Goodwin M A, Brown J, Waltman W D
Georgia Poultry Laboratory, Oakwood 30566, USA.
Avian Dis. 1996 Oct-Dec;40(4):894-9.
Outbreaks of neonatal multifocal encephalomalacia with sepsis have been reported among flocks of very young chicks in Belgium, Scotland, and the United States. The purposes of the present study were to describe intralesional bacterial cocci in chicks with this type of encephalomalacia and to determine its incidence during 1991-95, and to determine the importance of this lesion with respect to the frequency of all other brain lesions/ diseases during the same time period. All laboratory records of broiler chickens examined at the Georgia Poultry Laboratory from Jan. 1, 1991, through Dec. 31, 1995, where the histopathologic diagnoses included the letter string encephal were retrieved for further study. The leading etiology for brain disease was nutritional encephalomalacia (57%), followed by neonatal encephalomalacia (22%), septic meningoencephalitis (16%), and Marek's disease (14%), in turn followed by nonpurulent encephalitis (7%), avian encephalomyelitis (3%), and mycotic meningoencephalitis (3%). Diagnosis of neonatal multifocal encephalomalacia with sepsis in the brains of Georgia chicks is a perennial one. Microscopically, the condition is characterized by mild to maximal multifocal locally extensive fibrin thrombosis of blood capillaries, and necrosis (encephalomalacia, malacia) of surrounding zones of brain stem and/or cerebral hemisphere neuropile. In 44% of cases of neonatal encephalomalacia fibrin thrombosis of blood capillaries was accompanied by intralesional gram-positive coccoid bacteria that were most abundant in medium- and small-sized arterioles or venules. Only gram-positive coccoid bacteria are found in cases of neonatal encephalomalacia (P < 0.05), and only gram-negative rod-shaped bacteria are found in cases of septic meningoencephalitis (P < 0.05). Therefore, bacterial culture and routine light microscopic histopathology are sufficient for diagnosing the condition when the differential diagnosis for neurologic disease in chicks includes neonatal encephalomalacia.
在比利时、苏格兰和美国，已报道了雏鸡群中爆发的伴有败血症的新生儿多灶性脑软化症。本研究的目的是描述患有此类脑软化症的雏鸡病灶内的细菌球菌，确定其在1991 - 1995年期间的发病率，并确定该病变在同一时期相对于所有其他脑部病变/疾病频率的重要性。检索了1991年1月1日至1995年12月31日在佐治亚州家禽实验室检查的所有肉鸡实验室记录，这些记录的组织病理学诊断包含字母串“encephal”，以供进一步研究。脑部疾病的主要病因依次为营养性脑软化症（57%）、新生儿脑软化症（22%）、化脓性脑膜脑炎（16%）和马立克氏病（14%），其次是非化脓性脑炎（7%）、禽脑脊髓炎（3%）和霉菌性脑膜脑炎（3%）。佐治亚州雏鸡脑中伴有败血症的新生儿多灶性脑软化症的诊断是常年存在的。在显微镜下，该病的特征是轻度至重度多灶性局部广泛的毛细血管纤维蛋白血栓形成，以及脑干和/或大脑半球神经纤维周围区域的坏死（脑软化症、软化）。在44%的新生儿脑软化症病例中，毛细血管纤维蛋白血栓形成伴有病灶内革兰氏阳性球菌样细菌，这些细菌在中小动脉或小静脉中最为丰富。在新生儿脑软化症病例中仅发现革兰氏阳性球菌样细菌（P < 0.05），而在化脓性脑膜脑炎病例中仅发现革兰氏阴性杆状细菌（P < 0.05）。因此，当雏鸡神经系统疾病的鉴别诊断包括新生儿脑软化症时，细菌培养和常规光学显微镜组织病理学足以诊断该病。
