DR. JAVEED KAKROO
The most common question to healthcare workers is what the best practices are in keeping the hospitals hygienic and safe for the patients, who live in the environment for prolonged periods. The protocols associated with scientific surveillance and decontamination of surfaces with chemical disinfectants. Several monitoring strategies exist, which range from simple visual inspection to microbiologic testing of surface contamination, to techno logic innovations that measure the adequacy of surface cleaning. As the variety of options for cleaning, disinfecting, and monitoring grow, hospitals are faced with many choices, but limited evidence exists on the comparative effectiveness of these interventions, especially related to HAI rates within the hospital. This Technical Brief is designed to summarize and map the current evidence base addressing EC to prevent HAIs and highlight future research needs
Surveillance: Microbiologic Methods have been used to evaluate microbial contamination of environmental surfaces. Methods typically utilize swab cultures, in which a moistened sterile swab is used to sample a surface and then inoculate agar, often with broth enrichment. Swab cultures are easy to use and are often used to sample irregular surfaces, medi cal equipment, and healthcare workers’ hands. Swab cultures are most often used to identify specific pathogens during the epidemiologic investigation of an outbreak. We do in instances when there are outbreaks of infections with MRSA VRE and MDR-associated Enterobacteriaceae. Importantly, the use of aerobic culture (with or without enumerating colony counts) is the only method that can provide information about the viability of our pathogens of interest (e.g. MRSA, VRE).
Another method for sampling is the use of Rodac contact plates, which are small Petri plates filled with agar. A sampling of flat environmental surfaces is performed via direct application of the plate to the surface, with the surface area typically measuring 25 cm2. Advantages of contact plates include ease of use and standardization of an approach for quantitative measurement (e.g., results are often expressed as colony-forming unit spercm 2).
However, contact plates can be expensive and allow for sampling of only a small area per plate. We in many teaching Hospitals use 9 cm Petri dishes embedded with blood agar, and they are exposed to a specified time and yet many matters are arbitrary and not calculated to utmost precision
An overall limitation of methods utilizing Acts is the lack of acceptance criteria for defining a surface as “clean” using Acts. Additional limitations include the cost of processing (e.g., identifying isolates in the microbiology laboratory), delay in results, small sample area per swab or slide, and the need to determine re-cleaning levels of microbial contamination for each object or surface being evaluated.
In addition, clinical microbiology laboratories do not always perform quality -control assessments in the use of ACCs, including maintenance of certification for environmental microbiologic testing. As such, testing using microbiologic methods for environmental monitoring in the hospital setting could benefit from oversight by a certified environmental microbiology laboratory.
Newer technologies in surveillance: Polymerase chain reaction–based technology polymerase chain reaction (pcr)–based assays for assessing ec are currently investigational. PCR-based assays offer rapid turn around time for detecting the presence of specific organisms (e.g., MRSA,C.difficile) and are performed in the microbiology laboratory following sampling of surfaces, usually via swabs.
However, these assays currently do not differentiate between the presence of viable versus nonviable microorganisms. As these technologies become less expensive, they may have a larger role in assessing the effectiveness of cleaning and disinfection, particularly in the outbreak setting.
A wide variety of cleaning agents and disinfection technologies are commercially available, each with potential benefits and disadvantages. Additionally, hospitals often monitor the quality of room cleaning and disinfection to ensure that surfaces have been treated appropriately.
Assessing Contamination Following Environmental Cleaning: Clinical and environmental services staff are faced with distinct challenges as pathogens are capable of surviving for prolonged periods of time on environmental surfaces and may be transmitted to new room occupants following discharge of colonized or infected patients,even when terminal cleaning has been performed. Effective strategies must therefore be put in place to assess the effectiveness of environmental cleaning and disinfection in healthcare settings to reduce HAIs.
Yet most of developing countries lack resources to study all this on a regular basis and matter are evaluated whenever there is a higher incidence of hospital-associated infections
Dr. Javeed Kakroo is a Clinical Microbiologist, Kidney Hospital Srinagar