The precision of epidemiological investigation of COVID-19 transmission in Shanghai, China

Reduced SARS-CoV-2 infection risk is associated with the use of Seven-Flavor Herb Tea: A multi-center observational study in Shanghai, China

OBJECTIVE

Omicron, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, is responsible for numerous infections in China. This study investigates the association between the use of Seven-Flavor Herb Tea (SFHT) and the risk of SARS-CoV-2 infection to develop precise and differentiated strategies for control of the coronavirus disease 2019 (COVID-19).

METHODS

This case-control study was conducted at shelter hospitals and quarantine hotels in China. A total of 5348 laboratory-confirmed COVID-19 patients were enrolled between April 1 and May 31, 2022, while 2190 uninfected individuals served as healthy controls. Structured questionnaires were used to collect data on demographics, underlying diseases, vaccination status, and use of SFHT. Patients were propensity-score-matched using 1:1 nearest-neighbor matching of the logit of the propensity score. Subsequently, a conditional logistic regression model was used for data analysis.

RESULTS

Overall, 7538 eligible subjects were recruited, with an average age of [45.54 ± 16.94] years. The age of COVID-19 patients was significantly higher than that of uninfected individuals ([48.25 ± 17.48] years vs [38.92 ± 13.41] years; t = 22.437, P < 0.001). A total of 2190 COVID-19 cases were matched with uninfected individuals at a 1:1 ratio. The use of SFHT (odds ratio = 0.753, 95% confidence interval: 0.692, 0.820) was associated with a lower risk of SARS-CoV-2 infection compared to untreated individuals.

CONCLUSION

Our findings suggest that taking SFHT reduces the risk of SARS-CoV-2 infection. This is a useful study in the larger picture of COVID-19 management, but data from large-sample multi-center, randomized clinical trial are warranted to confirm the finding. Please cite this article as: Zhang SX, Chen XX, Zheng Y, Cai BH, Shi W, Ru M, Li H, Zhang DD, Tian Y, Chen YL. Reduced SARS-CoV-2 infection risk is associated with the use of Seven-Flavor Herb Tea: a multi-center observational study in Shanghai, China. J Integr Med. 2023; Epub ahead of print.

Epidemiological characteristics of patients from fever clinics during the COVID-19 epidemic in 2022 in Shanghai, China

An outbreak of COVID-19 in Shanghai, China, in March 2022 was caused by the Omicron variant. The epidemic lasted for more than 3 months, and the cumulative number of infected people reached 626,000. We investigated the impact of clinical factors on disease outcomes in patients with COVID-19. Using a case-control study design, we examined cases from fever clinics with confirmed Omicron variant infection, analyzed their population and laboratory diagnostic characteristics, and provided theoretical support for subsequent epidemic prevention and control. Logistic regression was used to identify factors associated with infection with the Omicron variant. The results of this study show that the COVID-19 vaccine can protect against infection with the Omicron variant, and more than 50% of infected people had not been vaccinated. Compared with the epidemic in Wuhan 2 years ago, most of the patients in the hospital in the Shanghai epidemic had underlying diseases (P = 0.006). A comparison of patients infected with the Omicron variant in Shanghai and patients with other respiratory tract infections showed no significant difference in the levels of neutrophils, lymphocytes, eosinophils, white blood cells, hemoglobin, or platelets (P > 0.05). People over 60 years old and those with underlying diseases were at risk for pneumonia (OR = 14.62 (5.49-38.92), P < 0.001; OR = 5.29 (2.58-10.85), P < 0.001, respectively), but vaccination was a protective factor (OR = 0.24 (0.12-0.49), P < 0.001). In summary, vaccination has a potential effect on infection with Omicron variant strains and provides protection against pneumonia. The severity of illness caused by the Omicron variant in 2022 was significantly lower than that of the original SARS-CoV-2 variant from two years previously.

Lessons drawn from Shanghai for controlling highly transmissible SARS-CoV-2 variants: insights from a modelling study

BACKGROUND

The continuous emergence of novel SARS-CoV-2 variants with markedly increased transmissibility presents major challenges to the zero-COVID policy in China. It is critical to adjust aspects of the policy about non-pharmaceutical interventions (NPIs) by searching for and implementing more effective ways. We use a mathematical model to mimic the epidemic pattern of the Omicron variant in Shanghai to quantitatively show the control challenges and investigate the feasibility of different control patterns in avoiding other epidemic waves.

METHODS

We initially construct a dynamic model with a core step-by-step release strategy to reveal its role in controlling the spread of COVID-19, including the city-based pattern and the district-based pattern. We used the least squares method and real reported case data to fit the model for Shanghai and its 16 districts, respectively. Optimal control theory was utilized to explore the quantitative and optimal solutions of the time-varying control strength (i.e., contact rate) to suppress the highly transmissible SARS-CoV-2 variants.

RESULTS

The necessary period for reaching the zero-COVID goal can be nearly 4 months, and the final epidemic size was 629,625 (95%CI: [608,049, 651,201]). By adopting the city-based pattern, 7 out of 16 strategies released the NPIs more or earlier than the baseline and ensured a zero-resurgence risk at the average cost of 10 to 129 more cases in June. By adopting the district-based pattern, a regional linked release can allow resumption of social activity to ~ 100% in the boundary-region group about 14 days earlier and allow people to flow between different districts without causing infection resurgence. Optimal solutions of the contact rate were obtained with various testing intensities, and higher diagnosis rate correlated with higher optimal contact rate while the number of daily reported cases remained almost unchanged.

CONCLUSIONS

Shanghai could have been bolder and more flexible in unleashing social activity than they did. The boundary-region group should be relaxed earlier and more attention should be paid to the centre-region group. With a more intensive testing strategy, people could return to normal life as much as possible but still ensure the epidemic was maintained at a relatively low level.

Effect of anxiety and depression on self-reported adverse reactions to COVID-19 vaccine: a cross-sectional study in Shanghai, China

BACKGROUND

The association of anxiety and depression with adverse reactions after receipt of coronavirus disease 2019 (COVID-19) vaccine is not clear among the general population. This study aims to evaluate the effect of anxiety and depression on self-reported adverse reactions to COVID-19 vaccine.

METHODS

The cross-sectional study was conducted during April-July 2021. Participants completing the two doses of vaccine were included in this study. Sociodemographic information, anxiety and depression levels and adverse reactions after the first dose of vaccine for all participants were collected. The anxiety and depression levels were assessed by the Seven-item Generalized Anxiety Disorder Scale and the Nine-item Patient Health Questionnaire Scale, respectively. The multivariate logistic regression analysis was used to examine the association between anxiety and depression and adverse reactions.

RESULTS

A total of 2161 participants were enrolled in this study. The prevalence of anxiety and depression was 13% (95% confidence interval (CI), 11.3-14.2%) and 15% (95%CI, 13.6-16.7%), respectively. Of the 2161 participants, 1607 (74%; 95% CI, 73-76%) reported at least one adverse reaction after the first dose of the vaccine. Pain at the injection site (55%) and fatigue and headache (53% and 18%, respectively) were the most commonly reported local and systemic adverse reactions, respectively. Participants with anxiety or depression or both were more likely to report local and systemic adverse reactions (P < 0.05).

CONCLUSION

The results suggest that anxiety and depression increase the risk of self-reported adverse reactions to COVID-19 vaccine. Consequently, appropriate psychological interventions before vaccination will help to reduce or alleviate symptoms of vaccination.

Policy choices for Shanghai responding to challenges of Omicron

Background

A new wave of Coronavirus disease 2019 (COVID-19) infection driven by Omicron BA.2 subvariant hit Shanghai end of February 2020. With higher transmissibility and milder symptoms, the daily new confirmed cases have soared to more than 20 K within one and a half months. The greatest challenge of Omicron spreading is that the rapidly surging number of infected populations overwhelming the healthcare system. What policy is effective for huge cities to fight against fast-spreading COVID-19 new variant remains a question.

Methods

A system dynamics model of the Shanghai Omicron epidemic was developed as an extension of the traditional susceptible-exposed-infected-susceptible recovered (SEIR) model to incorporate the policies, such as contact tracing and quarantine, COVID-19 testing, isolation of areas concerned, and vaccination. Epidemic data from Shanghai Municipal Health Commission were collected for model validation.

Results

Three policies were tested with the model: COVID-19 testing, isolation of areas concerned, and vaccination. Maintaining a high level of COVID-19 testing and transfer rate of the infected population can prevent the number of daily new confirmed cases from recurring growth. In the scenario that 50% of the infected population could be transferred for quarantine on daily bases, the daily confirmed asymptomatic cases and symptomatic cases remained at a low level under 100. For isolation of areas concerned, in the scenario with most isolation scope, the peak of daily confirmed asymptomatic and symptomatic cases dropped 18 and 16%, respectively, compared with that in the scenario with least isolation. Regarding vaccination, increasing the vaccination rate from 75 to 95% only slightly reduced the peak of the confirmed cases, but it can reduce the severe cases and death by 170%.

Conclusions

The effective policies for Omicron include high level of testing capacity with a combination of RAT and PCR testing to identify and quarantine the infected cases, especially the asymptomatic cases. Immediate home-isolation and fast transfer to centralized quarantine location could help control the spread of the virus. Moreover, to promote the vaccination in vulnerable population could significantly reduce the severe cases and death. These policies could be applicable to all metropolises with huge population facing high transmissible low severity epidemic.

Home quarantine or centralized quarantine? A mathematical modelling study on the COVID-19 epidemic in Guangzhou in 2021

Several outbreaks of COVID-19 caused by imported cases have occurred in China following the successful control of the outbreak in early 2020. In order to avoid recurrences of such local outbreaks, it is important to devise an efficient control and prevention strategy. In this paper, we developed a stochastic discrete model of the COVID-19 epidemic in Guangzhou in 2021 to compare the effectiveness of centralized quarantine and compulsory home quarantine measures. The model was calibrated by using the daily reported cases and newly centralized quarantined cases. The estimated results showed that the home quarantine measure increased the accuracy of contact tracing. The estimated basic reproduction number was lower than that in 2020, even with a much more transmissible variant, demonstrating the effectiveness of the vaccines and normalized control interventions. Sensitivity analysis indicated that a sufficiently implemented contact tracing and centralized quarantine strategy in the initial stage would contain the epidemic faster with less infections even with a weakly implemented compulsory home quarantine measure. However, if the accuracy of the contact tracing was insufficient, then early implementation of the compulsory home quarantine with strict contact tracing, screening and testing interventions on the key individuals would shorten the epidemic duration and reduce the total number of infected cases. Particularly, 94 infections would have been avoided if the home quarantine measure had been implemented 3 days earlier and an extra 190 infections would have arisen if the home quarantine measure was implemented 3 days later. The study suggested that more attention should be paid to the precise control strategy during the initial stage of the epidemic, otherwise the key group-based control measure should be implemented strictly.

Health system impact of COVID-19 on urban slum population of Bangladesh: a mixed-method rapid assessment study

OBJECTIVE

We aimed to rapidly assess the health system impact of COVID-19 in the urban slums of Bangladesh.

DESIGN

Setting and participantsA cross-sectional survey among 476 households was conducted during October-December 2020 in five selected urban slums of Dhaka North, Dhaka South and Gazipur City Corporation. In-depth interviews with purposively selected 22 slum dwellers and key informant interviews with 16 local healthcare providers and four policymakers and technical experts were also conducted.

OUTCOME MEASURES

Percentage of people suffering from general illness, percentage of people suffering from chronic illness, percentage of people seeking healthcare, percentage of people seeking maternal care, health system challenges resulting from COVID-19.

RESULTS

About 12% of members suffered from general illness and 25% reported chronic illness. Over 80% sought healthcare and the majority sought care from informal healthcare providers. 39% of the recently delivered women sought healthcare in 3 months preceding the survey. An overall reduction in healthcare use was reported during the lockdown period compared with prepandemic time. Mismanagement and inefficient use of resources were reported as challenges of health financing during the pandemic. Health information sharing was inadequate at the urban slums, resulting from the lack of community and stakeholder engagement (51% received COVID-19-related information, 49% of respondents knew about the national hotline number for COVID-19 treatment). Shortage of human resources for health was reported to be acute during the pandemic, resulting from the shortage of specialist doctors and uneven distribution of health workforce. COVID-19 test was inadequate due to the lack of adequate test facilities and stigma associated with COVID-19. Lack of strong leadership and stakeholder engagement was seen as the barriers to effective pandemic management.

CONCLUSION

The findings of the current study are expected to support the government in tailoring interventions and allocating resources more efficiently and timely during a pandemic.