This study describes overall incidence rate of SSI and associated risk factors. This study suggested that substantial number of patients developed SSI (28.57%) with maximum number of patients developed in the health institution/before discharge. Previous studies done in different countries including Ethiopia (9), Cameron (10), Brazil (11) and Nepal (12) are not go hand in hand. This discrepancy could be unlike previous studies, in our study, we included dirty and contaminated wounds which are more prone to develop infection. In addition, it might be because of health facility related and absence of adequately trained health professionals. Moreover, types of instruments and suture material being used, technique of wound closure could be possible reasons as evidenced by previous study (13). All these might be the reasons why we find out high incidence rate of SSIs compared to previous studies.
Regarding the type of surgery done, the most common surgical procedure performed was caesarean section and with less frequently developed SSI. In present study, the incidence of SSIs was highest in dirty wound followed by contaminated wounds and the lowest rate was observed in clean wound. This finding is in agreement with previous study in Cameron (10), India (14), Nepal (12) and India (15) in which, patients who had dirty wound were more likely developed SSI as compared to patients having clean, clean contaminated and contaminated. Dirty and contaminated wound creates conducive environment for bacterial proliferation. Patients undergoing gastrointestinal surgery share large numbers among patients who developed infection.
In present study, patients who had history of surgical procedures were about three times more likely to develop SSIs compared with patients who had no previous exposure for surgical procedure/s which was in line with other study in Ethiopia (9) in which patients who had history of surgical procedures were 3.64 times more likely to develop SSIs and Brazil (16). We also found prolonged operation is risk factor for SSIs which also in line with previous reports (14), India(4), Rwanda (17), Brazil (11), Indonesia (18) and Finland (19)in which procedures that lasts more than 2 hours prone to develop SSI. This high incidence associated with prolonged duration of surgery might be because wound is exposed to external environment and pave the road for microorganisms to enter the wound. In this study preoperative use of steroid is significantly associated with SSI. Steroid is responsible to suppress immunity and easily exposed to infection. It is contradict with the study done by Sehgal et al (7). The difference might be the duration of steroid treatment.
The increased rate of SSI found in this study with increase in preoperative hospital stay. Patients who stay more than one week were more likely develop as compared to those less than one week. This is because patients who stay in the hospital for long time have high probability to exposed Nosocomial infection including resistant microorganism.
The occurrence of SSI is significantly associated with age. Patients with age less than 30 years old were less likely developed infection compared with patients with age > 70 years. The result was in agreement with other study (9) confirming that as age increases the risk of SSI occurrence increases. The reason behind might be as age increases blood flow decrease which prolong wound healing time and creates good opportunity for microorganism growth. Not only this, the occurrence of chronic disease increases as age increases that decrease the immunity of the patient, both of which synergistically predispose the patient to have SSIs.
We found that patients with BMI < 30kg/m2 were 1.68 times less likely to develop SSI as compared to patients having BMI≥30kg/m2. This may be a result of the standard dose of prophylactic antibiotics
achieve inadequate tissue concentrations in obese patients; tissue perfusion is compromised, contribute poor wound healing and suppress immunity. Furthermore, incision time for obese patients may be longer and therefore involve more tissue becoming exposed to bacteria. This showed that health professionals better to counsel patients about life style modification so as to reduce their weight.
We found that patients who have co-morbidity were not significantly associated with SSIs. It is contradict with the study done in Ethiopia (9). As different studies showed that presence of co-morbidity suppress immunity and lead to the patient easily infected. However, in our study, it is not significant predictor. Observed cases with co-morbidity were low in our case and previous studies majority of patients with diabetes mellitus (highly compromise immunity) that might be possible reason for co-morbidity not to be independent predictor for SSIs.
In this study, administration of surgical prophylaxis before 1 hour of surgery done was observed to be independent predictor for development of SSIs. The result is in agreement with previous study Ethiopia (9) administration of first dose surgical antimicrobial prophylaxis before 1 hour of skin incision increased SSIs risk by 11.10 times compared with administration of first dose of surgical antimicrobial prophylaxis within 1 hour of skin incision. If the first dose of surgical antimicrobial prophylaxis administered 1hour earlier to before starting surgery, then the tissue as and serum concentration of antimicrobials is suboptimal to prevent the occurrence of SSI. However, co-morbidity, administration of antibiotics more than 24hours, sex and operator had no significant impact on development of SSI. This suggests that administration of antibiotics for more than 24 hours have no value rather it could lead to increment of health care costs and drug resistance.
Limitation: acknowledgment of limitation is very important for future researchers. Our study is not cover the sanitary profile of health facility and hygiene related practice of health professionals during patient care.