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A Study of Streptococcus Pneumonia Colonisation and Invasive Disease in Cambodian Children

Completed
Conditions
Streptococcal Pneumonia
Interventions
Other: Prospective study
Other: Cross-sectional surveys
Registration Number
NCT03331952
Lead Sponsor
University of Oxford
Brief Summary

Streptococcus pneumoniae (the pneumococcus) remains a leading cause of childhood mortality and morbidity. Between 2007 and 2012, Angkor Hospital for Children (AHC), Siem Reap, Cambodia documented that S. pneumoniae was responsible for around 10% of bloodstream infections in hospitalised children, with a case fatality rate of 15.6%.

The use of pneumococcal conjugate vaccines (PCV), covering between 7 and 13 of the \>90 pneumococcal serotypes, has resulted in significant declines in invasive pneumococcal disease (IPD) incidence in countries where they are included in routine childhood immunisation schedules. Paediatric radiologic pneumonia incidence is also reduced by PCV, but the impact on clinical pneumonia is minimal. The vaccines have had an effect on reducing the burden of drug resistant IPD, although this may not be sustained. Given the large number of serotypes not included in the current PCV formulations, it is not surprising that initial declines in overall IPD incidence have been eroded by, for the time being, small increases in IPD due to non-vaccine serotypes. To date most data on this serotype replacement disease has come from high-income countries. It less clear how much serotype replacement will occur in low and middle income countries, where pre-PCV disease incidence is generally higher and other factors, such as unregulated antimicrobial consumption, may play a role in encouraging non-vaccine serotype infections.

Nasopharyngeal colonisation by S. pneumoniae is common in childhood and is an essential prerequisite for invasive disease. Surveillance of pneumococcal colonisation can provide important data regarding serotype replacement and disease-associated serotypes, and may also allow prediction of likely IPD incidence changes post-vaccine introduction. A recent study of pneumococcal colonisation in children attending the AHC out-patients has documented an overall colonisation prevalence of approximately 65%.

In January 2015, Cambodia will introduce the 13-valent PCV (PCV13; serotypes covered 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19F, 19A, 23F). The vaccine will be rolled out nationally with a 3+0 dosing schedule (6, 10 and 14 weeks) and no catch up campaign. There is no robust national surveillance system in place to monitor the effects of PCV13 introduction.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
4111
Inclusion Criteria

Not provided

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Exclusion Criteria

Not provided

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Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
Invasive pneumococcal disease study (PCV-D)Prospective studyProspective study of children with invasive pneumococcal disease / probable bacterial meningitis (PCV-D) Clinical procedures At study enrolment: * Admission clinical findings / laboratory results will be recorded. * A questionnaire will be administered to the parent / guardian or caretaker to assess the child's immunisation status, household structure, environmental exposures, and recent antimicrobial use. Radiology procedures As part of routine clinical management at AHC, a digital chest radiograph (CXR) may be performed as part of a child's diagnostic work up. CXRs will be read and interpreted primarily by the AHC radiologists. All CXR will subsequently be re-read by two study clinicians and interpreted according to the WHO paediatric radiologic pneumonia criteria. Laboratory procedures • Residual routine clinical specimens further analysed as part of the study protocol: * Blood and cerebrospinal fluid culture specimens. * EDTA / serum specimens. * Urine.
Pneumonia study (PCV-P)Prospective studyProspective study of children hospitalised with clinical and/or radiologic pneumonia (PCV-P) Clinical procedures As described for PCV-D. Radiology procedures As part of routine clinical management at AHC, a digital chest radiograph (CXR) is performed on all children with an admission diagnosis of pneumonia. CXRs will be handled as described for PCV-D. Laboratory procedures * Study specific specimens: o Nasopharyngeal swab at enrolment. * Residual routine clinical specimens further analysed as part of the study protocol: * As described for PCV-D.
Pneumococcal colonisation study (PCV-C)Cross-sectional surveysCross-sectional pneumococcal colonisation surveys in children attending the AHC out-patient department (PCV-C) Three annual surveys, enrolling 450 children each year, will be done to identify and characterise pneumococcal nasopharyngeal colonisation in AHC out-patient department (OPD) attendees. Clinical procedures • Subjects will be recruited from the OPD waiting area after nurse triage. A questionnaire will be administered to the parent / guardian or caretaker to assess the child's immunisation status (by review of the handheld immunisation card where possible), household structure, environmental exposures, and recent antimicrobial use. Laboratory procedures • Study specific specimens: o Nasopharyngeal swab at enrolment. A nasopharyngeal swab will be collected from each participant and these will be processed as described for PCV-P.
Primary Outcome Measures
NameTimeMethod
Invasive pneumococcal disease hospitalisation rates3 years
Characteristics of invasive S. pneumoniae isolates in children <5 years of age admitted to Angkor Hospital for Children, in relation to national introduction of PCV13 in Cambodia3 years
Secondary Outcome Measures
NameTimeMethod
Changes in pneumonia (both clinical and radiologic) hospitalisation rates in children <5 years of age, in relation to national introduction of PCV13 in Cambodia3 years
Genotype in relation to national introduction of PCV133 years
Serotype in relation to national introduction of PCV133 years
Compare pneumococcal serotype colonisation in pneumonia cases with children attending the hospital out-patients for minor illnesses3 years
Pneumococcal colonisation prevalence3 years
Antimicrobial susceptibility profiles in relation to national introduction of PCV133 years

Trial Locations

Locations (1)

Angkor Hospital for Children

🇰🇭

Siem Reap, Cambodia

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