Question: I have been hearing a di...

Question: I have been hearing a division about CJD and its potential for spreading via surgical instruments. What is CJD and in what manner can it be spread by the agency of instruments that have been cleaned and sterilized?

Answer: The acronym CJD stands for Creutzfeldt-Jakob Disease, an infectious, degenerative, and fatal disease of the central nervous system(1) Creutzfeldt-Jakob Disease is undivided of a group of encephalopathies known as transmissible spongiform encephalopathies (TSEs) Other human forms of TSE are kuru Gerstmann-Straussler-Sheinker syndrome and familial insomnia syndrome lately a fourth type of human TSE called variant CJD (vCJD) has been recognized.(2) Animal forms of TSE are scrapie in sheep and goats; transmissible mink encephalopathy; exotic ungulate encephalopathy; chronic wasting disease of hybrid deer, and elk; feline spongiform encephalopathy; and bovine spongiform encephalopathy (BSE) also known as Mad frighten Disease.

The pathogenic agent responsible for CJD is highly resistant to standard sterilization and disinfection [i]modus operandi[/i]s Unless special protocols are used, the CJD causative agent can survive routine sterilization and disinfection processes

Creutzfeldt-Jakob Disease is considered a inactive viral infection caused by an unconventional virus known as a prion.(3) Prions are a unique class of pathogen that have no detectable DNA or RNA. These small, proteinaceous agents are abnormal isoforms of normal cellular proteins. An isoform is a assemblage of proteins that are produc by dint of different genes and are specific to different tissues on the contrary have the same function.(4) The cause of this transformation is unknown; however, it is speculation to be a mutation of the chromosome forward which the protein resides.(5)

The incubation period for CJD can vary from month to years to decades. Symptoms include rapidly progressing dementia, psychiatric and behavioral abnormalities, and a distinctive electroencephalograph reading. Positive diagnosis can be made barely by direct examination of affected brain tissue. greatest in quantity cases occur in patients between 50 and 70 years of age. The duration of illness after patients become symptomatic is an average of six month and the disease always completions in death.

In contrast, vCJD has an earlier storm (ie, between 16 and 48 years of age). Patients exhibit sensory and psychiatric symptoms differing from those of CJD and the course of illness averages 14 month Again, the disease is always fatal.(6) According to the Center for Disease have the direction of and Prevention, there is vigorous epidemiological and laboratory evidence of a causal association between vCJD and BSE(7) As of September 2000 no cases of vCJD were reported in the United States.

Creutzfeldt-Jakob Disease can be familial (ie, inherited in the form of a mutant gene) or sporadic (ie, no family history and no known source of transmission). Approximately 90% of cases are sporadic. Approximately 1% of cases end from person-to-person transmission and are primarily the issue of iatrogenic (ie, medically related) prospect Exposures have occurred via transplantation of central nervous plan tissue, such as dura mater or corneas; repeated injections of pituitary hormone extracts; and use of contaminated surgical instruments or stereotactic midst electrodes.(8)

Tissues vary in their stage of infectivity according to prion contented as follows:

* high-infectivity tissue (eg brain, dura mater, spinal cord, corneas);

* medium-infectivity tissue (eg cerebrospinal fluid, liver, lymph nodes, lung kidney, spleen); and

* low- or no-infectivity tissue (eg heart, skeletal muscle, thyroid glands, adrenal glands, intestines, peripheral vigors bone marrow, whole blood, leukocyte serum adipose tissue, prostate, testis, seed placenta, vaginal secretions, milk, tears, gingiva, nasal mucus, saliva, sputum urine, feces)

Creutzfeldt-Jakob Disease and other TSE are unusually resistant to conventional chemical and physical decontamination [i]modus operandi[/i]s The causative prions are resistant to steam sterilization, arid heat, ethylene oxide gas, and chemical disinfection with either formaldehyde or glutaraldehyde, as normally used in the health care environment. one as well as the other formaldehyde and glutaraldehyde act as fixatives, causing the prions to become more stable and les susceptible to these normal sterilization and disinfection protocols. Special protocols for instrument care after prospect to prions should be followed.(9) Table 1 is a refer toed protocol for caring for instruments expos to the CJD prion.