510 likes | 810 Views
Epidemiology of Poliomyelitis Polio End Game Strategy. Dr Abhay S. Nirgude M.D.,DHA,PGDBEME, Faimer Fellow. Professor & Head, Community Medicine. Specific Learning Objectives. Discuss the epidemiology of poliomyelitis
E N D
Epidemiology of Poliomyelitis Polio End Game Strategy Dr Abhay S. Nirgude M.D.,DHA,PGDBEME, Faimer Fellow. Professor & Head, Community Medicine Dr Abhay Nirgude
Specific Learning Objectives • Discuss the epidemiology of poliomyelitis • Discuss the polio surveillance and polio end game strategy in India • Discuss how surveillance impacted the NPEP. • Understand potential use of polio surveillance model in control of other diseases. Dr Abhay Nirgude
Polio Cases & SIAs Dr Abhay Nirgude
WPV2 24/10/1999 Aligarh (UP) WPV3 22/10/2010 Pakur (JH) WPV1 13/01/2011 Howrah (WB) Last wild poliovirus cases by type, India Dr Abhay Nirgude
Prevention Dr Abhay Nirgude
National Polio Eradication Program • Achieving and maintaining high routine coverage in infants younger than 1 year with at least 3 doses of oral polio vaccine (OPV). • Administering supplemental doses of OPV to all children aged <5 years during national immunization days to rapidly interrupt transmission. • Surveillance of Acute Flaccid Paralysis cases. • Conducting “mop-up” vaccination campaigns. Dr Abhay Nirgude
Salk versus Sabin vaccine Dr Abhay Nirgude
Acute Flaccid Paralysis • Acute flaccid paralysis is defined as sudden onset of weakness and floppiness in any part of the body in a child < 15 years of age or paralysis in a person of any age in whom polio is suspected. • Sensitive surveillance for AFP must be able to detect a minimum of 1 case per 100,000 children less than 15 years of age. Dr Abhay Nirgude
Acute Flaccid Paralysis • AFP surveillance substantially increases the sensitivity of the surveillance system. • Helps us to identify areas of priority for focusing immunisation activities. • It is the most reliable tool to measure the quality and impact of polio immunisation activities. • AFP Surveillance also helps to monitor progress in polio eradication. Dr Abhay Nirgude
AFP Surveillance Network Dr Abhay Nirgude
Weekly Reporting Dr Abhay Nirgude
AFP Surveillance AFP Case Investigation Visit to Reporting Unit Dr Abhay Nirgude
STOOL COLLECTION, STORAGE , TRANSPORT. • LRF • Adequate Stool. • 2 Specimens, 24 Hours Apart. • 8 gms. • Within 14 Days of Paralysis Onset & with proper Cold Chain • Reverse Cold Chain. Dr Abhay Nirgude
Surveillance System Performance Indicators • Non – Polio AFP Rate > 2.0 (India) • Adequate Stool Samples > 80% • Timeliness of Reporting > 80% • Reported AFP cases investigated within 48 hours of notification (target >80%). • Timeliness of weekly reporting (target >80%) Dr Abhay Nirgude
Surveillance System Performance Indicators • Completeness of weekly reporting (target >90%). • Stool specimens reaching a WHO accredited laboratory within 72 hours of being sent ( >80%). • Stool specimens reaching laboratory in good condition (target >80%) . • Stool specimens with a turn around time <28 days (>80%) Dr Abhay Nirgude
Identify Areas/ Population at risk • Real time and credible data. • Tailored strategies to ensure coverage • Migrant population • Vulnerable population • High risk areas Dr Abhay Nirgude
Laboratory Methods • Primary Isolation Of Poliovirus In Cell Culture • Intratypic Differentiation Test (ITD) • Genetic Sequencing Dr Abhay Nirgude
Area under Kosi,Kamala, Kareh river basin Kosi Operational Plan Dr Abhay Nirgude
Kosi Operational Plan • Kosi operational group • Head :- Principal secretary HFW • Social Mobilization :- UNICEF • Technical & Operational Inputs:- WHO-NPSP • Key field personals :- Health department. Dr Abhay Nirgude
Development of Underserved Strategy Dr Abhay Nirgude
Influence Policy Makers • Advocacy. • Facilitating communication. • Resolving disputes. • Liasoning with stakeholders at all levels. Dr Abhay Nirgude
Environmental Surveillance • Detect poliovirus circulation by means of sewage sampling. • Polioviruses (WPV & VDPV) are sequenced to characterize their genetic relationship to polioviruses isolated from other environmental samples and from AFP cases. • The combination of AFP and ES data are then used to identify areas of increased risk and to specifically target vaccination strategies to better reach susceptible populations. Dr Abhay Nirgude
Environmental Surveillance • On at least a few occasions, WPVs of the same genetic lineage were isolated from sewage samples before the detection of a paralytic case through AFP surveillance. • Genetic sequencing may allow the ability to trace the origin of polioviruses to other circulating polioviruses with similar sequences. Dr Abhay Nirgude
Environmental Surveillance Sites • Mumbai 2001 • Delhi 2010 • Patna & Kolkata 2011 • Punjab & Gujarat 2013 • Telangana & Uttar Pradesh Dr Abhay Nirgude
From: Environmental Surveillance for Polioviruses in the Global Polio Eradication Initiative J Infect Dis. 2014;210(suppl_1):S294-S303. doi:10.1093/infdis/jiu384 J Infect Dis | Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US. Dr Abhay Nirgude
VAPP OPV Replicate in the pharynx and the intestine During replication, the Sabin strains mutate toward more genetically stable variants. Sometimes reverting to neurovirulent variants that may enter the central nervous system and cause paralysis VAPP is caused by a strain of poliovirus that has genetically changed in the intestine from the original attenuated vaccine strain contained in OPV. Dr Abhay Nirgude
cVDPV • If a population is seriously under-immunized, an excreted vaccine-virus can continue to circulate for an extended period of time. • The longer it is allowed to survive, the more genetic changes it undergoes. • In very rare instances, the vaccine-virus can genetically change into a form that can paralyse Dr Abhay Nirgude
VAPP VDPV cVDPV Dr Abhay Nirgude
Objectives of the Polio Eradication & Endgame Strategic Plan 2013-2018 Dr Abhay Nirgude
Risks of OPV2 now outweigh the benefits Dr Abhay Nirgude
Withdrawal of OPV type 2 will leave a gap in population immunity against type 2 poliovirus • Increased risk of outbreaks due to type 2 poliovirus following reintroduction • Re-introduction could occur if: • cVDPV type 2 emerged during or shortly after OPV type 2 withdrawal • Importation of cVDPVs occurs • Break in bio-containment process in laboratories storing viruses.
Potential Use In Other Diseases • National Public Health surveillance Project:- Technical support :- • VPD’s • Outbreak management IDSP • Neglected tropical diseases • Measles • Zika Virus Dr Abhay Nirgude
Thank You Dr Abhay Nirgude