Today is our topic of discussion Definition of Poliomyelitis
Definition of Poliomyelitis
Definition:
Polio is an acute viral illness that in its most severe form causes paralysis, difficulty breathing and sometimes death.
Epidemiology:
Occurrence:
Poliomyelitis can occur sporadically, endemically or epidemically. One in 200 infections their breathing leads to irreversible paralysis (usually legs). Among those paralysed, 5% to 10% die when muscles become immobilized.
Agent factors:
Agent:
Poliovirus, an enterovirus. The virus can survive for long periods in the external environment.
Reservoir of infection:
Man (cases and carriers). Housefly & cockroach may carry the virus.
Infectious material:
Faeces and oropharyngeal secretions of an infected person.10
Period of communicability:
7 to 10 days before and after onset of symptoms.
Host factors:
a. Age: Polio mostly affects children <5 years. The most vulnerable age is between 6 months to 3 years.
b. Sex: Male and female ratio is 3:1.
c. Risk factors: The very young, immunodeficiency states, operative procedures undertaken during
polio epidemic, trauma, pregnancy etc.
d. Immunity: Maternal antibodies of immune mothers give protection for first 6 months. One attack
confers lasting immunity.
Environmental factors:
More common during rainy season, particularly June to September. The environmental sources of infection are contaminated water, food and flies.
Mode of transmission:
Faecal-oral route:
Directly through contaminated fingers where hygiene is poor and indirectly through contaminated water, milk, foods, flies and articles of daily use.
Droplet infection:
This may occur in the acute phase of disease when the virus occurs in throat.
Incubation period:
Usually 7 to 14 days (range 3 to 35 days).
Clinical feature:
Inapparent (sub-clinical) infection:
The vast majorities of people who are infected with the poliovirus don’t become sick and are never aware they’ve been infected with polio.
Abortive polio or minor illness:
A self-limiting illness with quick recovery.
Nonparalytic polio:
Stiffness and pain in the neck and back. Recovery is rapid. The disease is synonymous with aseptic meningitis.
Paralytic polio:
Occurs in <1% of infections. Initial S/S (fever and headache), often mimic those of nonparalytic polio. Within a week, S/S specific to paralytic polio appears –
a. Loss of reflexes dini V90 to esgot not ris
b. Severe muscle aches or spasms
c. AFP-Loose and floppy limbs, often worse on one side of the body
Complications:
Paralytic polio can lead to temporary or permanent muscle paralysis, disability, and deformities of the hips, ankles and feet.
Investigation:
A sample of throat secretions, stool or cerebrospinal fluid is examined for virus.
Treatments:
No cure for polio exists; the focus is on increasing comfort, speeding recovery and preventing complications –
1. Bed rest
2. Antibiotics for secondary infections (if any)
3. Analgesics for pain
4. Portable ventilators to assist breathing
5. Physiotherapy to prevent deformity and
6. A nutritious diet
Prevention and control:
1. Active immunization to all children with polio vaccine (OPV or Sabin vaccine) o
2. Reporting of cases of paralytic poliomyelitis
3. Disinfection of contaminated articles bas
4. Improving public sanitation
5. Careful personal hygiene
6. Isolation of cases (little value)
Factors favouring eradication of polio:
1. Man is the only host
2. No long term carrier state
3. OPV is easy to administration
4. OPV is cheap
5. Live attenuated viruses in OPV multiply in intestine and interrupt transmission of wild viruses
6. OPV induces both humoral and intestinal immunity
7. Antibody is quickly produced
8. Viruses transmis from a recently vaccinated child to close contacts who has not immunized
9. No insect vector or animal is involved in the transmission of the disease algen
10. Having international cooperation
Q. ‘Poliomyelitis can be eradicated’ give points in favour it.
Ans. Above ‘factors favouring eradication of polio’.
Polio Eradication Programme in Bangladesh.
In compliance with the resolution of Global Polio Eradication Initiative adopted in the forty-first World Health Assembly-1988, Bangladesh also launched the polio eradication programme.
Strategies:
1. High infant immunization coverage with four doses of OPV in the first year of life.
2. Supplementary doses of OPV to all children less than five years of age during NIDS.
3. Surveillance for wild poliovirus through reporting and laboratory testing of all AFP cases among children <15 years of age.
4. Targeted “mop-up” campaigns.
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