High Diversity of Group A Streptococcal emm Types among Healthy Schoolchildren in Ethiopia

• Published in: Clinical infectious diseases Vol. 42; no. 10; pp. 1362 - 1367
• Main Authors: Abdissa, Alemseged, Asrat, Daniel, Kronvall, Göran, Shittu, Belay, Achiko, Dilachew, Zeidan, Mohammed, Yamuah, Lawrence K., Aseffa, Abraham
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 15-05-2006; University of Chicago Press; Oxford University Press
• Subjects: Adolescent; Antigens, Bacterial - genetics; Articles and Commentories; Bacteria; Bacterial diseases; Bacterial Outer Membrane Proteins - genetics; Base Sequence; Biological and medical sciences; Carrier Proteins - genetics; Child; Deoxyribonucleic acid; DNA; DNA Primers; DNA, Bacterial - genetics; Epidemiology; Ethiopia; Female; Genetic Variation; Heart diseases; Human bacterial diseases; Humans; Infections; Infectious diseases; Male; Medical sciences; Medicin och hälsovetenskap; Microbiology; Polymerase Chain Reaction; Reference Values; Rheumatic fever; Rheumatic heart disease; Staphylococcal infections, streptococcal infections, pneumococcal infections; Streptococcal infections; Streptococcus; Streptococcus pyogenes; Streptococcus pyogenes - genetics; Streptococcus pyogenes - isolation & purification; Throat; Vaccination; Ethiopia; Africa; Human; Infection; Streptococcaceae; School age; Streptococcal infection; Streptococcus A; Bacteriosis; Bacteria; Micrococcales; Child
• ISSN: 1058-4838; 1537-6591; 1537-6591
• DOI: 10.1086/503422

Background. Although the prevalence of rheumatic heart disease in Ethiopia is one of the highest in the world, the epidemiology of group A streptococci (GAS) in this country is little known. GAS typing is a hallmark of both the epidemiology and understanding of diseases caused by these organisms. We have therefore conducted this study to investigate the emm (M-protein gene) type distribution of GAS carriers among Ethiopian schoolchildren. Methods. In the present study, we performed emm typing of 82 GAS isolates collected from the throats of healthy schoolchildren (6–14 years of age) residing in 3 different urban sites in Ethiopia: Addis Ababa, Gondar, and Dire Dawa. Results. We report high diversity of GAS isolates recovered from healthy schoolchildren. Eighty-two isolates represented 43 different sequence types. Thirteen newly described subtypes were detected in this study. Of the emm types prevalent in the study communities, 46% were not included in the 26-valent GAS vaccine. Conclusions. The high diversity of emm types encountered within 3 months of collection suggest that production of a vaccine candidate based on the M-protein amino termini appears to be impractical for this population. We suggest that investigations of other vaccine candidates, including the C5a peptidase, GAS carbohydrate, and fibronectin-binding proteins, as well as conserved M-protein region vaccines, should be intensified to address the needs of this population.