Epidemiology & prevention of Polio , Rotaviral Ds

1. Epidemiology, Prevention of
Other VPDs –Polio, Rotavirus,
PCV
Dr. Ananya Ray Laskar
Associate Professor, Community
Medicine, LHMC
Former Public health specialist (NCDC)
MBBS, MD (MAMC)

2. POLIOMYELITIS
“Poliomyelitis" comes from the Greek word for
gray, polio, and myelo, meaning spinal cord. The
Latin suffix ‘itis’ refers to inflammatory diseases.
• Polio belongs to the enterovirus - infect the
intestines.
• Smallest RNA viruses - 25 nm in diameter.

4. EPIDEMIOLOGY
Agent factors
• Agent : Polio
• Type : 3 serotypes (Type-1,Type-2,Type-3)
• No cross-immunity b/w serotypes
• Reservoir : Man
• Infectious material : Faeces, Oropharygeal
secretions
• Incubation period : 7 to 14 Days ( 3- 35 days )
• Period of communicability : 7 to 10 Days
Host factors : commonly affects <5yrs
Maternal antibodies are protective

5. EPIDEMIOLOGY Triad contd…
Environment Factors
• Rainy season (June to September )
• Overcrowded condition with poor sanitation & open field
defecation
Mode of transmission :
• Faeco -oral route (major route)
• Droplet infection also in some cases

6. • Unapparent (sub-clinical) infection: 95 %
- no presenting symptoms.
- Recognition only by virus isolation.
• Abortive Polio (Minor Illness) : 4-8 %
- mild or self limiting illness due to viraemia.
- The patient recovers quickly.
• Non paralytic polio: 1 % of all infections.
- stiffness and pain in neck and back.
- The disease lasts for 2-10 days. Recovery is rapid.
CLINICAL PRESENTATIONS

7. EPIDEMIOLOGY
Paralytic polio: < 1 % of infections. The virus enters
the brain and causes varying degree of disability.
▫ Predominant sign – asymmetric flaccid paralysis
▫ History of fever at onset
▫ Descending paralysis – starts at hip and moves distally
▫ Proximal muscles > distal
▫ Signs of meningeal irritation , tripod sign
▫ Cranial nerve involvement in bulbar and bulbospinal
forms

9. Terminologies
• Vaccine-derived polioviruses (VDPVs) stem from
mutated live poliovirus, which is contained in the
Oral Polio Virus vaccine (OPV). In addition, the
emergence of VDPV is one of the global challenges
for the eradication of poliomyelitis.
• Vaccine-associated paralytic poliomyelitis (VAPP)
is an adverse event following exposure to OPV.
OPV is made with live attenuated (weakened)
polioviruses that can cause sporadic and rare case of
paralytic polio. IPV can prevent VAPP

10. BURDEN OF POLIO Global Status 1988

11. GLOBAL STATUS 2004

12. Last cases in India
WPV 2- 1999
WPV3-2010
WPV1- 2011

14. Global Polio Eradication Initiative (1988)
• The Global Polio Eradication Initiative is a public-private
partnership led by national governments with 5 core partners -
the World Health Organization (WHO), Rotary International, the
US Centres for Disease Control and Prevention (CDC), the United
Nations Children’s Fund (UNICEF) and the Bill & Melinda Gates
Foundation.
• GOAL: to complete the eradication and containment of all wild,
vaccine-related and Sabin polioviruses, such that no child ever
again suffers paralytic poliomyelitis.
• Launched in 1988 after the World Health Assembly passed a
resolution to eradicate polio.
• The Global Polio Eradication Initiative, along with its partners,
has helped countries to make huge progress in protecting the
global population from this debilitating disease
• As a result, global incidence of polio has decreased by 99.9%
since GPEI’s foundation.

15. History of Polio in India
200,000
50,000
1934 1126 265 268 1600 225 134 66 676 874 559 741 42 1 0
0
50,000
100,000
150,000
200,000
Before
1978*
1994* 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012-
19**
Based on estimates by Indian Academy of Pediatrics and World Health Organization
1999: Last type-2 Poliovirus 2010: Last Type 3 Poliovirus
1978: OPV Introduced in RI
1995: SIAs Started
** data as on 13 July 2019
Number of polio cases
2011: Polio Transmission
Stopped
Polio-Free India: Major Public Health Achievement
OPV, Oral Polio Vaccine
RI, Routine Immunization
SIAs, Supplementary Immunization Activities
2014: SEAR
Certified Polio-
Free
15
2015-IPV introduced in EPI 2016-t OPV –b OPV switch

16. CURRENT STATUS POLIO
• Polio has been eradicated from most of the countries
of the world
• Remains endemic in two countries Afghanistan
and Pakistan.
• Until poliovirus transmission is interrupted in these
countries, all countries remain at risk of importation
of polio
(vulnerable countries with weak public health and
immunization services & travel or trade links to
endemic countries)

17. CURRENT STATUS in India
• Polio has been eradicated from India
• Last case reported in 2011
• In Feb 2012 India was removed from global list
of endemic countries
• WHO SEARO got polio free status on:
March 2014
• Focus is now on maintaining polio free status

18. PREVENTION OF POLIO
Primordial level of prevention
• Awareness generation about the disease
• Practice good hand hygiene
• Inclusion in school curriculum about the disease
• Provision of safe water & sanitation
• Discouragement to open-field defecation

19. PREVENTION OF POLIO
Primary Level of prevention
Routine immunisation (1978)–
< 1 yr (primary imm)– 4 doses - UIP
OPV (bivalent) Birth 6, 10 & 14 weeks
Booster at 15-18 moths
f-IPV -6, 14wks & booster 9months
Earlier : Pulse Polio Immunization - National
Immunization days (NID’s 1995 onwards)/ PPI / Sub-
national immunization days (SIDs) –Additional doses of
OPV , 4 to 6 weeks apart to every child aged < 5 yrs
- ‘Mop–up’ rounds house to house ‘search and vaccinate’
component

20. OPV (Sabin) IPV (Salk)
Type Live vaccine Killed
Protects against bOPV (1& 3) All strains
Forms Mono/bi/trivalent
Route Oral Intradermal
Immunity Gut Humoral
Cold chain Deep freezer ILR +2 to 8◦
Temp to be maintained
strictly
Frozen vaccine to be
discarded
Administration Easy & cold chain Needs Skill Training
Efficacy High Very High
Herd Immunity + -
Outbreak control Used for control To be strictly avoided
Immunocompromis-
ed
Not Safe
Cost of production Moderate High

21. PREVENTION OF POLIO
Secondary Level of prevention
• Prompt reporting of AFP to health authorities &
appropriate action
• Early diagnosis
• Avoidance of injectable medicines during
acute phase of suspected polio
• Notification to higher authorities for AFP
surveillance (SMO of the area & Dist.
Immunization Officer)

22. Tertiary level of Prevention
• Corrective surgeries
• Physical therapies that support the rehabilitation of
children with paralytic i.e. they can reduce the
impact of paralysis on the child's quality of life
• Vocational Rehabilitation
• Benefits under the GoI Ministry of Social Justice &
Empowerment

23. Current risks to Polio Program
• Complacency (Decreased program efficiency –
Increase in number of unimmunized children)
• Surveillance gap (Decreased reporting of AFP cases
from the facilities)
• Importation of Virus (Transmission from
international travellers)
• Delayed response to Importation of Virus
• Emergence of VDPVs (Poor RI coverage)

24. • Nationwide AFP (acute flaccid paralysis) surveillance is the
gold standard for detecting cases of poliomyelitis.
4 steps of AFP surveillance:
• Finding AFP (active search/passive)
• Reporting children with acute flaccid paralysis (AFP)
• Transporting stool samples for analysis.
• Isolating and identifying poliovirus in the laboratory.
The consequences of missing polio cases is more serious than
occasionally including an ambiguous cases in the final stage of
global polio eradication.
Surveillance for AFP case

25. Acute Flaccid Paralysis(AFP)
Acute flaccid paralysis is defined as sudden
onset of weakness or floppiness in any part of
the body in a child < 15 years of age (irrespective of
diagnosis/cause)
OR
Paralytic illness in a person of any age in which polio is
suspected.
Onset Within past six months

26. What To Notify – A.F.P.
o Name
o Age
o Father’s name & occupation.
o Address and Phone no. (if available)
o Date of onset of Paralysis
o Part of the body affected
Immediate Reporting - of AFP cases
Because-
Virus shedding is brief, The sooner the stool samples are examined, the better the
chance of detecting poliovirus.

29. Burden of Rotaviral Diarrhoea
• 11.37 million episodes of acute gastroenteritis
(AGE) in children < 5 years annually in India,
requiring 3.27 million outpatient visits and
872,000 hospitalization (2012)
• Rotavirus is the leading cause of acute
gastroenteritis in the world.
• Studies estimate that approximately 200,000
people die annually from infection.

30. Previously used Rotavac dosage

31. Shs Shift to Rotasiil
aro

32. Pnuemococcal Conjugate Vaccine
• PCV - to reduce the burden of Pnuemonia &
other illness due to streptococcus pnuemoniae
• introduced in the UIP in a phased manner (June
2017) in select districts of Bihar, Himachal
Pradesh and UP.
• Further phase-wise expansion throughout the
country to help achieve 90% immunization
coverage by 2020
• 2 Primary (6wk &14wk) and booster in 9month