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Asymptomatic pharyngeal carriage rate of Streptococcus pyogenes, its associated factors and antibiotic susceptibility pattern among school children in Hawassa town, southern Ethiopia

BMC Research Notes volume 12, Article number: 564 (2019) Cite this article

Abstract

Objectives

The aim of this study was to determine the asymptomatic pharyngeal carriage rate of S. pyogenes, antimicrobial pattern and related risk factors among school children in Hawassa, southern Ethiopia.

Results

Out of 287 school children’s screened, 35 (12.2%) were colonized with S. pyogenes. The carriage rate was significantly associated with factors such as sex (female p = 0.013) occupational status of mother (p = 0.002), lower income source (500–900 ETB, 1000–1500 ETB) (p = 0.001, and p = 0.042), history of hospitalization (p = 0.00) and residence of the children (p = 0.002). High level resistant to tetracycline and low level to vancomycin were observed, while penicillin, amoxicillin, erythromycin, chloramphenicol, and ceftriaxone were found to be effective.

Introduction

Streptococcus pyogenes (S. pyogenes) is a species of gram positive, aerotolerant, beta-hemolytic bacterium in the genus Streptococcus. It is classified as Lancefield Group A Streptococcus (GAS). S. pyogenes has continued as a significant human pathogenic organism for centuries. It causes a several diseases in humans including mild skin disease, upper respiratory tract (URT) infections, severe life-threatening conditions such as Rheumatic fever, glomerulonephritis, septicemia, pneumonia and streptococcal toxic shock syndrome [1].

Infection begins with colonization of the URT or injured skin surfaces. All age group may carry GAS on throat and epidermis of skin, however, children aged 5–15 years old are a major reservoir of pharyngeal carriage of GAS [2].

GAS is highly communicable and can cause disease in individuals of all ages. School-age children (5–15 years) are considered as the major reservoir of GAS, with a prevalence of 2.5–25% or more depending on the study setting [3]. In Ethiopia, the asymptomatic carriage rate of GAS among healthy school children was 9.7–16.9% [4, 5].

An educational status, employment status of the family, separation of mother and father [6], sex [7,8,9,10], socioeconomic and environmental factors, lack of awareness of disease transmission are the risk factor for colonization of the S. pyogenes among school children [11, 12].

GAS has not been developed resistance to any of the penicillin’s over the last decades. Nowadays, it is starting to appear antimicrobial drug resistant strain from asymptomatic children [13] including penicillin [6]. However, in Ethiopia, antimicrobial resistance pattern to the GAS isolated from throat/phalanx were not adequately explicated. Therefore, the present study was aimed to determine the carriage rate of S. pyogenes, associated risk factors and antibiotic susceptibility pattern among school children in Hawassa, South Ethiopia, 2018.

Main text

Methods

Study area and period

Hawassa is the capital city of the Southern Nation Nationalities and people’s Government. It is located 275 km South of Addis Ababa, and has an altitude of 1665 m above sea level with mean annual temperature and rainfall of 20.9 °C and 997.6 mm, respectively.

Study design

A school based cross-sectional study design was conducted from May to October 2018 in Hawassa, South Ethiopia.

Source population

All school children who attached governmental primary schools found in Hawassa town during the study period.

Inclusion criteria

All children aged 5–15 years who attend the class in selected schools during the study period and children whose parents had accepted the consent to participate in the study.

Exclusion criteria

All children who were on antibiotics for the last 2 weeks those with any signs and symptoms of respiratory diseases such as fever, soreness and throat, cough and watery nasal discharge were excluded.

Study population

A total of 295 school children were enrolled in this study. The study participants were selected by using a multi-stage stratified sampling technique. From the total of 19 governmental primary schools 30% (5 of the schools) were included. Simple random sampling technique was used to select the schools. Proportionate amount of samples were assigned to each selected schools. Then study participants were identified by the lists of students using simple random sampling technique.

Specimen collection

The sample was collected from different school children from May to October 2018. The schools were sampled at the same period of time. All the swabs were immediately transferred to Amies transport medium (Oxoid, UK). Each sample was labeled very well. Within 2 h the collected swab were transported to the Microbiology laboratory [9, 14, 15].

Isolation of GAS

The throat swabs were directly inoculated to 5% sheep blood agar plates (Blood agar base, Oxoid UK) by rolling the swab over a small area of the plate and streaking the sample using a sterile loop and incubated at 37 °C with 5% CO2 atmosphere and examined beta-haemolytic colonies after 24 h and 48 h. Beta-haemolytic streptococci were identified by their colony morphology and beta-haemolysis.

All plates with beta-haemolytic colonies were sub-cultured with 0.04 U Bacitracin disks (Oxoid, UK) in blood agar plates similar manner as an earlier. All grams positive, catalase negative and any zone of inhibition around the disk were candidate for Pyrrolidonyl arylamidase (PYR) tests. A purple color in PYR tests were identified as S. pyogenes according to publications [16,17,18].

Antimicrobial susceptibility testing

Antibiotic susceptibility test (AST) was performed on disc diffusion method for all S. pyogenes using penicillin (10 U), erythromycin (15 µg), amoxicillin (10 µg), chloramphenicol (30 µg), ceftriaxone (30 µg), vancomycin (30 µg) and tetracycline (10 µg).

Data management and quality control

Quality of the data was ensured by using pre-structure questionnaire. For laboratory analysis the sterility of the prepared media was checked by incubating 5% by of prepared with in 5% CO2 enriched atmosphere at 37 °C for 24 h before using it. A quality control strain of S. pyogenes (ATCC19615) was used a positive control for each test.

Data processing and analysis

Data entry and analysis was performed by using SPSS version 20. The frequency of variables the prevalence of S. pyogenes, and antibiotic susceptibility pattern was determined. The association between risk factors and S. pyogenes colonization was determined by using logistic regression. A p value < 0.05 at 95% confidence interval (CI) was considered statistically significant.

Result

Socio-demographic characteristics

Out of 295 school children who participated in the present study, 147 (51.2%) were males, 250 (87.8%) were within the age of 5–12 years. About 41.8% of the study participant’s parents/guardian found to have no formal education. A fifty percent of students’ mothers were a house-wife. About 162 (56.4%) of a total children’s parents/guardian had a monthly income between 500 and 900 ETB, 33 (11.5%) had 1000–1500 ETB and 92 (32.1%) had higher than 1500 ETB per month. However, the average income source of this area was 1560.00 ETB.

The prevalence of S. pyogenes

Among 287 school children 35 (12.2%) 95% CI [19–27.8] were confirmed to have S. pyogenes in throat swabs. A colonization rate of S. pyogenes among children who were 5–8 years old, 9–12 years old, 13–15 years old, those who live with employed mother, those who live with poor income source were 12 (17.1%), 18 (10.0%), 5 (13.5%), 8 (17.0%), and 26 (16%), respectively (Table 3).

The prevalence of S. pyogenes was higher among children with employed mother 8 (17.0%) than other occupations. Highest carriage rate was detected in low socioeconomic class 500–900 ETB per month 26 (16.0%) followed by 1000–1500 ETB 4 (12.1%). Among a total of 35 (12.2%) S. pyogenes isolates, the highest carriage rate was observed in student’s family size more than 5 person per house 23 (12.6%).

Out of 35 S. pyogenes isolated in this study, 35 (100%), 26 (74.3%), and 15 (42.9%) were susceptible to penicillin, vancomycin and tetracycline, respectively. About 34 (97.1%) of S. pyogenes isolates were sensitive to erythromycin, chloramphenicol, ceftriaxone and amoxicillin (Tables 1 and 2).

Table 1 Antimicrobial susceptibility pattern of S. pyogens isolated from school children at Hawassa city from May to October 2018 (n = 35)
Full size table
Table 2 The predominant multiple antibiotic resistant phenotypes for S. pyogenes isolated from school children at Hawassa city from May–October 2018 (n = 24)
Full size table

Risk factor analysis for pharyngeal carriage

The possible risk factors such as age, sex, children living status, parents/guardians occupation, parents/guardians education, income of parents, family size, person per bed room sharing, and past history of recurrences of URTI were evaluated for pharyngeal carriage of S. pyogenes. It was observed in bivariate analysis that, female children (COR = 2.212; 95% CI 1.055–0.638; p = 0.013), low income of parents (COR = 3.326; 95% CI 1.231–8.990; p = 0.001), children being with mother(COR = 0.34; 95% CI 0.2–1.6; p = 0.301), and occupational status of mothers (COR = 1.8 (1.2–4.40) 95% CI 1.2–4.40; p = 0.02 were observed.

The female children (AOR = 2.730; 95% CI 1.24–6.037; p = 0.013), and low income of parents (AOR = 11.917; 95% CI 2.729–2.032; p = 0.001) were associated with S. pyogenes carriage. Conversely, Occupational status of mothers (AOR = 100; 95% CI 0.023–0.437; p = 0.002) was associated with reduced likelihood of risk for asymptomatic pharyngeal carriage of S. pyogenes (Table 3).

Table 3 Distribution and association of S. pyogenes among school children in Hawassa from May–October 2018
Full size table

Discussion

The overall asymptomatic pharyngeal carriage rate of S. pyogenes among school children was 12.2% which is higher than the reports in Ethiopia 9.7% [4], in Tunisia 9.0% [19], in Nigeria 10% [20], Pemba 8.6% [21], India 8.4% [12], and Mangalore 5% [7] and lower than the report of Ethiopia 16.9% [5], Turkey 13.9% [22], Pennsylvania 15.9% [11], Australia 19.5% [23] and Turkey 25.9% [15]. The possible explanation for the variation might be due to vaccination status and age differences. Moreover, sample size, seasonal variation and method if used, geography and socio-demographic variation are another possible explanation of the difference [4, 11, 21, 24].

In the present study we assessed different factors that could possibly increase colonization rate of S. pyogenes. Having female children 23 (16.4%) were 2.21 times more risk than male children for S. pyogenes colonization (p = 0.013). Similar result was reported from India [6], Turkey [4] and Nepal [5] and Ethiopia [4, 11, 21, 24]. This is might be due to social attitude towards female children or high contact with the others during supporting their mother in daily tasks.

The detection rate of S. pyogenes were high in children who had illiterate parents 19 (15.8%) (p > 0.05). It was in-lined with study reveled in India 44.9% [14], and in Iraqi 66.7% [25]. This might be reflects the literate parents had better awareness of the hygiene, hand washing and not sharing utensils than the illiterate parents.

There was clear association of pharyngeal carriage rate and children from low income families in our finding which 26 were (16.0%). It was in accordance with the earlier finding in Ethiopia [5] and other studies carried out in many parts of the world [7, 25].

The carrier group of S. pyogenes was higher 10.9 times more among children living within families of more than 5 members than less family members in our study (p > 0.05). Similarly, S. pyogenes carriage was significantly higher in large family size as reported in different authors (p < 0.05) [2, 23, 26]. This might be an increasing the number of family members increases the rate of prevalence of many infectious diseases including GAS.

A Children with a history of hospital admission had 4.1 times chance to be colonized with GAS (p = 0.00) which is comparable to other’s studies [27]. A children with history of recurrent pharyngitis show higher incidence 8 (80%) of carrier than those with no history of pharyngitis 16 (17.8%) [25].

A children from rural resident were 3 times (p = 0.002) more likely to have S. pyogenes carriage. This finding is similar to that the report found in Uganda at Wakiso district [28]. In the current study, a high proportion (12.8%) of previously diseased children was colonized with S. pyogenes even though it was not statistically significant (p > 0.05).

Out of 35 of S. pyogenes isolated in this study, 35 (100%), 26 (74.3%) and 15 (42.9%) were susceptible to penicillin, vancomycin and tetracycline, respectively. However, 34 (97.1%) of S. pyogenes were susceptible to erythromycin, ceftriaxone, chloramphenicol and amoxicillin. The finding is similar as compared with the report found in Ethiopia [4] and in different parts of the world [7,8,9, 12,13,14, 29,30,31,32,33,34]. About 7 (29.2%) of isolated GAS strains were showed multiple drug resistant (two or more drugs). This is might be due to the ease of availability of antibiotics and misuse of the drugs.

Conclusion

The prevalence of S. pyogenes among school children in this study was high. The gender difference and low income of parents, residence of the children and occupational status of the mother are the prime risk factors associated with the carriage rate. All S. pyogenes isolates were susceptible to penicillin but most isolates were susceptible to chloramphenicol, Erythromycin and Ceftriaxone. Low level of resistant was observed against vancomycin and high level was observed against tetracycline. Further study in the area by using large sample size and all predisposing factors should be investigated.

Limitation of the study

Serotyping of Group A streptococci and ASO titer was not performed due to lack of antisera.

Availability of data

The data used/analyzed during the current study available from the corresponding author on reasonable request.

Abbreviations

ETB:

Ethiopian birr

ATCC:

American type culture control

References

  1. Ferretti JJ, Stevens DL, Fischetti VA, editors. Streptococcus pyogenes: basic biology to clinical manifestations. Oklahoma: The University of Oklahoma Health Sciences Center; 2016.

  2. Saleh MMS. Carriage state of Gaβhs among Yemeni School children and the upper limit of Normal for ASO in different population groups. Iraqi J Sci. 2010;51(1):63–70.

    Google Scholar 

  3. Revelas A, Taxmazidis O. Group A streptococcal infections in children. S Afr J Epidemiol Infect. 2012;27(3):98–103.

    Google Scholar 

  4. Abdissa A, Asrat D, Kronvall G, Shitu B, Achiko D, Zeidan M, et al. Throat carriage rate and antimicrobial susceptibility pattern of Group A Streptococci (GAS) in healthy Ethiopian school children. Ethiop Med J. 2011;49(2):125–30.

    PubMed  Google Scholar 

  5. Tewodros W, Muhe L, Daniel E, Schalen C, Kronvall A. One-year study of streptococcal infections and their complications among Ethiopian children. Epidemiol Infect. 1992;109:211–25.

    Article  CAS  Google Scholar 

  6. Nabipour F, Tayarzadeh M. Prevalence of beta-hemolytic streptococcus carrier state and its sensitivity to different antibiotics among guidance—school children in Kerman-Iran. Am J Infect Dis. 2005;1(2):128–31.

    Article  CAS  Google Scholar 

  7. Chand P, Arvind N, Vishrutha K, Vidyalakshmi K, Shenoy S. Surveillance of Group A Streptococcal throat infections among school children in Mangalore. Int J Biol Med Res. 2013;4(4):3585–9.

    Google Scholar 

  8. Muthusamy D, Boppe A, Suresh SP. The prevalence of the Group A beta haemolytic streptococcal carriers among school children in Coimbatore, South India. J Clin Diagn Res 2012;6(4).

  9. Raza S, Kundu KK, Dutta SK. Prevalence of asymptomatic pharyngeal carriage of (3-hemolytic Group A Streptococcus pyogenes among school going children of age 5–12 years in Bharatpur, Nepal. J Kathmandu Med Coll. 2013;2(3):18–20.

    Google Scholar 

  10. Vijaya D, Sathish JV, Janakiram K. The prevalence of Group A Streptococci carriers among asymptomatic school children. J Clin Diagn Res. 2013;7(3):446–8.

    Google Scholar 

  11. Martin JM, Green M, Barbadora KA, Wald ER. Group A Streptococci among school-aged children: clinical characteristics and the carrier state. Pediatrics. 2004;114:1212–9.

    Article  Google Scholar 

  12. Lloyd CAC, Jacob SE, Menon T. Pharyngeal carriage of group A streptococci in school children in Chennai. Indian J Med Res. 2006;124:195–8.

    PubMed  Google Scholar 

  13. Dumre S, Sapkota K, Adhikari N, Acharya D, Karki M, Bista S. Asymptomatic throat carriage rate and antimicrobial resistance pattern of Streptococcus pyogenes in Nepalese school children. Kathmandu Univ Med J. 2009;7(28):392–6.

    CAS  Google Scholar 

  14. Fatima F, Shubha S. Prevalence survey for assessing intensity of group a beta hemolytic Streptococci (GABHS) Subclinical infection rate in school children: a cross sectional study. Glob J Med Res. 2013;13(3):1–6.

    Google Scholar 

  15. Ozturk E, Yavuz T, Kaya D, Yucel M. The rate of asymptomatic throat carriage of Group A Streptococcus in school children and associated ASO titers in Duzce. Turkey. Jpn J Infect Dis. 2004;57:271–2.

    PubMed  Google Scholar 

  16. Gheni AI. Detection of Streptococci in the throat swabs from upper respiratory tract infections in Kurdistan Region. J Life Sci. 2014;8(3):283–9.

    Google Scholar 

  17. Agency HP. UK standards for microbiology investigations. Identification of Streptococcus species, Enterococcus species and morphologically similar organisms. UK: Standards Unit; 2011. p. 1–22.

  18. WHO. Basic laboratory procedures in clinical bacteriology. In: J. Vandepitte et al. 2nd ed. Geneva: Switzerland: WHO; 2003. p. 1–188.

  19. Mzoughi R, Selmi H, Ben Said H, Essoussi AS, Jeddi M. Group A streptococci in children with acute pharyngitis in Sousse, Tunisia. East Mediterr Health J. 2004;10:488–93.

    CAS  PubMed  Google Scholar 

  20. Sadoh AE, Omokhodion SI. Streptococcal throat isolates in school children in an urban centre in Nigeria—are there other rheumatogenic strains? Niger J Cardiol. 2007;4:50–5.

    Google Scholar 

  21. Braito A, Galgani I, Mohammed MR, Iozzi C, Ame SM, Haji HS, et al. Epidemiology of Streptococcus Group A in school aged children in Pemba. East Afr Med J. 2004;81:307–13.

    Article  CAS  Google Scholar 

  22. Gür E, Akkus S, Arvas A, Güzeloz S, Can G, Diren S, et al. Prevalence of positive throat cultures for Group A beta-hemolytic streptococci among school children in Istanbul. Indian Pediatr. 2002;39:569–73.

    PubMed  Google Scholar 

  23. McDonald MI, Towers RJ, Andrews RM, Benger N, Currie BJ, Carapetis JR. Low rates of streptococcal pharyngitis and high rates of pyoderma in australian aboriginal communities where acute rheumatic fever is hyperendemic. Clin Infect Dis. 2006;43:683–9.

    Article  Google Scholar 

  24. Kumar R, Vohra H, Chakraborty A, Sharma YP, Shah B, Dhanda V. Epidemiology of group A streptococcal pharyngitis & impetigo: a cross-sectional & follow up study in a rural community of northern India. Indian J Med Res. 2009;130:765–71.

    CAS  PubMed  Google Scholar 

  25. Al-Gabban N, Al-Ani WA, Al-Kinany BJ. B-Haemolytic streptococcal carrier among school age children. Iraqi J Community Med. 2008;21(2):91–5.

    Google Scholar 

  26. Prajapati A, Rai SK, Mukhiya RK, Karki AB. Study on carrier rate of Streptococcus pyogenes among the school children and antimicrobial susceptibility pattern of isolates. Nepal Med Coll J. 2012;14(3):169–71.

    CAS  PubMed  Google Scholar 

  27. Danchin MH, Rogers S, Kelpie L, Selvaraj G, Curtis N, Carlin JB, et al. Burden of acute sore throat and Group A Streptococcal pharyngitis in school-aged children and their families in Australia. Pediatrics. 2007;120:950–7.

    Article  Google Scholar 

  28. Nayiga I, Okello E, Lwabi P, Ndeezi G. Prevalence of group a streptococcus pharyngeal carriage and clinical manifestations in school children aged 5–15 yrs in Wakiso District, Uganda. BMC Infect Dis. 2017;17:248.

    Article  Google Scholar 

  29. Rubio-López V, Valdezate S, Álvarez D, Villalón P, Medina MJ, Salcedo C, et al. Molecular epidemiology, antimicrobial susceptibilities and resistance mechanisms of Streptococcus pyogenes isolates resistant to erythromycin and tetracycline in Spain (1994–2006). BMC Microbiol. 2012;12(215):1–11.

    Google Scholar 

  30. Rijal K, Dhakal N, Shah R, Timilsina S, Mahato P, Thapa PS, et al. Antibiotic susceptibility of Group A Streptococcus isolated from throat swab culture of school children in Pokhara, Nepal. Nepal Med Coll J. 2009;11(4):238–40.

    CAS  PubMed  Google Scholar 

  31. Ksia S, Smaoui H, Kechrid A, Bouvet A. Streptococcus pyogenes isolated in a Tunisian pediatric population: emm types, T types, virulence factors and genes of resistance to macrolide and tetracycline. Malay J Microbiol. 2013;9(1):24–32.

    CAS  Google Scholar 

  32. Ibrahim SB, El-Sokkary R, Elhewala AA, El-Anwar MW, Awad WM, Hamed MA, et al. Emerging resistance to erythromycin and penicillin among Streptococcus pyogenes isolates in Zagazig, Egypt. Int J Curr Microbiol App Sci. 2014;3(10):750–6.

    CAS  Google Scholar 

  33. Graydon C, McKay R, Patrick D. Antimicrobial resistance trends in the Province of British Columbia. British Columbia Communicable Disease Prevention and Control Services Centre for Disease Control. 2011 AMR trends report, www.bccdc.ca. 2011. p. 1–88.

  34. Devi U, Borah PK, Mahanta J. The prevalence and antimicrobial susceptibility patterns of beta-hemolytic streptococci colonizing the throats of schoolchildren in Assam, India. J Infect Dev Ctries. 2011;5(11):804–8.

    Article  Google Scholar 

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Acknowledgements

We would like to acknowledge data collector, all staff working at kindergarten school that facilitated data collection, Hawassa University College of Medicine and Health Sciences, Jimma University Health Science institute for their support during the study. We would also acknowledge parents who allowed their children to participate in this study.

Funding

This study was supported by Jimma University, institute of Health Sciences. The support included payment for data collectors and purchase of materials and supplies required for the study. The support did not include designing of the study, analysis, and interpretation of data, and manuscript preparation.

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Authors and Affiliations

  1. Dilla University College of Medicine, Dilla, Ethiopia

    Asrat Anja

  2. Jimma University Institute of Health Sciences, Jimma, Ethiopia

    Getenet Beyene & Zewdineh S/Mariam

  3. Hawassa University College of Medicine and Health Sciences, Hawassa, Ethiopia

    Deresse Daka

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  1. Asrat Anja
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  2. Getenet Beyene
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Contributions

AA: conceived and designed the study, performed the laboratory work, analyzed the data, involved in manuscript preparation. GB and ZS: involved in protocol development and manuscript write up. DD: conceived and designed the study, supervised the study, involved in analysis and manuscript preparation. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Deresse Daka.

Ethics declarations

Ethics approval and consent to participate

This study was ethically cleared from the Institutional Review Board (IRB) of the College of Medicine and Health Sciences, Hawassa University. Official permission was obtained from the study site and written informed consent was obtained from all parents/guardians of the children.

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Not applicable.

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The authors declare that they have no competing interests.

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Anja, A., Beyene, G., S/Mariam, Z. et al. Asymptomatic pharyngeal carriage rate of Streptococcus pyogenes, its associated factors and antibiotic susceptibility pattern among school children in Hawassa town, southern Ethiopia. BMC Res Notes 12, 564 (2019). https://doi.org/10.1186/s13104-019-4601-9

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