Modeling the hepatitis A epidemiological transition in Brazil and Mexico
Background: Many low- to middle-income countries have completed or are in the process of transitioning from high or intermediate to low endemicity for hepatitis A virus (HAV). Because the risk of severe hepatitis A disease increases with age at infection, decreased incidence that leaves older childr...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2017-08-01
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| Series: | Human Vaccines & Immunotherapeutics |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/21645515.2017.1323158 |
| _version_ | 1797677572901830656 |
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| author | Thierry Van Effelterre Adrienne Guignard Cinzia Marano Rosalba Rojas Kathryn H. Jacobsen |
| author_facet | Thierry Van Effelterre Adrienne Guignard Cinzia Marano Rosalba Rojas Kathryn H. Jacobsen |
| author_sort | Thierry Van Effelterre |
| collection | DOAJ |
| description | Background: Many low- to middle-income countries have completed or are in the process of transitioning from high or intermediate to low endemicity for hepatitis A virus (HAV). Because the risk of severe hepatitis A disease increases with age at infection, decreased incidence that leaves older children and adults susceptible to HAV infection may actually increase the population-level burden of disease from HAV. Mathematical models can be helpful for projecting future epidemiological profiles for HAV. Methods: An age-specific deterministic, dynamic compartmental transmission model with stratification by setting (rural versus urban) was calibrated with country-specific data on demography, urbanization, and seroprevalence of anti-HAV antibodies. HAV transmission was modeled as a function of setting-specific access to safe water. The model was then used to project various HAV-related epidemiological outcomes in Brazil and in Mexico from 1950 to 2050. Results: The projected epidemiological outcomes were qualitatively similar in the 2 countries. The age at the midpoint of population immunity (AMPI) increased considerably and the mean age of symptomatic HAV cases shifted from childhood to early adulthood. The projected overall incidence rate of HAV infections decreased by about two thirds as safe water access improved. However, the incidence rate of symptomatic HAV infections remained roughly the same over the projection period. The incidence rates of HAV infections (all and symptomatic alone) were projected to become similar in rural and urban settings in the next decades. Conclusion: This model featuring population age structure, urbanization and access to safe water as key contributors to the epidemiological transition for HAV was previously validated with data from Thailand and fits equally well with data from Latin American countries. Assuming no introduction of a vaccination program over the projection period, both Brazil and Mexico were projected to experience a continued decrease in HAV incidence rates without any substantial decrease in the incidence rates of symptomatic HAV infections. |
| first_indexed | 2024-03-11T22:47:14Z |
| format | Article |
| id | doaj.art-c8d3df7d082448a884aff8576732d273 |
| institution | Directory Open Access Journal |
| issn | 2164-5515 2164-554X |
| language | English |
| last_indexed | 2024-03-11T22:47:14Z |
| publishDate | 2017-08-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Human Vaccines & Immunotherapeutics |
| spelling | doaj.art-c8d3df7d082448a884aff8576732d2732023-09-22T08:17:50ZengTaylor & Francis GroupHuman Vaccines & Immunotherapeutics2164-55152164-554X2017-08-011381942195110.1080/21645515.2017.13231581323158Modeling the hepatitis A epidemiological transition in Brazil and MexicoThierry Van Effelterre0Adrienne Guignard1Cinzia Marano2Rosalba Rojas3Kathryn H. Jacobsen4GSK VaccinesGSK VaccinesGSK VaccinesInstituto Nacional de Salud PùblicaGeorge Mason UniversityBackground: Many low- to middle-income countries have completed or are in the process of transitioning from high or intermediate to low endemicity for hepatitis A virus (HAV). Because the risk of severe hepatitis A disease increases with age at infection, decreased incidence that leaves older children and adults susceptible to HAV infection may actually increase the population-level burden of disease from HAV. Mathematical models can be helpful for projecting future epidemiological profiles for HAV. Methods: An age-specific deterministic, dynamic compartmental transmission model with stratification by setting (rural versus urban) was calibrated with country-specific data on demography, urbanization, and seroprevalence of anti-HAV antibodies. HAV transmission was modeled as a function of setting-specific access to safe water. The model was then used to project various HAV-related epidemiological outcomes in Brazil and in Mexico from 1950 to 2050. Results: The projected epidemiological outcomes were qualitatively similar in the 2 countries. The age at the midpoint of population immunity (AMPI) increased considerably and the mean age of symptomatic HAV cases shifted from childhood to early adulthood. The projected overall incidence rate of HAV infections decreased by about two thirds as safe water access improved. However, the incidence rate of symptomatic HAV infections remained roughly the same over the projection period. The incidence rates of HAV infections (all and symptomatic alone) were projected to become similar in rural and urban settings in the next decades. Conclusion: This model featuring population age structure, urbanization and access to safe water as key contributors to the epidemiological transition for HAV was previously validated with data from Thailand and fits equally well with data from Latin American countries. Assuming no introduction of a vaccination program over the projection period, both Brazil and Mexico were projected to experience a continued decrease in HAV incidence rates without any substantial decrease in the incidence rates of symptomatic HAV infections.http://dx.doi.org/10.1080/21645515.2017.1323158clean waterhepatitis alatin americamathematical modelseroprevalenceurbanization |
| spellingShingle | Thierry Van Effelterre Adrienne Guignard Cinzia Marano Rosalba Rojas Kathryn H. Jacobsen Modeling the hepatitis A epidemiological transition in Brazil and Mexico Human Vaccines & Immunotherapeutics clean water hepatitis a latin america mathematical model seroprevalence urbanization |
| title | Modeling the hepatitis A epidemiological transition in Brazil and Mexico |
| title_full | Modeling the hepatitis A epidemiological transition in Brazil and Mexico |
| title_fullStr | Modeling the hepatitis A epidemiological transition in Brazil and Mexico |
| title_full_unstemmed | Modeling the hepatitis A epidemiological transition in Brazil and Mexico |
| title_short | Modeling the hepatitis A epidemiological transition in Brazil and Mexico |
| title_sort | modeling the hepatitis a epidemiological transition in brazil and mexico |
| topic | clean water hepatitis a latin america mathematical model seroprevalence urbanization |
| url | http://dx.doi.org/10.1080/21645515.2017.1323158 |
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