Antibiotic utilization and resistance in diarrheagenic Escherichia coli isolated from children under 5 Years in Nakuru County: a case-control study

Introduction

A significant portion of the global health burden is caused by enteric infections and diarrheal diseases (EIDD), which are frequently found in developing nations and are closely linked to inadequate water supply, sanitation, and hygiene conditions (Saka et al., 2019). The prevalence of EIDD is high throughout the world and is a major cause of morbidity and mortality in developing nations, with higher rates among children and the elderly. Notably, various microbial agents, such as viruses, bacteria, and parasites, are capable of causing diarrhea. Escherichia coli, belonging to the Enterobacteriaceae family (Wallace et al., 2020), is one of the most frequent bacterial causes of diarrhea among children under 5 years of age.

Up to 40% of all diarrheagenic cases in developing nations are caused by strains of diarrhoeagenic E. coli (DEC), including enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), and enterotoxigenic E. coli (ETEC), with an estimated 2.5 million child fatalities worldwide (Raghavan et al., 2017). Antibiotics have always been used to manage and treat enteric infections and diarrheal diseases (EIDD) majorly caused by DEC strains. Resistance patterns are currently on the rise among clinical cases of diarrhea in children under the age of five. These cases have been linked to the current emergence of new strains that are resistant to antibiotics. According to the World Health Organization [WHO] (2017), multi-drug resistance among important medical bacteria, including DEC, is causing global concern. Resistance to several antibiotics is largely caused by genetic mutations in bacteria allowing them to evade the lethal effects of these antibiotics (Verstraete et al., 2022). However, the acquisition of mobile genetic elements, such as gene cassettes, integrons, and mobile genetic elements, is connected to the use of third-generation cephalosporins and β-lactams (amoxicillin or ampicillin) (Rozwadowski & Gawel, 2022).

Cephalosporin resistance has been linked to extended-spectrum β-lactamases (ESBLs), enzymes involved in the degradation of β-lactams (Ali et al., 2018). Numerous asymptomatic DEC infections have been documented as a result of DEC’s widespread distribution, which is frequently characterized by the development of DEC-specific antibodies in young children (Buskirk et al., 2022). Children in DEC-prone and endemic areas, including urban slums, have been observed to experience this phenomenon. Kenya, one of Africa’s developing nations, deals with the threat of DEC antimicrobial resistance brought among children under the age of 5 years (Gitahi et al., 2018; Leting et al., 2022). Due to their multi-drug resistance, these resistant bacterial strains are proving challenging to control. In Kenya, just like other countries globally, drug-resistant pathogens are primarily caused by the improper and excessive use of antibiotics (Webale et al., 2020). This study, therefore, investigated the cases of multi-drug resistance in children under the age of five with prior use of the selected antibiotic agents in Nakuru County.

Methods

Results

Figure 1 depicts a graphical distribution of resistant cases. All DEC samples were resistant to amoxicillin while only 12.5% of DEC samples were susceptible to ampicillin (Suge, 2023). Further, the DEC strains from the samples were 81.3%, 37.5% and 33.3% resistant to erythromycin, cefoxitin and nalidixic acid respectively (Table 1). Resistance was noted to decrease moving from β-lactam antibiotics through macrolides to cephalosporins and quinolones.

Figure 1. Resistant patterns of the isolated diarrheagenic Escherichia coli.

The analysis observed that the number of respondents whose children used antibiotics within the last 12 months was 384 (100%). This is an indication that all the children in Nakuru were frequent users or had been exposed to antibiotics within the study period (2017/2018). The study results also indicated that 148 (38.5%) children consumed antibiotics acquired over the counter and that 236 (61.5%) children in Nakuru county consumed prescription acquired antibiotics (see Table 2).

From the analysis, it can be observed that the β-lactam antibiotics were the most used antibiotics in Nakuru (248, 64.6%). The results also indicate that sulfonamides were the least used antibiotics drug (16, 4.2%). The study further shows that most children used antibiotics for less than one week, with 288 (75%) of the total respondents. While 96 (25%) indicated usage of more than one week. Consequently, it can be observed that 156 (40.6%) of the children were on medication/self-medication with antibiotics when rarely sick. While 192 (50%) of the children were on medication/self-medication with antibiotics sometimes when they were sick. Finally, it can be observed that 36 (9.4%) of the children were on medication/self-medication with antibiotics always when sick. This show that there is a substantial proportion (90.6%) of the children who are on medication/self-medication with antibiotics (see Table 2).

Based on the level of satisfaction, 140 (36.5%) parents indicated that they were not satisfied, while 244 (63.5%) of the respondents recorded that they were satisfied. Further, 148 (38.5%) of the children rarely finished the full prescription when using antibiotics. The study also indicates that 236 (61.5%) of the children within Nakuru always or sometimes finished the full prescription when using antibiotics (see Table 2).

Furthermore, 140 (36.5%) of the respondents indicated that they always made an informed decision that an antibiotic was needed for the child’s illness. The results also indicated that 244 (63.5%) of the respondents sometimes decided on their own that an antibiotic was needed for the child’s illness (see Table 2).

Finally, 200 (52.1%) of the respondents, based on experience, would make personal decisions on using antibiotics in the future. The results also indicate that 184 (47.9%) of the respondents do not foresee making a personal decision on using antibiotics on children in the future (see Table 2).

The analysis showed that the likelihood of a child occasionally completing the entire antibiotic prescription was 1.439 (0.605, 3.425), with a p-value of 0.000, which is significant at the 0.05 level. This odds ratio tells us that individuals who finished the full prescription of antibiotics were not a risk factor for antimicrobial resistance. The results also indicate that the odds of rarely a child finishing the full prescription was 6.75(2.754, 16.546), a p-value = 0.000< 0.05 significant level. This odds ratio tells us that individuals who rarely finished the full prescription of antibiotics have seven times the odds of antimicrobial resistance than individuals who always finished the full prescription (see Table 2).

The results also indicate that the odds of always making an informed decision on their own that antibiotics were needed for the child’s illness was 1.31(0.864, 1.988) with a p-value = 0.122 > 0.05. This odds ratio tells us that individuals who always made an informed decision on their own that antibiotics are needed for the child’s illness were not a risk factor for antimicrobial resistance (see Table 2).

The results showed that the odds to foresee making a personal decision on antibiotic use was 0.3 (0.197, 0.456) with a p-value = 0.000 < 0.05 significant level. Thus, the odds of antimicrobial resistance among individuals who foresee making a personal decision on antibiotic use was only 0.3 times the odds among individuals who did not foresee making a personal decision. This adjusted odds ratio indicates that individuals who foresee making a personal decision on antibiotic use seem to be protective against antimicrobial resistance (see Table 2).

The results show that the odds of how the antibiotic was acquired was 2.692 (1.759, 4.122) with a p-value = 0.000 < 0.05 significant level. These odds show that individuals who obtained antibiotics by walking into a pharmacy without a prescription have three times the odds of antimicrobial resistance than individuals who obtained antibiotics by walking into a pharmacy with a prescription. The results also indicate that the odds of β-lactam 6.167(4.076, 9.330) with a p-value = 0.000 < 0.05 significant level. This odds ratio tells us that individuals who used β-lactams antibiotics during medication/self-medication have six times the odds of antimicrobial resistance than individuals who didn’t use them. The results also indicate that the odds of macrolides 0.909 (0.581, 1.423) with a p-value = 0.422 > 0.05 significant level. This odds ratio tells us that individuals who used macrolides antibiotics during medication/self-medication were not a risk factor for antimicrobial resistance. The results also indicate that the odds of sulfonamide 0.35 (0.184, 0.667) a p-value = 0.000 < 0.05 significant level. Thus, the odds of antimicrobial resistance among individuals who used sulfonamide antibiotics during medication/self-medication were only 0.35 times the odds among individuals who didn’t use them. This adjusted odds ratio tells us that the use of sulfonamide antibiotics during medication/self-medication seems to be protective against antimicrobial resistance. The results also indicate that the odds of quinolones 0.818 (0.529, 1.265) a p-value = 0.25 > 0.05 significant level. This odds ratio tells us that individuals who used quinolones antibiotics during medication/self-medication were not a risk factor for antimicrobial resistance (see Table 3).

The results indicate that the odds on the length of usage of antibiotics by the child of less than a week was 0.8 (0.504, 1.272) a p-value = 0.205 > 0.05 significant level. This odds ratio tells us that the length of usage of antibiotics for a period of less than one week was not at risk factor for antimicrobial resistance (see Table 3).

The results indicate that the odds of sometimes a child being on medication/self-medication with antibiotics when sick was 0.228 (0.077, 0.672) a p-value = 0.000 < 0.05 significant level. The results also indicate that the odds of a child always being on medication/self-medication with antibiotics when sick was 0.038 (0.012, 0.113)), a p-value = 0.000 < 0.05 significant level. Thus, the odds of antimicrobial resistance among individuals who sometimes/always had their child being on medication/self-medication with antibiotics when sick was only 0.23 and 0.038 times, respectively, the odds among individuals who rarely had their child on medication/self-medication with antibiotics when sick. This adjusted odds ratio tells us that individuals who sometimes/always had their child being on medication/self-medication with antibiotics when sick seems to be protective against antimicrobial resistance (see Table 3).

The results indicate that the odds of unsatisfaction with experience of antibiotic medication was 4.705 (2.995, 7.391) a p-value = 0.000 < 0.05 significant level. This odds ratio tells us that individuals who were unsatisfied with the use of antibiotic medication have five times the odds of antimicrobial resistance than individuals who were satisfied with antibiotic medication (see Table 3).

Discussion

Particularly in developing nations, DEC poses a concern to children’s health. In this study, 384 children under the age 5 years with acute diarrhea from Nakuru Provincial General Hospital (NPGH) were assessed for the incidence of DEC, epidemiological traits, and patterns of drug resistance. The DEC isolates showed the highest resistance to amoxicillin followed by ampicillin, erythromycin, cefoxitin and nalidixic acid.

Our findings generally indicated that first-line antibiotics, such as ampicillin, were more resistant to DEC infection than second-line antibiotics, such as erythromycin, cefoxitin, and nalidixic acid. Notably, there exist a six-fold risk of developing antimicrobial resistance for individuals who used β-lactams antibiotics during medication/self-medication than those who did not use them. Both previous and current studies concur with these findings (Eltai et al., 2020; Cannatelli et al., 2016; Aslani et al., 2011; Jafari et al., 2009). Due to their affordability (mostly, because they are readily available over the counter) and accessibility first-line antibiotics are frequently, empirically and indiscriminately used to treat diarrhea in developing nations (Shah et al., 2016).

Interestingly, at least all the children in this study had prior exposure to antibiotics within 12 months of birth. There are several studies that support this finding (Marra et al., 2009; Scott et al., 2016). This observation could be attributed to several factors including sensitivity of the immune system during childhood, teething and general propensity of children to harbor diverse pathogens.

Additionally, a large proportion of the children sampled obtained antibiotics directly from pharmacies without prescriptions. Seemingly, the policies governing the use of antibiotics are flawed. It is evident that most African countries, including Kenya, have non-stringent regulations regarding the use of antibiotics. Due to the need to maximize the profit margins and ensure constant flow of medicines, pharmacies tend to bend the regulations to meet such demands. Several studies have observed this tradition. Compounding this observation, most first line antibiotics, more specifically β-lactams (in case of the current study) are the mostly used. However, sulfonamides account for only a small fraction of the total medications used during treatment. The availability of and affordability of the first line antibiotics could be largely attributed to these observations. Several studies have been able to explain this trend in many populations. For example, a study by Erku et al. (2017) demonstrated that amoxicillin was the most commonly utilized antibiotic due to its easy acquisitions and affordability. Also, Saleem et al. (2019), while exploring the use of antibiotics inappropriately by Pakistani hospital patients, observed a significant use of cephalosporins and penicillin and thus their potential risk of developing resistance against them. A similar study by Okubo et al. (2018) also supports this observation. Also, Singh et al. (2018) showed the existence of a high prevalence of antibiotic resistance to widely used drugs like ampicillin, ceftazidime, cefoxitin, streptomycin, and tetracycline.

Notably, the duration of use of antibiotics seems to be a factor contributing overall to the emergence of resistance among the sample population. Only a quarter of the population used medications past one week. In contrast, the majority of the sampled population used antibiotics for less than seven days. Most of the antibiotics that are correctly prescribed are more than a week. This observation indicates that the majority of the children could be withdrawn of their medications when their caregivers/parents observe their improved health status. Also, based on the data of how often a child finishes the entire prescription, it was noted only 7% finished their medications. As it is expected that the medications, especially antibiotics be used completely, this trend indicates a higher possibility of emergence of resistant DEC strains due to exposure to the sub-lethal doses of these antibiotics as compared to children completing their dosages. This study concurs with several studies. For instance, Atif et al. (2019) showed that majority of patients, including pediatric patients, stopped the antibiotic course when they felt better and did not finish. Thus the ‘feeling better’ contributes significantly on inconsistent use of antibiotics.

Interestingly, it was observed that more than 90% of the children were under medications despite not having any symptoms of infections. This trend augments inappropriate use of antibiotics. It is expected that existence of active infections warrants the correct use of antibiotics. Cases of non-adherence to recommended antibiotic usage thus are the majority. As mentioned above, most antibiotics used in such medications are the β-lactams especially amoxicillin and ampicillin due to their affordability and availability. Thus, high number of usages of these antibiotics can be described by the need to ‘protect’ or ‘boost’ children’s immunity against the looming infections. The findings of the study however, further confirm the protective effect of using antibiotics only when sick against antimicrobial resistance. A report by Malik and Bhattacharyya (2019) indicates that combined effects of the economy, infections, and self-medication produce synergistic interactions through feedbacks on each other, portraying the evolution of drug resistance as a self-reinforcing loop in the population. Thus self-medication, compounded by other socio-economic factors, play a major role in the distribution of resistant strains. Other studies are further consistent with the current study (Ajibola et al., 2018; Gillani et al., 2017). There is however limited information on extent to which self-medication and without presentation of any symptoms among children.

Satisfaction levels on the use of antibiotics showed that majority of the parents were satisfied with the extent to which antibiotics were efficacious and beneficial to their children. The findings further showed a five-fold protective effect against antimicrobial resistance of being satisfied with medication. This could be explained by the positive effect of satisfaction to adherence to prescribed antibiotics and hence reduction in the cases of antibiotic resistance. Conversely, unsatisfaction on the effectiveness of antibiotics is one of the major potential risks associated with antimicrobial resistance. Conversely, Cohen et al. (2017) presumes that there is little strong evidence that patient satisfaction will lead to better medical results. Thus, patient satisfaction levels are based on the progression of the disease and the inherently equivocal and unstable character of human reactions. This means therefore that if there have been situations of improved child’s health after medication, there are higher chances that the subsequent prescriptions will be adhered.

With regards to finishing antibiotics, majority of the children completed their prescriptions of antibiotics fully. Only 7% did not finish their doses. Evidently, finishing a full prescription of antibiotics is not a risk factor for antimicrobial resistance. However, the 7% are seven times more likely to develop antimicrobial resistance. Therefore, findings have indicated that there is a seven-fold likelihood of developing antimicrobial resistance when one does not complete their prescriptions. From this study we can establish that sub-lethal exposure of bacteria is a major factor contributing to antimicrobial resistance. Jamhour et al. (2017) demonstrated that in developing nations, knowledge of antibiotics and self-medication techniques is a power driver of antimicrobial resistance. Most of the populations including the caregiver prefer not to use antibiotics to treat a cold. The study further demonstrated that the majority of the people did not prefer completing doses, instead keeping them for future use. This situation exacerbates emergence of antimicrobial resistant strains.

The decision to use antibiotics is solely dependent on the caregiver. The majority of the parents/guardians who participated in the study reported that they always make decisions on their own regarding when and how their children should use antibiotics. Informed decision seems to be a protective factor in the development and emergence of antimicrobial resistance. These decisions could be made based on the experience with antibiotic use. Interestingly, there is a probability slightly above 50% that the caregiver will make an informed decision regarding the use of antibiotics by their children. Nonetheless there exists a protective effect of making personal informed decisions on antimicrobial resistance. Boiko et al. (2020) demonstrated that expectations and experiences on antibiotic use constitute many reasons for the choices and decisions on the use of antibiotics.

Conclusion

The current study established an interplay of various factors associated to antimicrobial resistance among the DEC isolates. The results are consistent with almost all the studies that have been conducted to assess resistance patterns of DEC isolates. That is, first-line antibiotics such as amoxicillin, ampicillin and erythromycin almost always present the highest proportions of resistance. Also, it is explicit that self-medication is significantly associated with the escalating rates of resistance among children under five years of age.