The indirect impacts of nonpharmacological COVID-19 control measures on other infectious diseases in Yinchuan, Northwest China: a time series study

Abstract

Background Various nonpharmaceutical interventions (NPIs) against COVID-19 continue to have an impact on socioeconomic and population behaviour patterns. However, the effect of NPIs on notifiable infectious diseases remains inconclusive due to the variability of the disease spectrum, high-incidence endemic diseases and environmental factors across different geographical regions. Thus, it is of public health interest to explore the influence of NPIs on notifiable infectious diseases in Yinchuan, Northwest China. Methods Based on data on notifiable infectious diseases (NIDs), air pollutants, meteorological data, and the number of health institutional personnel in Yinchuan, we first fitted dynamic regression time series models to the incidence of NIDs from 2013 to 2019 and then estimated the incidence for 2020. Then, we compared the projected time series data with the observed incidence of NIDs in 2020. We calculated the relative reduction in NIDs at different emergency response levels in 2020 to identify the impacts of NIPs on NIDs in Yinchuan. Results A total of 15,711 cases of NIDs were reported in Yinchuan in 2020, which was 42.59% lower than the average annual number of cases from 2013 to 2019. Natural focal diseases and vector-borne infectious diseases showed an increasing trend, as the observed incidence in 2020 was 46.86% higher than the estimated cases. The observed number of cases changed in respiratory infectious diseases, intestinal infectious diseases and sexually transmitted or bloodborne diseases were 65.27%, 58.45% and 35.01% higher than the expected number, respectively. The NIDs with the highest reductions in each subgroup were hand, foot, and mouth disease (5854 cases), infectious diarrhoea (2157 cases) and scarlet fever (832 cases), respectively. In addition, it was also found that the expected relative reduction in NIDs in 2020 showed a decline across different emergency response levels, as the relative reduction dropped from 65.65% (95% CI: -65.86%, 80.84%) during the level 1 response to 52.72% (95% CI: 20.84%, 66.30%) during the level 3 response. Conclusions The widespread implementation of NPIs in 2020 may have had significant inhibitory effects on the incidence of respiratory infectious diseases, intestinal infectious diseases and sexually transmitted or bloodborne diseases. The relative reduction in NIDs during different emergency response levels in 2020 showed a declining trend as the response level changed from level 1 to level 3. These results can serve as essential guidance for policy-makers and stakeholders to take specific actions to control infectious diseases and protect vulnerable populations in the future.

Temporal shifts in 24 notifiable infectious diseases in China before and during the COVID-19 pandemic

“…RIDs, notably HFMD and mumps, displayed a pronounced susceptibility to PHSMs 27 . Conversely, the impact of PHSMs on BSTDs was more limited, consistent with previous research findings 9 , 10 , 26 . For most RIDs, the implementation of PHSMs significantly curtailed their transmission (Fig.…”

“…Although many published studies 9 – 13 have analyzed the impact of PHSMs on notifiable infectious diseases (NIDs), there remains a significant gap in our understanding of this relationship. Most of these studies 9 , 10 have focused primarily on the impact of PHSMs in their early stages and have tended to overlook the potential impact of PHSMs of varying durations. Additionally, most published studies have predominantly concentrated on the impact of PHSMs on common RIDs and IIDs, with limited quantitative analysis on BSTDs and ZIDs 11 , 12 .…”

Heterogeneity of influenza infection at precise scale in Yinchuan, Northwest China, 2012–2022: evidence from Joinpoint regression and spatiotemporal analysis

“…Notably, we identified three turning points whose timings closely align with the implementation of NPIs in Ningxia. Previous studies 42 , 48 observed similar trends in other respiratory diseases. Therefore, we have reasons to believe that NPIs significantly influence the incidence of influenza.…”

“…Influenza reached its first peak period in 2019, with an incidence of 32.62/100,000. Then, we observed a remarkable decline in 2020, staying in step with the United States, Singapore, and China 42 – 44 . After nearly two years, influenza up-resurgence and reached another peak in 2022, as was reported in several studies before 15 .…”

“…Some researchers 12 , 46 , 47 have come to the same conclusion. Non-pharmaceutical interventions (NPIs), such as mask-wearing, social distancing, travel restrictions, patient isolation, and other public health measures have limited people's exposure to the influenza virus, leading to a downward trend 42 , 48 . Since 2021, Ningxia achieved significant success against the epidemic.…”