No abstract

Abstract. Murray Valley encephalitis (MVE) virus is a mosquito-borne flavivirus causing severe encephalitis with a resultant high morbidity and mortality. In the period 1989-1993, we undertook a cross-sectional and longitudinal study by annually screening members of a small remote Aboriginal community in northwestern Australia for MVE virus antibodies. Of the estimated 250-300 people in the community, 249 were tested, and 52.6% had positive serology to MVE. The proportion testing positive increased with increasing age group, and males were slightly more likely to be positive than females. During the study period, a high proportion of the population seroconverted to MVE; the clinical/subclinical ratio seems to be lower than previously reported. Although MVE is mostly asymptomatic, the devastating consequences of clinical illness indicate that advice should be provided regarding the avoidance of mosquito bites. Our longitudinal study showed that the risk of seroconversion was similar for each age group, not just the young.

No abstract

In a dose-response study, 120 weanling, crossbred pigs were used to determine the effect of 7.5, 15, 30, 60, 120 and 240 ppm total dietary Cu on animal performance and Cu and Fe stores in selected tissues. Pigs were killed at 56 or 91 kg average body weight. Average daily gain was not affected by dietary treatment. Dietary Cu concentrations of 7.5, 15, 30 and 60 ppm had no appreciable effect on Cu and Fe concentrations in liver and kidney of pigs slaughtered at 91 kg. However, 120 and 240 ppm dietary Cu increased (P less than or equal to .01) liver Cu 4.5- and 16-fold and decreased (P less than or equal to .05) liver Fe by 50 and 60%, respectively, compared with the other dietary treatments. A fit of liver Cu and Fe data to linear plateau models resulted in an inflection point of approximately 60 ppm dietary Cu. Kidney Cu was also increased (P less than or equal to .05) by 120 and 240 ppm dietary Cu, but the magnitude of the change was smaller than that of liver Cu. Muscle Cu and Fe were not significantly affected by dietary Cu.

No abstract