|Year : 2017 | Volume
| Issue : 1 | Page : 12-17
Prevalence of surgical site infections and antimicrobial sensitivity pattern in patients attending a Tertiary Care Hospital in South India: A prospective study
Giridharan Shanmugam1, Selvi Rangam1, KK Kayalvili1, Lakshmi Sundaram2
1 Department of Microbiology, Government Stanley Medical College, Tamil Nadu Dr. M. G. R. Medical University, Chennai, Tamil Nadu, India
2 Department of Microbiology, Government Stanley Medical College, Tamil Nadu Dr. M. G. R. Medical University; Anna University, Chennai, Tamil Nadu, India
|Date of Web Publication||18-Aug-2017|
26, Geetha Villa, Thulukanathamman Koil Street, Kottur, Chennai - 600 085, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Background: Nosocomial infections account for 1.7 million cases every year costing between $35.7 billion and $45 billion of losses to the system and surgical site infections (SSIs) were responsible for 77' of the death of patients. This study aims to analyse the factors involved and thereby reduce them.
Materials and Methods: Ninety-six patients undergoing both emergency and elective procedures in the surgery department during a period of 1 month were selected and followed up pre-operatively, intraoperatively, post-operatively and till 30 days after surgery.
Results: The prevalence rate of SSI was 41.6' with women (52') and patients of the age group of 41–60 years (30') being affected more. Alcohol, smoking, tobacco use, diabetes, hypertension, tuberculosis, duration of surgery hospital stay and the American Society of Anesthesiologists classification proved to be important factors in the prevalence rate. Emergency surgeries had twice the rate than electives. Staphylococcus aureus (22') and Escherichia coli (22') followed by Pseudomonas aeruginosa (18') and Proteus mirabilis (17') were the organisms isolated. All S. aureus isolates were methicillin sensitive but erythromycin resistant. E. coli isolates were sensitive to the antibiotics except for cefotaxime and ampicillin (41.6'). Pseudomonas showed resistance to bacitracin (80') and ampicillin (90'), and all were sensitive to ceftazidime. The Proteus species were all resistant to cefotaxime.
Conclusion: The high prevalence rate in the study can be reduced by following a systematic approach during pre-operative workup of the patient with proper pre-operative hair removal and smoking cessation at least 1 month before surgery and post-operative monitoring and educating the patient.
Keywords: Antimicrobial sensitivity, hospital acquired infections, nosocomial infections, surgery, surgical site infections
|How to cite this article:|
Shanmugam G, Rangam S, Kayalvili K K, Sundaram L. Prevalence of surgical site infections and antimicrobial sensitivity pattern in patients attending a Tertiary Care Hospital in South India: A prospective study. J Patient Saf Infect Control 2017;5:12-7
|How to cite this URL:|
Shanmugam G, Rangam S, Kayalvili K K, Sundaram L. Prevalence of surgical site infections and antimicrobial sensitivity pattern in patients attending a Tertiary Care Hospital in South India: A prospective study. J Patient Saf Infect Control [serial online] 2017 [cited 2019 Jun 18];5:12-7. Available from: http://www.jpsiconline.com/text.asp?2017/5/1/12/213288
| Introduction|| |
Nosocomial infections are defined as hospital-acquired infections (HAIs) which were not present or incubating at the time of admission for a patient who was admitted for a reason other than that infection. It also includes infections appearing after discharge (for surgical site infection [SSI], a period of 30 days and for prosthesis and implants, 1 year). More than 1.7 million people suffer from nosocomial infections at any given time in the USA alone. The number could be far more in a developing country like India. It is a serious burden to both the patients as well as the healthcare system. The overall cost of HAI in hospitals in the USA ranges between $35.7 billion and $45 billion, and the benefits of prevention range from $25 billion to $31.5 billion as 70% can be prevented with adequate precautions and protocols. Nosocomial infections include SSIs, urinary tract infections (UTI), lower respiratory tract infections and blood stream infections. SSIs were one of the most common HAIs along with UTI and bloodstream infections.,,,,,,,
With the already overburdened public healthcare system in India and understaffed medical field, these infections increase the expenditure and workload of hospitals. They increase the health costs and also cause loss of productivity and discomfort to the patients. Nosocomial infections are also associated with drug-resistant strains of bacteria. 16% of all HAIs were associated with multidrug-resistant pathogens. The most common include methicillin-resistant Staphylococcus aureus (8%), vancomycin-resistant Enterococcus faecium (4%), carbapenem-resistant Pseudomonas aeruginosa (2%) and extended-spectrum cephalosporin-resistant Klebsiella pneumoniae (1%). The Centers for Disease Control (CDC) and the WHO have bought out Guidelines for the prevention of nosocomial infections and the CDC established the National Nosocomial Infection Surveillance programme which shows a decrease in nosocomial infections in developed countries., Whereas in India, in spite of the advancements in medical technology and awareness among healthcare professionals regarding nosocomial infections, they continue to occur due to poor patient compliance, immune-compromised state of patients, transmission of drug-resistant pathogens, unhygienic environment and increased workload of the hospitals.
Risk factors for SSIs include pre-operative hand washing, skin preparation, hair removal, prophylactic antibiotics, surgical site and duration of operation. For example, limb amputations had the highest risk of developing SSI's followed by complex hepato-pancreatico-biliary surgery (11.3-fold increase) and small bowel surgery (10.1-fold increase). Patients who did not receive antimicrobial prophylaxis had a greater incidence if infections (19%) than those who received (6%). Diabetes, smoking, alcoholism, use of immunosuppressive drugs, anaemia, age and poor nutritional status are some of the other factors. The maximum numbers of SSI's for abdominal surgery were in the age group of 41–60 years (38%) followed by 21–40 years (37.5%). Diabetes mellitus (20%) was the major risk factor in cases of SSI, followed by smoking (8.3%) and alcohol (5.4%). SSIs were also common in patients having a pre-existing illness such as malignancy (5%) and others (14.29%).
Previous studies on this subject have mostly focused on the above factors causing nosocomial infections. This study has included most of the variables that would have a bearing on the occurrence of the infection. It aims to explore the relationship between patient's age, gender, socioeconomic status, level of literacy, nutrition, personal habits and history of illness with the pattern of infections. It integrates the surgical, epidemiological and microbiological aspects to present a comprehensive outlook. Nosocomial infections can easily be prevented by following some simple steps and effective protocols. With increase in virulence and drug resistance among organisms causing nosocomial infections, currently, the need of the hour is to identify the aetiology of HAIs and further reduce their prevalence and incidence.
| Materials and Methods|| |
A total of ninety-six patients who were admitted to the wards of the General Surgery Department during a period of 1 month were selected for finding the period prevalence rate. Informed consent and the data for the questionnaire were obtained from the patients. It contained questions on the demographic data of the respondents, socioeconomic status, personal habits, a history of previous illnesses such as diabetes mellitus, hypertension, tuberculosis, jaundice and anaemia and operative data. A checklist was also drawn up to indicate whether all precautions were followed and to confirm that the infection was indeed nosocomial. The patients were assessed pre-operatively, intraoperatively and post-operatively. Pre-operatively hair removal using hair clippers, antimicrobial prophylaxis, blood glycaemic control, smoking cessation for 30 days, normothermia monitoring for colorectal surgery and blood loss risk was assessed. Intraoperatively surgical site disinfection, equipment sterilisation, dead space drainage, preparedness for critical procedure and hand hygiene of surgeons were checked.
The swabs were collected from the surgical site after a minimum of 24 h post-operatively and thereafter. The samples were collected in sterilised cotton swabs and immediately transported to the laboratory for processing. The organisms were identified by Gram staining and biochemical reactions. Antimicrobial sensitivity testing was done by Kirby–Bauer disk diffusion method using Mueller-Hinton agar. Extended-spectrum beta-lactamases (ESBL) producing organisms were identified using double-disk diffusion method. Wound infection was fulfilled if any one of the following criteria was fulfiled: serous or non-purulent discharge from the wound, pus discharge from the wound, signs of inflammation (oedema, redness, warmth, raised local temperature, fever >38°C, tenderness, induration) and wound deliberately opened up by the surgeon due to localized collection of serous/purulent material and based on the CDC (USA) guidelines. The patients were monitored till discharge from the hospital and were reviewed for 30 days from the date of operation. The data collected was entered in the Microsoft Excel computer programme and checked for any inconsistency. The socioeconomic profile of the patients was calculated using Kuppuswamy modified scale Ravi Kumar et al. The results are presented in proportions/percentages. Mean, standard deviation, percentage and coefficient of variation calculations were calculated. The data were analysed using IBM SPSS (version 21) (IBM) computer programme. Detailed analysis of subgroups was done and relationship between subgroups was determined.
| Results|| |
Out of 96 patients selected for this study, a total prevalence rate of 41.67% was reported in both elective and emergency procedures.
By age, the average age of the study group was 41 years. The most affected was the 41–50 years age group (30%) followed by the 61–80 years (25%). The younger age group of 14–30 years was relatively less affected (10%) [Figure 1].
There was a linear increase in prevalence when compared to socioeconomic status with those belonging to low socioeconomic status having higher SSI rate [Figure 2].
Patient factors such as diet, alcohol, smoking, tobacco, diabetes, hypertension, tuberculosis and a history of previous illnesses like anaemia contributed to the rate, which are depicted in [Figure 3], [Figure 4], [Figure 5], [Figure 6] and [Table 1].
Among the operative factors, the American Society of Anesthesiologists physical status classification and duration of operation played an important role. Infected patients had an average hospital stay of 15 days compared to non-infected patients with only 8.5 days. Similarly, post-operative stay was twice as high for patients with SSI (9.4 days) than those without SSIs (4.3 days) [Figure 7].
Of the forty patients who were positive 14 (35%) had polymicrobial isolates.
Antimicrobial sensitivity pattern showed that all S. aureus were methicillin sensitive but erythromycin resistant and only 1 was vancomycin resistant. A total of 11 were bacitracin resistant and 9 were ampicillin resistant. Most Escherichia coli isolates were sensitive to the antibiotics except for cefotaxime and ampicillin (41.6%). Pseudomonas showed resistance to bacitracin (80%) and ampicillin (90%) and all were sensitive to ceftazidime. Coagulase-negative S. aureus also showed resistance to ampicillin (87.5%). The Proteus species were all resistant to cefotaxime and Proteus vulgaris to ceftazidime. A total of 1 E. coli, 1 Proteus mirabilis and 3 Proteus vulgaris were found to be ESBL producing.
Swabbing of the wards was done. The beds, linen, bedside table, floors, walls, instruments and materials used for wound dressing were checked. P. aeruginosa was found in the instruments used. Air sampling was also done, but no significant organism was detected.
| Discussion|| |
The prevalence rate of our study correlated with the one done by Umesh S. et al. (30.7%). The higher prevalence among females [Figure 1] can be attributed to the reduced pre-operative hair removal. Analysis of the data revealed that only 21% of all the females had complete pre-operative shaving compared to 97% of the males. Nearly 81% of the patients did not have proper pre-operative hair removal. However, Anusha et al. observed a higher prevalence in males, and in that study, the highest rate was recorded in the 41–50 age groups, which was similar to ours. Of the patients with a habit of smoking [Figure 2], 87.5% did not stop smoking even 24 h before the operation which lead to a 62.5% prevalence in smokers. Diabetic and tobacco consumers [Figure 3] are at an increased risk of developing nosocomial infections due to their immune-compromised state. Since surgery, being a stress, leads to increased secretion of glucocorticoids that can suppress immunity.
Sharan et al. also reported an increased rate in emergency surgeries [Figure 4] because they are done under a very narrow time span without proper patient preparation and surgical preparedness. Lilani et al. had similar observations of the infection rate increasing during longer operative period [Figure 5] and post-operative stay. He observed a four-fold increase compared to a two-fold increase in this study. Further evaluation is required to determine if prolonged hospital stay caused the SSI or if the SSI led to an increase in post-operative stay. S. aureus was seen to be the most common isolate in multiple studies [Figure 7]. E. coli and P. aeruginosa followed it. In this study, hernioplasty operations were frequently contaminated by S. aureus (57.1%) and E. coli were found mainly in laparotomies (42.8%), indicating that a normal intestinal commensal had turned into a pathogen. P. mirabilis was frequently associated with wound debridement (80%). All three infected varicose vein operations had P. aeruginosa.
The standard antimicrobial prophylaxis given for the patients included cefotaxime pre-operatively (1 h before surgery) and cefotaxime, gentamicin, amikacin and bacitracin post-operatively. However, significantly 91.67% of S. aureus and 80% of Pseudomonas were resistant to bacitracin. All 9 Proteus mirabilis and all 3 Proteus vulgaris isolates were resistant to cefotaxime. However, most of the organisms were sensitive to gentamycin and amikacin. The use of broad-spectrum antibiotics may further lead to the development of multidrug-resistant organisms. For example, all three varicose vein stripping operations involved infection with P. aeruginosa. Giving a cephalosporin, as a prophylactic drug, to those patients will serve no use.
| Conclusion|| |
Nosocomial infections can easily be prevented by determination of the aetiology, analysis of the risk factors and taking precautions against adverse factors. Using a systematic approach during pre-operative workup of the patient, intraoperative preparedness, post-operative monitoring and educating the patient are also required. The study showed the prevalence and factors associated with SSI. It also brought to the fore the lacunae in prevention and prophylaxis of infections. The high rate of 41.67% can be reduced by following all the preventive measures. Instead of an empirical treatment therapy, as currently followed, a more unique and specific antimicrobial therapy depending on the patient profile and type of operation will go a long way in eradication of SSIs. In spite of the costs involved in individualised drug regimens, it is miniscule compared to the additional expenditure incurred for treatment of HAIs. Reduction in the rate will lead to elimination of drug-resistant pathogens. Proper pre-operative hair removal with hair clippers rather than blades and smoking cessation at least 1 month before surgery can help decrease the prevalence. With researches predicting a rise in non-communicable diseases in the future, nosocomial infections will most probably be one of the few infectious diseases still surviving along with AIDS and tuberculosis.
The authors wish to acknowledge The Indian Council for Medical Research for financially supporting the research work under the scheme “Short Term Studentship” for the year 2013.
Financial support and sponsorship
The Indian Council for Medical Research.
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]