Mortality in Niue, 1978-82.

This report is an analysis of mortality in the population of Niue Island over the years 1978-82. The overall level of mortality in Niue is low. Life expectancy at birth is correspondingly high (66.5 years). Because of the extensive migration of Niueans during the period of study the death rate may be underestimated and the life expectancy correspondingly overestimated. Infant mortality has dropped from over 200 deaths per 1000 live births during the 1940s to around 10 per 1000 during the period under study. The major causes of premature mortality in Niuean males were injury/poisoning followed by cardiovascular disease. In females infection, injury/poisoning and neoplasia were the major causes of mortality. The 1980 epidemic of dengue fever had an appreciable effect on mortality in this small population. Except for dengue fever, the pattern of mortality in Niue is similar to that in many developed countries. Preventive efforts against metabolic and cardiovascular disease (including hypertension and diabetes) should continue in order to control mortality from these causes, Mosquito programmes, and emergency measures if epidemics threaten, are required so that deaths from haemorrhagic dengue are prevented.

Glucose tolerance in Polynesia. Population-based surveys in Rarotonga and Niue.

Glucose tolerance and the prevalence of impaired glucose tolerance (IGT) and diabetes in the Polynesian populations of Rarotonga and Niue were studied in 1980. Both Rarotongans and Niueans have been considerably influenced by sociocultural modernization and (in the case of Rarotonga) tourism. In both populations, the prevalence of abnormal glucose tolerance exceeded 10% in men and 15% in women. There was an association between glucose tolerance and age and obesity in both sexes, but not between glucose tolerance and physical activity. Glucose tolerance did not differ between Rarotongans and Niueans after allowing for differences in age and obesity. Comparisons between normal subjects, those with impaired glucose tolerance (IGT) and diabetic subjects with respect to factors that are traditionally associated with glucose intolerance provided some support for IGT as a truly intermediate diagnostic category of glucose tolerance.

An epidemic of influenza in the population of Niue.

An epidemic of influenza A occurred in the Niue population during May-June 1983. The infection was introduced by two index cases returning from New Zealand to the village of Makefu. The epidemic started in this village and then spread rapidly around the island. The incidence of infection was calculated to be 41 per 100 population based on 1981 census figures. There was no predilection for the infection to affect any particular age bracket, although the elderly were over-represented amongst the hospital admissions because of greater severity of illness in this age group. Two deaths occurred, and 3.4% of cases received treatment in hospital. Apart from generalised symptoms (fever, body pain, and headache), respiratory symptoms, particularly cough, were prominent. Gastrointestinal symptoms were reported in a minority. The average duration of illness was 6 days. Virology results indicated that the epidemic was due to influenza A/Bangkok/1/79(H3N3). Paired serological studies also revealed five cases of dengue fever. Previous records reveal that epidemics of influenza are a frequent occurrence in Niue, although not a major cause of mortality since the 1950s. It is suggested that early treatment of complications is the most important measure to decrease the impact of influenza and that measures such as isolation of cases, restriction of population movement and quarantine of incoming cases may be useful to prevent the propagation of epidemics in a small and isolated population.

Serological markers of hepatitis B infection in Niue children.

Hepatitis B infection is hyperendemic in the adult population of Niue. In order to determine the age at which infection is acquired and the contribution of vertical and horizontal transmission, the sera from 1055 children were tested for markers of hepatitis B infection. Eleven percent (11.0%) were found to be carriers of hepatitis B surface antigen (HBsAg) and a further 33.6% had antibody to hepatitis B surface antigen (anti-HBs). While less than 15% of the population were infected before the age of two years, these children had the greatest risk of becoming chronic carriers. The simplest method of controlling hepatitis B infection in Niue would be to immunise all newborn babies.

A cross sectional study of markers of hepatitis B infection in Niue.

To determine whether the island of Niue would be a suitable location to evaluate the efficacy of hepatitis B vaccine, the prevalence of hepatitis B infection in the adult population was studied. Sera were collected from 1147 of 1244 residents above the age of 20 years, and tested for the presence of hepatitis B surface antigen (HBsAg) and specific antibody to the surface and core antigens (anti-HBs and anti-HBc) by solid-phase radioimmunoassay (SPRIA). Hepatitis B was found to be hyperendemic; 11.9% of those tested were found to be carriers of HBsAg and an additional 84% had detectable levels of anti-HBs or anti-HBc indicative of current or past infection. In this population HBV infection appears to occur early in life as the peak prevalence of serological markers was found in young adults. The almost universal infection of the population, their high rate of compliance with the study and the relatively high birth rate indicate that Niue would be a suitable location to evaluate methods of preventing hepatitis B infection.

Wheezing bronchitis in children on a South Pacific Island.

Retrospective and prospective studies were done on children with wheezing bronchitis on the small Pacific island of Niue. Wheezing bronchitis was found to be a common cause of morbidity, but not mortality in these children. Episodes of the disease were most common in children under the age of 4 years and tended to disappear as they became older. A case-control study indicated smoking by the mother (P less than 0.0001), positive stool examination for parasites (P less than 0.001), mother with a history of wheezing bronchitis (P less than 0.01) and father smoking (P less than 0.05) were all correlated with wheezing bronchitis. Skin testing and serologic results indicated that hypersensitivity to house dust mite (Dermatophagoides pteronyssinus) and plantain (Plantago lanceolata) antigens were also associated with having wheezing bronchitis. This study demonstrates the multifactorial etiology of wheezing bronchitis on a Pacific island.