Analysis of the Genetic Diversity of Neisseria Meningitidis in South Africa
Date
2006-11-15T07:58:01Z
Authors
Coulson, Garry Brian
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Abstract
Meningococcal disease is an important cause of morbidity and mortality worldwide,
particularly in children and young adults. Epidemics caused by Neisseria meningitidis
continue to plague many countries on a global scale, none more so than countries of the
African ‘meningitis belt’, where attack rates can reach up to 1000/100,000 population. It has
been well recognized that most epidemic and endemic cases of meningococcal disease are
caused by a limited number of genetically defined clonal groups. The objective of this
molecular epidemiological study was to genotypically characterize strains of N. meningitidis
collected in South Africa from July 1999 to July 2002. Characterization of meningococcal
strains belonging to serogroup A, B, C, W135 and Y, by PFGE and MLST allowed us to
determine the genetic population structure of N. meningitidis in South Africa, and thus identify
the predominant clonal groups responsible for the majority of meningococcal disease in the
country over this period. The results from the genotypic characterization revealed that the
greatest majority of meningococcal disease in South Africa was caused by a strains belonging
to only a few “hyperinvasive lineages”, most notably strains of the ST-44 complex (lineage
III), ST-32 complex (ET-5 complex), ST-11 complex (ET-37 complex), and the ST-1 complex
(subgroup I/II) which have all been responsible for major epidemics worldwide. These
findings have direct implications on public health decision, particularly with regards to the
development of effective intervention and control strategies, and emphasize the need for
continuous long-term monitoring of the circulation of these strains in the population.
Description
Student Number : 9704202D -
MSc dissertation -
School of Clinical Microbiology and Infectious Diseases -
Faculty of Science
Keywords
epidemiology, molecular epidemiology, genotypic techniques, populaton genetics, genetic diversity