Cranfield M R, Graczyk T K, Beall F B, Ialeggio D M, Shaw M L, Skjoldager M L
Baltimore Zoo, Maryland 21217.
J Wildl Dis. 1994 Jul;30(3):372-6. doi: 10.7589/0090-3558-30.3.372.
The subclinical and clinical Plasmodium elongatum and Plasmodium relictum infections of captive-reared African black-footed penguins (Spheniscus demersus) were evaluated in nine adult and 29 juvenile penguins in the Baltimore Zoo (Maryland, USA) during summer 1988 and winter 1989. Two diagnostic methods were used: Giemsa-stained thin blood films, and subinoculation of penguin blood into 1-day-old Peking ducklings. Chloroquine and primaquine treatment was applied to all parasitemic juvenile penguins. Twenty-nine parasite-free, juvenile penguins were monitored for parasitemia by Giemsa-stained thin blood films every two weeks for 26 weeks of their first outdoor exposure. Eighteen of 29 penguins experienced naturally acquired malaria; 14 were infected with P. elongatum, three with P. relictum, and one bird had a mixed P. relictum and P. elongatum infection. Eleven of 18 juveniles became parasitemic again after chloroquine and primaquine treatments. Based on Giemsa-stained thin blood smears and subinoculation of penguin blood into 1-day-old ducklings, performed in a mosquito-free environment in winter, nine adult penguins had no evidence of Plasmodium spp. infection. After dexmethasone-induced immunosuppression, four of six of these nonparasitemic adult penguins were found to be infected with P. relictum by the blood inoculation method.
1988年夏季和1989年冬季，在美国马里兰州巴尔的摩动物园，对9只成年和29只幼年非洲黑脚企鹅（斑嘴环企鹅）的亚临床和临床恶性疟原虫及残疟原虫感染情况进行了评估。采用了两种诊断方法：吉姆萨染色薄血膜，以及将企鹅血液接种到1日龄北京雏鸭体内。对所有出现寄生虫血症的幼年企鹅应用了氯喹和伯氨喹治疗。对29只无寄生虫的幼年企鹅在首次户外暴露的26周内，每两周用吉姆萨染色薄血膜监测一次寄生虫血症。29只企鹅中有18只自然感染了疟疾；14只感染了恶性疟原虫，3只感染了残疟原虫，1只同时感染了残疟原虫和恶性疟原虫。18只幼年企鹅中有11只在氯喹和伯氨喹治疗后再次出现寄生虫血症。基于冬季在无蚊环境中进行的吉姆萨染色薄血涂片以及将企鹅血液接种到1日龄雏鸭体内的检查，9只成年企鹅没有疟原虫属感染的证据。在通过地塞米松诱导免疫抑制后，通过血液接种法发现，6只无寄生虫血症的成年企鹅中有4只感染了残疟原虫。
