The incidence of and factors associated with wound infection among post caesarean section mothers in Mulago Hospital

Abstract

INTRODUCTION: Caesarean section is a common operation in obstetrics practice. Although, life saving for both mother and infant, caesarean section poses a documented medical risk to the mother’s health including wound infections, haemorrhage, injury to the organs, thrombosis, phychological complications and maternal mortality. Wound infection rates as high as 27.1% have been reported in Africa. Wound infections are a major problem on obstetric and gynaecological surgery, especially following caesarean section. They are painful to the patient and costly to society. OBJECTIVES: The objectives of this study were to determine the incidence of wound infection among caesarean section mothers in mu7lago hospital, to identify the risk factors for wound infection among caesarean section mothers in mulago hospital and to identify micro-organisms responsible for wound infection and their patterns of antibiotic sensitivity. METHODOLOGY: This was a prognostic cohort study. The exposure of interest was caesarean section and the outcome was wound infection. All the mothers who underwent caesarean section and consented to participate in the study were consecutively recruited into the study until a sample size of 303 participants was attained. All patients had a pre and post test HIV counseling. Information was obtained from the mother, the case notes and from the attending surgeon by the principal investigator and 6 researcher assistants (midwives) with counseling skills. The research assistants and the principal investigator inquired about the condition of wounds twice daily from the mothers. Presence of pus from the wound was an indication of wound infection. Wounds deemed infected were aseptically cleaned at the margins and a sterile swab taken for culture and sensitivity. Results from microbiology were given to the attending surgeon for appropriate antibiotic treatment. DATA ANALYSIS AND MANAGEMENT Data was cleaned and edited using EPI-INFO version 6.4 and analyzed by the SPSS software package version 10. Frequency o wound infection per 100 caesarean sections was calculated. For continuous variables, the frequency distribution, the mean, standard deviation and range was calculated. Independent t test was used to assess associations between the continuous variables and wound infection. For the categorical variables, the data was presented in frequency tables and proportions. The chi-squared test was used to assess associations between the categorical variables and wound infection. A stepwise logistic regression model was used to identify the risk factors independently associated with wound infection while controlling for other variables included in the model. Confidence intervals of 95% for proportions and means were calculated. All levels of statistical significance were established at p<0.05 RESULTS: The incidence of wound infection among a cohort of 303 mothers who underwent caesarean section was 14.5%. The risk factors identified for wound infection were longer time of operation (p=0.007), obstructed labor (p=0.003) and poor progress of labor (p=0.012). The predominant micro-organisms identified were staphylococcus aureus and E. coli. Both these organisms were resistant to commonly used antibiotics such as tetracycline, chloramphenicol, cotrimoxazole, cloxacillin, amoxicillin, augmentin and gentamicin. CONCLUSION: In mulago hospital, 1 in 7 of the mothers who deliver by caesarean section develops wound infection. Factors independently associated with wound infection include obstructed labour and prolonged surgical procedure. The commonest pathogens isolated were staphylococcus aureus and E. coli. Most of these pathogens are resistant to commonly used antibiotics such as cotrimoxazole and chloramphenicol; and are partially sensitive to gentamicin, oflaxacillin, ceftriaxazole, augmentin, amoxycilin and erythromycin. Meropenem seems to remain the only drug with almost 100% sensitivity. RECOMMENDATIONS: To reduce the wound infection rate in mulago hospital, there is need to address factors contributing to obstructured labour and devise ways of expediting surgical procedures. An antibiotic policy should be developed to give proper guidelines on the use of antibiotics in patients with post caesarean section wound infection. There will be need for a study exploring the possible contribution of wound skin preparation and nursing procedures in the causation of post caesarean wound infection.