Neonatal tetanus is an ancient disease previously called lockjaw known to be common in agrarian communities and communities involved in animal husbandry. It is one of the diseases for which a vaccine was developed for.
epidemiology of neonatal tetanus
Most of the cases of neonatal tetanus are from Sub-Sahara Africa, with about 500-1000 cases per year. In University of Benin Teaching Hospital, Nigeria, there have been a dropped incidence from about 3-4 to 1-2 cases per year. Tetanus is caused by spread of toxins of toxins of Clostridium tetani.
causative organism of neonatal tetanus
Clostridium tetani is a non-motile, gram negative, obligate anaerobic rod that has a terminal spore which gives it a drum-stick appearance. It is heat sensitive and cannot survive in the presence of oxygen. In the spore form however, normal antiseptics or boiling will not destroy it.
Clostridium tetani can be found in the intestines of animals, soil, mouth, leaves, faces(dung) of farm animals. Animals implicated are cattle, dog, sheep, cat, chicken. Manure treated soil has a lot of Clostridium tetani. Autoclaving may not be helpful in sterilizing spores.
causes/risk factors/mode of transmission of neonatal tetanus
- The portal of entry in neonatal tetanus is the umbilical cord. Others are:
- Poor cord care, unhygienic cord cutting, detachment of cord is important in cases of suspected tetanus.
- Babies from un-immunized mothers
- Circumcision
- Ear piercing
- Traditional birth attendants and unhealthy cord practices
- Scarification
The spores come in contact with body tissue, germinate and produce the toxins which lead to the disease. It is important to note that tetanus is not infection by C. tetani, but presence of its toxins in blood. Not all strains of Clostridium tetani produce toxins.
pathogenesis of neonatal tetanus
Clostridium tetani produces 2 exotoxins:
- Tetanolysin
- Tetanospasmin
The role of tetanolysin is not fully known, but it is thought to aid the entrance of tetanospasmin, which goes into the muscles, the motor end plate and undergoes axonal transport into the central and peripheral nervous system.
The toxin must attach to the neuron of which it particularly attaches to the anterior abdominal wall. Hence the first presentation is anterior abdominal wall rigidity.
The toxin interferes with the transmission of the inhibitory neurotransmitters known as Gamma amino butyric acid (GABA) and glycine. This leads to unopposed motor contractions and spasm. In the absence of an enabling environment for it to travel; infection will not be established.
Every case of neonatal tetanus is severe tetanus. Tetanospamin irreversibly binds to the vesicle of those inhibitory neurotransmitters, preventing their release, it has a half-life of 7 days after which new vesicles are formed.
Tetanus is an infection that is difficult to acquire and easy to wade-off in immunized patients, thus if a child is infected with tetanus, the child most likely has other infections present.
symptoms of neonatal tetanus
- Incubation period of 3-21 days – the incubation period is the time between when the neonate sustained the injury to the time of appearance of the first symptom which is trismus (lockjaw).
- Onset time in neonates is almost the same time as the incubation period. The onset time is the period between trismus and the first spasm.
- Symptoms usually appear from the 4th-14th
- Neonatal tetanus occurs in infants without the protective passive immunity.
- This is because the mothers are not immunized
symptoms of neonatal tetanus include;
- Poor suck
- Weak cry
- Generalised spasm
- Opisthotonus position- hyper-extension of the back due to spasm
- Laryngospasm
- Difficulty in breathing(dyspnea), fast breathing(tachypnoea)
- Respiratory distress
- Cyanosis (bluish discoloration of the skin and mucus membrane)
- Apnea- temporary cessation of breathing
- If fever is present, it is due to other causes. Fever is not a usual feature of neonatal tetanus.
or symptoms of Complications
- Fever; due to autonomic dysfunction
- Omphalitis: infection of the cord. Cord is septic and discharges purulent matter.
- Features of aspiration; florid chest
complications of neonatal tetanus
- Spasm
- Laryngospasm
- Aspiration pneumonitis
- Fractures
- Hypotension
- Arrythmias
- Nosocomial infections
- Pulmonary embolism
- Hypoxic ischaemic encephalopathy
- Autonomic dysfunctions like fever, excessive sweating, labile blood pressure, tachycardia
- Renal failure
- Urinary tract infections
classification of neonatal tetanus
There are 3 major ways of classifying neonatal tetanus;
- Hendrickson classification
- ABLET classification
- Dakar classification
Hendrickson classification is the commonest.
diagnosis of neonatal tetanus
Tetanus cannot be diagnosed in the laboratory. Diagnosis is clinical. Laboratory investigation can be done to support treatment. Only 30% of cases can be cultured from the wound.
treatment of neonatal tetanus
- There are laid down protocols for the treatment of neonatal tetanus
- Identify the portal of entry
- Debride the wound
- Mop up the circulating toxins using Anti-Tetanus Globulin. Dose: 300im/kg. Anti-Tetanus Serum(ATS) can also be used especially in developing nations. A test dose should be given prior to administration to prevent anaphylactic reactions. The equine type of ATS is used
- Commence active immunization of the newborn
- Give antibiotics to mop up circulating organisms. Drug of choice is metronidazole. Penicillin can be used, but not encouraged in neonates.
- Control spasm. Give phenobarbitane or diazepam
- Adequate sedation with diazepam
- Remove triggers of spasm like noise, bright light
- Adequate nursing care
The hallmark of treatment of neonatal tetanus is adequate nursing care and management of respiratory complications.
prevention of neonatal tetanus
The only and the best form of prevention of neonatal tetanus is immunization of women of child-bearing age (15-49 years) either before or during pregnancy. The recommended 5 doses tetanus toxoid vaccine for females include:
Tetanus toxoid 1————— first contact—————no protection
Tetanus toxoid 2————–4 weeks later—————80% protection for 3 years
Tetanus toxoid 3————–6 months later————– 95% protection for 5 years
Tetanus toxoid 4——1 year later or in subsequent pregnancy—99% protection for 10years
Tetanus toxoid 5——1 year later or in subsequent pregnancy—protection for life
