[Neurologic diseases transmitted by ticks]. / Durch Zecken übertragene neurologische Krankheiten.

Apart from causing various dermatological disorders, ticks, which also widespread in our part of the world, can transmit diseases that affect the nervous system. The difficulty of carrying out differential diagnosis and the possibility of administering causal treatment in cases of meningopolyneuritis Garin-Bujadoux-Bannwarth and progressive Borrelian encephalomyelitis are giving rise to demands for an improvement in immunodiagnosis.

The effect of colostrum-derived antibody on neo-natal transmission of caprine arthritis-encephalitis virus infection.

Two groups of 6 newborn goat kids were artificially fed colostrum containing antibody to caprine arthritis-encephalitis (CAE) virus, obtained from clinically affected does. Kids in group A were fed the colostrum from birth until 7 days of age, while kids in group B were fed colostrum from 1 to 3 days after birth for 7 days. Kids were fed cow's milk at all other times. Serum antibody resulting from the consumption of colostrum, detected by agar gel immunodiffusion (AGID) tests, lasted for up to 8 weeks in group A, but none was detected in group B. Four kids from each group became infected with CAE virus as demonstrated by the emergence of active immunity and by virus isolation procedures. It appeared that uptake of colostral antibody by group A did not prevent viral transmission, interfere with development of active immunity, or modify the outcome of the CAE virus infection.

Transmission and control of caprine arthritis-encephalitis virus.

Caprine arthritis-encephalitis virus was isolated from goat milk and transmitted most efficiently to kids through both milk and colostrum. In addition, it appeared that transmissions through other secretions of the doe occurred, but were less important than transmission in milk and colostrum. Intrauterine infection may have occurred in 2 of 32 cesarean-derived goats, but postpartum horizontal transmission could not be ruled out. Transmission by the aerosol route was not demonstrated, and even short-term direct contact between virus-infected bucks and virus-free does during breeding did not result in transmission. Prolonged direct contact for over 12 months between weaned cesarean-derived goats and virus-infected goats was necessary before horizontal transmission could be demonstrated under nondairy conditions. However, when uninfected does were milked with infected does, a high percentage became infected in less than 10 months. Heat inactivation (56 C) reduced approximately 10(5) median tissue culture infective doses of caprine arthritis-encephalitis virus to below titratable levels, and virus was not transmitted to kids fed virus-infected colostrum that had been heated at 56 C for 1 hour. A program of eradication is discussed in which kids are removed from their dams at birth, fed safe sources of colostrum and milk, and isolated from other goats until weaning.

The biology of Encephalitozoon cuniculi.

Encephalitozoon cuniculi is a widespread and often sub-clinical microsporidian parasite of homeothermic animals, including man. The biology, pathology and taxonomy of the organism is reviewed and the available diagnostic methods discussed. Transmission is almost invariably via the oral route either by ingestion of contaminated tissues and other foods or by ingestion of infected urine, perhaps on food, or when animals lick the coats of others. Transplacental transmission does not seem common but can probably occur when susceptible animals are infected during pregnancy. It has been demonstrated once in mice and once in rabbits. The possibility of arthropod vector transmission awaits thorough investigation but this is unlikely to be as important as the oral route. No drugs have yet been found to be effective against E. cuniculi but control of the spread of encephalitozoonosis in laboratory animals, at least, can probably be achieved by maintaining laboratory hygiene.

Biological properties of a canine distemper virus isolate associated with demyelinating encephalomyelitis.

A canine distemper virus (CDV), DESIGNATED R252, originally recovered from a dog with demyelinating encephalomyelitis was shown to reproduce this disease in gnotobiotic dogs with a high incidence as compared to other CDV strains, which produced an acute fatal infection. In this investigation, R252 was propagated for the first time in Vero cells and compared to two known strains of CDV, Snyder-Hill (SH) and Onderstepoort (Ond). The results of this study revealed that intracellular R252 accumulated more slowly than either SH or Ond. There was extensive destruction of Vero monolayers infected with either R252 or SH. Each virus induced the formation of intracytoplasmic and intranuclear inclusions. Ond infection resulted in minimal cytopathic changes and intracytoplasmic inclusions. Immunofluorescence studies indicated that the spread of R252 infection within the monolayers was intermediate between the rapidly spreading SH and slowly spreading Ond. R252-infected cells developed characteristic immunofluorescent cytoplasmic inclusions. Initially, each stained homogeneously and later appeared as a non fluorescent body surrounded by a fluorescent ring. This characteristic pattern of fluorescence was observed only infrequently in thelate stage of SH infection and was absent in Ond-infected cultures. Reciprocal neutralization studies indicated that the three strains are of one serotype. These findings suggest that R252-CDV has biological properties which differ from two other strains of CDV and which may have bearing upon the in vivo capability of this virus to produce demyelinating encephalomyelitis.