CP 1: Tetanus Flashcards
What is tetanus?
A life-threatening infection caused by an exotoxin synthesized by the bacterium Clostridium tetani. This toxin causes muscle spasm, which may lead to death if not treated correctly. Spasms of the masster muscles have led to the name lockjaw.
Every time a patient with a wound is examined, the physician must determine the appropriate immunization for the prevention of tetanus.
What is the difference between toxin and toxoid?
A toxin is a deadly poison; tetanus toxin should NEVER be administered, because it is fatal.
A toxoid is an inactive protein version of toxin that retains its antigenic properties, allowing the body via active immunization to identify and eliminate toxin antigens before they can begin their toxic activity.
What are active, primary, booster, and passive immunization?
Active immunization is the injection of weakened or inactive infectious protein, stimulating the production of antibody. Booster immunization (for exposure to diseases like tetanus), which supports primary immunization, can lead to the production of adequate amounts of protective antibody within 3-5 days if there are memory lymphocytes primed by a previous injection (for most diseases, the disease itself will stimulate the immune response).
Passive immunization is the transfer of protective antibodies to a vulnerable individual, such as with human tetanus immune globulin (TIG) or equine tetanus antitoxin; it is analagous to the protection afforded from mothers to babies across the placenta. Passive immunization will provide instantaneous immunity, but the antibodies will have a half-life of only three weeks, and memory lymphocytes are NOT produced. Always use human antiserum if possible.
If TIG/equine antitoxin and tetanus toxoid (Td) are administed simultaneously, ensure that each is injected at different sites (e.g., different arms).
What is the difference between homologous and heterologous antisera?
Homologous antiserum: antiserum from one species to the same species (e.g., human tetanus immune globulin to humans)
Heterologous antiserum: antiserum from one species to another species (e.g., equine tetanus antitoxin to humans)
What is the difference between specific and nonspecific immunity?
Specific immunity: immune response that is antigen-specific (e.g., immunity to a disease for which one has been vaccinated)
Nonspecific immunity: immune response that is not antigen-specific (e.g., the skin provides immunity to many antigens)
What is the difference between disease caused by bacterial infection and disease caused by bacterial toxin?
The body is able to produce antibodies in response to bacterial infections.
Bacterial toxins are potent enough to kill at low concentrations, before the body is capable of mounting an immune response. Active immunization against bacterial toxins requires exposure to toxoids instead.
Does a history of acute tetanus provide long-lasting immunity against future exposure?
No, because the body cannot produce antibodies against tetanus.
What is the difference between cell-mediated and antibody-mediated immunity?
Cell-mediated = T-lymphocyte-mediated
Antibody-mediated = B-lymphocyte-mediated
When is it appropriate to administer tetanus toxoid?
Td acts as a booster.
- Clean, minor wounds: in all cases (uncertain history, no vaccinations, several vaccinations) unless it is within 10 years of the last booster
- All other wounds: in all cases (uncertain history, no vaccinations, several vaccinations) unless it is within 5 years of the last booster
When is it appropriate to administer tetanus immune globulin?
TIG provides immediate, passive immunization.
- Clean, minor wounds: N/A
- All other wounds: when the immunization history is uncertain, zero, or one; when the immunization history is two, IF the wound is more than 24 hours old
