Tetanus

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tetanus pathogenesis clinical features management and prevention ,Neonatal tetanus also

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Tetanus : 

Tetanus Dr.N.Bayapa Reddy MBBS,(MD) Post Graduate Dept.of Community Medicine S.V.Medical College Tirupati

Tetanus (cont’d) : 

Tetanus (cont’d) Tetanus is not common in U.S.A. because of mandatory vaccination However, a few cases/year in non- vaccinated or improper booster individuals Tetanus is still very common in Third World countries—causing several hundred thousand deaths per year Many of these deaths involve neonatal tetanus due to the umbilical cord being unsterilely cut

India : 

India Tetanus is important endemic infection in india Factors : Hand washing Delivery practices Traditional birth customs Interest in immunization prior to the national immunization programme an estimated 3.5 lack children are died annually 70,000 cases continue to occur largely in the OBIMARU states were TT immunization coverage is less than national average (70%)

Tetanus agent : 

Tetanus agent Clostridium Tetani Gram positive Spore-forming Anaerobic rod

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Clostridium tetani Gram Stain NOTE: Round terminal spores give cells a “drumstick” or “tennis racket” appearance.

Tetanus (cont’d) : 

Tetanus (cont’d) Entry of C. tetani into the body usually involves implantation of spores into a wound After gaining entry, C. tetani spores can persist in the body for months, waiting for the proper low oxygen growth conditions to develop

Tetanus (cont’d) : 

Tetanus (cont’d) When the oxygen levels of the surrounding tissue is sufficiently low, the implanted C. tetani spore then germinates into a new, active vegetative cell that grows and multiplies and most importantly produces tetanus toxin

Tetanus (cont’d) : 

Tetanus (cont’d) As growing cells of C. tetani produce tetanospasmin at the wound site, the toxin starts to migrate along nerves and acts mainly on 4 areas of nervous system Motor end plate Spinal cord Brain Sympathetic system where it blocks the release of inhibitory neurotransmitters As a consequence of too much “activator transmitters”, muscles are Over stimulated to repeatedly contract—called spastic paralysis

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Mechanism of Action of Tetanus Toxin

Reservoir : 

Reservoir Spores of C. tetani are found in soil, dust, intestinal tracts of animals and humans throughout the world Spores are very resistant to harsh conditions like heat radiation chemicals drying Spores can survive for a long time in environment---100yrs possibly! Communicability Tetanus is not contagious from person to person. It is the only vaccine-preventable disease that is infectious but not contagious. Temporal pattern: Peak in winter and summer season Incubation Period: 8 DAYS ( 3-21 DAYS)

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Host Factors Age : I t is the disease of active age (5-40 years), New born baby, female during delivery or abortion Sex : Higher incidence in males than females Occupation : Agricultural workers are at higher risk Rural –Urban difference: Incidence of tetanus in urban areas is much lower than in rural areas Immunity : Herd immunity does not protect the individual Environmental and social factors: Unhygienic custom habits,Unhygienic delivery practices

Sequence of events : 

Sequence of events Lock Jaw Stiff Neck Difficulty Swallowing Muscle Rigidity Spasms

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Risus Sardonicus in Tetanus Patient A person suffering from tetanus undergoes convulsive muscle contractions of the jaw--called LOCKJAW

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Opisthotonos in Tetanus Patient The contractions by the muscles of the back and extremities may become so violent and strong that bone fractures may occur

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CEPHALIC TETANUS : A Rare Form of Localized TetanusCourtesy : Google image on tetanus) Unfortunately, the affected individual is conscious throughout the illness, but cannot stop these contractions

Tetanus (cont’d) : 

Tetanus (cont’d) Death may occur from tetanus, often from cardiac (heart) and respiratory (lung) effects or secondary complications from the infection

Types of tetanus : 

Types of tetanus Traumatic Puerperal Otogenic Idiopathic Tetanus neonatorum (8th day disease)

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Local tetanus is an uncommon form of the disease,in which patients have persistent contraction of muscles in the same anatomic area as the injury. Local tetanus may precede the onset of generalized tetanus but is generally milder.Only about 1%of cases are fatal. Cephalic tetanus is a rare form of the disease,occasionally occurring with otitis media (ear infections)in which C.tetani is present in the flora of the middle ear,or following injuries to the head.There is involvement of the cranial nerves,especially in the facial area. The most common type (about 80%)of reported tetanus is generalized tetanus .The disease usually presents with a descending pattern.

Diagnosis of Tetanus : 

Diagnosis of Tetanus Tetanus is suspected upon exposure to a bite or puncture wound Because C. tetani exhibits such exquisite sensitivity to oxygen, it is very difficult to recover and/or grow from clinical specimens As a result, diagnosis is made on the basis of clinical findings and history

Three Objectives of Management of Tetanus : 

Three Objectives of Management of Tetanus To provide supportive care until the tetanospasmin that is fixed in tissue has been metabolized To neutralize circulating toxin To remove the source of tetanospasmin.

Treatment of Tetanus : 

Treatment of Tetanus Very difficult to treat once symptoms have developed Antitoxin is administered Muscle relaxants Supportive therapy (ventilator) Cleansing of the wound

PREVENTION : 

PREVENTION

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Spores are extremely stable,although immersion in boiling water for 15 minutes kills most spores. Exposure to saturated steam under 15 lbs.of pressure for 15-20 minutes at 121°c is highly effective against spores . Sterilization by dry heat is slower than by moist heat (1 -3 hrs at 160 °C),but it is also effective against spores. Ethylene oxide sterilization is also sporocidal.

Fumigation : 

Fumigation Sterilization of operation theatre 500 ml of formaline, 200gms of Pot.permanganate/30 cu.meters of space All windows and doors are closed except one Fissures between the panels of the doors and windows are closed with adhesive tape After 12 hours the doors and windows are opened and the theatre is aired for 24 hours before decommissioning it

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Active Immunization Passive Immunization Active and passive Immunization Antibiotics

TETANUS TOXOID : 

Tetanus toxoid was developed by Descombey in 1924, Tetanus toxoid immunizations were used extensively in the armed services during World War II. Tetanus toxoid consists of a formaldehyde-treated toxin. There are two types of toxoid available —adsorbed (aluminum salt precipitated)toxoid and fluid toxoid. Although the rates of seroconversion are about equal,the adsorbed toxoid is preferred because the antitoxin response reaches higher titers and is longer lasting than that following the fluid toxoid. TETANUS TOXOID

Active Immunization : 

Active Immunization 1st dose - 6th week (DPT) 2nd dose - 10th week (DPT) 3rd dose - 14th week (DPT) 1st booster - 18th month (DPT) 2nd booster - 6th year (DT) 3rd booster - 10th year (TT)

Passive Immunization : 

Passive Immunization ATS(equine) Ig- 1500 IU/s.c after sensitivity test (or) 2. ATS(human) Ig- 250-500 IU, no anaphylactic shock, very safe and costly.

Slide 29: 

Immunization requires at least three doses of Td. 1st dose should be administered on the First visit 2nd dose 4 – 8 weeks after the first dose of Td and 3rd dose after 6 months of the second Td. A booster dose of Td should be repeated every 10 years throughout life Persons Seven Years of Age or Older Who Have Not Been Immunized

Treatment of Tetanus (cont’d) : 

Treatment of Tetanus (cont’d) If recovery does occur, there are usually no long-term side effects. Recovered individuals do not necessarily develop “natural Immunity” against the infection--- because the very small amount of tetanus toxin produced during the infection does not elicit a strong, protective immune response which would produce enough antibodies against future re-infection

Slide 33: 

Photo Courtesy of U.S. Centers for Disease Control and Prevention

Slide 34: 

Newborn showing risus sardonicus and generalized spasticity

Slide 35: 

Maternal tetanus, defined as tetanus occurring during pregnancy or within 6 weeks after any type of pregnancy termination, is one of the most easily preventable causes of maternal mortality. It includes postpartum or puerperal tetanus (i) postpartum or puerperal tetanus, usually resulting from septic procedures during delivery, (ii) postabortal tetanus, following septic maneuvers during induced abortion (iii) Tetanus during pregnancy, generally resulting from inoculation through a nongenital portal of entry

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Neonatal tetanus (NNT), a disease preventable by immunization, is a major problem and a leading cause of neonatal mortality. It is easily preventable by 2 tetanus toxoid injections and ‘5 cleans’ while conducting deliveries. 2 major programs are in operation for the prevention of NNT in the country – the immunization of pregnant women with tetanus toxoid vaccine (TT) under the expanded program on immunization (EPI) The training of dais under the rural health program.

Slide 37: 

NNT will be prevented if the women and the dais (who are still associated with almost 70-75% of the deliveries in many areas with high NNT mortality rates) are convinced of the need for TT vaccination during the antenatal period and practice the basic principles of cutting cord and keeping the umbilical stump free of unclean dressings.

Elimination of Neo natal tetanus : 

Elimination of Neo natal tetanus High risk district: a) Neo natal death rate > 1/1000 live births b) 2 doses of tetanus toxoid coverage < 70% c) Deliveries attended by trained dais < 50% Medium risk district: a) Neo natal death rate < 1 / 1000 live births b) 2 doses of tetanus toxoid coverage> 70% c) Deliveries attended by dais > 50% 3. Low risk district: a) NNT <0.1/1000 Live Birth b) 2 Doses of T.T Coverage >90% c) Delivery attended by Trained Dais >75%

PREVENTION OF NEONATAL TETANUS : 

PREVENTION OF NEONATAL TETANUS 2 doses of T.T to all pregnant women between 16 to 36 weeks of pregnancy with an interval of 1 to 2 months between the two doses. The first dose as early as possible & the second dose a month later preferably 3 weeks before delivery. If the pregnant woman is previously immunized, a booster dose is sufficient. If the pregnant woman is not immunized, then the new born should be protected against tetanus by giving tetanus human immunoglobulin 750 IU with in 6 hours of birth.

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