Cloth-covered chiropractic treatment tables as a source of allergens and pathogenic microbes☆

Sampling 

A teaching clinic at one chiropractic college was examined for the presence of treatment tables that were covered in cloth. In the case of the clinic examined, there were 9 cloth-covered treatment tables and 5 benches where a patient can be placed on in a kneeling position with the face in a similar slot as the treatment table. All of these apparatus were in a clinic where student interns may treat other students and family members as part of their supervised training in spinal manipulation.

Samples were taken of the facial piece of each of the tables and benches in this facility. Bilateral cultures of the face piece with the paper removed were made using a special RODAC plate (Becton, Dickinson, and Company, Sparks, MD) containing a nutrient agar in which the plate has the agar overfilled such that a meniscus of agar is exposed above the rim of the plate. A recessed cover is then placed over the plate to protect the sample during transport and incubation. Because the goal was to assess for bacteria and nonbacteria alike, this nutrient agar was used. Plates taken of each apparatus facial piece were labeled as to left or right surface and given a number assigned to each table or bench. Cultures were grown at 37°C for 24 hours and examined for any presence of growth.

Isolation and confirmatory testing 

Plates were examined by the team's microbiologist and assessed for presences of both allergens and microbacteria. Suspicious cultures were then subcultured when necessary and Gram-stained and/or confirmed with other accepted confirmatory methodologies. These included coagulase testing for suspected Staphylococcus strains and CHROMagar MRSA (Becton, Dickinson, and Company) for suspected methicillin-resistant S aureus (MRSA).

Limitations of the study 

This study did not quantify bacterial counts. Although this would be helpful in knowing how much of an organism was present, it was felt by the investigators that any presence of pathogenic organisms or allergens was of significance. In addition, a teaching clinic with high volumes of patients may not be generalizable to private practice. However, this still indicates a primary problem with cloth-covered tables, primarily how to disinfect them. This is likely a problem that is generally found in teaching clinics and private practice offices as well.

Significance of this study 

A study on vinyl tables has indicated that wiping with a simple disinfection agent can significantly reduce the risk of bacteria on the surface of the treatment apparatus.4 This process was found to be fast and cost-effective. Cloth tables that were the subject of this study were not routinely cleaned with anything and were very porous. The fabric was thick and could theoretically hold dirt, secretions from the human body, and a host of other substances from dust and mites to the bacteria and mold found in the study. The investigators could see visible stains on surfaces of the face pieces and table surface. It is difficult to estimate how these cloth surfaces can be effectively cleaned. In fact, at least one study of fabric-covered furniture in hospital environments concluded that nonporous surfaces were preferred in such a health care setting because of the ability of resistant bacteria to survive prolonged periods in cloth fabric.5 Furthermore, the investigators do not see an advantage during treatment to having a treatment table covered in cloth vs other nonporous materials that could be adequately disinfected.

Considerations for reducing risks of infection in chiropractic facilities 

Among the easiest procedures a health care provider can practice is regular hand washing or hand sanitizing.6 This should go without saying; but studies on hand sanitizing within medical, hospital, and chiropractic teaching environments will suggest there is more to be desired in this area.7, 8, 9 Perhaps, steam-cleaning existing cloth tables or spraying with a surface disinfectant could be of some temporary benefit. With that said, it is the opinion of the investigators that these findings noted in this study could be the transient flora of the day. Tomorrow, an entirely separate congregation of pathogens could be present on these tables, depending on who has been treated on them last and what they carried. For instance, S aureus is now suspected to be present in up to 40% of patients' anterior nares; and close to 1% of people may carry MRSA strains.10 Seasonally, many viral pathogens come to mind, including influenza. Currently, the chiropractic profession in the United States does not have a suggested guideline that it has adopted for disinfecting of treatment tables, although there are available models in the literature.4, 11 With many people living longer with immune compromise from chronic disease in today's health care environment, this becomes even more important.