis.

Retrospective study identifies infection related risk factors in close contacts during COVID-19 epidemic.

OBJECTIVES: This study aimed to compare the risk of infection of children with that of adults and to explore risk factors of infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) by following up close contacts of COVID-19 patients. METHOD: The retrospective cohort study was performed among close contacts of index cases diagnosed with COVID-19 in Guangzhou, China. Demographic characteristics, clinical symptoms and exposure information were extracted. Logistic regression analysis was employed to explore the risk factors. The restricted cubic spline was conducted to examine to the dose-response relationship between age and SARS-CoV-2 infection. RESULTS: The secondary attack rate (SAR) was 4.4% in 1,344 close contacts. The group of household contacts (17.2%) had the highest SAR. The rare-frequency contact (p < 0.001) and moderate-frequency contact (p < 0.001) were associated with lower risk of infection. Exposure to index cases with dry cough symptoms was associated with infection in close contacts (p = 0.004). Compared with children, adults had a significantly increased risk of infection (p = 0.014). There is a linear positive correlation between age and infection (p = 0.001). CONCLUSIONS: Children are probably less susceptible to COVID-19. Close contacts with frequent contact with patients and those exposed to patients with cough symptoms are associated with an increased risk of infection.

The status and high risk factors of severe psychological distress in migraine patients during nCOV-2019 outbreak in Southwest China: a cross-sectional study.

BACKGROUND: Psychological distress is highly prevalent among migraineurs during public health emergencies. The coronavirus disease 2019 (nCOV-2019) has created mass panic in China due to its highly contagious by contact and aerosols and lack of effective treatment. However, the emotion status of migraineurs stayed unclear during the nCOV-2019 outbreak. OBJECTIVE: To understand psychological distress of migraineurs by comparing with common population and identify potential high-risk factors of severe psychological distress among migraine patients. METHOD: We enrolled the migraineurs treated at the department of Neurology of West China Hospital and healthy controls with age- and sex-matched to migraineurs. Data on clinicodemographics and psychological distress in the month of February 2020 (during in the nCOV-2019 outbreak in China) were collected. We used the Kessler 6-item (K-6) scale to assess psychological distress. Potential risk factors of severe psychological distress were identified using univariate and multivariate logistic regression. RESULTS: The 144 migraineurs and 150 controls were included in the study. Migraineurs showed significantly higher K-6 scores than controls (P < 0.001). Migraine attack frequency in previous 30 days and time spent paying attention to outbreak showed significant in multivariate logistic regression with respective odds ratios of 2.225 (95%CI 1.361-3.628, P = 0.001) and 1.589 (95% 1.117-2.26, P = 0.01). CONCLUSION: During public health outbreaks, healthcare professionals should focus not only on controlling and reducing migraine attack but also on mental health of migraineurs, especially those with high frequency migraine attack.

Household secondary attack rate of COVID-19 and associated determinants in Guangzhou, China: a retrospective cohort study.

BACKGROUND: As of June 8, 2020, the global reported number of COVID-19 cases had reached more than 7 million with over 400 000 deaths. The household transmissibility of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains unclear. We aimed to estimate the secondary attack rate of SARS-CoV-2 among household and non-household close contacts in Guangzhou, China, using a statistical transmission model. METHODS: In this retrospective cohort study, we used a comprehensive contact tracing dataset from the Guangzhou Center for Disease Control and Prevention to estimate the secondary attack rate of COVID-19 (defined as the probability that an infected individual will transmit the disease to a susceptible individual) among household and non-household contacts, using a statistical transmission model. We considered two alternative definitions of household contacts in the analysis: individuals who were either family members or close relatives, such as parents and parents-in-law, regardless of residential address, and individuals living at the same address regardless of relationship. We assessed the demographic determinants of transmissibility and the infectivity of COVID-19 cases during their incubation period. FINDINGS: Between Jan 7, 2020, and Feb 18, 2020, we traced 195 unrelated close contact groups (215 primary cases, 134 secondary or tertiary cases, and 1964 uninfected close contacts). By identifying households from these groups, assuming a mean incubation period of 5 days, a maximum infectious period of 13 days, and no case isolation, the estimated secondary attack rate among household contacts was 12·4% (95% CI 9·8-15·4) when household contacts were defined on the basis of close relatives and 17·1% (13·3-21·8) when household contacts were defined on the basis of residential address. Compared with the oldest age group (≥60 years), the risk of household infection was lower in the youngest age group (<20 years; odds ratio [OR] 0·23 [95% CI 0·11-0·46]) and among adults aged 20-59 years (OR 0·64 [95% CI 0·43-0·97]). Our results suggest greater infectivity during the incubation period than during the symptomatic period, although differences were not statistically significant (OR 0·61 [95% CI 0·27-1·38]). The estimated local reproductive number (R) based on observed contact frequencies of primary cases was 0·5 (95% CI 0·41-0·62) in Guangzhou. The projected local R, had there been no isolation of cases or quarantine of their contacts, was 0·6 (95% CI 0·49-0·74) when household was defined on the basis of close relatives. INTERPRETATION: SARS-CoV-2 is more transmissible in households than SARS-CoV and Middle East respiratory syndrome coronavirus. Older individuals (aged ≥60 years) are the most susceptible to household transmission of SARS-CoV-2. In addition to case finding and isolation, timely tracing and quarantine of close contacts should be implemented to prevent onward transmission during the viral incubation period. FUNDING: US National Institutes of Health, Science and Technology Plan Project of Guangzhou, Project for Key Medicine Discipline Construction of Guangzhou Municipality, Key Research and Development Program of China.