|Year : 2015 | Volume
| Issue : 2 | Page : 193-196
Microbial contamination of the white coats among preclinical and clinical dental students: A comparative cross-sectional study
Siva Pydi1, Srinivas Pachava2, Suresh Sanikommu2
1 Department of Public Health Dentistry, Sree Sai Dental College and Research Institute, Srikakulam, Andhra Pradesh, India
2 Department of Public Health Dentistry, Sibar Institute of Dental Sciences, Guntur, Andhra Pradesh, India
|Date of Web Publication||18-Jun-2015|
Department of Public Health Dentistry, Sree Sai Dental College and Research Institute, Srikakulam, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
Introduction: White coat is associated with standard of professionalism and care and helps in gaining the trust of their patients. On the other hand, these white coats are known to be potentially contaminated with pathogenic bacteria and there has been always a concern about the risk of transmitting pathogenic bacteria in hospital settings. Aims: The aim was to know the difference in microbial contamination of white coats between preclinical and clinical dental students. Materials and Methods: A cross-sectional study done on dental students in a dental institution in a South Indian state. Fifty dental students (25 preclinical and 25 clinical) were included. Sterile saline dipped cotton swabs were used to collect samples from predetermined areas. Chi-square test and Mann-Whitney U-test were used to test the significance. SPSS version 20 was used for analysis. Results: Clinical students (16%) had more pathogens on their white coats than preclinical students (8%), whereas nonpathogenic commensals were more in nonclinical students (84%) compared to clinical students. Conclusions: White coats are contaminated by bacteria, but further research should be carried to know the virulence of these bacteria in susceptible individuals.
Keywords: Cross-sectional, dental students, microbial contamination, preclinical, white coats
|How to cite this article:|
Pydi S, Pachava S, Sanikommu S. Microbial contamination of the white coats among preclinical and clinical dental students: A comparative cross-sectional study. J Indian Assoc Public Health Dent 2015;13:193-6
|How to cite this URL:|
Pydi S, Pachava S, Sanikommu S. Microbial contamination of the white coats among preclinical and clinical dental students: A comparative cross-sectional study. J Indian Assoc Public Health Dent [serial online] 2015 [cited 2020 Feb 27];13:193-6. Available from: http://www.jiaphd.org/text.asp?2015/13/2/193/159068
| Introduction|| |
Most often, the profession of a person is reflected in the attire. White coat is worn by most of the science people which include medical and paramedical staff. The way of dressing and cleanliness brings in respect from others in many instances. White coat is associated with standard of professionalism and care and helps in gaining the trust of their patients. On the other hand, these white coats are known to be potentially contaminated with pathogenic bacteria  and there has been always a concern about the risk of transmitting pathogenic bacteria in hospital settings.  In spite of following strict infection control protocols, we unknowingly carry many micro-organisms on our white coats. Recently, the United Kingdom's Department of Health recommended that hospitals adopt a "bare below the elbows" dress code (i.e., short sleeves, no wrist watch and no jewelry), that personnel avoid wearing a tie when performing clinical activities in an attempt to decrease the transmission of bacteria. 
In a dental setup, the environment in the working area is contaminated due to the aerosols produced by high-speed handpieces and ultrasound scalers. The dentist working with the patients gets his attire directly contaminated with the bacteria present in the aerosol. In most of the dental schools, same white coat is worn in both clinical and nonclinical areas. It is not uncommon to see the students wearing white coat in nonclinical areas like canteens, library, and off the campus. There are research studies done on dental staff and clinical students attending patients which concluded that white coat may act as a transmitting agent.  This study is first of its kind in dentistry, involving preclinical students who will not attend patients. The aim of this study is to know the difference in microbial contamination of white coats between preclinical and clinical dental students. Student's way of handling the white coat and their perception toward its contamination were also investigated.
| Materials and methods|| |
A cross-sectional study was carried out on dental students (both preclinical and clinical) in a dental institution in South Indian state. Ethical approval was obtained from the Institutional Review Board of a dental Institute prior to the start of the study. Objectives were explicitly mentioned to the students and those who were willing to participate were included in the study. Fifty dental students were randomly included in the study, of which 50% of students were preclinical, while the remaining were clinical students.
A pretested self-administered anonymous questionnaire was given to the students to determine their perception about white coat contamination, way of handling, and frequency of washing. Questionnaire was in English language and "test-retest" approach followed to check the reliability during pilot study achieved a k = 0.96. Cronbach's alpha, which measures the internal consistency for the questionnaire was 0.89. Students were approached to their respective (clinical or preclinical) work area and were requested to fill and return the questionnaire.
Sterile saline dipped cotton swabs were used to collect a sample from white coats.  Swabs used were plain, cotton-tipped, sterilized and were carried in cotton plugged sterile test tubes. By using these swabs bacterial sample was collected from the aprons in two predetermined areas (chest region and mouth of the pocket). After collection, the swabs were again replaced into the sterile test tubes and were immediately carried to microbiological laboratory which is National Accreditation Board for Testing and Calibration Laboratories approved located in a medical institution, NRI Medical College and Hospital. Swabs were streaked onto the blood agar plates and incubated for 24 h at 37°C  and observed for growth. Bacteria from the colonies were collected and subjected to staining procedures and biochemical tests for the identification of bacteria. Plates showing no growth after 48 h incubation were declared negative. 
Data were compiled using Microsoft excel software and analyzed using SPSS Version 20.0 (IBM Corp. Armonk, NY). Chi-square test was done to find if any significant difference existed between the participants of the study according to their responses and the questions with Likert scale options were analyzed using Mann-Whitney U-test. The cut-off level for statistical significance was fixed at 0.05.
| Results|| |
Of the total 50 dental students who participated in the study, 25 (50%) include preclinical and 25 (50%) clinical students. Their mean age was 22.18 ± 2.85. Fifty-four percent of our subjects were males and the rest, 46% were females.
Ninety-two percent of the total white coats sampled were positive for one or the other bacteria and the remaining, 8% white coats were found sterile. Gram-positive cocci (62%) were the most predominant bacteria seen in the study sample followed by Gram-positive Bacilli (18%). Clinical students (16%) had more pathogens on their white coats than preclinical students (8%) (P = 0.180), whereas nonpathogenic commensals were more in nonclinical students (84%) compared to clinical students (76%) (P = 0.263) which can be attributed to their usage in nonclinical areas. [Table 1] shows the distribution of different pathogenic and nonpathogenic bacteria in the study samples. Gram-negative cocci, which are commonly present in saliva were seen only in clinical students 3 (12%) who attend patients, with no evidence in preclinical students (0%).
Majority (80%) of the study participants wear their white coat before entering the respective department or laboratory. More than half of the total sample (68%) are maintaining with only two white coats. 70% of the subjects felt that it is very important to wash the white coat regularly. Almost 50% got their white coat washed twice a week and 44%, once a week. Interestingly, more number of clinical students (28%) agreed that they had the practice of exchanging their white coat with their colleagues some or the other time compared to the preclinical students (20%) [Table 2].
Students' perception toward white coat contamination was assessed [Table 3]. Overall, 36% of the students thought that white coats are always contaminated while 16% considered clean if the collar and pockets are clean and the other 36% considered it completely clean if there was no stain on it. Totally 78% of the study sample agreed that their white coat carries germs, of which 48% of the clinical students strongly agreed in contrast to 8% of the preclinical students (P = 0.005). While 20% of the clinical students strongly agreed that white coat acts as a potential transmitting agent of micro-organisms, none of the preclinical students agreed with this statement.
|Table 3: Perception of preclinical and clinical students toward white coat contamination|
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| Discussion|| |
White coat itself brings dignity to the profession. It helps for easy identification and made doctors look more professional.  However, white coats have been shown to act as fomites and harbor potential contaminants. , Results of the current study confirmed previous findings, , in which Gram-positive cocci are the predominant bacteria. Gram-positive cocci are most commonly present as commensals on the skin. Coagulase-negative staphylococci are seen in the present study, whereas the study done in medical students observed the presence of Staphylococcus aureus,  where they are known to cause nosocomial infections.  Coagulase-negative staphylococci which are used to be considered as harmless commensals or contaminants, have emerged as major pathogens as medical technology has advanced which cause endocarditis, otitis media and infections of joint prosthesis, vascular grafts, and cardiac pacemakers.  Gram-negative Bacilli were identified which is consistent with previous studies.  However, in the current study further biochemical analysis was done to know the specific bacteria. The bacteria found were Escherichia coli, Pseudomonas. Gram-negative cocci were found in clinical students who attend patients with no evidence in preclinical students.
In the present study, 50% of the students washed their white coats twice a week and 44% once a week. The frequency of washing white coat was better in the present study as compared to the findings of another study,  where 34.4% of students washed their coats once a month; 15.6% once a week and 9.4% twice a month. Remaining 40.6% would wash their coats every 2 months or even longer. 36% of both preclinical and clinical students considered their white coat as contaminated with or without stain which was better when compared to other study,  where they are 45.8% and 52.2% respectively.
Our study has many limitations. First, despite the fact that this is the first study of its kind in dentistry which involved both preclinical and clinical dental students reported to date, we did not observe statistically significant differences in the contamination between the two groups, because of the size of the population studied. Second, our sample collection may have been less effective than that used in previous studies,  in which blood agar plates were touched directly to the clothing item. We did not use blood agar plates, as it could decrease participation due to concerns over possible staining of white coat.
Bacteria are omnipresent, so undoubtedly they will be present on all living and nonliving things where the conditions are favorable, to which white coat is not an exception. However, whether the bacterial load present on them will cause disease or not is a big question. However, further research should be carried to know the virulence of these bacteria in susceptible individuals. It is recommended to provide separate changing area in the hospital premises and the clinical students and dentists who attend patients should have a distinct dress code. Irrespective of whether white coats transmit micro-organisms or not, they should be maintained cleanly to uphold the dignity of any profession.
| Conclusion and recommendations|| |
Preclinical students white coats (8%) were less contaminated with pathogens than clinical students (16%). On the other hand, the nonpathogenic commensals (coagulase-negative staphylococci) which are acquired from the environment were more in preclinical students (36%) than the clinical students (12%) which may be attributed to their usage of white coats in the nonclinical areas like library, canteen and off the campus.
| References|| |
Wong D, Nye K, Hollis P. Microbial flora on doctors' white coats. BMJ 1991;303:1602-4.
Hambraeus A. Transfer of Staphylococcus aureus
via nurses' uniforms. J Hyg (Lond) 1973;71:799-814.
Government News Network. Johnson Outlines New Measures to Tackle Hospital Bugs. Available from: http://www.gnn.gov.uk/environment/fullDetail.asp? [Last accessed on 2008 Mar 25].
Priya H, Acharya S, Bhat M, Ballal M. Microbial contamination of the white coats of dental staff in the clinical setting. J Dent Res Dent Clin Dent Prospects 2009;3:136-40.
Muhadi SA, Aznamshah NA, Jahanfar S. A cross-sectional study of microbial contamination of medical students' white coat. Malays J Microbiol 2007;3:35-8.
Srinivasan M, Uma A, Vinodhkumaradithyaa A, Gomathi S, Thirumalaikolundusubramanian P. The medical overcoat - Is it a transmitting agent for bacterial pathogens? Jpn J Infect Dis 2007;60:121-2.
Douse J, Derrett-Smith E, Dheda K, Dilworth JP. Should doctors wear white coats? Postgrad Med J 2004;80:284-6.
Varghese D, Patel H. Hand washing. Stethoscopes and white coats are sources of nosocomial infection. BMJ 1999;319:519.
Neely AN, Maley MP. Survival of enterococci and staphylococci on hospital fabrics and plastic. J Clin Microbiol 2000;38:724-6.
Banu A, Anand M, Nagi N. White coats as a vehicle for bacterial dissemination. J Clin Diagn Res 2012;6:1381-4.
Neihart RE, Fried JS, Hodges GR. Coagulase-negative staphylococci. South Med J 1988;81:491-500.
Zachary KC, Bayne PS, Morrison VJ, Ford DS, Silver LC, Hooper DC. Contamination of gowns, gloves, and stethoscopes with vancomycin-resistant enterococci. Infect Control Hosp Epidemiol 2001;22:560-4.
[Table 1], [Table 2], [Table 3]