High Rate of Bacterial Contamination on Healthcare Worker's Mobile Phone and Potential Role in Dissemination of Healthcare-Associated Infection at Debre Berhan Referral Hospital, North Shoa Zone, Ethiopia

Bacterial contamination of healthcare workers' mobile phones in Africa: a systematic review and meta-analysis

BACKGROUND

Mobile phones are potential reservoirs for pathogens and sources of healthcare-associated infections. More microbes can be found on a mobile phone than on a man's lavatory seat, the sole of a shoe, or a door handle. When examining patients, frequent handling of mobile phones can spread bacteria. Nevertheless, evidence of bacterial contamination of mobile phones used by healthcare workers in Africa was inconclusive. Thus, this meta-analysis and systematic review was conducted to estimate the pooled prevalence of bacterial contamination of mobile phones used by healthcare workers and the most frequent bacterial isolates in Africa.

METHODS

We systematically retrieved relevant studies using PubMed/MEDLINE, POPLINE, HINARI, Science Direct, Cochrane Library databases, and Google Scholar from July 1, 2023 to August 08, 2023. We included observational studies that reported the prevalence of bacterial contamination of mobile phones among healthcare workers. The DerSimonian-random Laird's effect model was used to calculate effect estimates for the pooled prevalence of bacterial contamination in mobile phones and a 95% confidence interval (CI).

RESULTS

Among 4544 retrieved studies, 26 eligible articles with a total sample size of 2,887 study participants were included in the meta-analysis. The pooled prevalence of mobile phone bacterial contamination among healthcare workers was 84.5% (95% CI 81.7, 87.4%; I2 = 97.9%, p value < 0.001). The most dominant type of bacteria isolated in this review was coagulase-negative staphylococci (CONS) which accounted for 44.0% of the pooled contamination rate of mobile phones used by healthcare workers, followed by Staphylococcus aureus (31.3%), and Escherichia coli (10.7%).

CONCLUSIONS

In this review, the contamination of mobile phones used by HCWs with various bacterial isolates was shown to be considerable. The most prevalent bacteria isolates were coagulase-negative staphylococci, Staphylococcus aurous, and Escherichia coli. The prevalence of bacterial contamination in mobile phones varies by country and sub-region. Hence, healthcare planners and policymakers should establish norms to manage healthcare workers' hand hygiene and disinfection after using mobile phones.

Bacterial Contamination of Healthcare Students' Mobile Phones: Impact of Specific Absorption Rate (SAR), Users' Demographics and Device Characteristics on Bacterial Load

We quantitatively and qualitatively evaluated the bacterial contamination of mobile phones (MPs) in relation to users' demographics, habits, and device characteristics by administering questionnaires to 83 healthcare university students and sampling their MPs by following a cross-sectional design. The heterotrophic plate count (HPC) at 22 °C (HPC 22 °C) and 37 °C (HPC 37 °C), Enterococci, Gram-negative bacteria, and Staphylococci were evaluated. Higher bacterial loads were detected for HPC 37 °C and Staphylococci (416 and 442 CFU/dm², respectively), followed by HPC 22 °C, Enterococci, and Gram-negative bacteria; the vast majority of samples were positive for HPC 37 °C, HPC 22 °C, and Staphylococci (98%), while Enterococci (66%) and Gram-negative bacteria (17%) were detected less frequently. A statistically significant positive correlation (r = 0.262, p < 0.02) was found between the European head specific absorption rate (SAR) and both HPC 37 °C and Staphylococci; Enterococci showed a strong, significant correlation with HPC 37 °C, HPC 22 °C, and Gram-negative bacteria (r = 0.633, 0.684, 0.884) and a moderate significant correlation with Staphylococci (r = 0.390). Significant differences were found between HPC 22 °C and the type of internship attendance, with higher loads for Medicine. Students with a daily internship attendance had higher HPC 22 °C levels than those attending <6 days/week. Our study showed that bacteria can survive on surfaces for long periods, depending on the user's habits and the device's characteristics.

Biofilm formation by E. coli and S. aureus on cellphone cover: sensitivity to commercially available sanitizers

Presence of pathogens on the cellphones and their accessories poses a significant risk for public health. This study aimed to determine the biofilm-forming capability of S. aureus and E. coli on pieces made from a different commercially available cell phone and aadditionally to test the effectiveness of the most common commercially available sanitizers. Therefore, bacterial biofilm biomasses were quantitatively determined on cellphone covers using crystal violet assay in the presence and absence of common sanitizers. This study revealed that S. aureus and E. coli could form biofilms on the surfaces of all cellphones covers. Additionally, the sanitizers that contain sodium hypochlorite 5.25% and those composed of 38.9% ethanol and 0.05% dodecyl dimethyl ammonium chloride showed the highest log reduction in the number of viable cells after 5 minutes of exposure against biofilms formed by both E. coli and S. aureus compared to other tested sanitizers (chloroxylenol 4.8%, 2-propanol 64%, and ethanol 70%). Moreover, 4.8% chloroxylenol and 70% ethanol-based sanitizers showed log reductions significantly higher than 2-propanol-based ones. In conclusion, cellphone covers were shown to be suitable surfaces for microbial biofilm formation produced by S. aureus and E. coli. The antimicrobial activity of commercially available sanitizers against these bacterial biofilms was variable, with sodium hypochlorite and ethanol/dodecyl dimethyl ammonium chloride sanitizer being the most effective.