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Needle contamination in the setting of intravitreal injections
Background/Purpose:
To evaluate the risk of intravitreal needle contamination through speaking versus breathing in an office setting.
Methods:
This was a prospective sampling assay. Participants held a sterile 30-gauge half-inch needle 25 cm from their mouth for 30 seconds under 2 conditions: (1) while speaking and (2) while breathing silently. Needles were then cultured and assayed after 6 days of incubation. Absolute colony-forming units were compared between conditions and against control sterile needles and oral swab cultures.
Results:
Ten physicians were sampled with 15 samples per physician. Participants grew an average of 0.21 colonies (median = 1 CFU) from their talking samples and 0.07 colonies (median = 1 CFU) from their silent breathing samples. Oral swab plates grew an average of 373.4 colonies. None of the control needle plates grew colony-forming units. A nominal regression analysis showed no significant difference between talking and silent samples (P = 0.457).
Conclusion:
No significant difference in needle contamination was found between talking and breathing. Compared with oral swab plates, a significant difference exists between the amount of flora colonizing the oropharynx and that which was found on the needle cultures (P < 0.0001). These findings suggest that speaking versus remaining silent makes no difference in regard to needle contamination with oral flora during intravitreal injection.
Insights
Speaking versus silent breathing poses no significant difference in intravitreal needle contamination risk. This study found minimal microbial growth on needles, suggesting current practices are safe for preventing oral flora contamination.
Area of Science:
- Ophthalmology
- Infectious Disease Control
- Medical Microbiology
Background:
- Intravitreal injections require sterile techniques to prevent ocular infections.
- The potential for needle contamination from patient or provider respiration is a concern.
Purpose of the Study:
- To compare the risk of intravitreal needle contamination from speaking versus silent breathing.
- To assess the microbial load transferred from the oropharynx to a sterile needle.
Main Methods:
- A prospective study involved physicians holding sterile needles 25 cm from their mouths during speaking and silent breathing.
- Needles were cultured after incubation to quantify colony-forming units (CFUs).
- Results were compared between conditions and against control sterile needles and oral swabs.
Main Results:
- Average CFUs were 0.21 for speaking and 0.07 for breathing, with no statistically significant difference (P=0.457).
- Oral swabs showed significantly higher microbial counts (average 373.4 CFUs) compared to needles.
- Control needles showed no microbial growth.
Conclusions:
- Speaking during intravitreal procedures does not increase needle contamination risk compared to remaining silent.
- The microbial load on needles is significantly lower than that present in the oropharynx.
- Findings support the safety of speaking during intravitreal injections regarding oral flora contamination.
