Pseudomonas aeruginosa transmission is infrequent in New Zealand cystic fibrosis clinics.

Pseudomonas aeruginosa is an important pathogen in cystic fibrosis (CF). Although most patients harbour unique P. aeruginosa isolates, some clinics report patients sharing common strains. The overall importance of person-to-person transmission in P. aeruginosa acquisition and whether routine patient segregation is necessary remains uncertain. The present authors therefore investigated the extent of P. aeruginosa transmission in New Zealand CF clinics. New Zealand's seven major CF centres were assessed, combining epidemiological data with computer-assisted SalI DNA fingerprinting of 496 isolates from 102 patients. One cluster of related isolates was significantly more prevalent in the largest clinic than expected by chance. The seven patients with isolates belonging to this cluster had more contact with each other than the remaining patients attending this centre. No other convincing evidence of transmission was found in any of the other smaller clinics. Three P. aeruginosa strains believed to be transmissible between patients in Australian and British CF clinics are present in New Zealand, but there was no definite evidence they had spread. Pseudomonas aeruginosa transmission is currently infrequent in New Zealand cystic fibrosis clinics. This situation could change rapidly and ongoing surveillance is required. The current results confirm that computer-assisted SalI DNA fingerprinting is ideally suited for such surveillance.

Molecular screening of cystic fibrosis patients.

A method for the direct direction of the delta F508 mutation in the cystic fibrosis gene has been developed and applied to the analysis of over 280 individuals including 104 individuals with cystic fibrosis. This technique allows the rapid analysis of DNA from whole blood, Guthrie card blood spots, and the antenatal diagnosis of cystic fibrosis from chorionic villus biopsy samples. Based on these analyses, the delta F508 mutation is found in 77.88% of cystic fibrosis chromosomes in New Zealand cystic fibrosis patients. Thus this test can be used to establish a direct DNA diagnosis in over 60% of cystic fibrosis patients. Approximately a further 30% are heterozygous for this mutation.

Experience with neonatal screening for cystic fibrosis in New Zealand using measurement of immunoreactive trypsinogen.

Neonatal cystic fibrosis (CF) screening has been performed in New Zealand for a total of 7 years. This study reports the experience with this procedure in New Zealand over a 4 year period and compares it with 2 years when diagnoses of CF were suggested by clinical features only. A total of 72 infants were confirmed as having CF during 4 years of screening. Twenty-eight infants were found to have CF during 2 years in which screening was not performed. There were 29 false positive diagnoses during the screening years and six false negative diagnoses. Three of the false negative diagnoses occurred because of laboratory error, but three occurred because either the first or second measurement of immunoreactive trypsinogen (IRT) was normal. Faecal chymotrypsin was measured in samples from 434 infants at the time of the second IRT and assisted with the diagnosis for one infant which might otherwise have been missed. Only 42.5% of infants were asymptomatic at the time of the confirmatory sweat test. Significant morbidity and mortality was associated with meconium ileus which occurred in 24% of infants with CF. Improved ascertainment of cases of CF has occurred since screening began. Further follow-up is required to determine other benefits of newborn screening.

Enzyme-linked immunosorbent assay for ileal human goblet cell mucin.

A sandwich ELISA for measuring ileal human goblet cell mucin has been developed with a linear response range 0.2 to 1.5 ng mucin protein. It can be used to quantitate the mucin present in dilute and unpurified samples without interference from other glycoproteins and proteins. Reduction of the mucin decreased the reactivity by only 14% indicating that the assay reacts almost as well with mucin glycopeptides as with native mucin. The assay has the advantages over previously described immunoassays for mucin of giving a result in 6 h, detecting slightly lower concentrations of mucin, and is more sensitive, quantitative and specific than the traditional protein or periodic acid-Schiff assays used for glycoproteins.

Cystic fibrosis in New Zealand: incidence and mortality.

The incidence of and mortality from cystic fibrosis in New Zealand from 1960 to 1983, has been reviewed. Cystic fibrosis subjects have been located from data obtained from New Zealand paediatricians, the Cystic Fibrosis Association and hospital admission records. Mortality figures in the years 1960-1982 were also obtained. The incidence of cystic fibrosis of 1: 3179 non-Maori births was similar to that reported previously. Those born during 1970-1983, have a significantly better survival than those born before 1970. The survival figures are similar to those in England and Wales, but are considerably lower than those reported from Canada, or cystic fibrosis centres in the United States and Australia.

Structure of intestinal-mucus glycoprotein from human post-mortem or surgical tissue: inferences from correlation analyses of sugar and sulfate composition of individual mucins.

The carbohydrate composition of 14 human, small-intestine mucins, obtained at surgery or post-mortem, varied greatly from specimen to specimen with respect to individual sugars and average chain-length (ratio of total carbohydrate to N-acetylgalactosamine). Three monosaccharides, galactose, N-acetylglucosamine, and fucose gave good correlations with each other, and to total carbohydrate content, when expressed as a ratio to the chain-terminal N-acetylgalactosamine residue. In contrast, sialic acid gave a good correlation only with N-acetylgalactosamine. In eight specimens the molar sulfate to N-acetylgalactosamine ratios gave good correlation with the ratios of galactose to N-acetylgalactosamine, N-acetylglucosamine to N-acetylgalactosamine, and total carbohydrate to N-acetylgalactosamine. These results indicate that the intraspecies variability of intestinal-mucin carbohydrates arises from the interdependent addition of galactose, N-acetylglucosamine, fucose, and sulfate residues. Partial correlation-analysis indicated that proportions of N-acetylglucosamine and fucose were correlated only through a mutual dependence on galactose, suggesting that the key elongating-factors involve the addition of galactose residues. The number of sialic acid residues per oligosaccharide chain remained relatively unchanged from mucin to mucin, and this, coupled with the close correlation between the proportions of sialic acid and N-acetylgalactosamine, suggests that almost all sialic acid residues are bound to the core N-acetylgalactosamine residues in intestinal mucin. High fucose-to-sialic acid and high sulfate-to-sialic acid ratios reported in some disease states are explained as the consequence of chain elongation.

Child health of Great Barrier Island.

The health of 69 children on Great Barrier Island was studied. This is an isolated community without a permanent doctor, and most children were healthy. Ear disease was the commonest problem, especially in Maori children. Problems of impetigo, scabies, rheumatic fever and dental caries were not present. Comparisons are made with the results of a recent Auckland study.