Seroprevalence of Pertussis Among Healthy Children and Adolescents in Kazakhstan

Study Overview
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Brief Summary
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Seroprevalence of pertussis among older children and adolescents in Kazakhstan: A cross sectional study. Justification: to describe the distribution of anti-pertussis toxin (PT) antibodies (IgA and IgG) in a population aged 10-18 years old according to sociodemographic characteristics, vaccination history, and risk factors of pertussis infection.

Detailed Description
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Pertussis due to infection with Bordetella pertussis (B pertussis) is a well-known cause of persistent cough primarily affecting infants and young children. Repeated administration of the vaccine is often needed to reduce the disease burden and control its transmission. At this time, no data are available on the epidemiology of pertussis in adolescents and adults in Kazakhstan. The aim of the present study is to estimate the prevalence of pertussis infection in different age groups in Kazakh children and adolescents using the anti-pertussis toxin (PT) antibodies (IgA and IgG) as specific marker of pertussis infection or vaccination. The serosurvey will be conducted in 4 different regions: Aktobe, Karaganda, Taldykorgan, and Shymkent. Participants (≥ 10 years & < 19 years) attending the study centers will be asked to participate in the study. The adolescent participants and the parents/guardian(s) of all participants will be informed about the procedures and data handling. Written informed consent from one parent/guardian needs to be obtained by the physician before any blood samples can be taken. Upon obtaining informed consent for participant parent/guardian, the study coordinator will complete an investigation form (IF) for each participant and collect serum samples. The specimens will be coded by a unique participant number and delivered to the laboratory in charge of the assay. The specimens will be used for serological analyses.

Official Title
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Seroprevalence of Pertussis Among Healthy Children and Adolescents in Kazakhstan: A Cross-Sectional Study

Conditions
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Pertussis

Intervention / Treatment
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* Diagnostic Test: Blood samples for pertussis antibody testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 10-18 years old Informed consent obtained from parents or guardian(s) and assent from patient. Enrollment following a visit at the study center. Documented vaccination history Exclusion Criteria: Inclusion criteria: 10-18 years old Informed consent obtained from parents or guardian(s) and assent from patient. Enrollment following a visit at the study center. Documented vaccination history Exclusion criteria: ≤10 years and ≥ 19 years Pertussis immunization during the last 12 months No informed consent obtained from one parent or guardian. Immunocompromised patients Patients with acute infectious diseases

Ages Eligible for Study
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Minimum Age: 10 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pertussis antibodies testing will be conducted at the Reference Laboratory in NPCCEEM<br>serum samples will be taken and tested by enzyme-linked immunoassay (ELISA) using the SAVYON SeroPertussisTM kits (Savyon Diagnostics Ltd, Israel). | Diagnostic Test: Blood samples for pertussis antibody testing<br>* Blood samples will be sent to the laboratories of the National Centers of Expertise within 24-48 hours of blood collection. The samples will be transferred to the reference laboratory of SPCSEEM in Almaty, Kazakhstan. Serum samples will be stored in the reference laboratory at a temperature of -20 C.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The anti-PT IgG and Ig A concentrations (in IU/ml) in the population sample. | To estimate the prevalence of recent infection Bp infection, using increased anti-PT antibody levels as markers of Bp infection in the serology test. | 25.01.2021-17.10.2021 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The prevalence of recent Bp infection in the test in the selected population sample stratified by demographic and socio-economic criteria, vaccination history, and risk of infection. | To evaluate the risk factors associated with higher seroprevalence of pertussis. | 25.01.2021-17.10.2021 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pertussis, seroprevalence, immunity, antibodies, Kazakhstan, vaccination