Movement dynamics: reduced dengue cases during the COVID-19 pandemic
During 2020 and 2021, there appeared to be a decrease from previous years in the total number of dengue cases reported to the WHO, although the data for this period are not complete.
COVID-19 was first identified in early 2020, and by the end of that year, there were about 80 million COVID-19 cases across the globe.
As COVID-19 cases continued to rise, governments in the affected countries implemented mobility restrictions to suppress the rate of SARS-CoV-2 transmission, leading to behavioral changes that could also affect the transmission of other communicable diseases. , circulating in society. IN Lancet infectious diseasesYuyang Chen and colleagues
compared the annual incidence of dengue in 2020 in 23 countries in Latin America and Southeast Asia with a Bayesian regression model projecting a predicted incidence of dengue based on the monthly incidence, climatic and population variables in each country in 2014-19. Deviations in these occurrences were then assessed for any association with specific COVID-19-related public health and societal measures and human movement behavior.
the intensity of public health and societal measures and human movement behavior was highest at the beginning of the COVID-19 pandemic, and then diminished over the months as the epidemic curve flattened and economic pressures to loosen restrictions increased. Indonesia is a dengue endemic country hard hit by COVID-19 in 2020. The government introduced a restriction policy in early March 2020 that was not a full lockdown, but instead a compromise between transmission control and economic considerations, called large-scale social restriction, which was further relaxed in the following months. Due to a decentralized structure, the decision to initiate, extend or end the major social restriction was made by each district or provincial government based on each region’s epidemiological considerations and economic possibilities, leading to differences in the intensity and forms of large-scale social restrictions in each region.
found a strong link between COVID-19-related societal disorders and reduced dengue risk after taking into account climate, host immunity and other factors affecting dengue cycles, with school closures and reduced time spent in non-residential areas having the strongest evidence of correlation with reduced risk of dengue. These results add to the growing body of evidence that dengue is spread through human movement, with transmission occurring in common areas outside the home.
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These results could provide new insights into potential interventions to control various infections, including dengue. Particularly in countries where dengue is endemic, such as those included in the study by Chen and colleagues, interventions are often centered around surveillance, and vector control is focused around residential areas.
Implementing policies that limit community mobility in the context of dengue control under non-COVID-19 pandemic conditions may prove challenging, but opportunities to focus vector control interventions on multiple public areas could be potential alternatives.
Indonesia, a dengue endemic country with high annual incidence, observed a reduced annual dengue incidence in 2020 compared to the previous year,
which could have been affected by COVID-19-related mobility restrictions, but a formal study has yet to be conducted. The consistent results and the large scale of Chen’s and colleagues’ study, which includes many dengue endemic countries in Latin America and Southeast Asia, highlights the importance of countries having robust, stratified data in dengue surveillance that have been shown to be useful for disease modeling. and mitigation, and lays important foundations for more detailed, high-resolution studies in the future.
In 2022, the world will continue to face daily reports of COVID-19 cases with the introduction of the COVID-19 Omicron variant in various countries globally amid scattered mobility restrictions. Continuing to analyze the prevalence of dengue during the ongoing COVID-19 pandemic against the (early and spatially) varied mobility restrictions between different areas will be beneficial in advancing our understanding of how movement dynamics affect the transmission of infectious diseases.
We declare no competing interests.
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Published: March 2, 2022
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