Screening for Methicillin-resistant Staphylococcus aureus Carriage on the Hands of Healthcare Workers: An Assessment for Hand Hygiene Practices

INTRODUCTION

Nosocomial infections contribute to the important cause of morbidity and mortality in any hospital setting.¹ Contact among healthcare workers (HCWs) and patients appears to be the most common route of transmission of methicillin-resistant Staphylococcus aureus (MRSA).² Methicillin-resistant S. aureus is capable of causing a wide range of infections.³ It is believed that HCWs are more likely to be colonized than persons in the general population because of increased exposure.⁴ They increase the risk of spreading MRSA and other organisms from person to person with direct hand contact during a single opportunity. Therefore, colonized HCWs and contaminated hand-touch surfaces act as a potential source of MRSA in hospitals.⁵

This study was conducted to detect the carriage of MRSA in the hands of HCWs during patient care to evaluate the effective practice of hand hygiene protocol. After celebrating the “Global Hand Washing Day” on October 15 and subsequently the “International Infection Prevention Week” from October 16 to 21, 2017, we wanted to assess the follow-up awareness among HCWs.

MATERIALS AND METHODS

This study was a cross-sectional point prevalence study of three consecutive days and was conducted among HCWs posted in all wards and intensive care units (ICUs) of a tertiary care hospital. The limitation in this study is small sample size as the study setting involves a newly established hospital and the numbers of beds were 400 at the time of study. Many HCWs either used hand rub before giving hand cultures or avoided giving it and therefore were excluded from the study. The HCWs were asked not to the use hand rub, as because we needed real-time carriage rate; therefore, if they tried to use it seeing us, we excluded them from the study.

A total number of 62 HCWs were included in this study; of which, 14 were doctors. Hand cultures were obtained from HCWs after the clinical rounds without prior information about the procedure. Cultures were taken before and after the use of alcohol-based hand rub (after 1 minute of use). Hand cultures were obtained by asking HCWs to touch the surface of screen agar (MeReSa Chromogenic Agar from HiMedia Laboratory Pvt. Ltd, Mumbai, India) with their fingertips and thumbs of both the hands. Culture plates were incubated at 35°C aerobically for 48 hours. Bluish green colonies were further processed by conventional methods (Gram’s stain, catalase test, slide coagulase test, and tube coagulase test). Methicillin resistance was confirmed by using cefoxitin disk (30 μg) as surrogate marker. Resistance against other antimicrobial agents was tested by Clinical and Laboratory Standards Institute (CLSI) 2017 guidelines: ciprofloxacin (5 μg), clindamycin (2 μg), cotrimoxazole/trimethoprim–sulfamethoxazole (TMP/SMX, 1.25/23.75 μg), erythromycin (15 μg), and gentamicin (10 μg), on Mueller-Hinton agar with 24 hours of incubation at 35°C. For internal quality control a known clinical isolate of MRSA was used as a positive control and S. aureus ATCC 25923 as a negative control. Other colorless growth on the screening agar was identified as Candida spp.

RESULTS

Of a total of 62 HCWs screened for MRSA, 32 (51.61%) were positive. Among these 32 MRSA-positive HCWs, 7 (21.88%) were doctors and 25 (78.12%) were other HCWs including nursing staff. After the use of alcohol-based hand rub, 6 (9.68%) HCWs were still positive for MRSA.

Antimicrobial susceptibility pattern of MRSA isolates are shown in Figure 1. We also retrospectively analyzed the prevalence of MRSA in our hospital. A total of 29 MRSA isolates were reported from 1,524 samples during the 3 months preceding this study. Of these 29 isolates, only 7 were from indoor patients and 3 from pediatric ward. In this ward, the isolation of MRSA from the hands of HCWs was around 70%. Another interesting finding was that HCWs with long nails (3/5) showed the growth of Candida spp. on this screening agar for MRSA.

DISCUSSION

On the world map, Asia has the highest prevalence rates of MRSA. It is the most populated region in the world and self-medication with over-the-counter antimicrobial agents is a norm to treat common infections. This high antibiotic selection pressure among the overcrowded inhabitants creates an environment that is suitable for the rapid development and efficient spread of numerous multidrug-resistant pathogens.⁶ In a multi-centric Indian study (2008–2009), among patients the overall prevalence rate of MRSA was 41%.⁷ Various Indian studies show MRSA nasal carriage rate of 1.8–6.6% among HCWs.^8–10 In Nepal, the MRSA carriage rate was reported as 2%.¹¹ A very high MRSA nasal carriage rate of 38.9% is reported from Nigeria.¹²

Present study wanted to assess hand hygiene practices among our HCWs during real-life conditions with most convenient samples. It showed that 51.61% HCWs’ hand cultures was positive for MRSA before using hand rub and after use 9.68% was still positive. We were trying to show the compliance of HCWs to hand hygiene and also demonstrate that if they use hand rub on the visibly dirty hands, it will not bring the desired outcome of removing MRSA. Those HCWs positive for MRSA after using alcohol-based hand rub may be because of they using the rub on their visibly dirty hands. The collection time between the use of hand rub and hand culture was 1 minute, which may not be sufficient. This could be another reason for culture positivity for MRSA after using hand rub. But we did not get any reference about adequate time to remove MRSA from hands after the use of hand rub. The hand rub was International Organization for Standardization certified and was used adequately by the staff. In another study, MRSA was detected in 39% before hand hygiene and in 13% after hand hygiene, which is comparable to our study.¹³ Hospital environment has commonly touched surfaces. They can get contaminated either through HCWs’ hands or via infected or colonized patients. Admission to a room previously occupied by a patient infected with MRSA, vancomycin-resistant Enterococcus species (VRE), or Clostridium difficile increases the risk of the subsequent patient to acquire the same pathogen. Wille et al. report that the use of inadequate concentrations of disinfectants can lead to persistence of MRSA in the hands of HCWs. In their study, MRSA was isolated from the mobile phones of HCWs. It is well known that HCWs compliance with hand hygiene is lower following environmental contact (50%) compared to direct patient contact (80%). The contributors to this practice are understaffing, high workload, insufficient knowledge, and may be more significantly underestimating the importance of cleaning and disinfection of hands. Hence, training and assessment is continuously needed regarding this simple infection prevention measure.¹⁴

Till recently, hospitals focused on the control of healthcare-associated MRSA (HA-MRSA) lineages, which are poorly adapted for persistence in the community. This situation has undergone a fundamental shift with the emergence of community-associated MRSA (CA-MRSA), which can colonize young and healthy population for long periods. Furthermore, CA-MRSA is now displacing previously dominant HA-MRSA lineages.¹⁵ The HCWs who are at the interface between the hospital and the community may serve as agents of cross transmission.⁴ The crowded living conditions with high antibiotic pressure are ideal to select and transmit MRSA strains not only in hospitals but also in community and in animal population (poultry). This will result in more use of vancomycin and subsequently lead to increased prevalence and spread of vancomycin-resistant S. aureus (VRSA) and VRE. Though at present sporadic reports are available in resource-poor countries, this constitutes a substantial public health threat, especially, where diagnostic facilities are largely lacking and appropriate therapy is frequently unaffordable.⁶ In the United States, patients are screened for MRSA carriage before admission to ICUs and kept in isolation till reports clear them. When colonized patients are not isolated, susceptible patients are at risk of acquiring MRSA at a rate of approximately 1% per day. Screening of MRSA relies on rapid screening test such as chromogenic agar or polymerase chain reaction. The treatment cost and unfavorable patient outcomes are more dangerous and expensive than the screening tests.¹⁶ Finally, the goal of any surveillance is to improve performance. Muller and Detsky have described two approaches for performance improvement in hand hygiene, namely, evidence-based and indicator-based strategies. Evidence-based studies are designed to improve patient outcomes and would ultimately in the long run improve staff adherence rates to the suggested practices.¹⁷ Every year on May 5th, the World Health Organization and its committed partners all around the world celebrate the World Hand Hygiene Day as a call to action for health workers and also to stimulate the general public for why hand hygiene is so crucially important. This year, the slogan is “It’s in your hands—prevent sepsis in health care.”¹⁸

CONCLUSION

Regular monitoring of hand hygiene compliance is vital to prevent the spread of nosocomial MRSA and thereby the emergence of VRE and VRSA. The MRSA screening agar is rapid, simple, cost-effective, and useful to identify the carriage of not only MRSA but also Candida (it is important in the wake of nosocomial outbreaks with highly adverse outcomes due to Candida auris). Further studies are required to evaluate the transmission rate of MRSA from HCWs to patients in Indian hospitals.

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