Application and Verification of Quantitative Objective Videofluoroscopic Swallowing Measures in a Pediatric Population with Dysphagia.

OBJECTIVE: To investigate the feasibility of obtaining and utilizing objective measures of timing and displacement from videofluoroscopy performed in pediatrics. STUDY DESIGN: Children (n = 121; mean age 38 months, range 9 days-21 years, SD 4 years) referred for videofluoroscopy were recruited. All underwent a standardized protocol including a mid-feed 20-second loop recorded at 25 frames per second. Videos were analyzed using objective digital measures of timing and displacement. Radiation dose was recorded. RESULTS: Quantitative measures were obtained in all children. Maximum opening of the pharyngoesophageal segment and timing measures were correlated with increasing age. Values were congruent with validated adult data. Mean radiation time was 1.58 minutes (range 0.15-3.47, SD 0.66), and mean radiation dose was 30.16 cGycm2 (range 6.5-85 SD 15.17). Radiation dose (P = .21) and radiation time (P = .72) were not significantly different using the increased frame rate compared with an age-matched cohort (n =100) prior to protocol change. CONCLUSIONS: Objective quantitative measures of swallowing measurements can be obtained successfully from pediatric videofluoroscopy performed at high frame rates, without increasing radiation dose. Measures are biologically consistent, reproducible, demonstrate internal cross-correlation, and mirror adult data. These measures have potential to support targeted management and objective monitoring of change by pediatric feeding teams in the future.

Detection and significance of the potentially pathogenic amoeboflagellate Naegleria italica in Australia.

Thermophilic amoeboflagellates in the genus Naegleria include both virulent and benign species. One of the less studied species, N. italica, has not been detected in the environment since the first reports from Italy in the 1980s; its virulence is known only from infection of laboratory mice. Two recent strains from recreational water in Western Australia (AWQC NG960, NG961) were tentatively identified as N. italica from the characteristic mobilities of seven isozymes. Sequences of the 5.8S rRNA gene and its flanking ITS aligned with a 380+bp length of the published sequence for N. italica with 98% identity. Differences from the type strain were confined to ITS2. Shorter alignments (<320 bp) were observed with other Naegleria species, corresponding to conserved regions of the 5.8S gene and ITS. Unlike the European type strain of N. italica, the Australian isolates failed to infect laboratory mice intranasally, confirming that infectivity of this species is variable and often lower than in N. fowleri.