Disease eradication past and future

Past and future of eradication and elimination of different diseases. How to plan for elimination and eradication. What are the diseases can be eliminated? OPV to IPV shift!

1. Disease Eradication: Past and Future By Dr Arijit Kundu

2. CONTENT Definition Eradication Criteria Successful Eradication Programs Ongoing Eradication Programs Former Eradication Programs

3. Definition Eradication Termination of all transmission of infection by extermination of the infectious agent through surveillance and containment. Absolute process; an “ all or none ” phenomenon. R estricted to termination of an infection from the whole world .

4. Definition It is sometimes confused with: Elimination : interruption of transmission of disease from a large geographic region or political jurisdiction. When a disease stops circulating in a region, it’s considered eliminated in that region. If a particular disease is eliminated worldwide, it’s considered eradicated . For example, Polio was eliminated in the United States by 1979.

5. Eradication Criteria Both biological and technical features determine whether a pathogenic organism can be eradicated or not . The targeted organism must not have a non-human reservoir. Sufficient information on the life cycle and transmission dynamics is available at the time an eradication initiative is programmed . In case of animal diseases , the infection reservoir must be an easily identifiable species (as in the case of rinderpest ), and/or amplify in the environment .

6. Eradication Criteria An efficient and practical intervention (e.g., vaccine) must be available to interrupt transmission of the infective agent. The disease to be eradicated should be clearly identifiable, and an accurate diagnostic tool should exist . Economic considerations, as well as social and political support and commitment, are other crucial factors that determine eradication feasibility .

7. Eradication Programs T wo successful programs targeting S mallpox R inderpest

8. Eradication Programs Two former programs targeting Hookworm Yellow fever Four ongoing programs targeting Poliomyelitis Yaws Dracunculiasis Malaria

9. Eradication Programs Five more infectious diseases have been identified as of April 2008 as potentially eradicable with current technology: M easles M umps R ubella Lymphatic filariasis C ysticercosis

10. Successful Eradication Programs

11. Smallpox Smallpox was the first disease, and so far the only infectious disease of humans, eradicated by deliberate intervention. It became the first disease for which there was an effective vaccine in 1798 when Edward Jenner showed the protective effect of inoculation (vaccination) of humans with material from cowpox lesions Eradication was accomplished with a combination of focused surveillance—quickly identifying new smallpox cases—and ring vaccination .

12. Smallpox “ Ring vaccination ” meant that anyone who could have been exposed to a smallpox patient was tracked down and vaccinated as quickly as possible, effectively corralling the disease and preventing its further spread.

13. Smallpox Epidemiological factors which have led to eradication of smallpox: No known animal reservoir. No long-term carrier of the virus. Life-long immunity, after recovery from the disease. S imple detection of cases , the rash was so characteristic and occurred in visible parts of the body. Persons with subclinical infection did not transmit the disease Vaccine highly effective, easily administered, heat stable, and confers long term protection. International cooperation.

14. It is a viral disease which infected cattle and other ruminants and belonged to the same family as measles. During the 20th century, there were a series of campaigns to eradicate it, through the use of a live attenuated vaccine. The final, successful campaign was led by the Food and Agriculture Organization (FAO) of the United Nations . On 14 October 2010, with no diagnoses for nine years, the FAO announced that the disease had been completely eradicated. It is the first (and so far the only) disease of livestock to have been eradicated by human undertakings . Rinderpest

15. Ongoing Eradication Programs

16. Dracunculiasis ( Guinea worm disease) It is a painful and disabling parasitic disease caused by a worm, Dracunculus medinensi . It is spread through consumption of drinking water infested with copepods hosting the larvae . Guinea worm disease is set to become the second human disease in history, after smallpox, to be eradicated . It will be the first parasitic disease to be eradicated and the first disease to be eradicated without the use of a vaccine or medicine .

17. Dracunculiasis Eradication efforts have been based : On making drinking water supplies safer (e.g. through treating the water with larvicide ). C ontainment of infection. E ducation for safe drinking water practices.

18. Dracunculiasis The original goal for eradication was 1995 . T wo decades of eradication efforts have reduced guinea worm's global incidence to: m ore than 99.99%   to  126 cases in 2014 , down from an estimated 3.5 million in 1986. South Sudan , the world's youngest nation, reported 70 cases or 56 percent of the worldwide case total in 2014.

19. 2016: Dracunculiasis of humans was reported in three countries , namely: Chad : 16 cases Ethiopia : 3 cases South Sudan: 6 cases 2017: Chad has so far confirmed 3 human cases Dracunculiasis

20. Measles It is an airborne disease Spreads easily through the coughs and sneezes of those infected and contact with saliva or nasal secretions. Nine out of ten people who are not immune who share living space with an infected person will catch it.

21. Measles Vaccination has resulted in a 75% decrease in deaths from measles between 2000 and 2013 with about 85% of children globally being currently vaccinated. In 2009 the regional committee for Africa agreed a goal of measles elimination by 2020 .

22. Measles Europe had set a goal to eliminate measles transmission by 2010, but were hindered by : The MMR vaccine controversy ? They have set a new target of 2015 In 2016 , an international expert committee determined that America had eliminated endemic transmission of measles .

23. Measles The 11 member states of WHO South-East Asia Region committed to eliminate measles by 2020 at the 66th Session of the WHO Regional Committee for South-East Asia in sept 2013. On 13 June, 2017 , WHO declared that Bhutan and Maldives have eliminated measles.

24. Challenges Funding: specially for the follow-up campaigns : National managerial Capacity: Inadequate number and qualification of staff Competing priorities: Polio eradication Pockets of susceptible populations/groups Hard to reach populations in low income countries Pockets in countries with big expatriate population Security situation: rapidly deteriorating in the EMR Delayed implementation of planned activities Financial support from international partners Interest of the countries Polio infrastructures Opportunities Measles

25. History of polio… The disease of poliomyelitis has a long history. The first example may even have been more than 3000 years ago. Poliomyelitis (polio)

26. World Health Assembly launched the Global Polio Eradication Initiative (GPEI) in 1988. Since the GPEI was launched, the number of cases has fallen by over 99%. Polio remains endemic in: Nigeria, Pakistan and Afghanistan. Outbreak countries: Democratic republic of the Congo, Syrian arab republic. Poliomyelitis ( polio)

27. Poliomyelitis (polio) Middle East: June   2017:   In Syria, a cVDPV2 outbreak has been confirmed.  The virus strain was isolated from two cases of acute flaccid paralysis (AFP) and one healthy contact. Pakistan – one new WPV1- positive environmental sample in August 2017 .  

28. Poliomyelitis ( polio) India 2009 : India had half the number of polio cases in the world, and in less than two years, polio infections were brought down to zero . The last case of polio in the country was reported from Howrah, West Bengal on January 13, 2011 . India was declared non endemic for polio on 27 th march,2014.

29. http:// polioeradication.org Wild poliovirus type 1 and Circulating vaccine-derived poliovirus cases

30. Polio cases breakdown by country

31. The Global Polio Eradication Initiative(GPEI ) Objectives : T o interrupt transmission of wild poliovirus as soon as possible T o achieve certification of global polio eradication T o contribute to health systems development and strengthen routine immunization and surveillance for communicable diseases 4 Pillars of the Global Polio Eradication Initiative Strategy: Routine Immunization. Supplemental Immunization Activities. Acute Flaccid Paralysis (AFP) Surveillance. Targeted Mop-Up Campaigns.

32. 1. Routine Immunization According to WHO/UNICEF immunization coverage estimates, 86% of infants received three doses of oral polio vaccine in 2010 , compared with 75% in 1990 . Good routine OPV coverage: Increases population immunity Reduces the incidence of polio Makes eradication feasible plan of routine immunization for out reach areas . GPEI

33. GPEI 2. Supplemental Immunization Activities Mass polio immunization campaigns that complement routine immunization programs are intended to: Interrupt transmission by immunizing every child under the age of 5 with oral polio vaccine annually, regardless of the number of times they have been immunized previously.

34. GPEI 3. Acute Flaccid Paralysis (AFP) Surveillance As many as 90% of people infected with the poliovirus experience very mild or no symptoms. A single symptomatic case can therefore represent a significant community-wide outbreak. Robust surveillance to detect and investigate every case of polio-like AFP is essential to polio eradication .

35. GPEI 4. Targeted Mop-Up Campaigns Last stage in polio eradication Low routine immunization coverage: very dense or mobile populations, inadequate sanitation, and poor access to health services. In focal areas where polio cases have been confirmed within the previous 3 years and circulating virus is confirmed or suspected . In mop-up campaigns vaccinators go house-to-house to immunize every child under 5 and help to stop transmission .

36. OPV CESSATION OPV is extremely safe and effective at protecting children against lifelong polio paralysis. Over the past ten years, more than 10 billion doses of OPV have been given to nearly three billion children worldwide. The disease has been reduced by more than 99%. It is the appropriate vaccine through which to achieve global polio eradication .

37. On extremely rare occasions, use of OPV can result in cases of polio due to vaccine-associated paralytic polio (VAPP) and circulating vaccine-derived polioviruses ( cVDPVs ). For this, the global eradication of polio requires the cessation of all OPV in routine immunization, as soon as possible after the eradication of wild poliovirus (WPV) transmission . OPV CESSATION

38. OPV CESSATION: The switch The type 2 component of tOPV : – Causes > 90% of VDPV cases. – Causes approx. 40% of VAPP cases(approx. 200 cases per year worldwide). – Interferes with the immune response to poliovirus types 1 and 3 in tOPV . In  April 2016 a switch was implemented from trivalent OPV to bivalent OPV in routine immunization programs. Following WPV1 and WPV3 eradication, use of all OPV in routine immunizations will be stopped . Only IPV will be used by 2020. http://polioeradication.org/polio-today/preparing-for-a-polio-free-world/opv-cessation/

39. May 2015 World Health Assembly consider a resolution on the OPV switch December 2015 At least 1 dose of IPV introduced into routine immunization programmes in all countries April 2016 Withdraw type 2 OPV globally 2020? After all wild polioviruses have been fully eradicated , withdraw all OPVs OPV CESSATION Dates for the Endgame Plan:

40. GPEI Before a WHO region can be certified polio-free , the following conditions must be satisfied: At least three years of zero polio cases due to wild poliovirus Excellent certification standard surveillance Each country must illustrate the capacity to detect, report and respond to “ imported ” polio cases.

41. The goal of the 2013-2018 Polio Eradication and Endgame Strategic Plan is to complete the eradication and containment of all wild, vaccine-related and Sabin polioviruses , such that no child ever again suffers paralytic poliomyelitis. GPEI

42. At present , polio is endemic in three countries Until poliovirus transmission is interrupted in these strongholds, all countries remain at risk, as shown not only by the outbreak in Syria , but also in recurrent outbreaks across sub-Saharan Africa , including an ongoing outbreak in Somalia. O utbreak also serves as a reminder that high vaccination coverage is essential in countries where the disease is not currently circulating. Summary

43. Former Eradication Programs Hookworm Hookworm infection is caused by the transmission of the hookworm parasite common in warmer climates . Hookworm larvae live in soil and typically enter humans through the soles of their feet. Hookworm eradication campaign was started at US in 1909 . The Rockefeller Sanitary Commission (RSC) was created with the intention of eliminating the disease across the region. By implementing a three-pronged approach, including mapping the disease, curing patients, and providing education. RSC dramatically reduced the disease burden. http://rockefeller100.org/exhibits/show/health/eradicating-hookworm

44. Hookworm 700 million people worldwide, including 44 million pregnant women. Tropical or sub-tropical environments in poverty-stricken areas of Africa, Latin America, Southeast Asia and China. 2001: WHO adopted a resolution aimed at the deworming of 75% of all at-risk school-age children by 2010 . A hookworm vaccine is currently in Phase I clinical trial by Sabin PDP. The 2012 WHO Road Map added 75% coverage of all at-risk pre -school-age children . In United States , elimination of hookworm had been attained. http://www.nejm.org/doi/full/10.1056/NEJMra032492#t=article

45. Conclusion It is useful to consider the successful eradication p rograms, these programs could form the basis for eradication for other diseases. Both biological and technical features of the disease should be considered before starting an eradication programme. We have to put in our knowledge of the economic , social and political issues before setting a specific global target date for any eradication programme.

46. Resources WHO https ://ourworldindata.org/eradication-of-diseases/ http://www.nejm.org/doi/full/10.1056/NEJMra1200391#t=article http://www.iflscience.com/health-and-medicine/were-close-achieving-second-ever-global-eradication-human-disease /

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