Seroprevalence of Pertussis Among Children and Adolescents in Croatia

Study Overview
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Brief Summary
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Pertussis is a vaccine preventable disease caused by Bordetella pertussis. Older children and adolescents with pertussis continue to be a significant source of infection for incompletely vaccinated infants who are in harm for developing severe disease. The primary objective of our study is to estimate the duration of protection elicited by the current vaccination schedule against pertussis in Croatia.

Official Title
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Seroprevalence of Pertussis Antibodies Among Children and Adolescents in Croatia - Investigation of the Waning Vaccine-induced Immunity in Children and Adolescents

Conditions
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Immunogenicity, Vaccine

Intervention / Treatment
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* Diagnostic Test: ELISA IgG Testkit


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: children and adolescents from 6 to 18 years of age treated through Emergency room and/or Day hospital of Pediatric Infectious Diseases Department at UHID; appropriate vaccination with pertussis component containing vaccine by date and at the appropriate time, according to Croatian NIP proven by insight in the Vaccination Record Card written informed consent obtained from the subject's parent or caregiver, as well as from participants ≥ 16 years old. Exclusion Criteria: children under 6 years children and adolescents with acute respiratory symptoms children and adolescents with pertussis-like illness within 12 months children and adolescents with unknown, uncompleted or irregular vaccination record inpatients children and adolescents with immunodeficiencies

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Seroprevalence of pertussis among children and adolescents in Croatia<br>For all patients participating in the study one serum sample will be collected for serological analysis. | Diagnostic Test: ELISA IgG Testkit<br>* All samples will be tested for IgG antibody level to pertussis toxin using a commercial Bordetella pertussis ELISA IgG Testkit in accordance to the manufacturers' protocol in the laboratory at the University Hospital for Infectious Diseases in Zagreb.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Waning of vaccine-induced immunity | Number of Participants In Each Specific Age Group With Negative Pertussis Toxin IgG Antibody Titre Measured by ELISA IgG Testkit | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Seroprevalence | Prevalence of Pertussis Toxin IgG Antibody Titre At Each Specific Age Subgroup | up to 6 months |