Group A beta-hemolytic streptococcal pharyngitis and carriage rate among Egyptian children: a case-control study.
BACKGROUND
Improper prescription of antibiotics for treatment of acute pharyngitis predisposes to emergence of a carrier state and antibiotic-resistant strains of group A streptococci (GAS). We sought to identify the frequency and antimicrobial susceptibility patterns of group A streptococci among Egyptian children with acute pharyngitis compared with asymptomatic children.


METHODS
Case-control study conducted from September 2013 to August 2014 at a pediatric outpatient clinic in Egypt.


METHODS
Throat swabs were collected from children with acute pharyngitis and from asymptomatic children. We evaluated the accuracy of McIsaac scores and the rapid antigen detection test (RADT) for diagnosis of GAS pharyngitis with throat culture as a reference test. Antimicrobial susceptibility testing of GAS isolates was done by the disc diffusion method.


RESULTS
Of 142 children with acute pharyngitis (cases) and 300 asymptomatic children (controls) (age range, 4-16 years), GAS pharyngitis was diagnosed in 60/142 children (42.2%); 48/300 (16%) were found to be carriers. All GAS isolates in the case group were sensitive to penicillin; however, an MIC90 (0.12 micro g/mL) for penicillin is high and an alarming sign. The resistance rate to macrolides was 70% with the cMLSB phenotype in 65.1%. The sensitivities and specificities were 78.3% and 73.2% for McIsaac score of >=4 and 81.1% and 93.9% for RADT, respectively. GAS isolates in the control group were 100% sensitive to penicillin, while 12.5% and 37.5% were resistant to macrolides and tetracycline, respectively.


CONCLUSIONS
An increased MIC90 for GAS isolates to penicillin is an alarming sign. A high frequency of resistance to macrolides was also observed.
Dr. Shereen Mohamed Abd El-Ghany, Pediatrics Department,, Faculty of Medicine,, Ain Shams University,, Abbassia, Cairo 11566,, Egypt, shereen22eg@yahoo.com.
Shereen Mohamed
SM
Abd El-Ghany
Abeer Ahmed
AA
Abdelmaksoud
Sally Mohamed
SM
Saber
Dr. Shereen Mohamed Abd El-Ghany, Pediatrics Department,, Faculty of Medicine,, Ain Shams University,, Abbassia, Cairo 11566,, Egypt, shereen22eg@yahoo.com.
Dalia Hosni
DH
Abd El Hamid
D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000187:drug effects; D058345:Asymptomatic Infections / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004534:Egypt / Q000453:epidemiology; D005260:Female; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D010406:Penicillins / Q000494:pharmacology; D010612:Pharyngitis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D012680:Sensitivity and Specificity; D013290:Streptococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics
D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D018942:Macrolides; D010406:Penicillins