Incidence trend and disease burden of seven vaccine-preventable diseases in Shandong province, China, 2013-2017: Findings from a population-based observational study

Abstract

Introduction: Although vaccines provide a cost-effective solution to vaccine-preventable diseases (VPDs), the disease burden of VPDs is still very high in most parts of the world.

Methods: A population-based observational study was conducted in Shandong province, China, from 2013 to 2017, giving an insight into the epidemiological characteristics and disease burden of seven VPDs. The incidence trend was estimated using the Poisson regression model. The disease burden was calculated using the disability-adjusted life years (DALYs).

Results: Most VPDs included in the China's National Immunization Program had higher incidence density (ID) in inland cities. The ID of mumps decreased significantly, while herpes zoster increased (both P < 0.05). The top three causes of the disease burden as assessed with DALYs included tuberculosis, herpes zoster, and hepatitis B, with the rates of 72.21, 59.99, and 52.10 DALYs/100 000, respectively. The disease burden of influenza and herpes zoster were relatively high in people aged > 50 years, while highest DALYs of hepatitis B were found in young adults.

Conclusion: Inequalities in the vaccine coverage by geography, socio-economic status, and targeted population contribute to the increasing incidence and high burden of VPDs and call for renewed and sustained immunization strategies in China.

Keywords: China; Disease burden; Epidemiological characteristics; Incidence trend; Vaccine-preventable diseases.

Fig. 1

Geographic distribution of the seven vaccine-preventable diseases (VPDs). (A) Geographic distribution of cumulative cases of the seven VPDs. The size of the circles represents the number of cases, and each color represents one disease. (B) Geographic distribution of cumulative incidence density (ID) of the seven VPDs. (C) Geographic distribution of overall IDs for VPDs included in National Immunization Program (NIP) of China. (D) Geographic distribution of overall IDs for VPDs out of National Immunization Program (NIP) of China.

Fig. 2

Ranking of the seven vaccine-preventable diseases by estimated burden at population level (DALYs/year) and individual level (DALYs per 100 cases) in Shandong province, China, 2013–2017. The DALYs per year are shown on the x-axis and the DALYs per 100 cases are shown on the y-axis. Both axes are on logarithmic scale, of which the x-axis represents the disease burden at the population level and the y-axis represents the disease burden of the individual level. The size of the bubbles represents the estimated number of cases annually. DALYs: Disability Adjusted Life Years.

Fig. 3

Estimated annual disease burden of the seven vaccine-preventable diseases (DALYs per 100 000 population) by gender and age groups in Shandong province, China, 2013–2017. (A-G) The disease burden of influenza, herpes zoster, hepatitis B, hand, foot, and mouth disease, tuberculosis, mumps, and measles, respectively. DALYs: Disability Adjusted Life Years, YLDs, years lived with disabilities, YLLs, years of life lost.