POST 00947E : THINKING THE UNTHINKABLE

POST 00947E : THINKING THE UNTHINKABLE Follow-up on Posts 00917E, 00923E, 00931E, 00937E and 00942E 27 June 2006 _________________________________________________________________ The first contribution in this posting comes from Anil Varshney (mailto:[email protected]) from India. It is followed by a response to Dr. Suvedi by Rudolf Tangermann (mailto:[email protected]) from the PEI Team at WHO/HQ. For those who have read Global Immunization News of June 2006 (page 9), you may have seen that environmental monitoring is on the PEI agenda. I believe that sanitation is a critical factor in making the difference between eradication and elimination. One can thus wonder what are the precise criteria for undertaking such monitoring in any particular country. And consequently, why it would not be appropriate for border areas of Nepal with or without resuming NIDs? It is true indeed as Rudi writes below, that sanitation is beyond the means of disease control programmes. But the world is actually on track for missing this Millenium Goal. If you have explored the Dev-Zone site (Post 0945E), you may have noticed an interesting article by Richard Black, from BBC News, on the topic. You can access it directly at : http://www.who.int/vaccines-documents/DocsPDF03/www737.pdf and take the opportunity to bookmark the BBC News website. __________________________________ Dear All Suvedi has raised a very important issue. Many such polio in adults may be diagnosed as suffering from other viral disorders such as Guillain-Barré syndrome. I have two questions : 1. How was polio confirmed in this 15 years-old boy? 2. Were other causes of paralysis ruled out? It appears that eradication may not be possible like smallpox because both diseases have different social-medical connotations. In smallpox there is nothing hidden or silent and the disease spreads rapidly - people are scared and are willing to do anything to stop the wrath of the Goddess. So quarantine and containment and vaccination helped In polio for every case there will be few carriers without symptoms and there is low mortality as compared to small pox or even Japanese Encephalitis , response of public is not that great. Then is the question of immunity ( as seen in UP - India ) children having Polio even after few doses under NID How ever the most important factor, environmental eradication, has not been pursued. I say pursued because in the initial phase of the Polio eradication, there was talk and discussion on environmental eradication. However no agency or institution including governments took up the issue. In India if one was to plot the cases of polio and draw the sewer lines and Nallah, a correlation could be found But environmental eradication is NOT easy in terms of finance and resources for any donor and agencies to clear the muck and dirt in a country. Its a country’s job to first target the unhygenic condition, educate public and advise action at home for disinfection of lavatories, drains and nallahs. other - are we dealing with mutant polio virus or latent virus in the body which is now showing up like of herpes zoster? regards Dr Anil Varshney India ---------------------------- Dear TECHNET editor, We would like to reply to a recent posting on polio eradication by Dr B. K. Suvedi from Nepal. Dr Suvedi notes that a recent wild-virus confirmed case of polio reported from Nepal was a '17-year old', found not in a border district but the interior of Nepal. He suggests that there may be large pockets of susceptible adults in Nepal, which should be targeted by immunization activities. He also notes the very poor hygienic and sanitary conditions in the remaining polio-endemic areas and suggests to include measures directed at improving hygiene and sanitation as a polio eradication strategy element. According to data received from WHO Nepal, the case Dr Suvedi is referring to was born in 1991 and so was not 17 but 14 years old - so '< 15 yrs' and within the AFP surveillance age range - when developing paralysis in March 2006. Case investigation showed that he had reportedly never received oral poliovaccine, even though his birth cohort overall was likely to have already been well protected against polio: reported coverage of infants with three doses of OPV in Nepal nationwide was above 70% since 1987 (i.e., covering persons well who are now 19-20 years of age, reported coverage was 74% in 1991, the year this case was born). Pockets of lower coverage exist in all countries, of course, and it is possible that the March 2006 case would have 'escaped' routine vaccination as an infant. The 'susceptibility profile' of older people in Nepal - those born before the vaccine era - will be similar to other developing countries: virtually all of these will have developed natural immunity through exposure to wild poliovirus at very early age - a process greatly facilitated by the low levels of hygiene and sanitation as noted by Dr Suvedi. Thus, there is no reason to assume that large numbers of adults in Nepal remain susceptible to poliovirus infection, with no evidence from this importation episode that would support changing the target age group for supplementary campaigns. As expected, the virus isolated from the 14-year old boy is genetically linked to recent wild poliovirus type 1 found in Uttar Pradesh; while other recent importations into Nepal affected children in districts bordering India, it is not unexpected to see a case in the interior. Several recent episodes of virus importation, including some over long distances, confirm that wild poliovirus can travel in asymptomatic carriers before being transmitted to a susceptible person. Dr Suvedi is of course absolutely right when pointing out the prime importance of hygiene and sanitation problems in facilitating transmission of any enteric pathogen, including polioviruses. Factors determining progress in improving sanitation and hygienic practices are complex and closely linked to the overall status of education and socio-economic development in a country; it is of course beyond the means of a disease control programme, or even overall health services, to rapidly improve overall sanitation to a level that would significantly decrease the transmission of enteric pathogens. Thanks again to Dr Suvedi for his queries about polio eradication in Nepal. Rudi Tangermann, for the WHO-HQ polio eradication team ______________________________________________________________________________ Visit the TECHNET21 Website at http://www.technet21.org You will find instructions to subscribe, a direct access to archives, links to reference documents and other features. ______________________________________________________________________________ To UNSUBSCRIBE, send a message to : mailto:[email protected] Leave the subject area BLANK In the message body, write unsubscribe TECHNET21E ______________________________________________________________________________ The World Health Organization and UNICEF support TechNet21. The TechNet21 e-Forum is a communication/information tool for generation of ideas on how to improve immunization services. 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