Hepatitis a virus infection in Central-West Tunisia: an age structured model of transmission and vaccination impact.
BMC Infect Dis
; 20(1): 627, 2020 Aug 26.
Article
em En
| MEDLINE
| ID: mdl-32842988
ABSTRACT
BACKGROUND:
The epidemiological pattern of hepatitis A infection has shown dynamic changes in many parts of the world due to improved socio-economic conditions and the accumulation of seronegative subjects, which leads to possible outbreaks and increased morbidity rate. In Tunisia, the epidemiological status of hepatits A virus is currently unknown. However, over the past years higher numbers of symptomatic hepatitis A virus infection in school attendants and several outbreaks were reported to the Ministry of Health, especially from regions with the lowest socio-economic levels in the country. The aim of this study was to investigate the current seroprevalence of hepatitis A virus antibodies in central-west Tunisia and assess the impact of hepatitis A virus vaccination on hepatitis A epidemiology.METHODS:
Serum samples from 1379 individuals, aged 5-75 years, were screened for hepatitis A virus antibodies. Adjusted seroprevalence, incidence and force of infection parameters were estimated by a linear age structured SEIR (Susceptible-Exposed-Infectious-Recovered) compartmental model. A vaccine model was then constructed to assess the impact on hepatitis A virus epidemiology of 3 scenarios of vaccination strategies one dose at 12-months of age, one dose at 6-years and one dose at 12-months and another at 6-years of age during 6 years.RESULTS:
A rapid increase in anti-hepatitis A virus seroprevalence was noted during infancy and adolescence 47% of subjects under 10-years-old are infected; the prevalence increases to 77% at 15-years and reaches 97% in subjects aged 30-years. The force of infection is highest between 10 and 30-years of age and the incidence declines with increasing age. The vaccine model showed that the 3-scenarios lead to a significant reduction of the fraction of susceptibles. The two doses scenario gives the best results. Single-dose vaccination at 6-years of age provides more rapid decrease of disease burden in school-aged children, as compared to single-dose vaccination at 12-months, but keeps with a non-negligible fraction of susceptibles among children < 6-years.CONCLUSIONS:
Our study confirms the epidemiological switch from high to intermediate endemicity of hepatitis A virus in Tunisia and provides models that may help undertake best decisions in terms of vaccinations strategies.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vacinação
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Vírus da Hepatite A
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Hepatite A
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Modelos Teóricos
Tipo de estudo:
Incidence_studies
/
Prevalence_studies
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Prognostic_studies
/
Risk_factors_studies
Limite:
Adolescent
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Adult
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Aged
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Child
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Child, preschool
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Female
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Humans
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Male
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Middle aged
País/Região como assunto:
Africa
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article