The global incidence and trends of three common flavivirus infections (Dengue, yellow fever, and Zika) from 2011 to 2021

Abstract

Background: Flavivirus pose a continued threat to global health, yet their worldwide burden and trends remain poorly quantified. We aimed to evaluate the global, regional, and national incidence of three common flavivirus infections (Dengue, yellow fever, and Zika) from 2011 to 2021.

Methods: Data on the number and rate of incidence for the three common flavivirus infection in 204 countries and territories were retrieved from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. The estimated annual percent change (EAPC) was calculated to quantify the temporal trend during 2011-2016, 2016-2019, and 2019-2021, respectively.

Results: In 2021, an estimated 59,220,428 individuals were infected globally, comprising 58,964,185 cases of dengue, 86,509 cases of yellow fever, and 169,734 cases of Zika virus infection. The age-standardized incidence rate (ASIR) of the three common flavivirus infections increased by an annual average of 5.08% (95% CI 4.12 to 6.05) globally from 2011 to 2016, whereas decreased by an annual average of -8.37% (95% CI -12.46 to -4.08) per year between 2016 to 2019. The ASIR remained stable during 2019-2021, with an average change of 0.69% (95% CI -0.96 to 2.37) per year globally for the three common flavivirus infections. Regionally, the burden of the three common flavivirus infections was primarily concentrated in those regions with middle income, such as South Asia, Southeast Asia, and Tropical Latin America. Additionally, at the country level, there was an inverted "U" relationship between the SDI level and the ASI. Notably, an increase in the average age of infected cases has been observed worldwide, particularly in higher-income regions.

Conclusion: Flavivirus infections are an expanding public health concern worldwide, with considerable regional and demographic variation in the incidence. Policymakers and healthcare providers must stay vigilant regarding the impact of COVID-19 and other environmental factors on the risk of flavivirus infection and be prepared for potential future outbreaks.

Keywords: Zika infection; age-standardized incidence rate; dengue; estimated annual percentage change importance; flavivirus infections; global burden of disease; yellow fever.

Figure 1

The distribution and trend of the number and age-standardized rate of incidence for three prevalent flavivirus (DENV, YFV, and ZIKV) infections, by sex. (A) The number and age-standardized rate of incidence from 2011 to 2021. (B) The number and rate of incidence in 2021 across age groups. (C) The distribution of incident cases across the globe, in different World Bank income classification and 21 GBD regions, 2021. (D) The distribution of incident cases of dengue across the globe, in different World Bank income classification and 21 GBD regions, 2021. (E) The distribution of incident cases of yellow fever across the globe, in different World Bank income classification and 21 GBD regions, 2021. (F) The distribution of incident cases of ZIKV infection across the globe, in different World Bank income classification and 21 GBD regions, 2021. DENV, Dengue virus; YFV, yellow fever virus; ZIKV, Zika virus.

Figure 2

Proportion of cases infected with flavivirus stratified by age groups, worldwide and across four income levels, 2011–2021.

Figure 3

Estimated age-standardized incidence rate (ASIR) for three prevalent flavivirus infections in 2021, by country. (A) The combined ASIR of DENV, YFV, and ZIKV infections. (B) The ASIR of DENV infection. (C) The ASIR of YFV infection. (D) The ASIR of ZIKV infection. DENV, Dengue virus; YFV, yellow fever virus; ZIKV, Zika virus.

Figure 4

The correlation between age-standardized incidence rate (ASIR) of three prevalent flavivirus infections and socio-demographic index (SDI). (A) The combined ASIR of DENV, YFV, and ZIKV infections versus SDI. (B) The ASIR of DENV infection versus SDI. (C) The ASIR of YFV infection versus SDI. (D) The ASIR of ZIKV infection versus SDI. The different colors stand for different SDI quintiles. The ρ indices and p-values were derived from Pearson correlation analysis. DENV, Dengue virus; YFV, yellow fever virus; ZIKV, Zika virus.