Immune status to poliovirus among immigrant workers in Israel

Background An essential part of the progress towards the global eradication of poliomyelitis is the ongoing evaluation of populations immunity. Migration of unregistered individuals poses a challenge to such estimations. Moreover, partially immunized immigrants might enlarge immunity gaps and facilitate polio outbreaks in their destination countries. Objectives To study the level of immunity to polio in adult foreign workers in Israel. Methods Foreign workers (n = 145) from the Philippines, India, and Western Africa were tested for neutralizing antibodies against three IPV strains and an outbreak-associated wild virus. Demographic and immunization data were collected by questionnaires. Results Seropositivity rates and geometric mean titers (GMTs) for the Mahoney (type 1), MEF (type 2), and Saukett (type 3) poliovirus strains and the wild poliovirus type 1 strain were 99.3% (GMT—233.8), 98.6% (GMT—268.5), 99.3% (GMT—89.4), and 99.3% (GMT—139.5), respectively. Higher GMTs were associated with parenthood and older age. African individuals had significantly higher GMTs for the Saukett strain, compared with individuals from the Philippines and India. Conclusions Our results indicate a high level of immunity among foreign workers. More serosurveys are indicated in the future in order to monitor the level of immunity in residents in Israel.