Circulating Neutralizing Antibody Research Articles

Herpesvirus infection of guinea pigs. I. Isolation, characterization and pathogenicity.

Hsiung, G. D. (VA Hospital, West Haven, Conn. 06516), L S. Kaplow and J. Booss. Herpesvirus infection of guinea pigs. I. Isolation, characterization and pathogenicity. Amer J Epidem 93: 298–307, 1971.—In a survey study of over 200 guinea pigs of five different strains obtained from various sources, over 90% of strain 2 and 35% of muta strain guinea pigs showed a herpes-like virus infection. Isolation of the virus from infected animals required cultivation or co-cultivation of tissue cells. The virus was found to have a relatively narrow host range. Extensive cytopathic effect and high titer of virus yield were obtained in guinea pig and rabbit cell cultures. Primary cell cultures derived from other animal species including man, monkey, hamster and mouse as well as embryonated chicken eggs showed no cytopathic effect with this virus and virus titers, if any, were low. Virus was found widely distributed in the various tissues and organs as well as in white blood cells of infected animals in the presence of circulating neutralizing antibody. Non-strain 2 guinea pigs, including Hartley and FS, can be easily infected experimentally with the guinea pig herpes-like virus (GPHLV) isolated from strain 2 animals. Virus persisted in the white blood cells and tissues of inoculated guinea pigs for as long as 10 months without any evidence of clinical disease.

Experimental Infection of Cattle with Pantropic Rift Valley Fever Virus

When the titre of pantropic RVF virus was estimated in cattle, the results compared favourably with those obtained in adult mice and tissue cultures. The intensity of response to experimental infection did not depend on the amount of virus inoculated. The response of individual cattle to experimental injection varied considerably when judged by pyrexia, viraemia and circulating neutralizing antibody. The susceptibility of cattle could not be judged solely by the absence of neutralizing antibody in their pre-challenge sera, as assessed by the serum-virus neutralization test carried out in adult mice.

The progression of herpes simplex virus to the central nervous system of the mouse

1. The strain HFEM of herpes simplex virus is highly virulent for the 5-week-old mouse when inoculated intracerebrally; the LD50 and the ID50 both being close to the egg infectious unit. It is also virulent when given intraspinally.2. When inoculated peripherally it seldom causes nervous symptoms in the normal mouse but regularly does so if inoculated into skin which has previously been given a subcutaneous injection of 10% sodium chloride.3. After intradermal inoculation of pretreated mice with strain HFEM, the paralysis is preceded by the appearance of infective virus in the blood, the sciatic nerve and the central nervous system. Invasion of the central nervous system is prevented by interruption of the local peripheral nerve.4. There is no evidence that virus enters the central nervous system by way of the lymphatics or by direct extension through the tissues.5. After intravenous inoculation virus does not invade the central nervous system unless (a) massive inocula are used or (b) the brain is traumatized by injecting sterile saline. After peripheral inoculation insufficient virus to infect even traumatized brain seems to circulate in the cerebral vessels. Paralysis and invasion of the central nervous system are not prevented by circulating neutralizing antibody given 18 hours after inoculation.It therefore appears that invasion of the central nervous system takes place only by way of the peripheral nerve.

Progress in Medical Virology

Like its predecessors, the 1965 edition of Progress in Medical Virology covers a lot of virological ground, much of it of fundamental importance. Clinicians, especially pediatricians, will do well to read the section on viruses and mycoplasma that cause respiratory disease in man. The chapters on adenoviruses and picornaviruses also bring us up to date on the relationship of these agents to human illness. About 12 years ago there were less than half a dozen viruses known to cause acute respiratory disease in man. Today there are well over a hundred. Despite these recent discoveries, the etiology of about half the respiratory illnesses remains unknown. Although these factors present a tough roadblock to the prevention of acute respiratory disease by immunization, they are not the only obstacles. This books points out that the presence of circulating neutralizing antibody in a person convalescent from measles or poliomyelitis is associated with immunity