Predictors of surgical site infection among women following cesarean delivery in eastern Ethiopia: a prospective cohort study

Background:

Despite the availability of prophylactic antibiotics prior to skin incisions, surgical site infection (SSI) following cesarean section (CS) remains an unresolved health issue. As a result, this study aimed to assess the incidence and predictors of SSI after a CS.

Methods:

The authors conducted a prospective cohort study in eastern Ethiopia. The women were serially enrolled until the desired sample size was reached. A structured questionnaire was used to collect data. Women were followed at the hospital during their weekly visits. Culture-based microbiological methods were used to identify causal agents. A binary logistic regression model was used to identify the predictors of SSI after CS.

Results:

Among serially enrolled women, 336 were followed for 30 days. The incidence of SSI was 7.74% (95% CI: 7.68–7.80). Rupture of the membrane before operation [adjusted odds ratio (AOR)=3.75, 95% CI: 1.85–16.6], labor duration greater than 24 h (AOR=4.04, 95% CI: 1.52–10.79), and postoperative hemoglobin less than 11 g/dl (AOR=3.42, 95% CI: 1.32–8.87) were all significantly associated with SSI. The most common isolated pathogen was Staphylococcus aureus, followed by Escherichia coli.

Conclusions:

Nearly one-tenth of the women developed SSIs. Factors such as rupture of the membrane before the operation, absence of antenatal care, labor duration greater than 24 h, a midline skin incision, and postoperative hemoglobin less than 11 g/dl were the predictors of SSI. To reduce the incidence of SSI, policymakers should consider the importance of high-quality antenatal care, shorten the duration of labor, and maintain women’s hemodynamics in future SSI prevention bundles.

Introduction

Highlights

• Surgical site infection (SSI) after cesarean section is a common cause of maternal mortality and morbidity.

• In this study, the incidence of SSI was 7.74% (95% CI: 7.68–7.80).

• Staphylococcus aureus and Escherichia coli were the most common isolated pathogens.

• Strengthening antenatal follow-up and minimizing the long duration of labor can be solutions to decreasing the incidence of SSI after a cesarean section.

Surgical site infection (SSI) is an infection that occurs within 30 days of surgery and affects the skin, subcutaneous tissue, and the deep soft tissue surrounding the incision or organ/space1. Cesarean section (CS) is a surgical procedure that delivers the fetus, placenta, and membranes through an incision in the maternal abdomen and uterus2. According to a recent estimate, 22.9 million CSs are performed worldwide each year3.

Despite the fact that CS is a life-saving medical procedure for reducing unfavorable birth outcomes, various postoperative neonatal and maternal issues are difficult to control4. Though the CS is an important part of health care, infection and complications after surgery are the most difficult challenges2. SSI poses significant risks to the mother, including postpartum fever, puerperal sepsis, and maternal mortality5,6.

When compared to vaginal birth, women who had a CS had a 5-fold to 20-fold increased risk of puerperal infections7. SSIs after CS vary greatly and are more prevalent in developing countries than in developed countries8. SSI is the most common infection in Sub-Saharan Africa, affecting up to two-thirds of CS patients9. The rate of SSI after the CS in Ethiopia was 9.72%10. Evidence suggests that using an evidence-based approach that requires a multidisciplinary team approach can prevent half of the SSIs after CS11.

Despite the government’s commitment and the efforts of various stakeholders, the major risk factors for SSI continue to exist. In this regard, Ethiopia’s Health Minister adopted and implemented a SSI bundle to prevent SSI following CS. It includes preoperative, intraoperative, and postoperative care, such as glycemic control, maintaining normothermia, chlorhexidine with alcohol skin preparation, appropriate antibiotic use, avoiding unnecessary vaginal examination during labor, and a reduction in surgery duration12. Even if those standards of care were implemented, the infection rate remained unchanged. Because SSI is an ongoing challenge for the country’s healthcare system, follow-up studies are needed to identify the predictors of SSI after CS. Furthermore, infection is one of the leading causes of maternal mortality in Ethiopia. So, it needs to be investigated the causative agents as it differs from place to place. Identifying the predictors and causative agents is the one step forward to tackling the problem in the study area. Therefore, this study aimed to investigate the incidence, causative agents, and predictors of SSI among women following CS in eastern Ethiopia.

Methods and materials

Ethical approval

This prospective cohort study was done in accordance with the Declaration of Helsinki. It was approved by the Institutional Health Research Ethics Review Committee (IHRERC). Before data collection was started, informed, voluntary, written, and signed consent was taken from the respondents. For minors (under the age of 18), consent was obtained from their parents and guardians. But for those individuals without parents/guardians, we took assent from them. The IHRERC approved obtaining consent from minors that did not have parents or guardians. Any study participant willing to engage in the study and those who wanted to stop the study at any time were allowed to do so. Confidentiality was also assured.

Patient and public involvement

There is no patient or public involvement in research.

Protocol and study design

The work of this study has been reported in line with the STROCSS (strengthening the reporting of cohort, cross-sectional and case–control studies in surgery) criteria13. A prospective cohort study was carried out among women who had CSs.

Setting and time frame of the study

We conducted this study at a public hospital in eastern Ethiopia between 1 July and 30 October 2021. The hospital serves ∼232 000 clients referred by the Harari region, Dire Dawa city administration, Oromia region, and Somali region. It is an Eastern Ethiopian teaching center that also provides a variety of healthcare services. Every year, ∼4000 deliveries are attended in the hospital.

Study participants, study groups, and recruitment

The study population included all women admitted to the labor ward of the hospital who gave birth via CS. Women who had a tracing mechanism (if either the woman or her family had a phone number), a permanent address for reporting their condition, and were mentally fit to differentiate and report their status were eligible for enrollment within 24 h post-CS and were followed for 30 days to detect SSI. In contrast, women who were operated on outside of the hospital and women who died during or immediately after the surgical procedure were not eligible for enrollment.

Sample size and sampling procedures

The required sample size was determined using single population proportion formula (n=(Za/2)2p(1−p)/d ²), with the assumptions of Z=1.96 for a 95% CI, d=0.04 which is a margin of error, P=0.15 which is the rate of SSI in a study conducted in Addis Ababa Ethiopia, thus n=(1.96)2(0.15) (1−0.15)/(0.04)², n=306 by adding 10% nonresponse rate, the final sample size became 337.

Women were serially enrolled until the desired sample size was reached. During the study period, there were 401 women admitted to the hospital’s labor ward. Study participants were enrolled with inclusion and exclusion criteria as per the schematic presentation shown in Figure 1.

Figure 1.

Schematic presentation of the enrollment of study participants for surgical site infection and associated factors among women after cesarean deliveries in eastern Ethiopia.

Data collection methods

Data were collected by well-trained data collectors using a pretested, validated, and structured questionnaire that was recorded at each follow-up visit. The tools were modified and contextualized to fit the research objective after reviewing various pieces of literature10. This assessment tool includes sociodemographic variables such as age, marital status, residence, and educational status. Pregnancy and labor-related variables such as antenatal care (ANC) follow-up, parity, the onset of labor, and duration of labor were included, as well as intraoperative and postoperative variables such as types of CS, types of incision, types of skin suturing, blood loss, duration of procedures, anesthetic techniques, indication for CS, hemoglobin (Hg) level, and blood transfusion. A bacterial profile and antimicrobial susceptibility were also included in the tool. Furthermore, baseline information from the client’s medical records was extracted, including sociodemographic data, clinical data, surgical procedures, and postsurgical management.

During the inpatient stay, the wounds were inspected daily to ensure that no infection developed. The women were followed for 30 days to detect SSI, according to the Centers for Disease Control and Prevention. Patients were followed at their weekly visits to the hospital. Patients who failed to appear on time were contacted by phone number to determine whether they had SSI or not. After five unsuccessful phone calls during the follow-up period, a patient was considered lost to follow-up14.

Blood specimen collection and Hg determination

Four milliliters of venous blood (2 ml preoperative and 2 ml postoperative) were collected into an EDTA test tube from each study participant by Medical Laboratory Science professionals. Hemoglobin concentration was determined using UniCel DxH 800 (Beckman Coulter, USA) automated hematology analyzer by spectrophotometry method15. Hemoglobin concentration was analyzed at the hospital hematology laboratory and recorded for each study participant using a laboratory result registration form.

Wound specimen collection

The area around the surgical site was cleaned with normal saline to reduce contamination. Wound samples were collected by wound swab, Levine technique, and Z technique using sterile cotton swabs, needle aspiration, and wound biopsy depending on the type of wound. Wound exudate was collected before wound irrigation during wiping. Wound exudate was collected after wound irrigation using Levine Technology and Z technique16.

A cotton swab containing samples was placed in a test tube containing Amies medium with a semisolid tip and transported to the Institute of Microbiology. Samples are inoculated into blood agar (BAP) (Oxoid), MacConkey agar (Mac) (Oxoid), and Mannitol salt agar (MSA) (Oxoid Plates incubated aerobically at 37°C overnight. Bacterial identification was done using standard microbiology lab guidelines16.

A drug susceptibility test was performed following the Kirby Bauer disk diffusion technique. Isolates were tested for ampicillin (10 µg), ceftriaxone (30 µg), trimethoprim–sulfamethoxazole (23.75 µg), ciprofloxacin (5 µg), gentamicin (10 µg), cefoxitin (30 µg), cefepime (30 µg), chloramphenicol (30 µg), amikacin (10 µg), ceftazidime (30 µg), aztreonam (30 µg), and doxycycline (30 µg).

Operational definitions

SSI

It was diagnosed if it involves the skin and subcutaneous tissue at the surgical site with any one of the following: purulent discharge or organisms isolated from fluid/tissues of a superficial incision or at least one sign of inflammation (pain, fever, localized swelling, induration, dehiscence, overlying skin changes, and exudative purulent discharge) or wound deliberately opened by the surgeon for drainage or surgeon declares that the wound is infected17. Those who developed SSI during the 30-day follow-up period were classified as having SSI, while those who did not develop SSI during the follow-up period were classified as not having SSI.

Anemia

Anemia was diagnosed when the level of Hg was less than 11 g/dl18.

Duration of membrane rupture

The time lapsed in hours from either mother complaining of leakage of liquor or artificial rupture of the membrane to skin incision19.

Duration of labor

Time lapsed in hours from the mother’s complaint of symptoms of true labor to the skin incision20.

Duration of operation

Time lapsed in hours from skin incision to skin closure21.

Estimated blood loss

It is determined by the amount of blood accumulated via suction plus the number of packs and gauze used during the time of operation multiplied by the estimated absorbable amount of blood by a single pack (1 soaked pack=100 ml) and gauze (1 soaked gauze=20 ml of blood), respectively.

Statistical analysis

The data were coded, edited, cleaned, and entered into EpiData statistical software version 3.1 and then exported to SPSS version 20 for analysis. A descriptive statistical analysis was used to summarize the data. The information was presented using frequencies, tables, and figures.

Bivariable analysis and multivariable analysis were done to observe the association between independent variables and the outcome variable by using binary logistic regression. All variables with P 0.25 or less in the bivariate analysis were included in the final model of multivariate analysis to control all possible confounders. The model goodness-of-fit was tested by the Hosmer–Lemeshow statistic and Omnibus test. The model was considered a good fit since it was found to be insignificant for the Hosmer–Lemeshow statistic (P=0.81) and significant for Omnibus tests (P=0.000). The multicolinearity test was carried out to observe the correlation between independent variables using VIF and standard error; no variables were observed with VIF (variance inflation factor) of greater than 10 and standard error greater than 2. The direction and strength of statistical association were measured by the odds ratio with 95% CI. The adjusted odds ratio (AOR) along with 95% CI was estimated to identify predictors of SSI by using multivariate analysis in the binary logistic regression. In this study, P value less than 0.05 was considered to declare a result as a statistically significant association.

Result

Sociodemographic characteristics of participants

Among serially enrolled women, 336 were traced for 30 days and reserved for further analysis. The study participants ranged in age from 18 to 40 years, with a mean (±SD) age of 26.76±5.27 years. Around 72.4% (243) of them attended primary and above education (Table 1).

Table 1.

Sociodemographic characteristics of the women who underwent cesarean section at a public hospital, Harar, eastern Ethiopia 2021 (N=336)

Variable	Category	Frequency, N (%)
Age	≤19	21 (6.3)
	20–34	283 (84.2)
	≥35	32 (9.5)
Residence	Urban	122 (36.4)
	Rural	214 (63.6)
Religion	Muslim	264 (78.6)
	Orthodox	51 (15.2)
	Protestant	21 (6.2)
Ethnicity	Oromo	272 (81)
	Amhara	36 (10.7)
	Harare	16 (4.8)
	Others	12 (3.6)
Educational level	Unable to read and write	93 (27.7)
	Primary education	157 (46.8)
	Secondary and above	86 (25.6)

Preoperative-related characteristics

In terms of health, ∼34.8% (117) of study participants had preexisting anemia, 2.1% had diabetic cases, and 0.6% had chronic hypertension. Two hundred sixty-five (78.9%) of them had ANC follow-ups. Around 9.2%22 of study participants were diagnosed with pregnancy-induced hypertension. In terms of labor status, 80.4% (271) of the women had labor before the operation, and 73.5% (246) had spontaneous onset of labor (Table 2).

Table 2.

Preoperative-related characteristics of the women who underwent cesarean section at a public hospital, Harar, eastern Ethiopia 2021 (N=336)

Variable	Category	Frequency, N (%)
Parity	1	89 (26.5)
	2–4	195 (58)
	≥5	52 (15.5)
ANC visits	Yes	265(78.9)
	No	71 (21.1)
Anemia	Yes	117 (34.8)
	No	219 (65.2)
PIHTN	Yes	31 (9.2)
	No	305 (90.8)
GDM/DM	Yes	7 (2.1)
	No	329 (97.9)
Gestational age	<37	41 (12.2)
	37–41	289 (86)
	>41	6 (1.8)
Labor before the operation	No labor	65 (19.4)
	Labor <24 h	197 (58.6)
	Labor ≥24 h	74 (22)
Vaginal examination	No	66 (19.7)
	Yes <5	203 (60.4)
	Yes ≥5	67 (19.9)
Status of membrane	Intact	240 (71.4)
	Ruptured ≤12	81 (24.1)
	Ruptured >12	15 (4.5)
Chorioamnionitis	Yes	3 (0.9)
	No	333 (99.1)

ANC, antenatal care; GDM, gestational diabetes mellitus; PIHTN, pregnancy-induced hypertension.

Intraoperation and postoperation-related variables

Around 33.9% of operations were emergency CSs, with previous CS scars accounting for 22.9% (Fig. 2). All participants received prophylaxis, with 90% receiving 1 g ceftriaxone and the remainder receiving 2 g ampicillin for the same purpose, one dose preoperatively and 24 h postoperatively. All study participants had their skin prepared for a CS with alcohol and iodine. For 79.8% of operations, the abdomen was entered through a Pfannenstiel incision, while 21.2% of the incisions were midline incisions. A subcuticular suture was used to close the skin in 99.1% of the cases (Table 3).

Figure 2.

Indication for the cesarean section of study participants at a public hospital in eastern Ethiopia, 2021 (N=336).

Table 3.

Intraoperation and postoperation-related characteristics of the women who underwent cesarean section at a public hospital, Harar, eastern Ethiopia 2021 (N=336)

Variable	Category	Frequency, N (%)
Type of cesarean delivery	Emergency	114 (33.9)
	Elective	222 (66.1)
Prophylaxis antibiotics given	Yes	336 (100)
Skin incision	Pfannenstiel	265 (78.9)
	Midline	71 (21.1)
Procedure duration	<1 h	246 (73.2)
	≥1 h	90 (26.8)
Estimated blood loss	<1000 ml	250 (74.4)
	≥1000 ml	86 (25.6)
Intraoperation transfusion	Yes	9 (2.7)
	No	327 (97.3)
Skin closure	Subcuticular	333 (99.1)
	Interrupted	3 (0.9)
Qualification of surgeon	Senior	18 (5.3)
	Year 4-Res	91 (27.1)
	Year 3-Res	137 (40.8)
	Year 2-Res	86 (25.6)
	Year 1-Res	4 (1.2)

Res, residents.

Incidence of SSI

The rate of SSI was 7.74% (95% CI: 7.68–7.80). Eight of them were identified before discharge, while the remaining 18 were tracked down through follow-up and readmission. Three cases had deep SSIs, four cases had organ space, and the remaining 19 (73.1%) cases had superficial incisional wound infections.

Cases were treated daily with incision, drainage, and wound dressing. Antibiotics were administered based on the antibiogram, and wounds were left to close by secondary intention or as determined by the attending physician.

Bacteriological profile

After the wound infection was diagnosed, 19 wound specimens were collected from all study participants who had SSIs. There were 13 pathogenic bacteria isolated from these suspected clinical specimens. The infections were all caused by a single bacterial isolate. The vast majority of them (53.8%) were Gram-positive bacterial agents. The microbiological profile revealed that Staphylococcus aureus was the most frequently isolated pathogen in 26.3% (n=5), followed by Escherichia coli in 15.8% (n=3), Streptococcus pyrogens in 10.5% (n=2), and Proteus mirabilis, Klebsiella spp, and Aeromonas spp isolated in 5.3% (n=1). There were six cases (31.5% of clinical infections) with negative culture, and the remaining cases (26.9%, n=7) where culture was not taken for various reasons (Table 4).

Table 4.

Microbiological profile of surgical site infection after cesarean among women who underwent cesarean section at a public hospital, Harar, eastern Ethiopia 2021 (N=26)

Wound swab – bacteriological profile	Count	Percent (%)
Staphylococcus aureus	5	26.3
Escherichia coli	3	15.8
Proteus mirabilis	1	5.3
Klebsiella spp.	1	5.3
Streptococcus pyogenes	2	10.5
Aeromonas spp.	1	5.3
Negative culture	6	31.5
Total	19	100

Antibacterial susceptibility pattern

The majority of SSI isolates were resistant to commonly used antibiotics, including ampicillin (80%), ceftriaxone (60%), and trimethoprim–sulfamethoxazole (50%). Similarly, E. coli was completely resistant to ampicillin (100%), ciprofloxacin (100%), trimethoprim–sulfamethoxazole (50%), gentamicin (66.7%), and cefoxitin (33.3%). Multidrug resistance was found in all bacterial isolates from the SSI sample. Furthermore, S. pyogenes was 100% resistant to ampicillin, 50% resistant to trimethoprim–sulfamethoxazole, and 50% resistant to cefepime (Table 5).

Table 5.

Antimicrobial resistance profiles of surgical site infection after cesarean of the women who underwent cesarean section at a public hospital, Harar, eastern Ethiopia 2021 (N=26)

	Staphylococcus aureus		Escherichia coli		Streptococcus pyogenes		Proteus mirabilis		Aeromonas spp.
Antimicrobials	#T	R%	#T	R%	#T	R%	#T	R%	#T	R%
Ampicillin	5	80	3	100	2	100	1	100	1	100
Gentamicin	5	60	3	66.7	2	100	1	0	1	100
Ceftriaxone	5	60	2	100	2	ND	1	100	1	100
Ciprofloxacin	5	100	3	100	2	50	1	100	1	100
Chloramphenicol	4	50	2	50	2	50	1	ND	1	ND
Cotrimoxazole	5	40	3	66.7	2	100	1	0	1	100
Amikacin	5	40	3	25	2	50	1	0	1	100
Ceftazidime	5	60	2	100	2	50	1	0	1	100
Aztreonam	4	50	2	100	2	50	1	0	1	100
Cefepime	5	60	3	100	2	50	1	0	1	0
Cefoxitin	5	40	3	33.3	2	0	1	0	1	100
Doxycycline	5	ND	3	ND	2	ND	1	ND	1	0

ND, not defined; R, resistance; T, total.

Predictors of SSI

In a bivariate logistic regression analysis, SSI was predicted by operation after the onset of labor, absence of ANC follow-up, operation after rupturing of the membrane, multiple digital vaginal examinations, midline skin incision, and postoperative Hg of less than 11 g/dl.

Mothers who were in labor for more than 24 h before CS were 4.04 times more likely to develop SSIs than those who were in labor for less than 24 h (AOR=4.04; 95% CI: 1.52–10.79, P=0.004). The risk of developing SSIs was 3.75 times higher in patients who had ruptured membranes before CS (AOR=3.75, 95% CI: (1.85–16.6, P=0.03). Mothers who had midline abdominal incisions were 3.76 times more likely to develop SSIs as compared with Pfannenstiel abdominal incision (AOR=3.76, 95% CI: 1.47–9.58, P=0.001). The risk of developing SSI was 3.42 and 3.65 times higher among women who had postoperative anemia (AOR=3.42, 95% CI: 1.32–8.87, P=0.002) and no ANC follow-up (AOR=3.65, 95% CI: 1.42–9.37, P=0.001were found to be significantly associated with SSI (Table 6).

Table 6.

Predictors of surgical site infection among women who underwent cesarean section at a public hospital, Harar, eastern Ethiopia 2021 (N=336)

		SSI
Variable	Category	Yes	No	COR (95% CI)	AOR (95% CI)	P
Antenatal follow-up	No	13	58	4.34 (1.91–9.87)	3.65 (1.42–9.37)*	0.001
	Yes	13	252	1	1
Membrane status	Ruptured	15	81	3.87 (1.14–13.19)	3.75 (1.85–16.6)*	0.03
	Intact	11	229	1	1
Labor status	<24 h	13	247	1	1
	≥24 h	13	62	3.52 (1.14–13.19)	4.04 (1.52–10.79)*	0.004
Frequency of vaginal examination	<5	13	256	1	1	0.002
	≥5	13	54	4.20 (1.78–9.91)	4.77 (1.87–12.74)*
Types of CS	Emergency	17	97	4.15 (0.96–18.06)	2.03 (0.34–11.94)	0.43
	Elective	9	213	1
Skin incision	Midline	12	59	3.65 (1.60–8.29)	3.76 (1.47–9.58)*	0.001
	Pfannenstiel	14	251	1	1
Duration of operation	<1 h	12	234	1	1
	≥1 h	14	76	3.59 (1.59–8.10)	1.69 (0.63–4.56)
Estimated blood loss	<1000 ml	15	235	1	1
	≥1000 ml	11	75	2.30 (1.01–5.22)	1.56 (0.59–4.07)	0.367
Postoperative Hg level	<11 g/dl	17	101	3.92 (1.68–9.07)	3.42 (1.32–8.87)*	0.002
	≥11 g/dl	9	209	1	1

^*Significant with P<0.05, CI.

AOR, adjusted odds ratio; COR, crude odds ratio; CS, cesarean section; Hg, hemoglobin.

Discussion

This study assessed the rate of SSI and its predictors after CS. Furthermore, the common bacteriological profile and antibiotic susceptibility were also identified.

The study revealed that the rate of SSI was 7.74%. The finding was high compared with studies done in Nanjing at 3.34%23, southern India at 4.1%24, Israel at 3.7%25, and Rwanda at 4.9%26. These disparities could be attributed to differences in the quality of surgical care provision, with the latter assumed to provide high-quality care. Another explanation could be the difference in the study setting and follow-up duration. As a result, the quality of surgical care provided varies because high-income and middle-income countries are expected to provide high-quality service. Furthermore, this study is a follow-up study that can detect the effect of the exposure; thus, the incidence of SSI might be higher than in those studies. This finding implied that policymakers and different stakeholders should consider improving the quality of care in decreasing the incidence of SSIs.

On the contrary, the incidence of SSI was lower than in studies done in Debre Markos, Ethiopia, 25.4%21, Addis Ababa, Ethiopia, 15%14, and Ethiopia, 9.72%10. Nepal at 12.6%27, Karachi at 24.3%28, India at 13%29, and Nnewi, Nigeria at 12.5%30. These disparities may be due to differences in sample size and study duration. Another possible explanation is that Karachi women have a high prevalence of obesity and diabetes, which may have contributed to the increased SSI rate. Furthermore, 45 (13.4%) of the participants in this study were lost. This could contribute to the lower SSI incidence.

In this study, midline skin incision operations were about three times more likely to develop SSI than Pfannenstiel incision operations. This finding is inconsistent with the studies done in Nepal27, Nigeria30, Tanzania31, Assela, Ethiopia22, and Maichew, Ethiopia20. The most likely explanation is that intra-abdominal pressure affects vertical incisions, resulting in poor skin integrity and the entry of microorganisms that cause SSI. Furthermore, vertical incisions have lower perfusion of gases and nutrients than transverse incisions, delaying healing and increasing the risk of SSI32. Furthermore, a midline skin incision is recommended for patients with a complicated case, which in turn plays a role in which a confounding variable is prominently displayed.

This finding revealed that the absence of ANC predicted SSI. This is consistent with a study done in Jima, Ethiopia33. The possible explanation may be the absence of antenatal follow-up associated with the lack of getting appropriate prevention, screening, and management of maternal infections during pregnancy, which contributes to SSI after CS. Furthermore, women who had not had ANC misses information regarding infection prevention standard and additional precautions during the provision of routine ANC to pregnant women. This implied that ANC should be incorporated into the future SSI prevention bundle.

This finding indicated that a postoperative Hg level of less than 11 g/dl was a significant predictor of SSI after CS. Mothers with postoperative Hg levels less than 11 g/dl were about 3.5 times more likely to develop SSI than mothers with Hg levels at least 11 g/dl. This is in harmony with studies conducted in Thailand34, Oman35, and Hawassa36. The possible explanation might be due to hypoperfusion of the wound as a result of anemia and restricted postoperative ambulation are two factors that may contribute to the development of SSI after CS.

According to this study, women who had a CS after the rupture of the membrane were four times more likely to develop a SSI than those who had not. This finding is consistent with the study conducted in Mekelle, Ethiopia, and Nigeria30,37. The fetal membrane has the potential to act as an infection barrier. When the fetal membrane is ruptured prematurely, it loses its protective function, allowing germs to easily enter the surgical site. As a result, the mother is vulnerable to SSIs. This conclusion was supported by research conducted in Brazil, China, Nepal, and Sub-Saharan Africa27,38–40. This finding suggested that treating a prolonged rupture of the membrane as soon as possible could reduce the risk of SSI.

This study also found that having prolonged labor before surgery was a predictor of SSI after CS. Women who had experienced prolonged labor were four times more likely to develop SSIs than their counterparts. This association between labor duration and SSI could be explained by increased exposure time, which increases the risk of infection, as well as the fact that the frequency of vaginal examinations increases as labor duration increases. Studies in Brazil, China, and Tanzania27,38–40 found a substantial link between SSI and frequent vaginal examinations.

In this study, the bacteriological profile of patients with SSI revealed a predominance of microflora, primarily S. aureus (19.2%) and E. coli (11.6%). S. aureus was found in 28.1% of positive samples after cesarean birth, according to a study conducted at Kosovo’s University Clinical Center41. The finding from this study is congruent with the study conducted in Gondar42, which found that S. aureus (41.6%) and E. coli (19.8%) are the most common infections that cause SSI. The fact that the infected people had cesarean deliveries, which favors diverse bacterial colonization, particularly S. aureus, which lives on skin surfaces, could be the reason for their predominance. Nearly all the pathogens identified were resistant to the prophylactic antibiotics used. This is supported by findings from Ethiopia which showed that S. aureus and. E. coli were antimicrobial resistants43. This may contribute to the high burden of SSIs.

Strength and limitation

One limitation of the current study is that a significant number of participants were lost, which may have influenced the results. This study did not include maternal factors such as nutrition, which could have influenced the findings. This study did not consider preoperative Hg. Thus, the risk factor could be anemia antenatally, high blood loss, or a combination of both. Some of these limitations would be addressed more thoroughly in a larger cohort study. Due to limited laboratory resources, only aerobic agents were cultured. Conducting a follow-up study is the strength of this study.

Conclusions

Nearly one-tenth of the study participants developed SSIs after CS in eastern Ethiopia. The absence of ANC follow-up, prolonged labor, rupture of membranes, frequent digital vaginal examinations, midline skin incision, and postoperative anemia were predicted SSIs after CS. The most common pathogen isolated in clinical samples were S. aureus and E. coli. To reduce the incidence of SSI, policymakers should consider incorporating the importance of improving ANC, shortening labor, maintaining the quality of care, and maintaining women’s hemodynamics in the future surgical site bundle.

Ethics approval and consent to participate

Ethical clearance was taken from the Institutional Health Research Ethics Review Committee (IHRERC) of the College of Health and Medical Sciences of Haramaya University. In addition, permission to proceed was obtained from all public hospitals. And also, informed voluntary written and signed consent was obtained from each participant.

Consent for publication

Not applicable.

Source of funding

The funder (Haramaya University) has no role in the design of the study, collection, analysis, and interpretation of data and in writing the manuscript.

Author contribution

A.A.: participated in the conception of the study, design of the study, data collection, statistical analysis, data interpretation, and drafted the manuscript; L.G., T.T., A.E., M.A., S.T., T.G., A.D., E.Y., L.A., and M.D.: participated in the design of the study, data analysis, interpretation, and drafting of the manuscript. All authors have agreed on approval of the final manuscript and are accountable for all aspects of the work.

Conflicts of interest disclosure

The authors declare that there are no conflicts of interest.

Data availability statement

All relevant data are included in this study. However, additional data will be available from the corresponding author upon reasonable request.

Provenance and peer review

Not commissioned, externally peer-reviewed.