Low-cost, simultaneous, single-sequence genotyping of the HLA-A, HLA-B and HLA-C loci.

New automated DNA sequencing technology has enabled the development of an assay for genotyping the three major HLA class 1 loci from a single sequence of each gene containing exon 3, intron 2 and exon 2. The assay allows 31 subjects (with 3 negative controls) to be genotyped at all three loci simultaneously, using a 96-well plate format. Genotypes were assigned by comparing each sequence to a database of 307 HLA-A, 563 HLA-B and 166 HLA-C alleles. Unequivocal, 4-digit allele assignments were made for 40 of 130 HLA-A genes, 82 of 130 HLA-B genes and 97 of 130 HLA-C genes from 21 European, 20 Tongan and 24 Niuean subjects. Ambiguity in interpretation of the sequence contributed to 66 of the 170 equivocal allele assignments, and 105 equivocal assignments were due to polymorphisms outside exons 2 and 3. All known alternative interpretations of ambiguous genotypes were identified, and seven HLA-B and two HLA-C ambiguities were resolved by reading the out-of-phase exon 2 sequence that followed an indel in intron 2. The genotypes of a subgroup of 27 heterozygous subjects, whose genotypes contained all of the alleles identified in this study, were confirmed with commercial, generic PCR-SSP typing. In European subjects, the repertoire of HLA-B/HLA-C haplotypes was almost identical to previously published data. We identified five new HLA-B/HLA-C haplotypes in the Polynesian subjects, and the remaining haplotypes were of Asian origin. In summary, we are describing a low-cost, sequencing assay for the three major HLA class I loci that provides a level of resolution that is comparable with a commercial PCR-SSP assay.

Ethnic and gender differences in the use of coronary artery revascularisation procedures in New Zealand.

AIMS: To examine ethnic and gender variations in the use of coronary artery revascularisation procedures in New Zealand and to determine whether the introduction of priority scores affected intervention trends. METHODS: Analysis of the National Minimum Database for coronary artery bypass graft (CABG) and percutaneous transluminal coronary angioplasty (PTCA) intervention rates for New Zealand Pacific, Maori and other men and women aged 40 years and over during the decade 1990-1999. RESULTS: Coronary artery revascularisation rates were lower in women than in men in all ethnic groups and in Pacific and Maori men compared with other New Zealand men. Compared to all men, the mean age-standardised CABG and PTCA intervention rate ratios in all women were 0.34 and 0.36. Compared to other New Zealand men, the mean age-standardised CABG and PTCA intervention rate ratios were 0.64 and 0.25 in Pacific and 0.40 and 0.29 in Maori men respectively. Compared to other New Zealand women, the rate ratios for CABG and PTCA were 0.73 and 0.21 in Pacific and 0.74 and 0.43 in Maori women respectively. Introducing priority scores was neither associated with reduced cardiac procedures nor significantly reduced variation in procedures across all ethnic groups. CONCLUSIONS: Although Pacific and Maori peoples had higher rates of coronary artery disease morbidity and mortality, revascularisation rates were lower in both groups. Strategies beyond the use of priority scores are needed to address ethnic and gender disparities in coronary artery revascularisation procedures in New Zealand.

Cancer in Niue: analysis of a cancer register 1962-1985.

Cancer is becoming an important cause of morbidity and mortality in Niue. Analysis of a cancer register showed an overall age adjusted rated of 11.3 and 9.9 per 10000 among males and females, respectively. A significant increase in the trend of cancer during 1952 to 1985 cannot be explained by improved registration alone. This study when compared with other data sources on Niue indicated a gross under-reporting of cancer (over 70%). The establishment of national registers for chronic diseases like cancer is the most accurate, economic and technically achievable way to provide population-based information for the small Pacific Island states.

The epidemiology of breast cancer in Pacific women in New Zealand.

AIM: To describe the epidemiology of breast cancer in Pacific women in New Zealand and determine whether ethnic disparities exist. METHODS: Analysis of data obtained from the New Zealand Cancer Registry for breast cancer notifications from 1987-94 inclusive. Statistical analysis compared the age-specific incidence, tumour stage at presentation and pathological tumour type of Pacific, Maori and Other women. RESULTS: Notification data were analysed for 12,914 breast cancer cases including 688 Maori and 227 Pacific women. The age-standardised incidence rate per 100,000 person years for Pacific women (104.5) was statistically significantly (p<0.05) lower than that for Other (139.1) and Maori (148.6) women. Pacific and Maori women presented with significantly less localised tumours (31.4% and 41.3% respectively) than Other women (47.2%). CONCLUSION: Ethnic disparities in breast cancer epidemiology exist in New Zealand. Pacific women may have decreased incidence rates of breast cancer but they and Maori women present with a more advanced stage of breast cancer than Other women. The latter is a modifiable factor which could be targeted by improved participation in screening programmes.

Dietary intakes of middle-aged European, Maori and Pacific Islands people living in New Zealand.

AIM: To compare dietary intakes of Maori, Pacific Islands and European men and women in New Zealand. METHODS: A food frequency questionnaire was used to calculate nutrient intakes of 5523 New Zealand workers aged 40 years and over (3997 men, 1524 women) from a cross-sectional survey carried out between 1988 to 1990. RESULTS: Compared with European men and women, Maori women and Pacific Islands men and women consumed larger amounts of total energy per day. Age-adjusted nutrients expressed as percentage contribution to total energy intakes showed that Maori and Pacific Islands men and women consumed less carbohydrate, fibre and calcium, and more protein, fat, saturated fat and cholesterol than European men and women, respectively. These results were consistent with fewer servings of cereal and cheese per month, and more servings of red meats, fish and eggs in Maori and Pacific Islands participants compared with Europeans, after adjusting for age and total energy intakes. Pacific Islands men and women also consumed more servings of chicken, fewer cups of milk and fewer servings of fruit per month compared to Europeans. Maori men and women consumed more slices of bread and fewer servings of vegetables per month compared to European men and women. CONCLUSIONS: There were striking differences in dietary habits, food selections and cooking practices between European, Maori and Pacific Islands participants. Dietary intakes of Maori workers were closer to those of Europeans than those of Pacific Islands participants. Ethnic differences were due to larger portion sizes and increased frequency of most foods in Maori and Pacific Islands participants.

Incidence of cancer among Pacific Island people in New Zealand.

AIM: to describe the epidemiology of new cancer registrations among Pacific Island people in New Zealand with a view to identifying important cancers for preventive activities. METHODS: new cancer cases registered with the New Zealand Cancer Registry of the Health Statistical Services for the decade 1979-88 were analysed. Cancer cases among Pacific Island people were compared with cancer cases among Maori and the remainder of the New Zealand population (other). RESULTS: while the number of cases reported among Pacific Island people was relatively small (1884), age standardised rates for cancer of all sites were much higher than age standardised rates for Maori and other populations. The age standardised rate (per 100,000 person years) for cancer of all sites among males in all age groups was 400 for Pacific Island, 308.8 for Maori and 295.3 for others. The age standardised rate for cancer of all sites among women in all age groups was 373.3 for Pacific Island women, 324.2 for Maori and 313.4 for other women. Liver cancer was more common among Pacific Island men than could be explained by temporary migration from the Pacific Islands for treatment. The age standardised rate for liver cancer was 28.2 for Pacific Island men, 11.4 for Maori and 1.9 for other men. Cancer of the cervix was the leading site among Pacific Island women as in Maori women, compared with breast cancer among women in the rest of the population. The age standardised rate for cervical cancer was 61.8 for Pacific Island, 69.0 for Maori and 59.3 for other women. CONCLUSION: in the decade 1979-88 there was an excess number of new registrations for some cancers described among Pacific Island people compared with Maori and other ethnic groups. Temporary migration from the Pacific Islands for treatment may explain some of the excess cases.

Coronary heart disease among Pacific Island people in New Zealand.

Coronary heart disease is the leading cause of death in New Zealand. Death rates are higher among the Maori than the European population but rates have been declining in both groups over recent years. The occurrence of coronary heart disease among the Pacific Island population in New Zealand is unknown. Data from the National Health Statistics Centre (NHSC) and the Auckland coronary or stroke (ARCOS) study were used to describe the occurrence of coronary heart diseases among Pacific Island people. Age standardised mortality rates show that coronary heart disease is an important cause of death among Pacific Island men. Death rates have declined between 1973-77 and 1978-82 but this trend did not continue among men in the 1983-86 period. Age standardised mortality rates from coronary heart disease from the ARCOS data are 175/100,000 and 52/100,000 for Pacific Island men and women compared with 325/100,000 and 141/100,000 for Maori men and women. Age standardised rates for European men and women are 154/100,000 and 36/100,000 respectively.

Progress of impaired glucose tolerance to diabetes mellitus among Niueans.

Noninsulin dependent diabetes mellitus (NIDDM) is a major public health problem among Polynesians in the South Pacific. The prevalence of NIDDM on Niue Island is higher than other Pacific Islands and is increasing. NIDDM is preceded by a state of impaired glucose tolerance in some cases. Progress to NIDDM is associated with certain factors that are modifiable. In 1980, the South Pacific Commission conducted a metabolic disease survey on Niue. Sixty-one people were diagnosed as having impaired glucose tolerance. In 1985, 48 of these people (all those still on the island) were reexamined. Demographic, biological and indicators of westernisation were recorded. Thirty-one percent (6% per year) had progressed to diabetes mellitus. This was higher than rates described elsewhere but comparable with the rates described among the Pima Indians. Younger age, skilled occupations, high socioeconomic status and higher overall modernity were associated with progression to NIDDM.

An epidemic of type 3 dengue on Niue Island.

An epidemic of dengue fever type 3 occurred on the island of Niue late in 1985 and during the first quarter of 1986. Just over 18% of the population reported for medical attention, the disease predominantly affecting teenagers and young adults, with equal sex distribution. The epidemic was of the classical dengue syndrome and there were no deaths. There were some unusual features. The magnitude of antibody rise was unusually high in many of those with no preexisting antibody. Despite the large proportion of the population with preexisting dengue type 2 antibodies, no cases of dengue haemorrhagic fever/dengue shock syndrome were observed, confirming the observations made in many other epidemics that these serious complications do not always follow in sequential epidemics caused by two different types. A high level of awareness, combined public health measures and active community involvement helped to control the epidemic early.