Indirect immunoflourescent technique versus tissue culture method in diagnosis of poliomyelitis

ABSTRACT

Eighty stool samples were collected from paralytic children at Imbaba Poliomyelitis Institute. Isolation, identification and typing of polioviruses were done by both neutralization test [NT] and indirect immunofluorescent [IF] test. The indirect IF test gave negative results after 2 and 4 hours post-virus inoculation in Buffalo Green Monkey [BGM] cell line for all cases. After 6 hours post inoculation, it was found that the indirect IF test has a specificity rate of 100% in diagnosing and typing of polioviruses in comparison with the NT. The sensitivity of indirect IF test varies according to the type of polioviruses. It was high for type 1 [91%], the most prevalent one in Egypt, 75% for type 2, 88% for type 3 and 100% in cases of mixed infection with type 1 and 3. No cross reactions between the different types of polioviruses were detected by indirect IF technique, and its results were equivocal to that of the NT. The indirect IF test is a rapid test with 100% specificity and high sensitivity in diagnosing and typing polioviruses, and it is recommended to be used as a screening test, especially in endemic areas