This article is more than 5 years old. Information may no longer be current.
Meningococcal bacterial load varies by wide magnitude in adolescents
Click Here to Manage Email Alerts
Recent findings published in Pediatric Infectious Disease Journal suggest that the bacterial load of meningococcus in adolescents varies by up to four orders of magnitude between each individual.
“In this paper we describe for the first time the distribution of colonization density among young adults carrying meningococcus in the oropharynx,” Adam Finn, PhD, at Bristol Children’s Vaccine Centre in the United Kingdom, and colleagues wrote. “Using both culture and [quantitative] PCR, we demonstrate that the bacterial load varies between carriers by up to four orders of magnitude and that the large majority carry the organism at lower densities.”
Finn and colleagues sought to determine the existence of meningococcal bacteria in adolescent patients because their presence may be linked to a higher rate of transmission, which is important for evaluating the indirect effects of the vaccine. They performed plate cultures on 109 oropharyngeal swabs that were positive for Neisseria meningitidis and performed qPCR on 601 swabs.
The researchers found that density both by culture and qPCR varied by four orders of magnitude, with most being low and having less than 50 bacteria-gene copies per mL.
Vaccine studies that fail to measure the impact on bacterial density may underestimate the vaccine’s effects on the population, the researchers wrote.
“The most immediate question or importance that this observation raises is: What is the relationship between density of carriage and efficiency of onwards transmission?” Finn and colleagues wrote. “If studies can be done to identify the bacterial proteins, expression of which is associated with successful transit from one person to the next, design of vaccines targeting interruption of spread rather than individual protection against invasive disease, may be achieved.” – by Will Offit
Disclosure: Finn reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.
Click Here to Manage Email Alerts