Origins and control of bacterial contamination during spinal manipulation

Abstract

Background: Research has revealed that healthcare workers’ hands serve as a source and vehicle for the transmission of micro-organisms within the healthcare sector, thus resulting in nosocomial infections, better known as healthcare-associated infections. The chiropractic profession is traditionally known as a hands-on profession, where the fundamental treatment protocol includes manual manipulation of the spine. In order to perform these procedures hand-to-patient interaction is required, resulting in skin-to-skin contact. Poor hand hygiene practice has been attributed by the World Health Organization as the primary cause for the spread of micro-organisms within the healthcare environment. Unwashed hands harbour microbes, thus increasing contamination levels and subjecting patients to these potential pathogens. This study aimed to determine the presence and transfer of bacterial contamination occurring during spinal manipulation, as well as analysing the efficacy of decontaminants used by chiropractic practitioners against the isolated bacteria cultivated.

Research design: The study was located in the quantitative experimental paradigm and conducted as a cross-sectional investigation.

Method: Samples were obtained from chiropractors’ hands before and after spinal manipulation. Samples were then serially diluted, plated in duplicate (using the spread plate technique) and incubated for 24-48 hours at 37°C. Viable counts of colony forming units (CFUs) were then enumerated in order to verify the presence of bacteria on the chiropractors’ hands, as well as to establish the direction of transfer occurring during spinal manipulation. Macroscopic and microscopic characteristics of each bacterial isolate were used to identify the bacteria cultivated. A modified Kirby Bauer technique was used to ascertain the efficacy of decontaminants commonly used by chiropractors, against the isolated bacteria obtained from their hands.

Results: Bacterial flora were present on 100% of the chiropractors hands both pre- and post-spinal manipulation. A mean of 16,456 (27,718) cfu/ml⁻¹ were enumerated from the samples collected from the chiropractors’ hands during manipulation. A paired t-test

indicated a significant difference noted in the viable count of bacteria found on the chiropractors’ hands before and after manipulation (p<0.001). A significant difference was observed in the viable count of bacteria post-manipulation (70%), as opposed to the pre- manipulation readings (30%).This was indicative of a higher rate of bacteria being transferred from the patient to the chiropractor during spinal manipulation. The majority of the microorganisms identified were either primary or opportunistic pathogens. Staphylococci were most prevalent in the pre-spinal manipulation readings accounting for 53% of the colonies, followed by micrococci with 39%, bacilli with 4%, Staphylococcus aureus with 3% and streptococci with 1%. Pseudomonas spp. were present but uncommon. Escherichia coli were not present on the chiropractors’ hands in any of the samples obtained pre-manipulation. The post-manipulation readings constituted a high prevalence of micrococci accounting for 57% of the colonies, followed by staphylococci with 32%, Pseudomonas spp. with 5%, E. coli with 3%, Staphylococcus aureus with 2% and bacilli with 1%. Streptococci were present but uncommon. The decontaminants tested were most effective against gram-positive bacteria such as Bacillus, Micrococcus, Staphylococcus, Staphylococcus aureus and Streptococcus. The bacteria isolated were most susceptible to the D-Germ hand disinfectant, while the Dis-Chem instant hand sanitizer was the least effective decontaminant tested. Ciprofloxacin was the antibiotic used as a positive control. A significant difference was noted between the performance of the positive control and the decontaminants on the bacteria isolated.

Conclusions and recommendations: The study proved the presence of primary and opportunistic pathogens found on the chiropractors’ hands. These included Staphylococcus spp., Micrococcus spp., Bacillus spp., Pseudomonas spp., E. coli, Streptococcus spp. and Staphylococcus aureus. A higher rate of bacteria was observed being transferred from the patient to the chiropractor during spinal manipulation. The majority of the microorganisms identified were either primary or opportunist pathogens, thus predisposing both the patient and the chiropractor to potential infection. A significant difference was noted between the performance of the positive control and the decontaminants on the bacteria isolated. None of the decontaminants were as effective against the bacteria isolated as the positive control. It can therefore be deduced that each bacterial flora was not removed by some of the decontaminants currently used by chiropractic practitioners in practice.