Poliomyelitis

1. Poliomyelitis

2. Objectives 1- these two infectious diseases uncommon now but have very serious complications, so should know features of both for early diagnosis and management to reduce morbidity and mortality. 2- to know rout of acquired infection so can prevent or reduce this. 3- to avoid factors that can increased risk of paralysis in polio. 4- to know how manage wound and cord after delivery and prevent contaminations to reduce risk of tetanus. 5-to know the main preventive measures and encourage them.

3. Poliomyelitis ETIOLOGY. The polioviruses are positive-stranded RNA viruses belonging to the genus Enterovirus, and include 3 serotypes (types 1, 2, and 3). EPIDEMIOLOGY & Transmission : *Poor sanitation and crowding have permitted the continued transmission of poliovirus in certain poor countries . *Spread by the fecal-oral route.Poliovirus has been isolated from feces for >2 wk before paralysis to several weeks after the onset of symptoms. *Rarely paralytic poliomyelitis result from oral polio vaccine(OPV) which called vaccine-associated paralytic poliomyelitis (VAPP) .

4. *Active immunity after natural infection is lifelong but protects against the infecting serotype only; infections with other serotypes are possible. PATHOGENESIS : polioviruses enter the body via the gastrointestinal tract. The primary site of replication is in the M cells lining the mucosa of the small intestine. Regional lymph nodes are infected & the virus seeds multiple sites, including the reticuloendothelial system, and skeletal muscle.

5. The virus accesses the CNS along peripheral nerves .Itsprimarily infects motor neuron cells in the spinal cord (the anterior horn cells) and the medulla oblongata (the cranial nerve nuclei). CLINICAL MANIFESTATIONS : The incubation period 8–12 days, with a range of 5–35 days.Poliovirus infections may follow 1 of several courses: 1- inapparent infection :which occurs in 90–95% of cases and causes no disease and no sequelae but induce protective immunity.

6. 2-Abortive Poliomyelitis(minor illness) : In 5% of patients, a nonspecific influenza-like syndrome occurs 1–2 wk after infection. Fever, malaise, anorexia, and headache are prominent features, and there may be sore throat and abdominal or muscular pain. The illness is short up to 2–3 days. The physical examination may be normal. Recovery is complete, and no neurologic sequelae develop. 3-Nonparalytic Poliomyelitis(major illness) : In about 1% of patients signs of abortive poliomyelitis are present, with more intense headache, nausea, and vomiting, and stiffness of neck, trunk, and limbs(symptoms like aseptic meningitis). Its either improve over 7-10days or proceed into paralysis within 2-3days . Most paralytic polio. pass through major illness .

7. 4-Paralytic Poliomyelitis : It develops in about 0.1% of persons infected with poliovirus, causing 3 clinically recognizable syndromes: *Spinal paralytic poliomyelitis: may start as abortive poliomyelitis . The patient then appears to recover and feels better for 2–5 days, after which severe headache and fever occur . Severe muscle pain is present, and paresthesia, and spasms may develop . On physical examination : Single muscles, multiple muscles, or groups of muscles may be involved in any pattern. Within 1–2 days, asymmetric flaccid paralysis occurs. Involvement of 1 leg is most common, followed by involvement of 1 arm.

8. Bowel and bladder dysfunction with constipation and urinary retention often occur. Sensation is intact .Atrophy of the limb, and deformity is common . *Bulbar poliomyelitis : clinical findings occurs due to dysfunctions of the cranial nerves and medullary centers & include : 1- palatal and pharyngeal weakness 2- inability to swallow smoothly, resulting in accumulation of saliva in the pharynx which may cause irregular respirations . 3- absence of effective coughing .

9. 4- involvement of vital centers in the medulla, which manifest as irregular respiration; blood pressure changes (hypertension or hypotension and shock ), and cardiac arrhythmias; and as rapid changes in body temperature . 5-paralysis of 1 or both vocal cords, causing hoarseness, aphonia, and asphyxia . *Polioencephalitis:is a rare form of the disease in which higher centers of the brain are severely involved. Seizures, coma, and spastic paralysis with increased reflexes may be observed.

10. DIAGNOSIS: 1- Isolation and identification of poliovirus in the stool .2 stool specimens should be collected 24–48 hr apart . 2- CSF : with CNS involvement demonstrates a pleocytosis. 3- Serologic test : demonstrates seroconversion or a 4-fold or greater increase in antibody titers, when measured during the acute phase of illness and 3–6 wk later.

11. Differential Diagnosis : Poliomyelitis should be differentiated from other causes of acute flaccid paralysis in children : 1- Guillain-Barré syndrome. 2- Transverse myelitis. 3- Traumatic neuritis: as Intramuscular gluteal injection. 4-Pseudoparalysis :include unrecognized trauma, transient (toxic) synovitis, acute osteomyelitis, acute rheumatic fever, scurvy, and viral myositis . 5- Viral encephalitis & Rabies . 6- other enteroviruses infections as coxsackie A virus or ecovirus .

12. COMPLICATIONS: 1-Acute gastric dilatation. 2-single or multiple superficial intestinal erosions. Perforation is rare . 3- Hypertension 4- Hypercalcemia, nephrocalcinosis & renal stone . 5- Cardiac irregularities ,myocarditis . Acute pulmonary edema also can occurs .

13. TREATMENT : no specific antiviral treatment for poliomyelitis . *All intramuscular injections and surgical procedures are contraindicated during the acute phase of the illness, especially in the 1st week of illness, because these may result in progression of disease. Abortive Poliomyelitis : 1-Supportive treatment with analgesics, sedatives, an attractive diet, and bed rest until the child's temperature is normal . 2-Avoidance of exertion for 2 wk .

14. 3-careful neurologic and musculoskeletal examinations 2 mo later to detect any minor involvement . Nonparalytic Poliomyelitis : 1-Analgesics . 2- A firm bed is desirable . 3- Splint & Physical therapy. Paralytic Poliomyelitis : 1- Hospitalization with complete physical rest in a calm atmosphere for the 1st 2–3 weeks . 2- A neutral position with the feet at a right angle to the legs.

15. 3- Physiotherapy.. 4- hot packs relieve muscle pain and spasm. 5- Adequate dietary and fluid intake . Pure bulbar poliomyelitis: 1- maintaining the airway and avoiding all risk of inhalation of saliva, food, or vomitus. 2- Patients with weakness of the muscles of respiration or swallowing should be nursed in a lateral or semi-prone position with direct oral and pharyngeal aspiration . 3- Blood pressure should be taken at least twice daily .

16. 4- Tracheostomy indicated for vocal cord paralysis , spinal respiratory muscle paralysis, and bulbospinal paralysis . * Factors increased risk for paralytic poliomyelitis : 1-Pregnancy . 2- Tonsillectomy enhance the risk for acquisition of bulbar disease . 3- Intramuscular injections . 4- Increased physical activity, exercise, and fatigue during the early phase of illness .

17. PREVENTION : 1- Hygienic measures . 2- Immunization: 2 types of polio vaccine *live-attenuated OPV (sabin) which induces significantly greater mucosal IgA immunity in the oropharynx and gastrointestinal tract that limits replication of the poliovirus at these sites. *Inactivated polio vaccine (IPV) (salk)

18. Tetanus ETIOLOGY. Tetanus, also called lockjaw, is an acute, spastic paralytic illness caused by the neurotoxin(tetanospasmin or tetanus toxin) produced by Clostridium tetani, gram-positive, spore-forming anaerobe. EPIDEMIOLOGY. *The most common form, neonatal (or umbilical) tetanus. It occurs because the mother was not immunized. *maternal tetanus results from postpartum, postabortal, or postsurgical wound infection with C. tetaniin unimmunized women . *Most non-neonatal cases of tetanus are associated with a traumatic injury, often a penetrating wound by a dirty object.

19. PATHOGENESIS : After introduction of spores into the injury site, they germinate & multiply. Toxin is released after vegetative bacterial cell death and lysis . This toxin binds at the neuromuscular junction and prevents release of the neurotransmitters γ-aminobutyric acid (GABA), thus blocks the normal inhibition of antagonistic muscles & affected muscles sustain maximal contraction and cannot relax. CLINICAL MANIFESTATIONS : The incubation period typically is 2–14 days, but it may be as long as months after the injury. Tetanus either generalized, which is more common, or localized

20. 1- Generalized tetanus: The presenting symptom in 50% of cases is trismus (masseter muscle spasm, or lockjaw). Headache, restlessness, and irritability are early symptoms, followed by stiffness, difficulty chewing, dysphagia, and neck muscle spasm. The so-called sardonic smile of tetanus (risus sardonicus) results from intractable spasms of facial and buccal muscles. When the paralysis extends to abdominal, lumbar, hip, and thigh muscles, the patient may assume an arched posture of extreme hyperextension of the body (opisthotonos). The patient remains conscious, in extreme pain because tetanus toxin does not affect sensory nerves or cortical function .

21. Tetanic seizure then develop . Sight, sound, or touch may trigger a tetanic spasm . Dysuria and urinary retention result from bladder sphincter spasm . Fever, as high as 40°C, is common . Tachycardia, dysrhythmias, & hypertension also may occur. 2- Neonatal tetanus (tetanus neonatorum) : The infantile form of generalized tetanus, typically manifests within 3–12 days of birth as progressive difficulty in feeding , associated hunger, and crying. Paralysis, stiffness and rigidity to the touch are characteristic.

22. 3-Localized tetanus : results in painful spasms of the muscles adjacent to the wound site and may precede generalized tetanus. 4- Cephalic tetanus : is a rare form of localized tetanus involving the bulbar musculature that occurs with wounds or foreign bodies in the head, nostrils, or face. DIAGNOSIS : 1- Clinically. 2- leukocytosis result from a secondary bacterial infection of the wound. 3- The CSF is normal .Neither EEG nor EMG shows a characteristic pattern. 4- C. tetani is not always visible on Gram stain of wound material, and it is isolated in only about ⅓ of cases.

23. DIFFERENTIAL DIAGNOSIS : 1- Trismus may result from parapharyngeal, retropharyngeal, or dental abscesses. 2- Rabies .3-Hypocalcemic tetany . 4- epileptic seizures & narcotic withdrawal. COMPLICATIONS : 1- Aspiration of secretions and pneumonia. 2- seizures may result in lacerations of the mouth or tongue, in intramuscular hematomas or rhabdomyolysis with myoglobinuria and renal failure, or in long bone or spinal fractures.

24. 3- Venous thrombosis, pulmonary embolism. 4- Cardiac arrhythmias. TREATMENT : 1- Surgical wound excision and debridement are needed to remove the foreign body or devitalized tissue that created anaerobic growth conditions. 2- Tetanus immunoglobulin (TIG) should be given as soon as possible in order to neutralize toxin that diffuses from the wound into the circulation before the toxin can bind at distant muscle groups. If TIG is unavailable, use human intravenous immunoglobulin (IVIG) or tetanus antitoxin (TAT) .

25. 3- Antibiotics : Penicillin G (100,000 U/kg/day divided every 4–6 hr IV for 10–14 days) .Erythromycin and tetracycline (for persons >8 yr of age) are alternatives for penicillin-allergic patients. 4- Muscle relaxants. Diazepam provides both relaxation and seizure control . 5- Neuromuscular blocking agents such as pancuronium, which produce a general flaccid paralysis that is then managed by mechanical ventilation . 6- α- and β- blocking agents for autonomic instability . SUPPORTIVE CARE : * The patient should be sedated and protected from all unnecessary sounds, sights, and touch . *Endotracheal intubation or tracheostomyrequire in severe cases . *Cardiorespiratory monitoring, frequent suctioning, and maintenance of the fluid, electrolyte, and caloric needs .

26. PREVENTION : * Active immunization with tetanus toxoid (DTP) vaccine. *Immunization of women with 2 doses of tetanus toxoid prevents neonatal tetanus . Wound Management : - Tetanus toxoid should always be given after a dog or other animal bite & to all persons with any wound if the tetanus immunization status is unknown or incomplete. - Any patients with an unknown or incomplete immunization history with crush wound, wounds contaminated with saliva, soil, or feces; tetanus immunoglobulin(TIG) should be given .