All the undergraduate medical students who attended their clinical postings in the departments of Obstetrics and Gynaecology, Medicine, Community Medicine, and Surgery from July to September 2011 were eligible for inclusion in the study. Two students with evident eczema and one with onychomycosis were excluded from the data collection. A note of the students who wore rings was made before initiating the sampling. By taking the proportion of the students who were expected to have bacteria on their hands to be 50% and with a 95% confidence level and 80% power of the test, the minimum sample size which was required was 43. Thus, a total of 50 undergraduate medical students (12 to 13 volunteers from each department) were randomly selected from the college and they were requested to participate.

As soon as they were relieved from their clinics, they were asked to come to the Microbiology Lab at the central hospital. After obtaining written informed consents from them, we obtained pre-handwash samples of their hand flora by using the Broth Rinse Technique [9]. The participating students inserted both their hands (one after the other) in a sterile plastic bag which contained 50ml of Trypticase soy broth. The students were requested to open and close their fists for a total of 30 seconds, while they were immersed in broth. The broth was cultured onto Trypticase soy agar (Himedia Laboratories Pvt. Ltd.). Ten fold dilutions of the broth was made (1in10, 1in100, and 1in 1000) [10]. A sample of 0.1ml from each dilution was plated onto the Trypticase soy agar and they were incubated for 24-48 hours at 370C. The enteric pathogens were quantitated by plating 0.1ml of the broth onto Mac Conkey’s agar plates. The plates were examined after 24 to 48 hours of incubation [10]. The total number of aerobic bacteria per millilitre of the broth was determined by the colonies on the Trypticase soy agar plates. The viable counts were calculated from the average colony counts/plate which were multiplied by the dilution and they were expressed as colony forming units per millilitre of the broth. Once the colony counts of the rinsed broth were obtained, 30 students with the highest colony counts were called back to the lab within the next ten days after their clinics had got over. On their subsequent visit to the lab, their pre hand wash samples were taken by using the same Broth Rinse Technique [9]. The organisms were identified by using standard microbiological techniques [11]. The students were then divided into two equal arbitrary groups: the test and the control. The test group’s members were asked to wash their hands after having been shown the proper handwashing technique as per the WHO guidelines, whereas the control group members were not given any new instructions preceding the sample collection [2]. The quantity of antiseptic soap which had to be used for each handwash was fixed to 2ml, irrespective of the group. The antiseptic soap which was used in this study was BactoScrub^R, which contained 4% (w/v) Chlorhexidine Gluconate. A post hand wash sample was obtained by using the same method [9]. An ethics committee approval was taken before initiating all the microbiological sampling procedures. To avoid any technical errors during the sampling, the quality of all the media which were used was tested for performance as well as sterility. The collected data was preserved in Microsoft Excel and their analysis was done by using the Statistical Package for Social Sciences (SPSS), Version 11.5. An association was found by using the Chi square test.

Fifty undergraduate medical students took part in the study: 13 each from the departments of Surgery and Medicine and 12 each from the departments of Community Medicine, Obstetrics and Gynecology.

There were in total 26 men and 24 women. The mean of colonization among the students before the handwashing was 1.3+0.4 x 10⁶ cfus/ml of the broth. The colonization on the hands of the women contributed a mean of 1.7x10⁶ cfus/ml, which was significantly greater than the colonization on the hands of the men, which was 0.9x10⁶ cfus/ml (p=0.05). The students who wore rings possessed a greater contamination with bacteria.(p=0.05) [Table/Fig-1] Following the preliminary screening, 30 students (those with the highest colonization) from among the aforementioned 50 students, were arbitrarily allotted into a test group(n=15) and a control group (n=15) .The mean bacterial colonization on the members in the test group was 2.5x10⁵ CFU/ml and that on the members of the control group was 1.9x10⁵CFU/ml. S.aureus (100%) was the predominant microbe which was found to contaminate the hands in both the groups. Following the handwashing, a reduction in the bacterial colonization was noted in both the groups; however, it was significantly lower in the test group (p=0.011). Moreover, fewer members of the test group retained S.aureus as a part of their hand flora after the handwashing [Table/Fig-2].

[Table/Fig-2]:

A comparison of the No. of Student from the Test and control groups harbouring S.aureus on their hands before and after Hand washing. Handwashing effectively reduced the S. aureus in the test group.

In 1847, Ignaz Semmelweis insisted that the doctors who performed necropsies should wash their hands in chlorinated lime before delivering babies, thereby reducing the streptococcal puerperal sepsis from 22-23%. Many other studies have also shown that the doctors who decontaminated their hands between the patients could reduce nosocomial infections [12]. However, many observational studies have indicated that the compliance of handwashing, especially among doctors, is the least [12]. Though doctors have a lesser contact time as compared to nurses, they may still harbour harmful pathogens as their transient flora which can transmit infections. Health care associated pathogens have been recovered from patient wounds, and draining sites. They even colonize the intact skin of the patients [12].

In our study, the hands of the medical students who were screened, had a mean colonization of (1.3+0.4) x 10⁶ CFUs/ml of broth. Our figures were comparable with the data from similar studies which were conducted on health care workers, where the mean colonization was found to be 3.9 x 10⁴ to 4.6 x 10⁶ [13].

The hands of the women in our study were found to be more colonized than that of the men. It has been hypothesised that women have a greater diversity of flora on their hands, which could be due to the more alkaline pH of their skin, which favours the growth of bacteria [14].

The ring wearing students were found to have a greater colonization with transient flora. Trick et al., had similar findings, where they found that the ring wearing was associated with a 10-fold higher median skin organism counts [8]. S.aureus was the most prevalent organism (100%) which was detected. Borges et al., [9] studied the hands of nurses in a general hospital and found a prevalence of 23% for S. aureus.

It was noticed that the bacterial colonization in the test group after the handwashing was on an average, 2.3x10² cfus/ml, which was much lower than that in the control group (1.4x10⁴ cfus/ml). This was statistically significant (p=0.011), indicating that giving correct instructions regarding the hand washing technique preceding the task, results in a significant decline in the bacterial colonization. Various studies have indicated that giving repeated instructions to the health care workers regarding hand hygiene, helps in their adherence to the hand hygiene practices [15]. We would like to add that a frequent reinforcement ( in the form of instructions or visual aids) at least on a daily basis, regarding effective handwashing, would further benefit in reducing the bacterial counts and in improving the infection control.

Unfortunately, our study was limited and no correlation could be inferred between the contamination of the hands of students and the transmission of pathogens to susceptible patients.

Simple hand hygiene should be taught and learnt throughout the undergraduate course, both theoretically in the lectures and it should be practically reinforced in the laboratory, in the dissection room and in the clinical setting [16]. The handwashing which is performed by the correct technique in a clinical environment will be effective in infection control and it will also help in reducing nosocomial infections. This will go a long way in improving the adherence to handwashing and in the reduction of the bacterial counts among the health care personnel, thereby reducing transmission of nosocomial infections.