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One article not posted on this post********* [2] Date: 2 Oct 2005 From: ProMED-mail Source: Twin Cities Pioneer [edited] _____________________________________________________________ Infant found to have polio; risk to general public is nil, state health officials say ----------------------------------------------- Minnesota health officials said Saturday [1 Oct 2005] they are investigating the 1st case of polio reported in the state since 2000 but dismissed the potential for an outbreak of the crippling disease. --------------------------------- The case involves an infant from central Minnesota who already was hospitalized with a weakened immune system when the infection was discovered, the Minnesota Health Department said. The agency stressed that there is no risk to the general public. -------------------------------- Only people who have not been vaccinated and who had direct contact with the infant would be at risk, because the disease is transmitted through stools or oral secretions, said Health Department spokesman Buddy Ferguson. The vast majority of Minnesotans -- approximately 93 percent -- have been vaccinated, most as infants. ------------------------------------ "If you didn't have that kind of contact, you're not at risk," Ferguson said. "We're talking about health care workers who might have cared for the infant. We're talking about family members. We are going to be contacting people in those groups individually." --------------------------------- In the vast majority of cases, polio has no symptoms, but it can cause sore throats, vomiting, abdominal pain and flu-like symptoms, according to the Centers for Disease Control. In less than 2 percent of cases, the virus causes minor stiffness in the neck, back or legs, and in less than one percent of cases, it attacks the central nervous system and results in permanent paralysis, muscular atrophy and even death. The disease usually affects young children. ---------------------------------- Before the 1960s, the disease left hundreds of thousands of victims paralyzed across the United States. Outbreaks created panic. Many people became afraid of large public gatherings. In 1946, the Minnesota State Fair was canceled, as state health officials were recording as many as 50 new cases a day. ------------------------------------ Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said the most recent case has been managed well by state officials. "This is not a public health situation of any concern," he said. ----------------------------------- Health officials would not name the child, give an age or even which town or hospital the infant is in, citing state and federal privacy laws. -------------------------------------- The infant apparently contracted polio from someone infected with a mutated form of the polio strain used in oral vaccines, officials said. Even though the child is infected with the virus, he did not show any signs of paralysis, health officials said. ---------------------------------- The United States stopped using polio vaccines that contain weakened strains of the live virus in 2000. The live-virus vaccine still can cause polio, and about 8 people in the U.S. developed the disease annually before the country switched to using vaccine without the live virus. The last reported polio case in the U.S. occurred the final year that the live vaccine was in use. ---------------------------- Live-virus vaccine remains in use elsewhere in the world, in part because it helps expand protection in areas where not everyone receives the vaccine, Osterholm said. In essence, health officials rely on poor hygiene and inadequate sanitation in these areas to expose more people to the weakened form of the virus and thus give them protection. --------------------------------- At times, the weakened virus reverts to an infectious strain, which apparently is what happened to the infant in Minnesota, Osterholm said. ----------------------------------- Polio ceased to be a major threat in the United States decades ago and largely has been eliminated in the Western Hemisphere since Dr. Jonas Salk developed the 1st vaccine in 1955. Yet the disease remains a serious health threat in the developing world and retains a terrifying reputation in the United States. By one estimate, polio paralyzed 254 000 Americans, many of them children. Vaccination gradually eliminated U.S. outbreaks. In 1960, there were 2525 paralytic polio cases in the country, but by 1965, the number had dropped to 61, according to the Centers for Disease Control in Atlanta. ------------------------------------- The last U.S. outbreak -- and naturally occurring cases -- occurred in 1979, when Amish in several Midwestern states contracted the disease from a strain of the virus brought in from the Netherlands, according to the CDC. ---------------------------------- The last reported case of polio in Minnesota was caused by a vaccine in 1992. --------------------------------- In parts of Africa and Asia, however, polio remains a threat. In Indonesia, for instance, more than 230 children younger than 5 have been infected this year [2005]. The Associated Press contributed to this report. [Byline: Tim Huber] _______________________________________________________________ -- ProMED-mail [More information on the epidemiology of the infection in the above mentioned infant (including the exact age) would be appreciated. From the information presently available, it appears as though the poliovirus identified in this infant is genetically related to the viruses used in the preparation of the oral poliovirus vaccine (OPV). OPV has been associated with rare cases of vaccine associated paralytic poliomyelitis (VAPP) in individuals who have directly received the vaccine and in those who have had contact with recently vaccinated individuals. In addition, there have been reports of cases of paralytic poliomyelitis associated with circulating vaccine derived polioviruses (cVDPV) where there has been a reversion to neurovirulence of the involved circulating vaccine derived virus. -------------------------------- With respect to the former situation (VAPPs), during the period 1980-1994, of 133 confirmed cases of paralytic poliomyelitis reported in the USA, 125 (94 percent) were associated with administration of OPV (annual mean: 8 VAPP cases) (6 were imported cases and 2 were indeterminate without a poliovirus isolation, and no history of direct or indirect contact with the OPV). Of the 125 VAPP cases, 49 (39 percent) were among immunologically normal recipients of OPV, 46 (37 percent) among immunologically normal contacts of OPV recipients (including 6 cases among persons from whom vaccine-like poliovirus was isolated but who had no history of direct contact with vaccinees), and 30 (24 percent) among immunologically compromised OPV recipients or contacts of OPV recipients. ------------------------------------------ ______________________________________________________________ Since the USA changed vaccination policy to use IPV rather than OPV, there have been no further cases of VAPP reported in the USA. (see ref. below). (Please note that the above case is not VAPP, as the article mentions there is infection with the poliovirus, but there is no paralytic disease). -------------------------------------- Information that would be of interest is the age of the involved case, and possible contacts with known recent OPV recipients, either through travel of this case to countries where OPV is currently used or through known contact with recent OPV recipients visiting from countries where OPV is used. Other information on the investigation that is of interest is environmental sampling of sewage in the geographical area where the case originated to know whether there is evidence of cVDPV in the general area. As the above articles clearly state, if one has been adequately vaccinated, the risk of paralytic disease from contact with a cVDPV is very low, and with a 93 percent vaccination coverage rate with IPV in Minnesota, unless the virus "enters" a pocket of susceptibles, the risk of further cases associated with this event is low. However, there are concerns about chronic infection of an immune-compromised host with resultant neurovirulence reversion of the virus and potential spread of VDPV in the community. Nevertheless, we are all very interested to learn more about the epidemiologic findings and the possible source of infection of this immune-compromised child with a VDPV. ---------------------------------- 1: Kew OM, Sutter RW, de Gourville EM, Dowdle WR, Pallansch MA. Vaccine-Derived polioviruses and the endgame strategy for global polio eradication. Annu Rev Microbiol. 2005 Oct 13;59:587-635. ------------------------------------ 2: Alexander LN, Seward JF, Santibanez TA, Pallansch MA, Kew OM, Prevots DR, Strebel PM, Cono J, Wharton M, Orenstein WA, Sutter RW. Vaccine policy changes and epidemiology of poliomyelitis in the United States. JAMA. 2004 Oct 13;292(14):1696-701. ---------------------------------- 3: Dowdle WR, De Gourville E, Kew OM, Pallansch MA, Wood DJ. Polio eradication: the OPV paradox. Rev Med Virol. 2003 Sep-Oct;13(5):277-91. Review. ---------------------------------- 4. Cherkasova EA et al. Spread of Vaccine-Derived Poliovirus from a Paralytic Case in an Immunodeficient Child: an Insight into the Natural Evolution of Oral Polio Vaccine. J. Vir. January 2005, 79 (2):1062-1070 --------------------------------- 5: White FM, Lacey BA, Constance PD. An outbreak of poliovirus infection in Alberta -- 1978. Can J Public Health. 1981 Jul-Aug;72(4):239-44. ----------------------------------- 6: Bijkerk H. Poliomyelitis epidemic in the Netherlands, 1978. Dev Biol Stand. 1979;43:195-206. ---------------------------------- 7: Furesz J, Armstrong RE, Contreras G. Viral and epidemiological links between poliomyelitis outbreaks in unprotected communities in Canada and the Netherlands. Lancet. 1978 Dec 9;2(8102):1248. - Mod.MPP] _______________________________________________________________ [Elsevier on-line reference: Prevalence of vaccine-derived polioviruses in sewage and river water in South Africa, Water Research, September 2005, ] ------------------------------------ [see also: Poliomyelitis, vaccine derived - Madagascar: RFI 20050717.2043 2002 ------------------------------ ---- Poliomyelitis, vaccine-derived - Madagascar 20020719.4809 ----------------------------------- Poliomyelitis - Dominican Republic & Haiti 20020331.3848 ------------------------- 2001 ---- Poliomyelitis, vaccine-derived - Philippines: 2001 20011013.2506 Poliomyelitis - Dominican Republic & Haiti 20011005.2415 Polio, circulation of vaccine-derived virus 20010129.0205 2000 ---- Poliomyelitis - Dominican Rep.: control measures 20001218.2212 Poliomyelitis - Dominican Republic & Haiti: ALERT 20001202.2098 Poliomyelitis - Dominican Republic & Haiti: background 20001203.2102 Poliomyelitis - Dominican Republic & Haiti: comment 20001204.2110 Poliomyelitis - Dominican Republic & Haiti: update 20001208.2149 Poliomyelitis - Dominican Republic: visitor advice 20001215.2195] ........................mpp/msp/dk