TetanusClostridium tetani

By Amanda Kain and Nick Waller

What is tetanus?

Domain: Bacteria – Genus: Clostridium – Species: tetani

Gram positive, Bacillus (rod-shaped), Obligate anaerobe and in the presence of O2 it forms endospores changing the shape into what looks like a drumstick

Reservoirs:

Everywhere in the environment – primarily in the soil and dust (where O2 is not present)

Vegetative and Endospore Stage

Causes and Transmission

Common ways tetanus gets into the body

-Through broken skin, especially those breaks caused by a contaminated object

-Burns

-Cush Injuries

-Injuries with dead tissue

 

In more rare cases Tetanus can enter the body

-Through superficial wounds

-Surgical Procedures

-Insect bites

-Dental infections

-Compound fractures

-Chronic sores

-Intravenous drug use

(CDC, 2013)

Symptoms and ComplicationsSymptoms can emerge anywhere from 4 days to 3 weeks after infection. Most commonly taking about 10 days.

 

Muscular Symptoms 

-Muscle Spasms

-Usually starts in the jaw area

-Spams spread to the neck throat and face from there

-The spine can arch back in severe cases

 

Other Symptoms

-Bloody Stool

-Diarrhea

-Fever

-Headache

-Tachycardia

-Sensitivity to touch

Gone untreated the infection can cause death by way of heart attack, kidney failure, Septicemia or asphyxia

(Nordqvist, 2014)

Tetanospasmin the Neurotoxin

Clostridium tetani releases the neurotoxin tetanospasmin which causes the clinical characteristics of tetanus

Tetanospasmin is one of the most potent toxins known and has a LD (lethal dose) of 2.5 nanograms per kg of body weight

To put that in perspective that would only take 174 nanograms for someone 154lbs to receive a lethal dose. (CDC)

What it does:

When the infection reaches the spinal cord it selectively blocks nerve transmission from the spinal cord to muscles, thus, causing the uncontrollable spasms and prolonged contractions of muscles.

http://youtu.be/L2Dr929zjY4?t=2m32s (YouTube Video)

Diagnoses and Treatment

Clinical syndrome without confirming lab tests

Diagnosed by the characteristic painful muscle contractions, usually of the face and neck muscles as well as the abdomen

If they haven’t received the vaccination they may perform serological tests to look for antibody presence

TIG (Tetanus Immune Globulin) is given to remove unbound tetanus toxoid

Due to extreme potency of toxin, immunization with tetanus toxoid should be maintained ASAP *Tetanus disease doesn’t result in tetanus immunity

All wounds cleaned; Necrotic tissue and foreign material removed; If spasms, then supportive therapy & maintained adequate airway are critical

Vaccination!Tetanus vaccine – tetanus immune globulin prevents the toxin from binding

to nerve endings preventing tetanus symptoms

The vaccine does decrease in effectiveness over time and should be administered every 10 years for best prevention.

Prevention and Surveillance

http://www.cdc.gov/tetanus/surveillance.html

Toxoid vaccine introduced

Rate of cases and death is dramatically reduced

History

The etiology (or cause) of tetanus was discovered by Carle and Rattone in 1884

The first tetanus toxoid was produced in 1924 and administered to the military first during WWII and then the general population with the TDaP vaccine launching in 1942.

More Recently:

2001-2008 in the USA there has been 233 cases reported

49% 50yrs old +

59% male

Almost all reported cases were in persons that never had been vaccinated or had not had their booster in the preceding 10 yrs.

Research/Unusual Cases

Case 1:

31-yr old male admitted to ER with 2-day neck & jaw pain.

Tetanus antibody level of 8.4U/mL, which is considered protective, yet he presented signs of tetanus.

He was treated with TIG and by day 6 post ER his symptoms had cleared.

Case 2:

26-yr old male open fracture L tibia and fibula, contaminated with soil.

14 yrs since last vaccination

No clinical symptoms of tetanus

After many trips back and forth to ER – serological tests and biopsy’s confirmed an ongoing tetanus infection that remained for 17 mo post initial visit and resulted in amputation.

ReferencesCDC. 2011. Tetanus. Retrieved from www.cdc.gov/vaccines/pubs/pinkbook/downloads/tetanus.pdf

Kenyon College. 2011. Clostridium tetani. MicrobeWiki. Retrieved from http://microbewiki.kenyon.edu/index.php/Clostridium_tetani

Levy, P. 2014. Clostridium tetani Osteitis without Tetanus. NIH. Retrieved from http://www.ncbi.nlm.nih.gov.offcampus.lib.washington.edu/pmc/articles/PMC4178411/

Tetanus, Causes and Transmission, CDC. (2013). Retrieved from http://www.cdc.gov/tetanus/about/causes-transmission.html

Nordqvist, C. (2014, September 26). "What is tetanus? What causes tetanus?." Medical News Today. Retrieved fromhttp://www.medicalnewstoday.com/articles/163063.php.

Vollman, K. 2014. A case of tetanus infection in an adult with a protective tetanus antibody level. Retrieved from http://apps.webofknowledge.com.offcampus.lib.washington.edu/full_record.do?product=WOS&search_mode=GeneralSearch&qid=1&SID=3Fyvxb7T8OeWBrpdN65&page=1&doc=6

Tetanus is the only vaccine-preventable disease that is infectious but not contagious!

Questions?

Thank you!!