Graczyk T K, Shaw M L, Cranfield M R, Beall F B
Johns Hopkins University, School of Hygiene and Public Health, Department of Immunology and Infectious Diseases, Baltimore, Maryland 21205.
J Parasitol. 1994 Apr;80(2):302-8.
Twenty-nine juvenile, captive-reared African black-footed penguins (Spheniscus demersus) were hematologically monitored every 2 wk over the period of 24 wk during their first outdoor exposure. Blood samples taken from the penguins were screened for 12 blood evaluation parameters. Parasitemic penguins were medically treated. Eighteen birds (62.1%) experienced naturally acquired malaria and 11 birds (37.9%) remained nonparasitemic. A total of 32 avian malaria episodes were noted; 25 (78.1%) were identified as Plasmodium elongatum, 5 (15.6%) as Plasmodium relictum, and 2 (6.3%) as Plasmodium spp. One P. elongatum (3.4%) and 3 P. relictum (10.3%) infections were fatal. All deaths occurred during the first episode of parasitemia. Gross lesions of the birds that died included hepatomegaly and splenomegaly. Interstitial pneumonia with schizonts was observed on histological examinations. The range, mean, and SD of 12 hematological parameters were determined for nonparasitemic and parasitemic penguins. Differences between these groups in total white blood cell (WBC) counts and relative lymphocytosis (LYMPHS) were not significant. The combined classes of total WBC counts (> 20.0 x 10(3)/microliters) and LYMPHS (> 60.0%) are not indicative of avian malaria infection in African penguins. No correlations were found between changes in the values of blood parameters with season or age of penguins. Treatment of parasitemic birds significantly reduced expected mortality from 50.0% to 13.8%.
29只人工饲养的幼年非洲黑脚企鹅（斑嘴环企鹅）在首次户外暴露的24周期间，每隔2周进行一次血液学监测。从企鹅身上采集的血样针对12项血液评估参数进行筛查。对感染寄生虫的企鹅进行药物治疗。18只企鹅（62.1%）自然感染了疟疾，11只企鹅（37.9%）未感染寄生虫。共记录到32次禽疟疾发作；其中25次（78.1%）被鉴定为伸长疟原虫，5次（15.6%）为残疟原虫，2次（6.3%）为疟原虫属。1例伸长疟原虫感染（3.4%）和3例残疟原虫感染（10.3%）是致命的。所有死亡均发生在寄生虫血症的首次发作期间。死亡鸟类的大体病变包括肝脏肿大和脾脏肿大。组织学检查发现伴有裂殖体的间质性肺炎。测定了未感染寄生虫和感染寄生虫的企鹅12项血液学参数的范围、平均值和标准差。这些组之间在总白细胞（WBC）计数和相对淋巴细胞增多症（LYMPHS）方面的差异不显著。总白细胞计数（>20.0×10³/微升）和淋巴细胞增多症（>60.0%）的综合类别并不表明非洲企鹅感染了禽疟疾。未发现血液参数值的变化与企鹅的季节或年龄之间存在相关性。对感染寄生虫的鸟类进行治疗显著降低了预期死亡率，从50.0%降至13.8%。
