Estimating the Force of Infection with Helicobacter pylori in Japan
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 infe...
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| Format: | Article |
| Language: | English |
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Wiley
2019-01-01
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| Series: | Canadian Journal of Infectious Diseases and Medical Microbiology |
| Online Access: | http://dx.doi.org/10.1155/2019/1451490 |
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| _version_ | 1832560817000677376 |
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| author | Taishi Kayano Ki-Deok Lee Hiroshi Nishiura |
| author_facet | Taishi Kayano Ki-Deok Lee Hiroshi Nishiura |
| author_sort | Taishi Kayano |
| collection | DOAJ |
| description | 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. |
| format | Article |
| id | doaj-art-8ac93bac4c8d467e9a319e2554627973 |
| institution | Kabale University |
| issn | 1712-9532 1918-1493 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Canadian Journal of Infectious Diseases and Medical Microbiology |
| spelling | doaj-art-8ac93bac4c8d467e9a319e25546279732025-02-03T01:26:41ZengWileyCanadian Journal of Infectious Diseases and Medical Microbiology1712-95321918-14932019-01-01201910.1155/2019/14514901451490Estimating the Force of Infection with Helicobacter pylori in JapanTaishi Kayano0Ki-Deok Lee1Hiroshi Nishiura2Graduate School of Medicine, Hokkaido University, Kita 15 Jo Nishi 7 Chome, Kitaku, Sapporo 0608638, JapanGraduate School of Medicine, Hokkaido University, Kita 15 Jo Nishi 7 Chome, Kitaku, Sapporo 0608638, JapanGraduate School of Medicine, Hokkaido University, Kita 15 Jo Nishi 7 Chome, Kitaku, Sapporo 0608638, JapanBackground. 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.http://dx.doi.org/10.1155/2019/1451490 |
| spellingShingle | Taishi Kayano Ki-Deok Lee Hiroshi Nishiura Estimating the Force of Infection with Helicobacter pylori in Japan Canadian Journal of Infectious Diseases and Medical Microbiology |
| title | Estimating the Force of Infection with Helicobacter pylori in Japan |
| title_full | Estimating the Force of Infection with Helicobacter pylori in Japan |
| title_fullStr | Estimating the Force of Infection with Helicobacter pylori in Japan |
| title_full_unstemmed | Estimating the Force of Infection with Helicobacter pylori in Japan |
| title_short | Estimating the Force of Infection with Helicobacter pylori in Japan |
| title_sort | estimating the force of infection with helicobacter pylori in japan |
| url | http://dx.doi.org/10.1155/2019/1451490 |
| work_keys_str_mv | AT taishikayano estimatingtheforceofinfectionwithhelicobacterpyloriinjapan AT kideoklee estimatingtheforceofinfectionwithhelicobacterpyloriinjapan AT hiroshinishiura estimatingtheforceofinfectionwithhelicobacterpyloriinjapan |