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CSU 33/2007: THREE ON ERADICATION

Tuesday, 9th of October 2007 Print

 CHILD SURVIVAL UPDATE 33/2007: THREE ON ERADICATION
 
 1) THREE ON ERADICATION
 
 Scott Barrett makes the economic case for disease eradication as
 over against long term disease control in this article from the Bulletin of
 the World Health Organization. This article is also available at
 http://www.who.int/bulletin/volumes/82/9/683.pdf
 
 One point not always mentioned in discussions is the savings to
 industrialized countries from eradication. According to Barrett,
 
 "high-income countries typically benefit so much that they will
 be willing to finance elimination
 in developing countries. Full financing of an eradication
 effort by nation-states is not always guaranteed,
 but it can be facilitated by a variety of means. Hence, from
 the perspective of economics and international
 relations, eradication has a number of advantages over
 control."
 
 In "Eradication of Infectious Diseases," Isao Arita and colleagues
 take a different view of disease eradication. As polio eradication
 approaches the finish line, some readers will be skeptical of their
 skepticism. The article is also accessible at
 http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3155&itool=AbstractPlus-def&uid=14985628&db=pubmed&url=http://www.nih.go.jp/JJID/57/1.html
 
 
 In the unpublished discussion at the foot of this E-mail, the present
 writer looks at proof of concept for disease eradication. The WHA
 resolution of 1955, committing WHO and member states to time limited
 malaria eradication, rested on an inadequate evidence base, and has biased
 subsequent discussions of eradication initiatives. Smallpox, polio and
 measles furnish additional lessons learned.
 
 
 2) MALE CIRCUMCISION IN RWANDA
 
 This self-explanatory account from the semi-official New Times of Rwanda
 puts paid to the notion that African traditions preclude the introduction
 of male circumcision for HIV prevention.
 
 Since most Rwandese males are uncircumcised, one cannot circumcise the
 whole at risk population simultaneously. The government has decided to
 start with institutionalized populations. "Mass circumcision would kick off
 with the army, police and students from higher institutions of learning."
  
 
 Good reading.
 
 BD
 
 
 
 Proof of concept for four eradication efforts: malaria, smallpox, polio, and measles
 

Bob Davis, UNICEF/Nairobi
 
 
 MALARIA
 
 The 1955 decision by WHO's governing body to launch a worldwide war on
 malaria was made after stunning victories against malaria in the Balkans,
 southern Europe, and Taiwan. The proof of concept was so geographically
 narrow as not to demonstrate feasibility in countries and continents with
 different economic, political and environmental conditions. In particular,
 the colonial regimes of the 1950s were unwilling to make the massive
 outlays which could have advanced malaria eradication, along WHO
 guidelines, in subsaharan Africa. Also, the planners of 1955 underestimated
 the speed with which resistance to insecticides and antimalarials would
 compromise prospects of the global programme. No efforts were made to limit
 the use of DDT in agriculture, which may have speeded the development of
 insecticide resistance in malaria eradication.
 
 In 1969, after stagnation in most of Africa and setbacks in several large
 Asian programmes, the World Health Assembly passed a resolution saying
 that eradication was not possible except through primary health care. This
 was a tacit admission of defeat for what started as a vertical eradication
 programme.
 
 
 SMALLPOX
 
 The series of smallpox eradication resolutions, dating from the 1950s, was
 originally based on the assumption that mass vaccination campaigns were
 both necessary and sufficient to stop smallpox transmission. Many
 industrialized countries stopped smallpox transmission either by universal
 vaccination or by mass campaigns, or a combination of the two.
 
 It was only when, during Nigeria's civil war, surveillance and containment
 showed the feasibility of a more focal approach, that smallpox eradication
 became truly feasible. New emphasis on surveillance as a tool of focal
 containment produced dramatic results, first in Nigeria, then in other
 endemic countries.
 
 Finally, smallpox eradication was cheap. The total international outlays
 were on the order of $125 million, a mere fraction of the figures for other
 eradication programmes. A single organization, WHO, took the lead, with
 help from CDC, so there were few difficulties delineating tasks among
 partners.
 
 
 POLIO
 
 Industrialized countries eliminated polio through a combination of polio
 days and routine vaccination. Latin America showed that mass campaigns
 using trivalent oral polio vaccine could stop transmission even when
 routine coverage was suboptimal.. Over a period of years, the combination
 of routine vaccination and mass campaigns stopped transmission in the
 western hemisphere, then, less quickly, in Asia and Africa.
 
 When Type 2 wild poliovirus disappeared, the advantages of monovalent
 vaccines became evident. The post-2000 eradication efforts have brought
 several issues to the fore: the need to deal with circulating vaccine
 derived polio virus, the relative advantages of monovalent over trivalent
 vaccine for mass campaigns, and the need for faster outbreak response
 through new lab protocols with faster turnaround and immediate outbreak
 planning upon lab confirmation of wild poliovirus.
 
 Donor support continued, even during the period 2003-2006, when global
 cases stagnated between 1000 and 2000 per year. The current year has seen
 striking declines in incidence, both in the four endemic countries and in
 importation countries.
 
 
 MEASLES
 
 Because it is so contagious and travels so well, measles can only be
 tackled on a national and continental scale. This has been done
 successfully in the region of the Americas, but less so in the rest of the
 world. The successes of measles elimination in the western hemisphere have
 fueled both the global Measles Partnership, bringing together donors and
 other partners in a more coherent way than some previous efforts, and
 regional elimination resolutions in 4 out of 6 WHO regions. The future of
 measles elimination initiatives is largely a matter of funding. Will the
 international community opt for permanent control, or a "short, sharp
 shock" approach? There will be little enthusiasm for a two decade effort of
 the kind, now coming to a conclusion, against polio.
 
 
 THE AFRICA FACTOR
 
 In each of these four efforts, Africa has played a pivotal role. In the
 case of malaria, the then colonial governments ruling most of Africa failed
 to make the political and financial investments needed to launch malaria
 eradication along WHO guidelines. Ethiopia, always independent, was an
 exception, but even there the application of WHO guidelines did not bring
 about malaria elimination. The same decades of the '50s and '60s which saw
 progress in South America saw stagnation in most of Africa. The failure of
 malaria eradication in Africa and Asia led to the reappraisal of malaria
 eradication and to the WHA resolution of 1969, with subsequent
 retrenchments and, decades, later, a shift to new technologies and
 techniques, notably long life bednets and intermittent presumptive therapy.
 
 In smallpox, Africa was at the origin of the successful modification to the
 original strategy, with surveillance and containment developed in the
 Biafra war and disseminated to all remaining endemic areas.
 
 In polio, Africa remained a major reservoir of infection through the last
 decades of polio eradication, largely because of social, political and
 religious factors in Nigeria, the last endemic country on the continent.
 The year long suspension of polio vaccination in northern Nigeria
 occasioned additional expenditures, in Nigeria and elsewhere, of over $500
 million, slowing the global eradication effort.
 
 With measles, southern Africa became the test case for successful
 interruption of transmission, and remains so, amid setbacks linked to the
 slow progress of measles campaigns in other parts of the continent and to
 suboptimal follow-up campaigns in some countries. Among the six WHO
 regions, AFRO is one of two which have not opted for a regional elimination
 goal for measles.
 
 LESSONS LEARNED
 
 In every case, Africa is the touchstone for proof of concept. Once
 eradicability is demonstrated in Africa, worldwide eradicability becomes a
 more credible idea, and skepticism is discredited. Underestimating the
 African factor, as was done with the WHA malaria eradication of 1955, can
 have fatal consequences.
 
 Will rubella eradication move on to the global agenda in this century? This
 can happen if and only if African governments take congenital rubella
 syndrome and its elimination more seriously than they currently do.
 

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