The spongiform encephalopathies: prion diseases.

The spongiform encephalopathies may be caused by prions, infectious pathogens that differ from all other infectious agents in that they do not have deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). Very difficult to inactivate, they are composed of an abnormal protein. It is believed by many that prions cause sporatic and genetic neurodegenerative diseases, including scrapie and bovine spongiform encephalopathy in animals and kuru, fatal familial insomnia, Creutzfeldt-Jakob disease (CJD) and Gerstmann-Straussler-Scheinker disease in humans. Another, the new variant CJD in humans in England, is an example of a breech in the species barrier between humans and animals. Transmitted primarily via exposure to infected brain or spinal cord tissue or blood, there have been numerous iatrogenic cases from contaminated pituitary hormones, surgical equipment, dural grafts, corneal transplants and others. All facets of blood product manufacturing have been affected. Nurses should be aware of the latest developments, and able to practice infection control while providing the best patient/family information possible.

Toxoplasmic encephalitis in the AIDS patient.

Toxoplasmic encephalitis is recognized as a major cause of opportunistic infection of the central nervous system in patients with acquired immune deficiency syndrome (AIDS). Often this protozoal infection is benign, but in the AIDS patient it can cause life-threatening complications. Usually, toxoplasmic encephalitis is a latent infection activated in the brain in some 5% to 15% of AIDS patients. Treatment with oral antibiotics is effective, but relapse is common, and there may be permanent brain tissue damage with resultant neurological deficits. This article acquaints the rehabilitation nurse with the diagnosis and acute nursing care of toxoplasmic encephalitis. Rehabilitation nurses need to know about this chronic condition because rehabilitation is key to its successful long-term care and management.

Cryptococcal meningitis in patients with AIDS.

In the U.S., cryptococcal meningitis is the most common form of fungal meningitis and a major cause of morbidity and mortality among immuno-suppressed patients. In the AIDS patient, cryptococcal meningitis often presents with fever and headache and is best treated with intravenous amphotericin B and oral flucytosine, or fluconazole. However, toxic effects may result from the therapy. This disease frequently relapses necessitating life-long treatment to prevent reactivation. Essential management principles focusing upon health education are presented to promote comprehensive nursing care for patients testing positive for the human immunodeficiency virus who also have cryptococcal meningitis.

Toxoplasmic encephalitis in the AIDS patient.

Toxoplasmic encephalitis was observed early in the acquired immunodeficiency syndrome (AIDS) epidemic and has now been recognized as the major cause of opportunistic infection of the central nervous system after human immunodeficiency virus infection. This complication of AIDS usually represents a reactivation of latent infection. At present, the definitive diagnosis can be made only by demonstrating the protozoan causal agent, Toxoplasma gondii, in brain tissue. Pyrimethamine and sulfadiazine are effective treatments. Nurses are challenged to understand this neurological manifestation of AIDS. Since therapy is life-long, patient education is important in addressing discharge planning concerns and return-to-community issues.

Precautions prevent spread of Creutzfeldt-Jakob disease.

Currently some experts are predicting the incidence of the rare yet rapidly fatal Creutzfeldt-Jakob disease (CJD) is on the rise. Worldwide, there is about one case per million people per year, but iatrogenic transmission is increasing. There have been documented cases of CJD transmission through corneal transplants, stereotactic equipment, human growth hormone and dura mater grafts. In addition, there are now three cases of laboratory workers with CJD from exposure in the workplace. No known treatment alters the relentless course of CJD and there is no vaccine. In every rapidly progressive unexplained dementia CJD must remain a diagnostic possibility. Because the etiologic agent is virulent, definition of necessary precautions for staff members associated with such patients is needed. Thus it is imperative medical personnel be well trained in the practice of universal precautions.

Care and treatment of scabies.

In these days of Universal Precautions, the staff nurse can and should work with all patients as if they had a potentially infectious disease. A case in point is scabies which mimics many dermatological conditions and is transmitted by direct contact. Scabies is caused by infestation with the mite Sarcoptes scabiei, and can be a problem in nursing homes and hospitals, particularly among patients who are debilitated and require extensive hands-on care. A scabies outbreak need not result in chaos or epidemic. If nursing staff are well trained in Universal Precautions, especially handwashing, much transmission could be prevented. Moreover, if scabies is recognized early, accurately documented, and quickly treated, a scabies outbreak could be readily contained.

Slow virus diseases of the central nervous system.

Slow virus diseases are characterized by a long asymptomatic period, often months or years in duration, between the introduction of the infectious agent and the appearance of clinical illness. Two distinct groups cause serious degenerative diseases of the brain and spinal cord. The first to be identified are those caused by "unconventional agents," kuru and Creutzfeldt-Jakob disease. The second category, "conventional virus diseases," include SSPE (subacute sclerosing panencephalitis), PML (progressive multifocal leukoencephalopathy), progressive rubella encephalitis, and HIV encephalopathy. The universal focus on acquired immune deficiency syndrome (AIDS) has stimulated new research on slow viruses. The extreme neurological deficits, the chronic nature of these diseases, and the possible concern with infection control make patients with these diseases a challenge to nursing.