Comparative evaluation of the hygienic efficacy of an ultra-rapid hand dryer vs conventional warm air hand dryers.

AIMS: To compare an ultra-rapid hand dryer against warm air dryers, with regard to: (A) bacterial transfer after drying and (B) the impact on bacterial numbers of rubbing hands during dryer use. METHODS AND RESULTS: The Airblade™ dryer (Dyson Ltd) uses two air 'knives' to strip water from still hands, whereas conventional dryers use warm air to evaporate moisture whilst hands are rubbed together. These approaches were compared using 14 volunteers; the Airblade™ and two types of warm air dryer. In study (A), hands were contaminated by handling meat and then washed in a standardized manner. After dryer use, fingers were pressed onto foil and transfer of residual bacteria enumerated. Transfers of 0-10(7) CFU per five fingers were observed. For a drying time of 10 s, the Airblade™ led to significantly less bacterial transfer than the other dryers (P < 0·05; range 0·0003-0·0015). When the latter were used for 30-35 s, the trend was for the Airblade to still perform better, but differences were not significant (P > 0·05, range 0·1317-0·4099). In study (B), drying was performed ± hand rubbing. Contact plates enumerated bacteria transferred from palms, fingers and fingertips before and after drying. When keeping hands still, there was no statistical difference between dryers, and reduction in the numbers released was almost as high as with paper towels. Rubbing when using the warm air dryers inhibited an overall reduction in bacterial numbers on the skin (P < 0·05). CONCLUSIONS: Effective hand drying is important for reducing transfer of commensals or remaining contaminants to surfaces. Rubbing hands during warm air drying can counteract the reduction in bacterial numbers accrued during handwashing. SIGNIFICANCE AND IMPACT OF THE STUDY: The Airblade™ was superior to the warm air dryers for reducing bacterial transfer. Its short, 10 s drying time should encourage greater compliance with hand drying and thus help reduce the spread of infectious agents via hands.

Completed follow-up of 1,000 consecutive transcervical chorionic villus samplings performed by a single operator.

Completed follow-up data on 1,000 patients undergoing transcervical chorionic villus sampling (CVS) performed by a single operator at the Royal Hospital for Women is presented. Prior to the introduction of CVS, approximately 750 amniocenteses were performed annually in this unit. Over the past 5 years the total number of patients having CVS or amniocentesis has increased by 1/3 and almost 1/2 of procedures are now done by CVS. We have persisted with the transcervical route believing that once the learning curve is past, this route compares favourably with the transabdominal method in loss rate and perinatal outcome. We feel the transcervical approach is better tolerated by our patients and that less procedural difficulties are encountered. With increasing operator experience the total fetal loss rate to 20 weeks' gestation in our series declined to 2.1% and late complications were no more frequent than expected. In 98.4% of patients, sufficient villi were obtained for analysis. Culture failure was extremely uncommon, occurring only twice in our series. In 1.5% of patients, a follow-up amniocentesis was required, which compares favourably with other published series. It appears that many units abandoned the transcervical route before loss rates were stabilized. In units where transcervical CVS is still performed the transabdominal route is also utilized. The reverse is not true. The authors feel that both procedures have a role in modern antenatal diagnosis.

Prenatal diagnosis in 3,000 women for chromosome, X-linked, and metabolic disorders.

In 3,000 women referred for prenatal diagnosis, 110(3.7%) abnormal fetuses were detected and 85 therapeutic terminations were performed. These were five main reasons for referral. Among the 2,227 women referred because of maternal age 35 years and older, there were 51 (2.3%) who had aneuploid fetuses. In the 297 women referred because of a previous child with Down syndrome, 3 aneuploid fetuses (1.0%) were detected. Of the 55 couples where one spouse was a carrier of a balanced chromosome rearrangement, 6 chromosomally abnormal fetuses were found (10.9%) (all the offspring of maternal carriers). In the latter group, five of the six heterozygotes with abnormal findings were carriers of tdic (13;21) translocations. In the 82 cases with a history of X-linked disorders, there were 40 males (49%). Thirty-five women were referred because of inborn errors of metabolism: 10 affected fetuses were found (28%). There was a greater proportion of sex-chromosome aneuploids as compared to trisomy 21 fetuses in the 35 to 39 year maternal age group. This was reversed in the group of women 40 years old and older. Of the 25 abnormal fetuses not terminated, 6 were sex chromosome aneuploids and 10 involved X-linked conditions where the progeny could be further prenatally monitored (eg, X-linked hydrocephalus) or treated (eg, hemophilia). In the remaining 9 the parents expressed divers reasons for their choice. Repeat amniocentesis was required in 2.9% of cases. One case of maternal cell contamination and one case of unconfirmed mosaicism were the only diagnostic errors found in the study. In the last 1,000 specimens referred, the average time necessary for a karyotypic result was 15.6 +/- 5.6 days after amniocentesis.

Further dicentric X isochromosomes and deletions, and a new structure i(X)(pter to q2102 to pter).

A new dicentric X isochromosome i(X)(pter to q2102 to pter) of similar size to a normal X is described in a girl with gonadal dysgenesis. In this non-mosaic case with an X short arm duplication, most of the stigmata associated with Turner's syndrome were absent. This structure was compared with that of six i(Xq) and three del(X). The del(Xq) structures all possessed a regular sized C band, but in the i(Xq) this was double sized in each case. Phenotypic comparisons are made in the Xq deletions, and some presumptive short arm isochromosomes are reinterpreted as Xq deletions. Incomplete centromeric suppression is suggested as the causal mechanism of mosaicism of sex isochromosomes with 45,X cells, and it is argued that an exchange event between homologoues is an unlikely mechanism to explain sex isochromosome origin.

Familial dicentric translocation t(13;18)(p13;p11.2) ascertained by recurrent miscarriages.

A dicentric translocation is described involving chromosomes 13 and 18 in which the centromere of chromosome 13 was suppressed. The translocation was ascertained by repeated miscarriages and was found in three generations of phenotypically normal carriers.