Poliomyelitis.pptx

Poliomyelitis

1. POLIOMYELITIS

2. Specific Learning Objectives What is poliomyelitis How it originates (History) Problem statements World & India Epidemiology of poliomyelitis Prevention Eradication of polio AFP Surveillance

3. Poliomyelitis Polio is an acute viral infectious disease contracted predominantly by children that can lead to acute flaccid paralysis and can ultimately cause death by paralyzing the respiratory muscles. Sir Walter Scott’s was the first recorded poliomyelitis case.

4. HISTORY OF POLIO

5. HISTORY OF POLIO In 1988, WHO started the global polio eradication initiatives, which led to the decline of polio cases globally, i.e., from 3,50,000 cases in 1988 in more than 125 countries to 15 cases in the endemic countries in 2018 as per WHO report.

6. Problem Statement- World IN WORLD- In 1988- 3,50,000 cases in 125 Countries. In 2012- 299 cases in 7 Countries. In 2018- 33 cases. 80% of World population is now residing in Polio Free Certified Region. Only 2 Countries continue to report indigenous polio transmission. Pakistan Afghanistan

7. Problem Statement- India India successfully stopped polio transmission From January 2011. No natural case reported since 13 th January 2011 and was declared polio free in January 2014. No cases were reported due to Type 2 and Type 3 strain since 1999 and 2012, respectively. Vaccine Derived Polio Virus(VDPV) type 2 was found in sewage collected in Hyderabad and Rengareddy Districts of Telangana State during May - June 2016. Door to door Immunization activities. Active Surveillance for cases of Acute Flaccid Paralysis was done and no children were to be found to be affected.

8. Epidemiological determinants

9. Agent Factor (A) AGENT : The causative agent is the poliovirus belonging to Enterovirus of Picornaviridae family , which has three serotypes 1,2 and 3 . Most outbreaks of paralytic polio are due to type- 1 virus. In a cold environment . it can live in water for 4 months and in faeces for 6 months. Poliovirus cannot survive for long periods in the external environment. The virus may be rapidly inactivated by pasteurization , and a variety of physical and chemical agents.

10. Agent Factor (B) RESERVOIR OF INFECTION : Man is the only known reservoir of infection . Most infections are subclinical. (C) INFECTIOUS MATERIAL : The virus is found in the faeces and oropharyngeal secretions of an infected person. (D) PERIOD OF COMMUNICABILITY : The cases are most infectious 7 to 10 days before and after onset of symptoms . In the faeces, the virus is excreted commonly for 2 to 3 weeks, sometimes as long as 3 to 4 months.

11. Host factors AGE : -The most vulnerable age is between 6 months and 3 years. SEX : Sex differences have been noted in the ratio of 3 males to one female. Risk factors: Unvaccinated children, immunodeficiency, malnutrition, travelling to endemic area Immunity: Maternal antibodies are protective until six months of age -this protection gradually disappears.

12. Environmental factors Polio is more likely to occur during the rainy season. Approximately 60 per cent of cases recorded in India were during June to September . The environmental sources of infection are contaminated water, food and flies . Polio virus survives for a long time in a cold environment. Overcrowding and poor sanitation provide opportunities for exposure to infection.

13. Mode of transmission FAECAL-ORAL ROUTE : This is the main route of Spread in developing countries. The infection may spread directly through contaminated fingers where hygiene is poor, or 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 the throat. Close personal contact with an infected person facilitates droplet spread. This mode of transmission may be relatively more important in developed countries where faecal transmission is remote.

14. Incubation period Usually 7 to 14 days (range 3 to 35 days).

15. Prevention Immunization is the sole effective means of preventing poliomyelitis. Both killed and live attenuated vaccines are available, and both are safe and effective when used correctly. It is essential to immunize all infants by 6 months of age to protect them against polio. Two types of vaccines are used throughout the world; they are : 1. Inactivated (Salk) polio vaccine (IPV) . 2. Oral (Sabin) polio vaccine (OPV).

16. Difference between Salk (Killed) & Sabin(Live) Vaccine characteristics Salk (killed vaccine) Sabin (Live Attenuated Vaccine) Injectable form / IM Oral form / Oral drops Composition= 80 units Type 1 :40 Units, Type 2 :8 Units, Type 3 :32 Units Composition Type 1 :3 lakhs, Type 2 :1 lakh, Type 3 : 3 lakhs 4 doses, first 3 doses with 1-2 months gap followed by booster dose at 6-12 months gap 5 doses with 1 zero dose at birth followed by booster dose at 6-24 months 80-90% efficient 90-100% efficient Slow immune response Fast immune response Short duration of protection Long lasting No herd immunity Herd immunity present Can precipitate paralysis Can be used safely

17. Why polio can be eradicated?- Reason

18. Reason Potent vaccine Only reservoir of infection is man Virus cannot survive in environment for >48 hours Availability of rapid response team. In 1988, World Health Assembly Resoluted to Eradicate Polio by End of the Year 2000. India Launched National Polio Eradication Program in the Year 1995.

19. Program Includes Routine immunization: To achieve and maintain high level of coverage for OPV about 85% and above. Pulse Polio Immunization (PPI): Launched in India in 1995 WHO Recommended the age group 0-5 years under Pulse Polio Immunization . The success of PPI was seen as a reduction in cases from 35000 annually in 1995 to nil case in India

20. Program Includes AFP Surveillance : To identify and report all cases of acute flaccid paralysis (AFP) Mopping up round: mass supplementary immunization activities (SIA) are organized To immunize all children aged 0-5 years. Protection of high-risk population: Children belonging to migrant population, slums, construction sites, and brick-kilns.

21. AFP Surveillance Acute flaccid paralysis (AFP) is defined as sudden onset of weakness and floppiness in any part of body in a child <15 years of age or paralysis in a person of any age in whom polio is suspected. All cases of AFP among children <15 years of age should be reported and tested for wild polio virus or VDPV within 48 hours of onset. In India, AFP surveillance for polio started in the year 1997 by establishing national polio surveillance project(NPSP) in collaboration with WHO and GOI.

22. Objectives of AFP Surveillance To recognize and report AFP cases at the earliest and to ensure prompt outbreak immunization response with OPV To confirm the cases of wild polio virus through isolation of virus in the stool sample To measure the impact of routine immunization and PPI in India. All the districts in India should report AFP cases. AFP Rates of at least one case per 1,00,000 Population of children below 15 years of age per year should be achieved by each districts. This measures the quality and adequacy of AFP surveillance.

23. Steps for AFP Surveillance

24. Stool sample collection Two samples are collected at least 24 hours apart from suspected AFP Case. The results are good when samples are collected within two weeks of onset of paralysis up to two months. The specimen should be of eight grams or thumb size in amount in a sterile container. Samples should be transported by maintaining reverse cold chain To the laboratory.