Tetanus Overview and Prevention

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Questions and Answers

What is the principal risk factor for C.difficile infection?

Use of antibiotics (correct)

Advanced age

Surgical procedures

Close contact with infected individuals

Which antibiotics are most frequently associated with C.difficile infections?

Tetracyclines

Fluoroquinolones (correct)

Macrolides

Aminoglycosides

How does C.difficile primarily enter the susceptible host?

Sexual contact

Contaminated food

Fecal/oral transmission (correct)

Through respiratory droplets

Which type of C.difficile toxin is primarily responsible for causing symptoms?

Toxin A Signup and view all the answers

Which of the following groups is generally at higher risk for C.difficile infections?

Patients with prior antibiotic use Signup and view all the answers

What is the primary approach to diagnosing tetanus?

Clinical diagnosis based on early recognition Signup and view all the answers

Which of the following is NOT part of the treatment for tetanus?

Antiviral medications Signup and view all the answers

What is the standard vaccine used to prevent tetanus?

Diphtheria-tetanus-pertussis (DTP) vaccine Signup and view all the answers

In what situation should an individual receive a tetanus booster?

If they stand on a dirty nail and it has been more than 10 years since their last shot Signup and view all the answers

Which type of wound is considered tetanus prone?

Puncture type injuries in contaminated environments Signup and view all the answers

What factor increases the risk associated with certain wounds in relation to tetanus?

Heavy contamination with materials that may contain spores Signup and view all the answers

What is the clinical role of human tetanus immunoglobulin (TIG) in the management of tetanus?

To neutralize the toxin produced by Clostridium tetani Signup and view all the answers

What is a common misconception about recovery from tetanus?

Vaccination is unnecessary after recovery Signup and view all the answers

What is the primary result of botulinum toxin's action at the neuromuscular junction?

Inhibition of acetylcholine release Signup and view all the answers

Which form of botulism is most commonly associated with the ingestion of contaminated food?

Foodborne botulism Signup and view all the answers

What symptom is typically absent in cases of botulism?

Fever Signup and view all the answers

What is a common diagnostic method for confirming foodborne botulism?

Detection of toxin in stool or vomitus Signup and view all the answers

What is a significant preventive measure recommended for infants to avoid botulism?

No raw honey for infants under 12 months Signup and view all the answers

Which type of botulism occurs when spores are deposited in open wounds?

Wound botulism Signup and view all the answers

What type of management is specifically used for wound botulism?

Surgical debridement and metronidazole Signup and view all the answers

What is the primary cause of perfringens food poisoning?

Enterotoxin produced by Clostridium perfringens Signup and view all the answers

What was a notable event related to a botulism outbreak in 2023?

15 cases linked to contaminated sardines at a restaurant Signup and view all the answers

Which food types are commonly associated with perfringens food poisoning?

Contaminated meat products Signup and view all the answers

What is the recommended immediate treatment for gas gangrene?

Prompt debridement of nonviable tissue Signup and view all the answers

Which of the following antibiotics is part of the combination therapy for gas gangrene?

Clindamycin Signup and view all the answers

What is an effective way to prevent perfringens food poisoning?

Cook and keep food at proper temperatures Signup and view all the answers

Which condition is primarily linked to the occurrence of a Clostridium perfringens infection?

Trauma and necrosis Signup and view all the answers

What type of vaccine is used for the prevention of anaerobic infections?

Toxoid vaccine Signup and view all the answers

What is the potential mortality range associated with untreated gas gangrene?

40-100% Signup and view all the answers

What is true regarding recurrent Clostridioides difficile infection (CDI)?

It occurs within 8 weeks after the onset of a previous episode. Signup and view all the answers

Which symptom is NOT associated with Clostridioides difficile infection (CDI)?

Cough Signup and view all the answers

What is the first step to take if CDI is suspected?

Isolate the patient and implement contact precautions. Signup and view all the answers

Which antibiotic is no longer considered the first-line agent for treating CDI?

Metronidazole Signup and view all the answers

Which of the following is a key prevention strategy for CDI?

Strict adherence to hand hygiene protocols. Signup and view all the answers

What is the primary toxin produced by Clostridium perfringens related to gas gangrene?

Alpha toxin Signup and view all the answers

How is Clostridioides difficile primarily diagnosed?

Testing for toxin-producing C. difficile in stool. Signup and view all the answers

Which of the following accurately describes the environment in which Clostridium perfringens is commonly found?

Ubiquitous in nature, including soil and decaying vegetation. Signup and view all the answers

Study Notes

Tetanus

Tetanus is a clinical diagnosis
Early recognition is key
ABCs are essential, some patients may require intubation
Treat infected source tissue with wound debridement and antimicrobials such as benzylpenicillin or metronidazole
Neutralize the toxin with human tetanus immunoglobulin (TIG)
Manage spasms
Avoid touching, light, and other stimuli

Tetanus Prevention & Immunisation

Prevented by immunisation with toxoid vaccines
Recovery from tetanus confers natural immunity
Majority of cases are birth-associated in newborn babies, mothers not vaccinated
86% of infants worldwide vaccinated with 3 doses of diphtheria-tetanus-pertussis (DTP) in 2016
Toxoid vaccine is part of childhood vaccination programs
Clinical efficacy is almost 100%, but immunity wanes, and after 10 years may not provide protection
If the last tetanus shot was more than 10 years ago, individuals may need a booster

Post Exposure Prophylaxis

Tetanus prone wounds include:
- Puncture type injuries acquired in a contaminated environment
- Wounds containing foreign bodies
- Compound fractures
- Wounds or burns with systemic sepsis
- Some animal bites/scratches (most domestic pets unlikely to have saliva containing spores unless the animal is rooting in soil or lives in an agricultural setting)
High-risk wounds include:
- Heavy contamination with material likely to contain spores e.g. soil, manure
- Wounds or burns with extensive devitalized tissue (anaerobic environment)

Clostridium Botulinum

Botulism is a paralytic illness caused by Cl. botulinum neurotoxin
Botulinum toxin is used medically as “Botox”
Toxin inhibits the release of acetylcholine at the neuromuscular junction
Results in weakness/acute flaccid paralysis
Cl. botulinum can survive in soil and untreated water for protracted periods
There are several types of botulism:
- Foodborne botulism
- Wound botulism
- Infant botulism

Categories of Botulism

Foodborne: Most common form following ingestion of contaminated food (e.g., home canned foods)
- Food contaminated by spores
- If not cooked thoroughly and then put in an anaerobic environment (e.g., sealed jar)  spores germinate  toxin produced
- If the contaminated food is then eaten = Fast onset of symptoms 12–36 hours after ingestion
- Typically, the food will look and taste normal
Wound botulism: Spores deposited in open wounds
- Then germinate and produce toxin
Infant botulism: Ingestion of spores (e.g., via food)
- Germinate in the GIT
- Toxin then released in the GIT and absorbed

Botulism Presentation

Symmetrical descending flaccid paralysis
- Bilateral cranial nerve palsies = double vision, difficulty swallowing
- General muscle weakness
- Respiratory failure without impairment of consciousness
Fever is classically absent
Infant botulism
- Constipation and then muscle weakness / lethargy / poor feeding / ‘floppy’ baby

Botulism Outbreaks

Outbreak of botulism in Bordeaux, France in 2023 during the rugby world cup
15 cases, at least 8 hospitalized and required management in the intensive care unit
One person died
Linked to contaminated canned sardines produced at a local restaurant

Botulism Diagnosis & Management

Clinical picture: History of possible exposure
Laboratory tests confirm the diagnosis
- Foodborne: Detect toxin in stool/vomitus
- Infant botulism: Organism or toxin in stool
- Wound: Culture from wound site
Management:
- ABC
- Antitoxin: Botulism IG
  - There is an infant formulation - BabyBIG
- Wound: Debridement and metronidazole

Botulism Prevention

Care with home preserving
Infants: No raw honey less than 12 months
Hand hygiene and care with food preparation

Clostridioides Difficile

C. difficile can cause symptoms ranging from diarrhoea to life-threatening inflammation of the colon
Found in soil, air, water, human & animal faeces
Spores survive outside of the body
Up to 1 in 10 healthy adults carry C. difficile in the colon (colonisation)
- 70% of infants but infection is rare
Infection occurs typically in people in contact with healthcare/been on antibiotics
Infection with C. difficile occurs in ~half a million people/year in the US

Antibiotics & C. difficile

Antibiotic use predisposes to colonisation and infection
Antibiotics are the principal risk factor for infection
- Disruption of normal colonic flora
Virtually all antibiotics have been implicated
The most frequently associated are:
- Fluoroquinolones
- β lactam antibiotics, particularly co-amoxiclav, and third generation cephalosporins (cefotaxime and ceftriaxone)
- Clindamycin
Symptoms and signs are caused by toxins
- There are at least 2 types of toxin: A & B

C. difficile & the Chain of Infection

Infectious agent: C. difficile
Susceptible host: ‘At-risk’ patients or residents
- Advanced age
- Antibiotic use
- Hospitalisation
Reservoir: Bowel
- Contaminated environment
Means of Transmission: Faecal/Oral
Contact Transmission:
- Hands
- Equipment
- Environment

Two Categories of C. difficile Infections (CDI)

New: First episode
Recurrent:
- Occurs within 8 weeks after onset of a previous episode
- Risk of recurrence increases with each recurrence

C. difficile Infection Symptoms

Asymptomatic to potentially fatal
- Diarrhoea
- Fever
- Acute abdomen / pseudomembranous colitis

Responding to Suspected CDI

Suspect it where there is no clear alternative cause for diarrhoea (e.g., diarrhoea during or after antibiotics)
Isolate the patient
- Gloves and aprons
- Contact precautions
Hand washing (not alcohol gel) after each contact with the patient and their environment
Test the stool for toxin-producing C. difficile
- PCR for the toxin gene

CDI Diagnosis

Clinical suspicion, e.g. diarrhoea during or after antibiotics
Test faeces for C. difficile toxin
- Diarrhoeal specimen – same day test result
  - PCR for the presence of toxin gene tcdB - sensitive
  - EIA for the presence of toxin – confirmatory, specific

CDI General Treatment Principles

Isolation + contact precautions
Review and stop antibiotic(s) if possible: If not, switch to agents with a lower propensity to induce C. difficile infection
Supportive therapy (fluids etc)
Antibiotic treatment of CDI:
- (oral) Vancomycin OR
- Fidaxomicin
- Metronidazole no longer first-line agent (reduced efficacy v. vancomycin/fidaxomicin)

Clostridioides Difficile Infection: Prevention & Control

Antibiotic stewardship
Infection prevention and control guidelines, e.g., hand hygiene

Clostridioides Perfringens

Cl. perfringens causes tissue necrosis
Well known for its association with gas gangrene (clostridial myonecrosis) and emphysematous cholecystitis
Common cause of food poisoning
- Ingestion of food contaminated with toxin-producing organisms/spores
Cl. perfringens is ubiquitous in nature
- Decaying vegetation, soil, marine sediment, GIT of humans & animals

Clostridioides Perfringens Clinical Presentation

Produce many virulent toxins
- Toxin involved in gas gangrene is α toxin, a lecithinase
  - Inserts into the cell membrane causing holes and disrupting cellular function
- Cl. perfringens food poisoning is caused by an enterotoxin
Food poisoning: After ingestion of contaminated food
- Contaminated meat products (beef, poultry, gravy, dried or precooked foods) served without adequate reheating.
- Abdominal cramps/diarrhoea
Cellulitis/wound infection: Usually in devitalized tissue
Gas gangrene:
- Contaminated wounds with poor blood supply and tissue necrosis
- Progressive invasion and destruction of healthy muscle tissue

Gas Gangrene

Rapidly progressive infection
Destruction of muscle
Severe systemic toxicity
Investigations:
- Wound swab/blister fluid for culture
- Blood cultures
Management:
- Prompt debridement of all nonviable tissue is essential
- Antimicrobials:
  - Combination therapy:
    - High-dose penicillin/clindamycin
    - Antitoxin activity
Mortality: 40-100%

Clostridioides Perfringens Prevention

Food Poisoning:
- Cook and keep food at the correct temperature
- Serve meat dishes hot, within 2 hours after cooking
- Refrigerate leftovers and reheat them properly
- When in doubt, throw it out!
Cellulitis/Wound Infection, Gas Gangrene:
- Clean wounds thoroughly
- Remove foreign objects and dead tissue from wounds
- IV antibiotic prophylaxis with abdominal surgery
- Skin preparation and administer IV antibiotics if lower limb amputation in patients with peripheral vascular disease

Prevention of Anaerobic Infection

Non-specific = wound debridement, safe food preparation
Specific = toxoid vaccine
Clostridial infections already covered under individual clinical conditions
Surgery on bowel:
- Prophylactic antibiotics using an agent with anaerobic cover
- Care with surgery to avoid/minimise the risk of spillage of bowel content into the peritoneal cavity
- If peritoneal contamination occurs, treat with appropriate antimicrobial

Summary: Anaerobic Bacteria

Anaerobic bacteria are ubiquitous in nature and as part of normal flora
Predisposing conditions include trauma, necrosis, and ischemia
Spore-forming include clostridia that produce toxins with characteristic presentations (e.g., C. tetani)
Clostridioides difficile is a major cause of healthcare-associated diarrhea
Anaerobic Gram-negative bacilli such as Prevotella spp.

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Description

This quiz covers the clinical aspects of tetanus, including diagnosis, treatment, and prevention strategies. Learn about the importance of immunization and the management of tetanus-prone wounds. Test your knowledge on the efficacy of vaccines and post-exposure prophylaxis for tetanus.