Unimmunized Gypsy populations and implications for the eradication of poliomyelitis in

The certification of poliomyelitis eradication in Europe will eventually require that countries demonstrate there is a minimal risk of wild poliovirus reintroduction and sustained transmission through unimmunized subpopulations such as ethnic minorities. A serologic survey among a Gypsy community in Italy found that despite only 26 % documented immunization coverage, serum neu-tralizing antibodies to poliovirus types 1, 2, and 3 were detected in 81%, 94%, and 63 % of the 86 persons studied. While the high level of immunity found in this community may have been due to secondary spread of vaccine virus, the possibility of unrecognized circulation of wild polioviruses cannot be excluded. Targeted immunization of such groups may be the most efficient means of eliminating the risk of importation-associated outbreaks. Although indigenous wild polioviruses have been eliminated from western Europe for several years, unimmunized subpopu-lations will continue to present a risk of importation-associated outbreaks until such time as the global goal of polio eradication is achieved [1, 2]. In many European countries, Gypsies are at a particular risk of reintroducing wild polioviruses because of their low immunization coverage, ongoing contact with areas in which polio is endemic, and often nomadic lifestyles [3]. In November 1994, a case of acute flaccid paralysis in a 13-month-old Gypsy child from Rome was tentatively diagnosed as poliomyelitis on the basis of clinical and electromyographic findings. Although virologic studies did not detect evidence of a poliovirus infection, the case provided a rare opportunity to evaluate the risk of sustained poliovirus transmission in a Gypsy community and the potential for spread to the general population. Background The last case of poliomyelitis in Italy due to indigenous wild poliovirus was in a patient who developed paralysis in 1982 [4]. Since 1980, 6 cases of vaccine-associated poliomyelitis and 3 im