title: Prevalence of Group A beta-haemolytic Streptococcus isolated from children with acute pharyngotonsillitis in Aden, Yemen.
abstract: OBJECTIVE
  To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD).
  
  
  METHODS
  Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined.
  
  
  RESULTS
  Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of ≥4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1).
  
  
  CONCLUSIONS
  This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains.
authors.affiliation: Paediatric Department, Faculty of Medicine and Health Sciences, University of Aden, Aden, Yemen.
authors.forename: I A
authors.initials: IA
authors.lastname: Ba-Saddik
authors.forename: A A
authors.initials: AA
authors.lastname: Munibari
authors.forename: A M
authors.initials: AM
authors.lastname: Alhilali
authors.forename: S M
authors.initials: SM
authors.lastname: Ismail
authors.forename: F M
authors.initials: FM
authors.lastname: Murshed
authors.forename: J B S
authors.initials: JB
authors.lastname: Coulter
authors.forename: L E
authors.initials: LE
authors.lastname: Cuevas
authors.forename: C A
authors.initials: CA
authors.lastname: Hart
authors.forename: B J
authors.initials: BJ
authors.lastname: Brabin
authors.forename: C M
authors.initials: CM
authors.lastname: Parry
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000942:Antigens, Bacterial; D015373:Bacterial Typing Techniques; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D010612:Pharyngitis / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology*; D015995:Prevalence; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D015006:Yemen / Q000453:epidemiology
chemical_list: D000942:Antigens, Bacterial
keywords: Group A beta-haemolytic streptococcus; McIsaac score; acute pharyngotonsillitis; acute rheumatic fever, rheumatic heart disease; emm types; rapid GAS antigen detection test