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.