POST 01201E : ERADICATION EFFORTS

POST 01201E : ERADICATION EFFORTS Follow-up on Posts 01174E and 01179E 14 December 2007 ____________________________ TIP : If you consult TechNet archives on Listserv, most of you will not see the active links in the body of the text, depending on configuration. Please go to the very bottom below posting banners and you will see [text/html]. Click on this and the posting will show in HTML mode with all links active. Below is a response by [log in to unmask]">Bob Davis from UNICEF/ESARO to Robert Steinglass’ earlier contribution. ____________________________ I welcome the comments of my friend and colleague Robert Steinglass. He never fails to stimulate and inform, even if our views do not always coincide. His comments permit me to dilate on disease eradication, a favorite topic of mine. Your readers with interests in eradication are referred to the Bulletin of the World Health Organization, 1998, Supplement 2, which is devoted to the subject. Let’s look at how some of the eradicable pathogens have fared in the year now ending. POLIO AND MEASLES The year now ending has been a bad one for the wild poliovirus. We have seen a year to date reduction of 60 percent in the number of wild poliovirus cases in the world, amid constantly improving surveillance and lab systems. Within the present decade, polio should join smallpox in the history books. This is especially gratifying after several public health people voiced doubts in the media about polio eradicability. Measles, which (like rubella) has no reservoir in the environment and no possibility of generating vaccine derived virus, has different characteristics from polio, which make eradication in some ways a less difficult task. In 2007, the year started with a Lancet article by Wolfson and colleagues showing that the world is ahead of its 2005 targets for measles mortality reduction. The yearly Washington meetings of the Measles Initiative report more successes, more funding, and more countries with the virus controlled or eliminated. Only 4 of WHO’s 6 regional governing bodies have committed themselves to time bound regional elimination objectives. That is 2 short of 6, but 4 more than had made that commitment before 1994, when PAHO committed the governments of the Americas to regional elimination. Before the turn of the century, the question was "Should measles be eradicated?" In 2007, with the planet ahead of its own targets, it is a question of when. Writing in Current Topics in Microbiology and Immunology, Ciro de Quadros stated last year that "progress to date has been remarkable". Measles is no longer an endemic disease in the Americas and interruption of transmission has been documented in most countries. As of August 2005, 3 years have elapsed since the detection of the last indigenous case in Venezuela in September 2002. This experience shows that interruption of measles transmission can be achieved and sustained over a long period of time and that global eradication is feasible if appropriate strategy is implemented. Even in a new paradigm in which eradication is not followed by the discontinuation of vaccination, eradication of measles will be a good investment to avoid expensive epidemics and save the almost one million children that die every year to infection with the measles virus. It is not a dream to think that we will see a world free of measles by the year 2015. RUBELLA Rubella eradication is a different case, since the case for eradication is based on morbidity, not mortality. Politically, rubella eradication is not so easy a sell as measles. Few would oppose rubella vaccination, so it is a question of what objective to reach, with which strategies, once both developing and developed countries adopt the vaccine. Permanent control seems the more reasonable, until one runs the numbers. Scott Barrett makes the case for eradication. From an economics perspective, diseases that are eliminated in high-income countries are prime candidates for future eradication efforts. Second, the incentives for countries to participate in an eradication initiative can be strong; indeed they can be even stronger than for an international control programme. Moreover, 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.The 1998 supplement to the Bulletin of the World Health Organization devoted to disease eradication stated "challenges [to rubella elimination/eradication] include establishing rubella and congenital rubella syndrome as a priority in many developing countries; depending on the vaccination strategy, 30-40 years may be required for eradication/elimination of CRS; and lack of financial resources in many countries to sustain a vaccination programme because of the added cost of the rubella component of the vaccine and the necessity to ensure protection in reproductive-aged women." Rubella vaccination presents no technical obstacles, once one learns the lessons of countries like Greece, which went about rubella vaccination in the wrong way. Countries like India, still endemic for polio, should not try to eliminate rubella at this stage. In the words of William Shakespeare, the noted epidemiologist, "ripeness is all." The region of the Americas, free of wild poliovirus for the last decade, is well positioned to eliminate rubella. As with smallpox, polio and measles, the Region of the Americas has not waited for other regions to move. In 2003, the PAHO Directing Council committed its member states to "eliminate rubella and congenital rubella syndrome (CRS) from their countries by the year 2010." (Resolution CD44.R1, "Sustaining Immunization Programs - Elimination of Rubella and Congenital Rubella Syndrome (CRS)". PAHO covers only one of the six WHO regions. Africa has prudently refrained from rubella elimination goals because it has polio and measles to conquer, in that order. Iran has no such compunctions. Iran’s 2007 nationwide rubella campaign (report available on request) is the most prominent example of mass action against rubella in the Eastern Mediterranean region. It is unlikely to be the last, as EMR stops polio and measles, in that order. In the view of VPD/PAHO, " to accelerate control measles in the rest of the world without including rubella in the vaccine or strategy is a tremendous missed opportunity." (personal communication, Jon Andrus). So what is bizarre about putting in the history books both rubella and, with it, congenital rubella syndrome, a disease which causes irreversible damage in those born with it, and for which the correct methods are being test driven, as with previous eradication targets, in the Region of the Americas, one region down, five to go? Historically, disease eradication efforts have been launched in the Americas, to be adopted globally after the region of the Americas proved the soundness of concept. Will rubella be different from smallpox, polio and measles? With rubella, it is not a question of technical feasibility, but of political will. In public health, the world gets as much as it is willing to pay for. It has paid for polio eradication, and is generating the momentum for financing measles eradication, region by region. Will the world pay for rubella eradication, and will it do so in the present century? This is not a technical question. Only the politicians can answer it. Bob Davis ______________________________________________________________________________ All members of the TechNet21 e-Forum are invited to send comments on any posting or to use the forum to raise a new discussion or request technical information in relation to immunization services. 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