Experimental simian varicella virus infection of St. Kitts vervet monkeys

Abstract

Experimental simian varicella virus (SVV) infection of St. Kitts vervet monkeys was evaluated as an animal model to investigate human varicella-zoster virus (VZV) infections. During the incubation period, viremia disseminated infectious virus throughout the body via infected peripheral blood lymphocytes (PBLs). A vesicular skin rash in the inguinal area, and on the abdomen, extremities, and face appeared on day 7-10 postinfection. Necrosis and hemorrhage in lung and liver tissues from acutely infected monkeys were evident upon histologic analysis. Recovery from simian varicella was accompanied by a rise in the serum neutralizing antibody response to the virus. SVV latency was established in trigeminal ganglia of monkeys which resolved the acute infection. This study indicates that experimental SVV infection of St. Kitts vervets is a useful animal model to investigate SVV and VZV pathogenesis and to evaluate potential antiviral agents and vaccines.

Simian Varicella Virus Expresses a Latency-Associated Transcript That Is Antisense to Open Reading Frame 61 (ICP0) mRNA in Neural Ganglia of Latently Infected Monkeys

“…One animal (FV91) was part of a study to investigate the immunogenicity of recombinant SVV expressing SIV Env and Gag antigens (40). The clinical and virological parameters of simian varicella were evaluated as previously described (20). Viremia was monitored by harvesting peripheral blood mononuclear cells (PBMCs) from Ficoll-Hypaque gradients and determining infectious SVV titers by coculture of PBMCs on Vero cells.…”

“…The SVV and VZV genomes are similar in size and structure and are colinear in gene arrangement (17)(18)(19). The pathogenesis and clinical features of simian and human varicella are comparable (13,20). Following resolution of primary disease, SVV and VZV establish latent infections within neurons of the neural ganglia and may subsequently reactivate to cause a secondary disease, such as herpes zoster (13,22,26,30).…”

Herpesvirus infections of laboratory macaques

“…Viremia is transient and virus is cleared from the bloodstream by Day 11 post-inoculation. The incubation period for SVV following natural or experimental infection appears to be 7-14 days, and is similar to that of VZV infection in humans (Gray et al, 1998;Gray, 2004). The first clinical signs of disease appear around Day 10 post-inoculation as an inguinal rash and disseminate to a generalized cutaneous rash over the following two days that is particularly visible on the face, thorax and abdomen, with the palmar and plantar surfaces of the distal appendages being spared (Gray et al, 1998).…”

Pathogenesis of simian varicella virus

“…1) [Gray et al, 1998a]. Over the next 48 hours the rash becomes generalized appearing on the skin of the face, thorax, abdomen, and extremities.…”

“…The most widely used experimental model involves SVV infection of African green monkeys (Cercopithecus aethiops) by intratracheal inoculation with SVV-infected Vero cells [Gray et al, 1998a]. The incubation period of simian varicella following experimental infection is 7-10 days (Fig.…”