Background
Health care-associated infections (HAI) are acquired by patients while receiving care, and represent the most frequent adverse event affecting patient safety worldwide [
1]. It is estimated that hundreds of millions of patients are affected by HAIs each year, leading to significant mortality and financial losses for health systems [
2,
3]. Currently evidences shows that SSI is the most surveyed and frequent type of HAI in low and middle-income countries and affects nearly one third of patients who have undergone a surgical procedure [
4]. SSI is infection related to an operation procedure that occurs at or near surgical incision within 30 days of operation or after 1 year if an implant is placed. It can be either incision (superficial: involving the skin and subcutaneous tissues and deep: involving the deeper soft tissues of the incision, such as muscle or fascia) or organ space (involving any part of the anatomy other than the incised body layers (skin, fascia, and muscle layers)) [
5].
The number of surgical procedures performed now a day globally continues to rise, and surgical patients are initially seen with increasingly complex comorbidities. Cesarean section is one of the most commonly practiced surgical procedure [
6]. Potential complications such as: SSI that associated with any type of surgical procedure including cesarean section represents a well-known significant cause of surgical patient morbidity and mortality with consecutive human and economic losses. Despite of SSI is the most preventable HAIs using evidence-based strategies, still the problem is represented with high prevalence (11.7%) which accounts for high human and financial costs [
7]. A narrative review conducted in Sub-Sharan Africa (SSA) reported SSI after cesarean section was timely increasing (15.6%) [
8]. SSI patients required prolonged hospitalization, reoperation and readmission [
9]. The majority of infection-associated costs arise from prolonged hospitalization, with additional expenditure attributable to medical staff and treatment. As the demand for surgical procedures rises, the incidence and associated costs of SSI will likely escalate [
10].
Many factors influence surgical wound healing and determine the presence of infection. Patient-related (endogenous) and process/procedural-related (exogenous) variables are the primary factors that increase the chance of SSI. There are also non modifiable variables such as age and gender that contribute for high prevalence of SSI. On the other hand there are also other potential factors, such as good nutritional status, avoiding tobacco use, correct use of antibiotics and the intraoperative technique that can increase the likelihood of positive surgical outcome [
7].
The rate of cesarean section in Ethiopia was vary according to different individual studies report with a range from 11 to 34.4% [
11,
12], but based on the Ethiopian Demographic Health Survey of 2016, it was 2% [
13]. In Ethiopia, there are pocket and fragmented studies across regions that explore about the prevalence of SSI after cesarean section and associated factors among mothers [
14‐
24]. However the studies were inconclusive and there was no any concrete scientific evidence established at national level. Therefore, this systematic review and meta-analysis aimed to estimate the pooled prevalence of SSI after cesarean section and its associated factors (specifically labor, its comorbidity and type of incision related that can be modifiable as majority of included articles searched) at the national level.
Discussion
This Systematic review and meta-analysis was conducted to identify the pooled prevalence of SSI after cesarean section and associated factors in Ethiopia. We found high prevalence of SSI after cesarean section in Ethiopia with an overall prevalence of 9.72% (95%CI: 8.38, 11.05). This systematic review and meta-analysis reported a higher prevalence as it was compared with the sphere standard of CDC guidelines of SSI (which was 5%) [
35].
SSI after cesarean section is considered as an indication of quality of health care service. However, it represented with high figure that make the quality of health care service to be questionable in Ethiopia. Although several endogenous risk factors are there, it can be possibly explained by that limited and ineffective implementation of evidence based SSI prevention strategies recommended by CDC may increase the problems.
This includes limited and ineffective administering of antimicrobials before 1 h of procedure, prolonged preoperative admission of patients, longer duration of procedures and inability to prevent obstetric complications (PROM, chorioamnionitis) [
36]. It was also much higher than among studies conducted in Nova Scotia and New Zealand reports of SSI prevalence; 2.7 and 5.2% [
37,
38]respectively.
This systematic review and meta-analysis was lower as compared with a reports from India (8.9%,), England (9%), Norway (9.1%) and Nigeria (9.6%) [
39‐
42]. It was also much lower than from reports of Jordan (14.4%), Malaysia (18.8%), a systematic review from Sub-Saharan Africa (15.6%) and Egypt (16.7%) [
8,
43‐
45]. Hence, application of evidence based strategies should be there, like timely administration of appropriately selected prophylactic antibiotics, use of a chlorhexidine-alcohol based preparation, use of suture for skin closure, maintenance of glycemic control in the postoperative period, showering (full body) with soap (antimicrobial or non-antimicrobial) or an antiseptic agent on at least the night before the operative day, normothermia should be maintained in all patients, increased fraction of inspired oxygen should be administered during surgery and after extubation in the immediate postoperative period for patients with normal pulmonary function undergoing general anesthesia with endotracheal intubation and transfusion of blood products should not be withheld from surgical patients as a means to prevent SSI [
2,
7].
Our finding was also further investigated about the contributing factors of SSI after cesarean section. PROM > 12 h, duration of labor > 24 h, chorioamnionitis, anemia and having vertical skin incision all had increased risk of developing SSI after cesarean section.
Mothers who experienced PROM more than 12 h had increased risk of SSI than mothers who experienced PROM ≤12 h duration. This is possibly justified by that feto-placental membrane is one of the barrier essential for prevention or protection of ascending and iatrogenic infection of the membrane (chorioamnionitis). If this protective barrier is breached by any means, it will lose infection prevention. This can lead to ascending and iatrogenic (during per-vaginal examination) infections and will be bacteria reservoir (micro-organisms) and over growth. Unsterile membrane including the fluids which contain infection causing micro-organisms (such as bacteria) will have an access to other organs and tissues during cesarean section that can be potential source of infection after cesarean section. Supporting evidence was also reported from Egypt, India and Australia [
39,
45,
46].
The other finding from this systematic review and meta-analysis also indicated mothers who had history of labor duration more than 24 h had increased risk of developing SSI than mothers whose labor duration was ≤24 h. Supportive finding was also reported from different country wide studies from India, China, Brazil and Nigeria [
39,
41,
47,
48]. Hence, maternal early postpartum complication including infections (SSI) and exposure time where infection can be acquired increased as duration of labor increased. Beyond this, it is also the fact that prolonged labor along with increased number of vaginal examinations also increased the risk of SSI [
49]. Labor pain is the severe form of pain causing maternal fatigue and dehydration as well as prolonged vascular diminishing to reproductive tract tissue by the presenting part which make favorable condition for microbes and infection even after the procedure.
Sectional having this evidences, this systematic review and meta-analysis also identified that chorioamnionitis another risk of SSI. Mothers who were diagnosed positive for chorioamnionitis had increased risk of SSI following cesarean section than mothers who don’t diagnosed for chorioamnionitis. Consistent finding was also reported from Canada, Australia and Estonia [
38,
46,
50] . Chorioamnionitis is the inflammation of feto-placental membrane that can increase the chance of ascending or iatrogenic infection. This ascending infection can be complicated to sepsis for the both neonate and mother. This infection will affect or migrate to the sterile organs and tissues breached during cesarean section.
Moreover, anemia was also identified as medical factor which exacerbated SSI after cesarean section. Mothers who were diagnosed for anemia had increased risk of developing SSI after cesarean section than mothers who don’t diagnosed for anemia. This finding was consistent with a study conducted in Australia [
46]. Anemia is one of the hematologic disorders that negatively affect mothers’ body infection protection mechanism or immune system. Iron is essential element for proper functioning of the host immune system. Low iron level during anemia alters the function of host immune system. In addition, low hemoglobin level causes lower oxygen saturation at peripheral tissue [
51]. Delay in wound healing and low infection prevention finally leads to high risk of developing post procedure infection; SSI after cesarean section.
Once more, having history of vertical skin incision increases the risk of SSI. Mothers with history of vertical skin incision after cesarean section had increased risk of developing SSI than mothers with transverse skin incision. Comparable finding was also reported from Nepal [
52]. The potential reason may be that, having vertical skin incision is associated with involving more areas, delayed wound healing, higher risk of wound dehiscence, that will put the mothers for risk of developing SSI following the procedure [
53,
54].
In our study, a risk bias assessment showed that 7 (63.6%) studies had high quality scores and four (36.4%) had low quality scores. Representation and case-definition biases were the most commonly noted. To determine the influence of low methodological quality/high risk of bias on our estimates of pooled prevalence we estimated pooled prevalence without the low-quality studies. The confidence intervals of our estimates of pooled prevalence with and without these studies overlapped, indicating no significant difference between them. These results suggest that the majority of the primary study authors have met high quality standards. This lends credibility to our findings (Table
2).
Limitation of the study
This systematic review and meta-analysis included only articles reporting in English language, which may restrict our findings. The majority of the articles use small sample size, might be affect the prevalence estimation. All included studies were cross sectional study design in which the result might potentially affected by confounding variables. In addition the meta-analysis didn’t include all regions and administrative city which only includes four regions and one administrative city of the country. Therefore further country based studies to assess other confounding factors related to health service factors, health policy factors and health care giver related factors for the prevalent SSI in Ethiopia is recommended.
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