what stealth viruses are

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Cytopathic viruses that lack antigens required for protective anti-viral cellular immunity, have been grouped under the generic term "stealth." These viruses characteristically induce a vacuolating cytopathic effect (CPE) in cultures of normal human fibroblasts (Am J Path 1994; 145:440-51). The stealth virus infected cultures can be distinguished from cultures of conventional hepesviruses, adenoviruses, enteroviruses and retroviruses, by the appearance and host range of the CPE, and also by using selective immunological and molecular probe based assays.

Stealth-adapted viruses can acquire additional genetic sequences from infected cells, including cellular genes with potential oncogenic activity (Mol Exp Path 1999; 66: 15-18). Certain stealth viruses have also acquired genes from bacteria and have been co-designated as viteria (Mol Exp Path 1999; 66: 8-14). Over expression of the assimilated cellular and bacterial genes, probably explains the presence of intracellular and extracellular debris-like structures commonly seen in long-term stealth virus cultures.

Stealth viruses have been recovered from the blood, cerebrospinal fluid, urine, throat swabs, breast milk, brain biopsies and tumor samples, from patients with various neurological, psychiatric, auto-immune and neoplastic diseases. The characteristic vacuolating CPE and inclusion-like structures, can be seen in brain and other tissue biopsies obtained from infected patients and animals (Pathobiology 1995; 63: 115-118; Pathobiology 1996; 64: 1-8; Mol Exp Path 1999; 66:19-31).

The lipid-laden cells infected with a stealth virus appear especially favorable to the growth of intracellular bacteria, including Borrelia burgdorferi, the agent of Lyme disease. This is in keeping with the consistent finding of positive stealth viral cultures in patients diagnosed with chronic Lyme disease.

Specific therapy for stealth viral infected patients has mainly included anti-herpesviral medications, including acyclovir, valcyclovir, famciclovir, ganciclovir and forcarnet. Of these agents, ganciclovir administered either intravenously at 5mg/Kg once or twice a day, or orally at 3,000-4,500 mg/day, for a 4-6 weeks, has reportedly provided the most consistent, if still only partial, benefit. Not all patients have responded, however, and there is understandable reluctance to use potentially genotoxic compounds, especially in children. A trial of antibiotics and anti-fungal agents has helped certain patients, and may be addressing a possible reservoir of stealth viruses within a patient's bacterial and fungal flora.

Symptomatic relief is also indicated in stealth viral infected patients. The spatial segregation of brain functions renders this organ uniquely susceptible to localized stealth virus induced damage. Dysregulated neural networks and responses, reflecting an underlying viral encephalopathy, can be addressed using neurally active drugs and various forms of modified afferent stimulation of the brain. Altered autonomic system regulation of blood pressure and of other physiological adaptations, as well as any documented hormonal deficiencies should be treated with appropriate medications.

Benefits have been claimed by patients taking specific metabolic enhancing agents, such as S-adenosyl-methionine, creatine, betaine, folic acid, vitamin B6 and B12, NADH, etc. Dosages are not yet standardized and the caveat remains that one could conceivably be "feeding the virus." Studies on the effects of various alternative medications on the development and recovery from stealth viral induced CPE are currently underway within the laboratory.