Related Experiment Video
Updated: Jun 17, 2026
Experimental Human Pneumococcal Carriage
Published on: February 15, 2013
Modelling multi-type transmission of pneumococcal carriage in Bangladeshi families
1Department of Vaccination and Immune Protection, National Institute for Health and Welfare, FI-00271 Helsinki, Finland. panu.erasto@thl.fi
Insights
This study tracked pneumococcal carriage in Bangladeshi infants and families, revealing that family exposure significantly increases the rate of acquiring pneumococcus (Streptococcus pneumoniae). Understanding transmission is key to reducing disease burden.
Area of Science:
- Microbiology
- Epidemiology
- Public Health
Background:
- Pneumococcal carriage disproportionately affects developing nations, yet transmission data is scarce.
- Streptococcus pneumoniae causes significant global disease burden, particularly in young children.
Purpose of the Study:
- To investigate the dynamics of pneumococcal nasopharyngeal carriage and transmission in Bangladeshi infants and their families.
- To quantify the impact of age, serotype, and family exposure on pneumococcal acquisition and clearance rates.
Main Methods:
- Longitudinal study tracking nasopharyngeal carriage in 99 infants from birth to 1 year.
- Family members were sampled concurrently at regular intervals.
- A statistical model for incompletely observed data was used to estimate acquisition and clearance rates for multiple serotypes.
Main Results:
- Serotype prevalence influenced community acquisition rates, with common serotypes acquired more frequently.
- Family transmission significantly increased acquisition rates (over tenfold).
- When controlling for family exposure, transmission rates were comparable across different pneumococcal serotypes.
Conclusions:
- Family contact is a critical driver of pneumococcal acquisition in infants.
- Understanding transmission dynamics within households is essential for developing effective control strategies against pneumococcal disease in developing countries.
Abstract:
The burden of pneumococcal carriage is largest in developing countries from which, however, detailed studies on pneumococcal transmission are missing. In this study we followed nasopharyngeal carriage in Bangladeshi infants (n=99) from birth, with 2-week sampling intervals until age 4 months, and monthly thereafter until age 1 year, and also their family members at the same intervals. We assessed the dependence of pneumococcal acquisition rates on age, serotype, serotype-specific exposure (i.e. transmission) and current state of carriage (yes/no). A statistical model of pneumococcal transmission, taking into account incompletely observed data, was applied to estimate rates of acquisition and clearance for a large number of serotypes at the same time. Serotypes that were common in the study population were more often acquired from the community than rarer serotypes. However, when conditioning on serotype-specific exposure within the family, transmission rates were similar between different serotypes. Exposure within families signified more than tenfold increase in the rate of acquisition.
Related Concept Videos
01:28Infectious Diseases and Their Occurrence
01:24Transmission of Pathogens
01:20Infection
The chain begins with pathogens: bacteria, viruses, fungi, prions, or parasites such as protozoa helminths. These can be present on the skin as transient or resident flora, or they can be acquired from the environment. Identifying and treating the type of infection and...
01:14Atypical Pneumonia
01:25Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
01:17Transmission-based Precautions I: Contact, Enteric, and Droplets
Contact Precautions:
Contact precautions are the measures taken to prevent the transmission of infectious agents, especially epidemiologically important microorganisms such as MRSA or influenza, primarily transmitted through direct or indirect contact with an...