Poliomyelitis survey in Middle-East countries

The poliomyelitis survey was started in 1976 in Bahrain and Kuwait. For each paralytic case, diagnosis was done by virus isolation, neutralizing antibody titration and specific IgM characterization. More than 90% of the infants who were ill were less than 2 years old. In Bahrain, 17 paralytic cases in 1976 and 12 in 1977 occurred between January and July (annual incidence was respectively 7.7 and 5.4/100,000). The first epidemic was due to poliovirus type 2, the second one to poliovirus type1. From 29 cases, 13 occurred in vaccinated infants of which 9 received 3 or 4 oral vaccine doses. For 3 infants, paralysis occurred less than one month after vaccination. All the isolates were wild polioviruses (rct). In Kuwait, 119 cases were examined, and of them, 57 occurred between August 76 and May 77 (incidence 5.7/100,000). Poliovirus type 1 was responsible for 61% of cases, type 2 for 5% and type 3 for 12%. From October 1976 to December 1977, 350 stools samples were collected from contacts: 19% of them carried poliovirus (12% type 1, 1% type 2 and 6% type 3). All the viruses isolated from both paralytic cases and contacts were wild strains (rct). Of 119 cases, 35 occurred in vaccinated infants from which 4 had received 3 or 4 oral vaccine doses. For 11 infants paralysis occurred less than one month after vaccination. The virus spread was evaluated (i) just before vaccination in 337 infants or children from June to December 76: 8% carried poliovirus Sabin-like strains (and 18% non polioviruses), and (ii) one month after vaccination in 75 infants: 37% carried poliovirus Sabin-like strains.