DETECTION OF AVIAN MALARIA INFECTIONS IN WILD AND CAPTIVE PENGUINS

Sera from wild African black-footed penguins (Spheniscus demersus L., 1758), Adelie penguins (Pygoscelis adeliae Houbron, 1841), Gentoo peng uins (Pygoscelis papua Forster, 1781), king penguins (Aptenodytes pata gonicus Miller, 1778), and little blue penguins (Eudyptula minor Forst er, 1781) and from captive yellow-eyed penguins (Megadyptes antipodes Houbron, 1841) and Magellanic penguins (Spheniscus magellanicus Forste r, 1781) were tested by enzyme-linked immunosorbent assays for the pre sence of avian malaria antibodies (Ab). Plasmodium falciparum sporozoi te (R32tet(32)) and gametocyte (P.F.R27) antigens were used. Specifici ty of anti-S. demersus, anti-duck, anti-chicken, and anti-turkey Ige l abeled with alkaline phosphatase was determined for homologous and het erologous sera of 8 avian species (including 6 penguin species). The p enguin conjugate was the most specific for the various penguin species immunoglobulins. It was possible to detect penguin immunoglobulins at a dilution of 10(-4.11). The relative binding of anti-S. demersus IgG was equal to relative binding of commercial conjugates. Kinetic profi les and overall magnitudes of malarial Ab detected by the 2 antigens w ere not significantly different. Antarctic P. adeliae were negative fo r malarial Ab, all New Zealand M. antipodes were positive, and the pos itivity prevalence of the remaining penguins ranged from 33 to 92%. An tibody titers and the prevalence of infection of wild S. demersus were significantly lower than those reported for captive North American S. demersus.