According to the Centers for Disease Control and Prevention (CDC), surgical site infections (SSIs) include all infections occurring at or near the surgical incision within 30 days of follow-up after surgery or after 1 year of follow-up, whenever an implant was put during the surgery [1].

Studies have revealed an alarmingly increased trend of Surgical volume compared to previous years in the world, with >300 million people being operated on annually [2]. Thus, millions of people are at a high risk of getting SSI if preventive measures are not adequately observed.

Some of the open Surgeries commonly performed in the otorhinolaryngology department (ORL) include neck surgeries, such as neck dissection, tracheostomy, thyroidectomy, parotidectomy, and thyroglossal cyst excision. Nasal and paranasal surgeries such as septoplasty, rhinoplasty, and maxillectomy. Otological surgeries such as mastoidectomy, tympanoplasty, and Cochlear implant [3].

The burden of SSI is 20% of all types of nosocomial infections. In the United States of America (USA), the annual incidence of SSI varies from 160,000 to 300,000 of the performed cases [4]. The study in Uganda found the incidence of SSI to be 16.4% [5], whereas in Kenya, one study showed an incidence of 7% [6].

In Tanzania, recent studies on different surgical disciplines, such as obstetrics and gynecology, urology, revealed the rate of SSI to range between 10.9% to 26% [7]-[9]. However, there are no existing data on the magnitude, microbiological agents, and factors associated with SSI among otorhinolaryngology open surgeries.

According to the American College of Surgeons and Surgical Infection Society, surgical site infections are associated with several risk factors, which are grouped into patient-related, such as age, diabetes, obesity, alcohol intake, current smoking, Body Mass Index (BMI) status, immunosuppression, and high American Society of Anaesthesiologist (ASA) score. Preoperative-related, such as emergency versus elective, wound class, proper antibiotic prophylaxis, and Intraoperative-related factors such as longer duration of the procedure, and failure in antibiotics redosing to patients who take a long procedure time or those who lose >1.5 litres of blood [10].

Studies show that implementing or practicing effectively the above-mentioned factors, such as abstaining from alcohol 4 - 8 weeks before surgery, quitting smoking 2 weeks before surgery, taking precautions among patients with comorbidities such as >350 cells/µl of CD4 level among patients with Human immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS), and glucose control among diabetic patients, can reduce surgical site infection by 60% [4][11][12].

Puca et al. found that, of all microorganisms causing surgical site infections, Gram-negative bacteria were the most common (57.9%). Pseudomonas aureginosa species followed by Escherichia colispecies were predominant among Gram-negatives. Gram-positive bacteria accounted for 36.6%, with Staphylococcus aureus predominating (79.4%) [13]. Moreover, in the study done by Joel Manyahi on the bacteriological spectrum of postoperative wound infections at MNH and Muhimbili Orthopedic Institute (MOI), the three most common isolated organisms were Pseudomonas aeruginosa (16.3%), followed by Staphylococcus aureus (12.2%), and Klebsiella pneumoniae(10.8%) [14].

In ORL head and neck surgeries, one study on post-ear surgery found Escherichia coli to be the most common cause of SSI in patients who underwent mastoid surgeries, followed by Staph aureus[15]. Whereas a systematic review of 14 articles on cochlear implant surgical site infection prevention, Staphylococcus, and Pseudomonas species were found to be the most consistently reported isolates in those studies [16].

In a study of bacterial colonization following tracheostomy among patients in the ICU in one of the hospitals in Oman, Pseudomonas aeruginosa and Acinetobacter baumanii species were the most common isolates identified in that study [17].

The study enrolled 89 participants who had undergone open Surgeries, representing a 100% response rate. Their ages ranged from 13 to 78 years of age, and the median age was 44.5 years (IQR 36 - 59). Among all the study participants, those who were in the age group (36 - 53) were the majority, 31 (34.8%). Overall, the female respondents, 47 (52.8%), were the majority in this study, in a female: male 1.12:1 (Table 1).

Table 1. Social-demographic characteristics by age and sex.

IQR = interquartile range.

Among the postoperative complications, SSI is still a major problem in its entirety, more so in developing countries, which has led to prolonged hospital stays, unnecessary healthcare-associated costs, readmission, reoperation, and death among patients who undergo Surgeries [4].

The index study found an SSI incidence of up to 22.5%, consistent with the study done by Kibwana et al. at MNH, whose findings revealed a 22% rate of SSI [8]. These comparable findings can be best explained by the shared predictors, such as the same environmental setting, inadequate infection control policy enforcement, and limited resource supply for infection control strategies. Our findings were slightly higher compared to those found in the recent study done in Uganda, which showed incidences of SSI of 16.4% [5]. This can best be explained by sample size differences (110 study participants in the study in Uganda vs 89 in the index study). The incidence of SSI in this study is strikingly higher than that observed in Latin America and Asia, showing incidences of 7% and 4%, respectively [18]. This may be attributed to well-made preoperative plans, adequate use of antibiotics, adherence to preventive measures, and sufficient infrastructure to contain potential pathogens. The index study was conducted in a low-resource area.

In the study, which was done by Joel Manyahi on the bacteriological spectrum of postoperative wound infections in general surgery, obstetrics and gynecology, and orthopedics at MNH and MOI, the three most common isolated organisms were Pseudomonas aeruginosa (16.3%), followed by Staphylococcus aureus (12.2%), and Klebsiella pneumoniae(10.8%) [14], which is in agreement with the findings of the index study, which revealed Pseudomonas aureginosa (38.9%), followed by Staphylococcus aureus(16.7%), and coagulase-negative Staphylococcus (11.1%) to be the commonest isolates, which were all multidrug resistant, in keeping with the findings by Manyahi et al. [14]. This can best be explained by the same environmental setting, which acts as a potential exogenous source of microorganisms in surgical wounds.

Moreover, the index study had one culture-negative result, which was one SSI case from otology, unlike the previous study on microbiological patterns after mastoid surgeries that revealed Escherichiacoli followed by Staphylococcus aureus as the common isolated bacterial species [15], that culture-negative results can be due to the difficulty of culturing anaerobes in our setting.

In this study, though the p-value was >0.05, most surgical site infections were in the age group >71 years. This finding is supported by many other previous studies [19][20], and it is theoretically true that elderly patients are at risk of infections due to low immunity levels, comorbidities, smoking, and alcohol intake being prevalent in this age group [21].

In the same vein, although the P-value was >0.05, male patients were found to have a higher incidence of surgical site infection compared to females, which also displays the likeness of the findings of 10 years of surveillance in Germany [22]. Theoretically, this is true because of the impaired cell-mediated immunity in males due to the effects of testosterone [23].

Furthermore, as previous research shows [9][24][25], In those patients whose operation had taken a duration of >1 hour, SSI cases were proportionally higher compared to those without. The recommendation from the Surgical Care Improvement Project [26] (SCIP) is that antibiotic redosing must be given in addition to the first prophylaxis provided within 30 to 60 minutes before skin incision, for surgeries that take 1 - 2 times the half-lives of the first antibiotic prophylaxis given, or 1.5 liters of blood loss, or the procedure that lasts > 4 hours. In the index study, five patients met the criteria to receive antibiotic redosing; only one received antibiotic intra-op, and among the four who didn’t receive, 3 (75%) developed SSI. This may be because the longer the surgery lasts, the greater the danger of contamination and blood loss in those patients, resulting in an increased risk of SSI.

Bivariable analysis of this study showed that Patients who had alcohol drinking habits had a 3.94-fold increased risk of developing surgical site infections compared to those who didn’t. This finding is consistent with many other previous studies [19][27] This is because alcohol tends to impair cell migration to fight offending micro-organisms, and also, in the initial stages of wound healing, debris is not cleared up owing to the absence of macrophages on the incision site, hence harboring the nidus for infections.

Like the previous studies [9][28], patients who had HIV/AIDS had a risk of developing SSI 2.93 times higher than those who did not as shown by the bivariable analysis of the index study. This is because patients with HIV/AIDS usually have impaired cell-mediated immunity to tackle the offending pathogens, impaired immunological processes toward wound healing, and malnutrition [12].

Furthermore, bivariable analysis of the index study revealed those who didn’t receive antibiotic prophylaxis to have 3.05 times increased risk of developing SSI compared to those who received prophylaxis 30 to 60 minutes before surgery, in keeping with previous studies [29]-[32]. The truth of the matter is, absence of bacteriostatic or bactericidal activity offered by appropriate prophylactic antibiotics might lead to the proliferation of potential micro-organisms from either endogenous or exogenous sources in the surgical wound leading to SSI [33].

Multivariable analysis of the index study revealed an increased likelihood of developing surgical site infection among those with an American Society of Anaesthesiologists (ASA) score III, 3.65 times more than those with an ASA score I, similar to previous studies [20][24]. Patients with Higher ASA scores are physically constrained due to systemic diseases such as heart failure, hypertension, and diabetes mellitus, which impair immunological functions important for wound healing and the fight against infections.

This was a single-center study with a small sample size, making it difficult to generalize the study’s findings.

The study methodology used had a risk of selection bias.

Surgical expertise among surgeons and the ability of patients to comply to post operative care package of wounds could have influenced the results.

The incidence of SSI among open surgeries in the Otorhinolaryngology department is high (22.5%) and is chiefly caused by Pseudomonas aeruginosaspecies, which are sensitive to ciprofloxacin, piperacillin-tazobactam, and aztreonam, as well as Staphylococcus aureusspecies, all MRSA-positive and multiply resistant to nearly all the conventional antibiotics. It was significantly predicted by having an ASA score of III.

Patients who are planned for elective surgery should stop alcohol intake at least 4 to 8 weeks before surgery. Antibiotic prophylaxis is strongly recommended in most ORL open surgeries. Surgical patients with HIV/AIDS should be assessed thoroughly, including CD4 levels over 350 cells/μl. Antibiotic redosing among open surgeries that take >4 hours or >2 half-lives of the given first dose of antibiotics, or with blood loss of 1.5 L, is highly recommended. Patients with high ASA scores should be optimized before and after the operation according to CDC recommendations. Further research with a large sample size and a long study period is strongly recommended.

To God Almighty be the glory who gave the enablement in achieving all the work. Authors give appreciation to the head of the department of otorhinolaryngology for giving permission to collect data. The authors wish to thank all the study participants who gave their all and hence made the study possible. Gratitude goes to the Department of microbiology MUHAS, for their phenomenal contribution in identifying microbiological agents.

The MUHAS institutional review board (IRB) provided ethical clearance for my study.