Thursday, May 8, 2025

Pulse Polio Immunization Programme 1975

Poliomyelitis (Polio) is a viral infectious disease that can cause flaccid paralysis by affecting the central nervous system in about 0.5% of cases.

Etiopathogenesis of Poliovirus

1. Causative Agent:

  • Poliovirus is an enterovirus belonging to the Picornaviridae family.
  • There are three serotypes: PV1, PV2, and PV3 (PV1 is most commonly associated with paralysis).

2. Mode of Transmission:

  • Fecal-oral route (primary)
  • Oral-oral route (less common)

3. Pathogenesis:

  • Entry: Virus enters through the mouth and multiplies in the oropharynx and gastrointestinal tract (lymphoid tissue like tonsils and Peyer's patches).
  • Viremia: Virus enters the bloodstream and may spread to other sites.
  • CNS Invasion: In <1% of cases, the virus crosses the blood-brain barrier or is transported via peripheral nerves to the central nervous system (CNS).
  • Neuronal Damage: The virus targets anterior horn cells of the spinal cord, causing motor neuron destruction, leading to flaccid paralysis.
  • Outcomes:
    • Asymptomatic (90–95%)
    • Minor illness (4–8%) – fever, sore throat
    • Non-paralytic poliomyelitis (<1%) – aseptic meningitis
    • Paralytic poliomyelitis (<0.5%)

Pharmacotherapy of Poliovirus

There is no specific antiviral treatment for poliovirus. Management is primarily supportive and preventive:

1. Supportive Treatment:

  • Bed rest, analgesics for pain
  • Physical therapy to prevent deformities and improve mobility
  • Ventilatory support (iron lung or modern ventilators) in case of respiratory muscle paralysis

2. Preventive Pharmacotherapy (Vaccination):

  • OPV may rarely cause vaccine-associated paralytic polio (VAPP) or circulating vaccine-derived poliovirus (cVDPV).
  • IPV is introduced to mitigate VAPP and cVDPV risks.

 

Pulse Polio Immunization in India

  • Launched in 1995 as part of the global polio eradication initiative following the 1988 World Health Assembly resolution.
  • Targets children aged 0–5 years with polio drops during national and sub-national rounds.

Key Milestones

  • 1995: Pulse Polio Programme launched
  • 2009: India reported half of the global polio cases
  • 2011: Last polio case in India
  • 2012: WHO removed India from the list of endemic countries
  • 2014: India declared polio-free

Aims and Objectives

  • Immunize every child, especially in remote areas
  • Ensure no child is missed during immunization
  • Timely reporting of acute flaccid paralysis (AFP) cases and stool sample collection
  • Rapid outbreak response immunization (ORI)
  • Maintain strong surveillance systems

Steps to Maintain Polio-Free Status

  • Annual high-quality immunization rounds
  • Surveillance for any virus importation or circulation
  • Environmental surveillance through sewage sampling

Polio Eradication and Preparedness Efforts in India

Rapid Response and Emergency Plans

  • All States/UTs have Rapid Response Teams (RRTs) and Emergency Preparedness and Response Plans (EPRPs) to handle any polio outbreaks.

Preventing Importation

  • Continuous Vaccination Teams (CVTs) deployed at international borders to vaccinate eligible children around the clock.
  • As of August 31, 2015, approximately 7.8 million children vaccinated with OPV.
  • Since March 2014, mandatory polio vaccination for international travelers to and from India and affected countries like Afghanistan, Nigeria, Pakistan, etc.
  • A rolling stock of OPV is maintained for emergency response.

Introduction of IPV in Routine Immunization

  • In line with the Polio Eradication & Endgame Strategic Plan 2013–2018, India introduced the Inactivated Poliovirus Vaccine (IPV) in 2015.
  • IPV is given with the third dose of OPV at 14 weeks of age for infants.

Programme Outcomes

  • Over 17.4 crore children under 5 years receive polio drops annually.
  • Last polio case reported on 13 January 2011 in Howrah, West Bengal.
  • WHO removed India from the list of polio-endemic countries on 24 February 2012.

 

 

 

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