Stealth Virus Illnesses in Animals


The cats were friendly, frisky and a welcome change from mice and rats for the University of Oklahoma animal caretakers. But this was before Dr. Tom Glass injected them with the stealth virus cultures that I had sent him. Now the cats withdrew to the back of their cages, squinting from the light, not wanting to be touched. The virus was doing its thing.

Like many patients that I have seen, the cats seemed perplexed. Two of the initial five cats had bloody noses from clawing at their faces. Two others had large patches of hairless skin from rubbing against the cage. They squirmed when picked up by the heavily gloved animal caretakers. Their muscles were tender and their teeth displayed gingivitis. Following a pre-approved protocol, individual cats were euthanized so that their tissues could be studied at varying times post inoculation.

What did Tom and I learn? First, the illness caused by the cultured virus was severe, especially between the second and fourth weeks; after that the remaining cats showed noticeable improvement. Second, as anticipated, another cat inoculated with a heat-inactivated virus remained well. Better still, this cat did not succumb to clinical disease when re-challenged with two subsequent doses of the same virus isolate that is known to be derived from an African green monkey simian cytomegalovirus. The cat did, however, get sick when inoculated with a different stealth virus isolate. This virus had been cultured from a woman diagnosed as having systemic lupus erythematosus (SLE).

Painstaking histology by Tom revealed the widespread occurrence of foamy vacuolated cells, but with no accompanying inflammation. Viral particles, along with intracellular accumulations of viral and/or cellular derived debris, could be seen by electron microscopy. Overall, the findings strengthened the connection between the cellular changes seen in the stealth viral cultures and the changes inducible within many organ systems of the body, including the brain. The apparent protection afforded to the cat receiving a heated virus preparation was likely due to anti-viral antibody production. It is known that many more viral components can evoke antibody immunity than can evoke cellular immunity and such antibodies could provide a barrier to subsequent injections of the same virus from gaining entry into the brain. The chronic fatigue syndrome patient from whom the virus had been isolated also had antibodies reactive with the virus but presumably they developed after her illness had begun. Since stealth-adapted viruses are molecularly heterogeneous, they react quite differently to different antibodies. We knew the virus from the SLE patient did not react with the antibodies present in the CFS patient. This presumably explained why the cat subsequently became sick with the SLE patient derived virus. The lack of discernable anti-viral inflammation was also of interest since it suggested some non-immunological virus-suppressive mechanisms may have begun to operate in the cats allowed to survive beyond 4 weeks.

The SLE patient had previously noted that several of her own cats had developed unusual behaviors. For example, one cat was distracted when it was about to start eating. The cat returned to the room and seemingly had to be reminded that food had been served. The cat would occasionally balk when seeing a common object and respond in an inappropriate way. At one time, the cat was prepared to fight a hose, as if it were a snake. Other cats would lay around all day and even at night and show unsteadiness when climbing onto the back of a couch. Tom and I were aware of many other CFS patients with ill pets. One patient even maintained pet rats and could correlate her disease exacerbation with aberrant behaviors in some of her beloved animals. Sick children, especially, cling emotionally to their pets. It does not bode well when their pets also become sick and need to be taken away.

I discussed the various findings with the SLE patient. I suggested that by trying some medications on the cats, it might be possible to see what might help her. "No" she protested, "you try them on me and only if they prove safe, will they ever be given to my cats." There are, in fact, various prohibitions against experiments conducted with pets outside major medical centers. With institutional review approval, Tom did try one therapy on an ill cat, but without apparent benefit. Now again, Tom is ready, willing and able to help. Either to use cats (or preferably rodents) we could team up again if the funding was available.