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. 2019 Jan 30:2019:1451490.
doi: 10.1155/2019/1451490. eCollection 2019.

Estimating the Force of Infection with Helicobacter pylori in Japan

Taishi Kayano  1 , Ki-Deok Lee  1   2 , Hiroshi Nishiura  1
Affiliations

Estimating the Force of Infection with Helicobacter pylori in Japan

Taishi Kayano et al. Can J Infect Dis Med Microbiol. .

Abstract

Background: Although the seroprevalence against Helicobacter pylori (H. pylori) in Japan has declined over the birth year, Japanese people have yet exhibited a relatively high risk of gastric cancer. The present study employed mathematical models to estimate the time- and age-dependent force of infection with H. pylori in Japan, predicting the future seroprevalence by time and age.

Methods: We investigated the published seroprevalence data against H. pylori in Japan from 1980-2018. Solving the McKendrick partial differential equation model, the seroprevalence was modeled as a function of survey year and age. Maximum likelihood estimation was conducted to estimate parameters governing the time- and age-dependent force of infection.

Results: Among all fitted models, the time-dependent and age-independent model with an exponentially decaying force of infection over years was most favored. Fitted models indicated that the force of infection started to decrease during and/or shortly after the World War II. Using the parameterized model, the predicted fraction seropositive at the age of 40 years in 2018 was 0.22, but it is expected to decrease to 0.13 in 2030 and 0.05 in 2050, respectively.

Conclusion: The time dependence was consistent with the decline in the force of infection as a function of the birth year. The force of infection has continuously and greatly declined over time, implying the diminished transmission of H. pylori through the time course and small chance of persistence. These findings are critical to anticipate the future decline in gastric cancer incidence.

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Figures

Figure 1
Figure 1
Seroprevalence of anti-Helicobacter pylori antibody in Japan by birth year. Antibody positive fraction is reviewed as a function of birth year. Same marks represent the dataset arising from an identical publication in the same survey year. Whiskers extend to lower and upper 95% confidence intervals.
Figure 2
Figure 2
Comparison between observed and predicted seroprevalence against Helicobacter pylori in Japan by birth year. Observed data (filled marks) in various surveys are plotted by birth year and compared against model prediction (unfilled marks) that assumes time dependence in the force of infection with an exponential decay. Predictions were made as a function of survey year and age.
Figure 3
Figure 3
Estimated force of infection of Helicobacter pylori as a function of calendar time in Japan. Model 1 (bold straight line) is the estimate of time-dependent force of infection with an exponential decay. Model 2 (dashed line) is the estimate of time-dependent force of infection with Gompertz-type decay.
Figure 4
Figure 4
Prediction of the seroprevalence against Helicobacter pylori in the past and the future in Japan. (a) Comparison between observed and predicted seroprevalence by age and survey year. Marks represent observed data, while lines are the expected values derived from the time-dependent force of infection with an exponential decay. (b) Prediction of the future seroprevalence against Helicobacter pylori in Japan. Gradual right shift in the seroprevalence is captured by our time-dependent force of infection with an exponential decay.
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References

    1. Inoue M. Changing epidemiology of Helicobacter pylori in Japan. Gastric Cancer. 2016;20(1):3–7. doi: 10.1007/s10120-016-0658-5. - DOI - PubMed
    1. Marshall B., Warren J. R. Unidentified curved bacilli in the stomach of patients with gastritis and peptic ulceration. The Lancet. 1984;323:1311–1315. doi: 10.1016/s0140-6736(84)91816-6. - DOI - PubMed
    1. Chiba T., Marusawa H., Seno H., Watanabe N. Mechanism for gastric cancer development by Helicobacter pyloriinfection. Journal of Gastroenterology and Hepatology. 2008;23(8):1175–1181. doi: 10.1111/j.1440-1746.2008.05472.x. - DOI - PubMed
    1. Hooi J. K. Y., Lai W. Y., Ng W. K., et al. Global prevalence of Helicobacter pylori infection: systematic review and meta-analysis. Gastroenterology. 2017;153(2):420–429. doi: 10.1053/j.gastro.2017.04.022. - DOI - PubMed
    1. Watanabe M., Ito H., Hosono S., et al. Declining trends in prevalence of Helicobacter pyloriinfection by birth-year in a Japanese population. Cancer Science. 2015;106(12):1738–1743. doi: 10.1111/cas.12821. - DOI - PMC - PubMed

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