Abstract
Background
Bacterial pharyngitis is a common childhood infection involving inflammation of the pharynx and tonsils. Compared to viral causes, it often presents more severely and can result in complications if untreated. However, data on its bacterial etiology, resistance patterns, and associated risk factors are limited in developing countries, including Ethiopia.
Objective
To assess the prevalence, bacterial causes, antimicrobial susceptibility patterns, and risk factors of pharyngitis among children at comprehensive specialized hospitals, Northwest Ethiopia.
Methods
A hospital-based cross-sectional study was conducted from June 1 to August 30, 2024, among 254 children aged ≤ 14 years. Throat swabs were collected and cultured following standard microbiological techniques. Bacterial identification was performed through colony morphology, Gram staining, and biochemical tests. Antimicrobial susceptibility was tested using the Kirby-Bauer disk diffusion method. Data were analyzed using SPSS version 27, and logistic regression identified significant risk factors (p ≤ 0.05).
Results
The prevalence of culture-confirmed bacterial pharyngitis was 28.3% (95% CI: 22.5–33.9%). A total of 80 bacterial isolates were identified, predominantly Streptococcus pyogenes (35%), Staphylococcus aureus (32.5%), and Streptococcus pneumoniae (28.8%). High resistance was observed: S. pyogenes to ceftriaxone (64.3%) and chloramphenicol (53.6%); S. pneumoniae to penicillin (82.6%); and S. aureus to penicillin (80.8%) and tetracycline (57.7%). Overall, 41.3% of isolates exhibited multidrug resistance. Significant factors associated with bacterial pharyngitis included prior history of pharyngitis (AOR = 8.86), tonsillectomy (AOR = 5.65), contact with coughing individuals (AOR = 3.42), and weight loss (AOR = 2.58).
Conclusion
Bacterial pharyngitis is prevalent among children in the study area, with a high burden of multidrug-resistant organisms. Routine use of culture and antibiotic susceptibility testing is essential to guide effective treatment and reduce resistance.
Clinical trial number
Not applicable.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12879-025-12427-8.
Keywords: Pharyngitis, Drug resistance, Bacterial, Child, Ethiopia
Introduction
Pharyngitis, an inflammation of the pharyngeal mucosa and tonsillar structures, is among the most common upper respiratory tract infections, particularly affecting children. Because of its close proximity to the salivary glands, oral cavity, and external environment, the human pharynx—a mucus-rich, aerated anatomical region—is constantly exposed to a variety of microbial agents [1, 2]. A common cause of pediatric morbidity, bacterial pharyngitis is mostly caused by Streptococcus pyogenes (Group A Streptococcus, or GAS) and is frequently transmitted by direct contact with respiratory secretions or infected surfaces [3]. The illness burden is also influenced by other bacterial infections, including Moraxella catarrhalis, Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae [4].
Because of its high frequency and potential for major problems, particularly if left untreated, pharyngitis in children is a specific concern. These consequences include glomerulonephritis, rheumatic heart disease, otitis media, peritonsillar abscess, and even potentially fatal disorders including airway obstruction and septicemia [5, 6]. Young age, overcrowding, seasonal fluctuations, exposure to environmental factors (such as smoke and dust), and a history of recurrent infections or contact with sick people are all factors that increase the risk of contracting the disease [7, 8].
The rising incidence of antimicrobial resistance (AMR) among the bacterial pathogens that cause pharyngitis is a cause for increasing concern. Irrational antibiotic usage and self-medication have been the driving forces for resistance mechanisms, such as the creation of beta-lactamases, genetic mutation, and biofilm formation [9, 10]. The AMR epidemic has been made worse in resource-constrained environments such as Ethiopia by inadequate diagnostic infrastructure, restricted access to microbiological testing, and inappropriate use of antibiotics [11, 12].
In the study area, limited local epidemiological data exist [13] on the bacterial profile, antibiotic susceptibility patterns, and associated risk factors among pediatric populations, despite the clinical and public health importance of bacterial pharyngitis. Current and thorough information on the prevalence and microbiological characteristics of bacterial pharyngitis in children is lacking in northwest Ethiopia [14]. In order to ascertain the frequency of bacterial pharyngitis, pinpoint the causing organisms, ascertain their patterns of antibiotic susceptibility, and investigate the risk factors linked to it, this study was conducted among pediatric patients who were seen at comprehensive specialized hospitals, Northwest Ethiopia.
Materials and methods
Study design and setting
A hospital-based cross-sectional study was conducted from June 1 to August 30, 2024, at two specialized hospitals located in Northwest Ethiopia: Felege Hiwot Specialized Hospital (FHSH) and Tibebe Ghion Specialized Teaching Hospital (TGSH). These tertiary-level institutions provide comprehensive inpatient and outpatient services to a wide catchment area across the Amhara Regional State and surrounding regions.
Both FHSH and TGSH function as referral centers and are equipped with advanced diagnostic and therapeutic facilities. They serve as medical teaching and research hospitals affiliated with regional health science institutions. The hospitals include well-established pediatric departments, alongside other specialized units, and play a critical role in delivering healthcare services and clinical training in Northwest Ethiopia.
Study population
The source population included all pediatric patients visiting FHSH and TGSH during the study period. The study population consisted of children under 14 years old presenting with signs and symptoms of pharyngitis.
Inclusion criteria
Children ≤ 14 years with clinical features of pharyngitis.
Patients or guardians willing to provide informed consent.
Exclusion criteria
Children who had received antibiotics within the past two weeks.
Children or guardians who declined participation.
Variables
-
Dependent Variables
- Presence of bacterial pharyngitis
- Antimicrobial susceptibility patterns
-
Independent variables
- Socio-demographic: Age, sex, parental education, residence
- Clinical: History of pharyngitis, contact with coughing patient
- Environmental: Exposure to wood smoke, overcrowding, school attendance
- Clinical Signs: Tonsillar swelling, exudate, fever > 38 °C, difficulty swallowing, lymph node enlargement, tonsillectomy status, vaccination history
Operational definition and measurement of variables
Pediatric children: For this study, children aged 0–14 years.
Bacterial pharyngitis: Pharyngitis cases confirmed through positive bacterial culture.
Immunization status: defined as fully immunized or not fully immunized according to the Ethiopian National Expanded Program on Immunization (EPI) schedule for the child’s age. Immunization status was verified using vaccination cards when available or caregiver report otherwise.
Clinical Variables: History of pharyngitis: Recorded as a binary variable (Yes = previous episodes reported; No = no previous episodes).
Contact with a coughing patient: Recorded as binary (Yes = child had close contact with someone with cough in the past 2 weeks; No = no contact).
Environmental Variables: Exposure to wood smoke: Assessed by caregiver report of whether the child is regularly exposed to indoor cooking smoke (Yes/No).
Overcrowding: Measured as the number of persons per room in the household, categorized for analysis as ≤ 3 persons/room or > 3 persons/room.
School attendance: Recorded as binary (Yes = attending school; No = not attending school).
Sample size determination
The sample size was calculated using a single population proportion formula, assuming:
95% confidence level (Z = 1.96)
5% margin of error (d)
Prevalence (p) = 21.3% (based on a prior study in Harar, Ethiopia)
Single population proportion formula.
The sample size
 |
Z (α/2)2 = at 95% confidence interval = 1.96
P = Proportion of occurrence of the event to be studied 16.1% (0.213)
d = Margin of error at (5%)
 |
There were non-responsive patients; the final sample size was 254.
Sampling technique
A convenience sampling technique was employed to recruit eligible participants from the pediatric outpatient and emergency departments.
Data collection
A pre-tested, structured questionnaire was administered by trained clinical officers to collect demographic, environmental, and clinical information. The questionnaire was adapted from validated tools and pre-tested at Debre Tabor Comprehensive Specialized Hospital. The prepared questionnaires are attached in the supplementary file.
Sample collection and transportation
Throat swabs were collected aseptically using sterile cotton swabs by rotating across both tonsils and posterior pharyngeal wall. The swabs were placed in Amies transport medium and transported to the Bahir Dar University Microbiology Laboratory for processing within two hours of collection.
Laboratory investigation
Culture and identification
Swabs were inoculated on 5% sheep blood agar (HiMedia, India; Cat. No. M1301-100G(100g), chocolate agar (with 5 µg/mL gentamicin), and MacConkey agar (HiMedia, India; Cat. No. M081B‑100 g.
Plates were incubated at 37 °C for 18–24 h in 5% CO₂ candle jars.
-
Colonies were identified based on:
- Hemolysis pattern: β-hemolysis (S. pyogenes, S. aureus), α-hemolysis (S. pneumoniae), non-hemolytic (M. catarrhalis).
- Biochemical tests: catalase, coagulase, bacitracin, optochin, bile solubility, oxidase, indole, citrate, and TSI.
- Gram staining was performed for bacterial characterization.
Quality control strains
S. aureus ATCC 25,923
S. pneumoniae ATCC 49,619
H. influenzae ATCC 49,241
Antimicrobial susceptibility testing
Antibiotic susceptibility was assessed using the Kirby-Bauer disk diffusion method on Mueller-Hinton Agar (MHA) and MHA supplemented with blood for fastidious organisms. Suspensions were adjusted to 0.5 McFarland standard before inoculation. The zone of inhibition was measured and interpreted according to CLSI 2023 guidelines.
Data quality control
5% of questionnaires were pre-tested for clarity and consistency.
Standard operating procedures (SOPs) were strictly followed.
Culture media were tested for sterility and performance.
Laboratory processes were validated using reference strains.
Daily temperature logs and equipment calibration were maintained.
Data analysis
Data were entered into Epi Data version 4.6, cleaned, and exported to SPSS version 27 for analysis. Descriptive statistics were computed, and associations were examined using Chi-square tests and binary logistic regression, with a p-value ≤ 0.05 considered statistically significant. Prior to the multivariable analysis, multicollinearity among independent variables was assessed using Variance Inflation Factor (VIF) and tolerance statistics. Although values of VIF ≥ 10 or tolerance ≤ 0.1 are typically indicative of multicollinearity, more conservative thresholds (VIF < 2.5 and tolerance > 0.4) were applied due to the conceptual overlap between certain variables (e.g., school attendance and history of contact with symptomatic individuals). All predictors met these criteria, confirming the absence of significant multicollinearity, and were therefore retained in the final model.
Ethical considerations
Ethical clearance was granted by the Institutional Review Board (IRB) of the College of Medicine and Health Sciences, Bahir Dar University (Ref: CMHS 1037/2024). Support letters were provided to the study hospitals. Written informed consent was obtained from parents or legal guardians. Data confidentiality and participant anonymity were strictly maintained throughout the study in accordance with the Declaration of Helsinki.
Results
Socio-demographic features and prevalence of bacterial pharyngitis
In this study, of the total study participants, 124 (48.8%) were males and 111 (43.7%) were rural living. The participants’ age range was up to 14 years; of which 98 (38.6%) were ≤ 5 years and 83 (32.7%) were 6–10 years (Table 1).
Table 1.
Socio-demographic characteristics of pediatric participants and prevalence of culture-confirmed bacterial pharyngitis in specialized hospitals, Northwest Ethiopia, 2024
| Variables | Bacterial culture results | P value (χ2) | |||
|---|---|---|---|---|---|
| Frequency | Positive (%) | Negative (%) | |||
| Children age (Years) | ≤ 5 | 98 | 26 (26.5%) | 72 (73.5) | 0.45 (χ2 = 0.55) |
| 6–10 | 83 | 26 (31.3%) | 57 (68.7%) | ||
| 11–14 | 73 | 20 (27.4%) | 53 (72.6%) | ||
| Sex | Male | 124 | 44 (35.5%) | 80 (64.5%) | 0.014 (χ2 = 6.07) |
| Female | 130 | 28 (21.5%) | 102 (78.5%) | ||
| Residence | Rural | 111 | 39 (35.1%) | 72 (64.9%) | 0.035 (χ2 = 4.47) |
| Urban | 143 | 33 (23.1%) | 110 (76.9%) | ||
The overall prevalence of culture-confirmed bacterial pharyngitis was 28.3% (95% CI: 22.5–33.9%).
Clinical profiles of children with bacterial pharyngitis
Children with bacterial pharyngitis presented with a range of clinical symptoms, including high body temperature (≥ 38) in 175 (68.9%), weight loss in 136 (53.5%), and swollen lymph nodes in 156 (61.4%) (Table 2).
Table 2.
Clinical characteristics of pediatric patients with culture-confirmed bacterial pharyngitis in specialized hospitals, Northwest Ethiopia, 2024
| Variables | Bacterial culture results | P value and (χ2) | |||
|---|---|---|---|---|---|
| Frequency (%) | Positive (%) | Negative (%) | |||
| Weight loss | Yes | 136 (53.5) | 54 (39.) | 82 (60.3) | 0.0001 (χ2 = 18.6) |
| No | 118 (46.5) | 18 (15.) | 100 (84.7) | ||
| Tonsil structural Changes | Yes | 131 (51.6) | 75 (57.3) | 56 (42.7) | 0.0001 (χ2 = 54.01) |
| No | 123 (48.4) | 16 (13) | 107 (87) | ||
| Type of Pharyngitis | Acute | 95 (37.4) | 17 (17.9) | 78 (82.1) | 0.0001 (χ2 = 14.8) |
| Chronic | 80 (31.5) | 35 (43.8) | 45 (56.2) | ||
| Recurrent | 79 (31.1) | 20 (25.3) | 59 (74.7) | ||
| Body Temperature(fever) | 37 | 79 (31.1) | 17 (21.5) | 62 (78.5) | 0.105 (χ2 = 2.6) |
| ≥ 38 | 175 (68.9) | 55 (31.4) | 120 (68.6) | ||
| White pharyngeal Exudate | Yes | 88 (34.6) | 31 (35.2) | 57 (64.8) | 0.076 (χ2 = 3.2) |
| No | 166 (65.4) | 41 (24.7) | 125 (75.3) | ||
| Swollen lymph Nodes | Yes | 156 (61.4) | 50 (32.1) | 106 (67.9) | 0.098 (χ2 = 2.7) |
| No | 98 (38.6) | 22 (22.4) | 76 (77.6) | ||
| Difficult to swallow food | Yes | 146 (57.5) | 51 (34.9) | 95 (65.1) | 0.007 (χ2 = 7.3) |
| No | 108 (42.5) | 21 (19.4) | 87 (80.6) | ||
Factors contributing to bacterial pharyngitis in pediatric patients
Several factors were associated with culture-confirmed bacterial pharyngitis, including history of contact with symptomatic individuals, prior pharyngitis, tonsillectomy, immunization status, school attendance, and tonsillar structural changes (Table 3).
Table 3.
Factors associated with bacterial pharyngitis and prevalence of culture-confirmed cases among pediatric patients in specialized hospitals, Northwest Ethiopia, 2024
| Variables | Bacterial culture results | P value (χ2) | |||
|---|---|---|---|---|---|
| Frequency (%) | Positive F (%) | Negative F (%) | |||
| History of contact with cough patients | Yes | 124 (48.9) | 54 (43.5) | 70 (56.5) | 0.0001 (χ2 = 27.6) |
| No | 130 (51.1) | 18 (13.8) | 112 (86.2) | ||
| History of Pharyngitis | Yes | 131 (51.6) | 56 (42.7) | 75 (57.3) | 0.001(x2 = 27.5) |
| No | 123 (48.4) | 16 (13) | 107 (87) | ||
| Tonsillectomy | Yes | 129 (50.8) | 53 (41.1) | 19 (58.9) | 0.0001 (χ2 = 27.6) |
| No | 125 (49.2) | 76 (15.2) | 106 (84.8) | ||
| Immunization status | Yes | 129 (50.8) | 18 (16.4) | 107 (83.6) | 0.0001 (χ2 = 23.5) |
| No | 125 (48.2) | 54 (40.5) | 75 (59.5) | ||
| Attending school | Yes | 120 (47.2) | 50 (41.6) | 70 (58.3) | 0.0001 (χ2 = 19.8) |
| No | 134 (52.8) | 22 (16.4) | 112 (83.6) | ||
| Live overcrowded set up | Yes | 122 (48) | 47 (38.5) | 75 (61.5) | 0.0005 (χ2 = 11.9) |
| No | 132 (52) | 25 (18.9) | 107 (81.1) | ||
| Exposed dung/wood biofuel | Yes | 123 (48.4) | 44 (35.8) | 79 (64.2) | 0.011 (χ2 = 6.5) |
| No | 131 (51.6) | 28 (21.4) | 103 (78.6) | ||
Distribution of bacteria isolates
S. pyogenes 28 (35%) was the most frequently identified bacteria, followed by S. aureus 26 (32.5%), and S. pneumoniae 23 (28.8%) were found on throat swab samples. Mixed isolates were found: 5 (6.3%) S. pyogenes and S. aureus and 3 (3.8%) S. pneumoniae and K. pneumoniae (Fig. 1).
Fig. 1.
Distribution of bacterial isolates from pediatric patients with pharyngitis in specialized hospitals, Northwest Ethiopia, 2024
Bacterial isolates and their antimicrobial resistance
The most frequently identified bacterial isolates were S. pyogenes (35%), S. aureus (32.5%), and S. pneumoniae (28.8%), with a small proportion of mixed infections (9%).
Resistance was observed against commonly used antibiotics, including chloramphenicol (53.8%), gentamicin (52.5%), tetracycline (50%), and ceftriaxone (46.3%) (Table 4).
Table 4.
Antimicrobial susceptibility patterns of bacterial isolates from pediatric patients with bacterial pharyngitis in specialized hospitals, Northwest Ethiopia, 2024
| Antibiotics test | Percentage of bacterial isolates susceptible or resistant to, n (%) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| AUG | AMX | E | TE | C | CIP | GM | CRO | P | Total N (%) | ||
| S. pyogenes (28) | S = N% | 22 (78.6) | 20(71.4) | 16(57.1) | 15 (54) | 13(46.4) | 16 (57.1) | 14 (50) | 10(35.7) | 28(100%) | |
| R = N% | 6 (21.4) | 8 (28.6) | 12(42.9) | 13 (46) | 15(53.6) | 12 (42.9) | 14 (50) | 18(64.3) | 0 | 98 (39.7) | |
| S. aureus (26) | S = N% | 19 (73.2) | 18(69.2) | 16(61.5) | 11(42.3) | 10(38.5) | 11 (42.3) | 12(46.2) | 15(57.7) | 5 (19.2) | |
| R = N% | 7 (26.9) | 8 (30.8) | 10(38.5) | 15(57.7) | 16(61.5) | 15 (57.7) | 14(53.8) | 11(42.3) | 21(80.8) | 117(50) | |
| S. pneumoniae (23) | S = N% | 16 (69.6) | 14(60.9) | 15(65.2) | 13(56.5) | 13(56.5) | 20 (87) | 11(47.8) | 16(69.6) | 4 (17.4) | |
| R = N% | 7 (30.4) | 9 (39.1) | 8 (34.8) | 10(43.5) | 10 (43.5 | 3 (13) | 12(52.2) | 7 (30.4) | 19 (82.6) | 85(41,1) | |
| K. Pneumoniae (3) | S = N% | 1 (33.3) | 0 | 1 (33.3) | 1 (33.3) | 1 (33.3) | 3 (100) | 1 (33.3) | 2 (66.7) | 0 | |
| R = N% | 2 (66.7) | 3 (100) | 2 (66.7) | 2 (66.7) | 2 (66.7) | 0 | 2 (66.7) | 1 (33.3) | 3 (100) | 17(62.9) | |
| Total = 80 | R = N% | 22/80 (27.5) | 28 (35) | 32 (40) | 40(50) | 43(53.8) | 30 (37.5) | 42(52.5) | 37(46.3) | 43 (53. 8) | 319(39.8) |
CRO = Ceftriaxone AUG = Augmentin, AMX = Amoxicillin, E = Erythromycin, TE = Tetracycline, C = Chloramphenicol, CIP = Ciprofloxacin, GM = Gentamicin, p = penicillin, S = susceptible, R = resistance
Profiles of MDR bacterial isolates
The overall multidrug-resistance (MDR) rate of bacterial species was 33 (41.3%). The overall MDR of each bacterium, S. pyogenes, S. aureus, and S. pneumoniae was 9 (32.1%), 12 (46.2%), and 10 (43.5%) respectively (Table 5).
Table 5.
Profiles of multidrug-resistant (MDR) bacterial isolates from pediatric patients with bacterial pharyngitis in specialized hospitals, Northwest Ethiopia, 2024
| Antibiotics | S. pyogenes (28) | S.aureus (26) | S. pneumoniae (23) | K. pneumoniae (3) | Total (80) |
|---|---|---|---|---|---|
| R1 N (%) | 15 (53.6%) | 8 (30.8%) | 5 (21.7%) | 0 | 28 (35%) |
| R2 N (%) | 3 (10.7%) | 6 (23.1%) | 8 (34.7%) | 1 (33.3%) | 18 (22.5%) |
| R3 N (%) | 3 (10.7%) | 2 (7.7%) | 5 (21.7%) | 0 | 10 (12.5%) |
| R4 N (%) | 4 (14.2%) | 5 (19.2%) | 4 (17.4%) | 1 (33.3%) | 14 (17.5%) |
| R5 N % | 2 (7%) | 3 (11.5%) | 1 (4.3%) | 0 | 6 (7.5%) |
| R6 N % | 0 (0.0%) | 2 (7.7%) | 0 | 1 (33.3%) | 3 (3.8%) |
| Over all MDR N (%) | 9 (32.1%) | 12 (46.2%) | 10 (43.5%) | 2 (66.7%) | 33 (41.3%) |
Factors associated with bacterial pharyngitis
Bacterial pharyngitis was significantly associated with weight loss (AOR = 2.58, 95% CI: 1.1–6.05), chronicity (AOR = 2.93, 95% CI: 1.08–7.94), history of contact with patients (AOR = 3.42, 95% CI: 1.47–7.95), prior history of pharyngitis (AOR = 8.86, 95% CI: 3.37–23.29), tonsillectomy (AOR = 5.65, 95% CI: 2.37–13.46), immunization status (AOR = 4.22, 95% CI: 1.74–10.24), school attendance (AOR = 3.44, 95% CI: 1.44–8.2), and tonsillar structural changes (AOR = 2.53, 95% CI: 1.03–6.22).
Children with weight loss were 2.5 times more likely to be culture-positive for bacterial pharyngitis compared to those without. Similarly, school attendees were three times more likely to test positive than non-attendees. A history of contact with symptomatic individuals increased the odds 3.4-fold, while a prior history of pharyngitis raised it nearly nine fold. Children with a history of tonsillectomy, unimmunized status, or tonsillar structural changes were 5.7, 4.2, and 2.5 times more likely, respectively, to have culture-confirmed bacterial pharyngitis (Table 6).
Table 6.
Bivariate and multivariable analysis of factors associated with bacterial pharyngitis among pediatric patients in specialized hospitals, Northwest Ethiopia, 2024
| Variables | COR (95%CI) | P-value | AOR (95%CI) | P-value | |
|---|---|---|---|---|---|
| Sex | Male | 2 (1.15–3.49) | 0.014 | 1.49 (0.65–3.38) | 0.346 |
| Female | 1 | 1 | |||
| Residence | Rural | 1.8 (1.04–3.13) | 0.035 | 1.36 (0.60–3.08) | 0.46 |
| Urban | 1 | 1 | |||
| Weight loss | Yes | 3.7 (1.99–6.72) | < 0.001 | 2.58 (1.1–6.05) | 0.030 |
| No | 1 | 1 | |||
| Tonsil structural Change | Yes | 5 (2.66–9.37) | < 0.001 | 2.53 (1.03–6.22) | 0.043 |
| No | 1 | 1 | |||
| Type of Pharyngitis | Acute | 1 | 1 | ||
| Chronic | 3.6 (1.8–7.1) | < 0.001 | 2.93 (1.08–7.94) | 0.034 | |
| Recurrent | 1.6 (0.75–3.22) | 0.235 | 1.26 (0.43–3.69) | 0.678 | |
| Body T° | 37 °C | 1 | 1 | ||
| ≥ 38 °C | 1.7 (0.89–3.1) | 0.107 | 1.43 (0.55–3.73) | 0.468 | |
| White pharyngeal exudate | Yes | 1.7 (0.95–2.91) | 0.078 | 1.76 (0.76–4.08) | 0.188 |
| No | 1 | 1 | |||
| Swollen lymph nodes | Yes | 1.6 (0.91–2.92) | 0.100 | 1.05 (0.45–2.44) | 0.917 |
| No | 1 | 1 | |||
| Difficult to swallow food | Yes | 2.2 (1.24–3.99) | 0.007 | 1.64 (0.70–3.85) | 0.253 |
| No | 1 | 1 | |||
| History of Contact with patients | Yes | 4.8 (2.61–8.85) | < 0.001 | 3.42 (1.47–7.95) | 0.004 |
| No | 1 | 1 | |||
| History pharyngitis | Yes | 5 (2.66–9.37) | < 0.001 | 8.86 (3.37–23.29) | 0.001 |
| No | 1 | ||||
| Tonsillectomy | Yes | 3.9 (2.13–7.09) | < 0.001 | 5.65 (2.37–13.46) | 0.001 |
| No | 1 | 1 | |||
| Immunization status | Yes | 1 | 1 | ||
| No | 4.3 (2.34-8) | < 0.001 | 4.22 (1.74–10.24) | 0.001 | |
| Attending school | Yes | 3.6 (2-6.5) | < 0.001 | 3.44 (1.44–8.2) | 0.005 |
| No | 1 | 1 | |||
| Live overcrowded setup | Yes | 2.7 (1.52–4.73) | 0.001 | 1.82 (0.79–4.19) | 0.161 |
| No | 1 | 1 | |||
| Exposed wood biofuel | Yes | 2 (1.17–3.58) | 0.012 | 1.37 (0.59–3.17) | 0.462 |
| No | 1 | 1 | |||
Discussion
In this study, the prevalence of culture-confirmed bacterial pharyngitis among pediatric patients at specialized hospitals was 28.3% (95% CI: 22.5–33.9%). This finding is comparable to a study from Norway (27%) [15], but higher than studies from Brazil (20.6%) [16, 17] and Jimma, Ethiopia (8.8%) [18]. Conversely, it is lower than reports from Malaysia (43.4%) [19], Nigeria (83.3%) [4], Pakistan (78.1%) [20], Iraq (93.1%) [21], Somaliland (32.2%) [22], and Ethiopia (75.1%) [1]. The observed differences may be due to variations in sample size, geographical and environmental factors, immunization coverage, diagnostic methods, the use of self-medication, and the emergence of antimicrobial resistance.
Male children had a higher proportion of culture-confirmed bacterial pharyngitis, consistent with findings from Riyadh [23], Cairo [24], Iraq [25], Nigeria [4], and Ethiopia [26]. This is clinically meaningful, suggesting that targeted health education and preventive interventions may be needed for boys in school and community settings.
Children from rural areas showed a higher prevalence of bacterial pharyngitis than urban dwellers, aligning with findings from Hawassa [26] and Bahir Dar, Ethiopia [27]. This association is significant and highlights the need to improve healthcare access, vaccination coverage, and hygiene practices in rural communities.
Chronic pharyngitis was also associated with a higher bacterial isolation rate (43.8%), although slightly lower than the 57.7% reported in Somaliland [22]. The discrepancy may be explained by differences in chronicity definitions, local bacterial strains, self-medication practices, and immunization status.
Streptococcus pyogenes was the most frequently isolated pathogen (35%), lower than Tanzania (40%) [28], Sudan (41.4%) [29], Somaliland (55%) [22], and Ethiopia (42.5%) [30], but higher than in Nigeria (11.6%) [31] and Kenya (13.7%) [32]. Such variations may reflect differences in strain diversity, population density, antibiotic exposure, and diagnostic methods. S. pyogenes resistance to chloramphenicol (53.6%), gentamicin (50%), and ceftriaxone (64.3%) is clinically significant, indicating that empirical treatment regimens may need to be updated locally.
Staphylococcus aureus accounted for 32.5% of isolates, similar to findings from Somaliland (29%) [22] and Bahir Dar (29%) [27], but higher than in Iraq (19.5%) [25] and Kenya (16.6%) [32], and lower than Brazil (63%) [33]. Differences may be due to factors such as biofilm formation, antibiotic resistance, and tonsillar infections like tonsilloliths.
Streptococcus pneumoniae was isolated in 28.8% of cases, higher than reported in Nigeria (8.5%) [34], Kenya (10.3%) [32], and Somaliland (7%) [22]. This could be attributed to low immunization coverage, regional antimicrobial resistance patterns, or diagnostic variation.
Klebsiella pneumoniae was identified in 3.8% of cases, consistent with findings from Somaliland (4%) [22] and Addis Ababa (4%) [35], but lower than Libya (43.3%) [16] and Kenya (20.6%) [32]. Regional differences in pathogen prevalence, immunity levels, and healthcare access could explain these disparities. Importantly, recent molecular data from Iran show that K. pneumoniae frequently carries ESBL and carbapenemase genes, including blaSHV, blaTEM, blaCTX-M, and blaOXA-48, and demonstrates substantial MDR patterns [36]. Such emerging regional resistance trends highlight the need for surveillance in Ethiopia as well.
Regarding antimicrobial resistance, S. pyogenes showed high resistance to chloramphenicol (53.6%), gentamicin (50%), and ceftriaxone (64.3%). These rates are markedly higher than those reported in Gondar (5%, 9%, and 13%, respectively) [37]. Resistance mechanisms such as aminoglycoside-modifying enzymes and mutations in quinolone-resistance determining regions may be involved.
S. aureus demonstrated high resistance to penicillin (80.8%), tetracycline (57.7%), gentamicin (53.8%), and chloramphenicol (61.5%), comparable to findings from Bahir Dar (84.1%) [27], but higher than in Gondar (65%) [37] and Somaliland (38%) [22]. These patterns likely reflect overuse of antibiotics, poor prescribing practices, and resistance gene acquisition.
S. pneumoniae showed resistance to penicillin (82.6%) and gentamicin (52.2%), rates exceeding those from Germany (43%) [38], the USA (38.9%) [39], and China (56% and 21%, respectively) [40]. These findings underscore the consequences of limited vaccination, over-the-counter antibiotic access, and diagnostic gaps.
Antimicrobial resistance patterns showed alarmingly high resistance rates, particularly to penicillin, which reached 80.8% across isolates. S. pyogenes demonstrated high resistance to chloramphenicol (53.6%), gentamicin (50%), and ceftriaxone (64.3%), while S. aureus showed resistance to penicillin (80.8%), tetracycline (57.7%), gentamicin (53.8%), and chloramphenicol (61.5%). These findings highlight the increasing burden of multidrug-resistant organisms (41.3% MDR overall), likely driven by antibiotic overuse, self-medication, and limited diagnostic testing.
Several factors were significantly associated with culture-confirmed bacterial pharyngitis: incomplete or no immunization, prior history of pharyngitis, contact with coughing individuals, and history of tonsillectomy, chronic pharyngitis, school attendance, and visible tonsillar structural changes. These associations are consistent with findings from studies in India, Riyadh, Nigeria, Somaliland, and various Ethiopian regions [7, 22, 26, 41, 42]. These associations are clinically meaningful because they identify high-risk groups that can benefit from targeted interventions such as vaccination campaigns, health education, and early treatment programs.
This study provides valuable insights into the bacterial etiologies and antimicrobial resistance patterns of pediatric pharyngitis; however, it has limitations. These include the use of convenience sampling, the absence of molecular confirmation of bacterial isolates, and the lack of investigation for viral and fungal causes of pharyngitis.
Conclusion
The study identified S. pyogenes, S. aureus, and S. pneumoniae as the predominant bacterial pathogens in pediatric pharyngitis, with a notable proportion exhibiting resistance to commonly used antibiotics, including multidrug-resistant patterns. Factors such as incomplete vaccination, prior history of pharyngitis, contact with symptomatic individuals, tonsillar structural changes, school attendance, and prior tonsillectomy were significantly associated with bacterial pharyngitis.
These findings underscore the importance of local antimicrobial surveillance, cautious antibiotic use, and preventive strategies. Further research with larger, representative samples and molecular diagnostic approaches is recommended to strengthen these observations.
Supplementary Information
Below is the link to the electronic supplementary material.
Acknowledgements
The authors would like to thank Bahir Dar University, College of Medicine and Health Sciences, Department of Medical laboratory Science for the opportunity to conduct this study. Our sincere gratitude also goes to the Amhara Public Health Institute, TGTH, and FHCSH microbiology laboratory staff and pediatricians for their cooperation and support with sample access, laboratory materials, kind assistance and study participants.
Abbreviations
- AMR
Antimicrobial Resistance
- AST
Antimicrobial sensitivity testing
- CDC
Centre for Disease Control
- CLSI
Clinical Laboratory Standards Institution
- FHSH
Felege Hiwot Specialized Hospital
- MAC
MacConkey Agar
- MDR
Multidrug Resistant
- SOPs
Standared Oprative Procuder
- TGSH
Tibebe Ghion Specialised Hospital
- WHO
World Health Organization
Author contributions
Kefiyalew Mihrete: designed this study, collected and analyzed data, interpreted results, and drafted the manuscript; Addisu Melake: participated in data management and analyzed data; Bayeh Abera and Tewachew Awoke participated in the design, data collection, and analysis, interpretation of the results, supervising the overall work of this study, review and approval of the manuscript; Tadese Sisay: prepared the manuscript, data analysis and data collection. All authors read the manuscript and approve it for submission.
Funding
Not available.
Data availability
The data sets generated during and/or analyzed during the current study are available from the corresponding author upon reasonable request.
Declarations
Ethical approval and consent to participate
This study titled “Bacterial Pharyngitis, Antimicrobial Susceptibility, and Associated Factors among Children at Comprehensive Specialized Hospitals, Northwest Ethiopia” will be conducted in full compliance with national and international ethical research standards, including the Declaration of Helsinki. Ethical clearance was obtained from the Institutional Review Board (IRB) of Bahir Dar University. Written informed consent was obtained from the parents or legal guardians of all participating children. For children aged 7 years and above, we also obtained verbal or written assent using age-appropriate language. Throat swab sample collection was performed using sterile techniques by trained personnel to minimize discomfort or risk of infection. Participation in this study was entirely voluntary.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Supplementary Materials
Data Availability Statement
The data sets generated during and/or analyzed during the current study are available from the corresponding author upon reasonable request.