Asymptomatic pharyngeal carriage rate of Streptococcus pyogenes and its antimicrobial Susceptibility pattern among school children in Hawassa town, south ethiopia

Abstract

Background: S.pyogenes or Group A Streptococcus (GAS) causes each year hundreds of thousands mainly morbidity in developing countries. GAS differs from the other pyogenic bacteria in its potential to produce delayed, nonsuppurative sequelae. Asymptomatic pharyngeal carriage rate of GAS is important in transmission of infections. Report on prevalence, related factors, and antimicrobial susceptibility test of GAS among school children in Ethiopia were very limited. Objectives: To determine the asymptomatic pharyngeal carriage rate of S.pyogenes, to assess associated risk factors and to determine its antimicrobial susceptibility pattern among school children in Hawassa town, South Ethiopia Methods: A total of 287 school children aged 5-15years were enrolled in this study during May to October2014. Ethical clearance and informed consents were obtained before data collection. Demographic data were collected by structured questionnaire which was administered by a trained nurse. Throat swabs were collected and inoculated in to Amies transport media. S.pyogenes were identified by colony appearance, Gram stain, Catalase test, 0.04U Bacitracin disks and PYR tests. Antibiotic susceptibility test was performed using disc diffusion method. Results were interpreted as per the recommendations of National Committee for the Clinical laboratory standard institute guideline. Descriptive and Logistic regression modal were used for analysis. Results: Out of 287school children screened,140 (48.8%)were female and 147(51.2%) were male. Overall, S.pyogenes was isolated from 12.2% (35/287)of the children. Higher carriage rate was observed in females 23(16.4%) than males 12(8.2%)(P<0.05). Low income of family was significantly associated with carriage rate ( p<0.05).The higher susceptible group were; age 5-8yrs 12(17.1%), those with illiterate parents 19(15.8%), grade one 9(15.8%), with past history of recurrences of URTI 6(14.6%), and family size of more than 8 members 5(15.6%) observed. High level resistance to Tetracycline and low level resistance to Vancomycin was observed, while isolates were sensitive to Penicillin, Amoxacline, Erythromycin, Chloramphenicol, and Ceftriaxone. Resistance against one or more antibiotics was 68.6% (24/35).Out of a total, 29.2% (7/24) showed multiple drug resistances Conclusion and Recommendations: The present study showed that the carriage rates of S.pyognes among school children in Hawassa not different from others few findings in Ethiopia. Although, the further large scale study in the area should be undertaken; we recommend that emphasis has to be given to the female children, improvement of income of family as well as implementation of rational empirical usage of antibiotic therapy in the area should be mandatory