Hydranencephaly, Cerebellar Hypoplasia, and Myopathy in Chick Embryos Infected with Aino Virus

Abstract

Abstract. Pathogenesis of Aino virus (AIV), a suspected causative agent of congenital abnormalities of calves,has not yet been established by experimental infection of dams. To investigate the pathogenesis, lo3 median tissue culture infective doses per 0.2 ml of AIV strain JaNAr 28 was inoculated into the yolk sac of 8-day-old chick embryos. At 4, 7, 10, and 13 days post-inoculation (PI) 20 eggs were opened and macro-and microscopic studies combined with virus recovery and immunohistochemical detection of the virus antigen were performed. At 7 to 1 3 days PI chick embryos manifested marked hydranencephaly, cerebellar hypoplasia, arthrogryposis, and scoliosis, with the highest incidences of 86.7%, 73.3%, 80.0°/o, and 20.0%, respectively. At 4 days PI the viral antigen was found in nerve cells, gitter cells in mild necrotic foci of the central nervous system (CNS), degenerative myotubules, and macrophages in the interstitium, which was associated with the early phase of AIV-induced encephalitis and polymyositis, with occasional accompanying hemorrhage and clumping of myotubular fragments. From 7 to 10 days PI, AIV antigen increased markedly in the liquefactive necrosis and in both degenerative and normal-looking myotubules in conjunction with developing hydranencephaly and arthrogryposis. The encephalitis and myositis had a tendency to mitigate by 10 days PI, coincident with a slight decrease in amount of AIV antigen. At 13 days PI there was almost no detectable AIV antigen in CNS and skeletal muscles, probably due to depletion of cells having affinity to AIV.

Ovine and Bovine Congenital Abnormalities Associated With Intrauterine Infection With Schmallenberg Virus

“…From experimental infection studies with Akabane and Aino virus, using chick embryos 19,20,25 or primary cultures of fetal bovine brain, 18 it is known that these viruses preferentially infect neuronal and astroglial cells. Interestingly, vascular wall thickening in brain tissue was seen to be associated with necrotizing encephalitis in chickens at 7 days postinfection to form granulomatous lesions at 10 and 13 days postinfection.…”

Arthrogryposis, hydranencephaly and cerebellar hypoplasia syndrome in neonatal calves resulting from intrauterine infection with Aino virus

“…Although serologic data suggested that AINOV caused congenital abnormalities of cattle and sheep in Japan and Australia [1,12], the pathogenicity of AINOV in cattle has not been demonstrated. Viral teratogenicity in cattle and sheep has been well demonstrated for AKAV [2,8,11,13], a member of bunyavirus; however, the teratogenicity of AINOV has been examined only in chick embryos [5][6][7]. To determine the role of AINOV in inducing congenital malformation, fetal cattle were exposed to maternal and direct routes of infection with the virus and examined for transplacental activity of the virus and developmental abnormalities.…”

“…The results of this study revealed that AINOV was equally teratogenic for cattle as AKAV. It has been shown that chick embryos manifest marked hydranencephaly, cerebellar hypoplasia, arthrogryposis and scoliosis by inoculation into the yolk sac of eight days embryo with AINOV [5][6][7]. Kitano et al [6] mentioned that cerebellar hypoplasia in AINOV-infected chick embryos constitutes a distinctive difference from AKAV-infected chick embryos, which showed hydranencephaly and myopathy [9].…”

Polymerase Chain Reaction (PCR) Amplification of Parvoviral DNA from the Brains of Dogs and Cats with Cerebellar Hypoplasia

“…The most common cause of cerebellar hypoplasia in neonatal animals is an intrauterine viral infection during early or midgestation. A number of different viruses are capable of causing this malformation, including herpes simplex virus, 13 bluetongue virus, 14 Chuzan virus, 15 Akabane virus, 16 rift valley fever virus, 17 Cache Valley and Aino viruses, 4,17 the pestiviruses of bovine virus diarrhea (BVD) and hog cholera, 1,2 the flavivirus of Wesselbron disease, 17 Rubella, and the parvovirus of feline panleukopenia. 18 Cerebellar hypoplasia has been recognized in cats as early as 1888.…”

“…Viral infections occur most commonly in cats and cattle but have been described in sheep, pigs, goats, and chickens. [1][2][3][4][5] Cerebellar hypoplasia has not been described in the dog secondary to in utero viral infection. Congenital cerebellar malformations are reported occasionally in dogs, and typical lesions include partial or complete absence of the cerebellar vermis.…”