Related Experiment Video
Updated: Jan 18, 2026

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
Published on: February 23, 2014
Pneumococcal colonization rates in children and adults in two developing countries: A prospective cross-sectional
Phoeung Chan Leakhena1, Shally Awasthi2, Muriel Rabilloud3
1University of Health Sciences, 73 Preah Monivong Blvd (93), Phnom Penh, Cambodia.
Introduction:
Streptococcus pneumoniae is a major cause of lower respiratory infections, especially in children under 5 years old. While pneumococcal conjugate vaccines (PCVs) have reduced disease burden in many countries, data from low- and middle-income countries are still limited. The objective of this prospective, hospital-based, cross -sectional study was to measure the prevalence of pneumococcal colonization and identify circulating serotypes among children <5 years and their caregivers in Cambodia and India.
Methods:
Children aged 0-59 months free of severe respiratory infection according to WHO criteria and consulting at one of the participating hospitals were eligible. For each child, the accompanying guardian or parent residing in the same household as the child and not having respiratory infection was also recruited. Sociodemographic and clinical data were obtained; nasopharyngeal swabs were collected from enrolled child-adult pairs and tested for S. pneumoniae using PCR. Positive samples underwent serotyping.
Results:
A total of 708 adult-child pairs from Cambodia and 770 from India were included. The overall prevalence of nasopharyngeal S. pneumoniae carriage was 30.6 % (Cambodia: 31.4 %, India: 29.9 %) in children and 10.8 % (Cambodia: 8.5 %, India: 13.0 %) in adults. The highest colonization rate was found in children aged 12-24 months. In total, 99.2 % of children in Cambodia and 60.3 % of those in India had received at least one dose of PCV vaccine. Vaccine serotypes (VT) made up 37.9-48 % of isolates in children, the most common being VTs: 6 A/B, 19F, 14. In Cambodia, among vaccinated children, Overall, 52 and 31vaccinated children in Cambodia were carrier of VT in Cambodia and India respectively. Among non-vaccinated children, one in Cambodia and 18 in India carried VT. Non-vaccine serotypes were also common (15B/C, 34, 35B), indicating serotype replacement.
Conclusions:
Pneumococcal colonization remains common in young children, even after PCV introduction. Continued surveillance is essential to guide vaccine policy and monitor impact.
Related Concept Videos
Pneumonia I: Introduction
Risk Factors
Various factors influence the likelihood of developing pneumonia. Age plays a crucial role, with infants, children under two, and individuals over 65 at increased risk due to their...
Pneumonia II: Pathophysiology
Pneumonia V: Nursing management and Prevention
The nurse must practice strict medical asepsis and adhere to infection control guidelines to minimize healthcare-associated infections.
Enhance airway patency
Position the patient correctly to facilitate drainage of the affected lung segments. Manual or mechanical percussion and vibration can also be employed....
Pneumonia III: Complications and Assessment
Sputum Studies II: Culture and Sensitivity
Sputum culture and sensitivity is a medical procedure used to diagnose bacterial infections in the respiratory tract and select the most appropriate antibiotics for treatment. This process involves analyzing sputum samples of thick and opaque secretions produced in the lungs and airways. These samples are collected from patients and then sent to the laboratory for analysis.
The test can identify various pathogens responsible for respiratory infections, including Streptococcus,...
Factors Affecting the Risk of Infection
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin...

