title: Indirect haemagglutination test for the assay of antibodies against Japanese encephalitis viral antigen in human & animal sera.
abstract: The indirect haemagglutination (IHA) test was standardized for the assay of antibodies against Japanese encephalitis (JE) virus. Glutaraldehyde fixed sheep erythrocytes were sensitized with purified and concentrated JE vaccine (200-300% brain concentration). The JE vaccine made from Nakayama-NIH strain of JE virus was purified by protamine sulphate treatment and by ultracentrifugation in a sucrose gradient. The sensitized cells were quite stable in liquid as well as in lyophilized state both at -70 degrees C and 4-8 degrees C. These cells could be used for two years without much loss (4-8 times loss) in titre. The IHA test was as sensitive as the neutralization (N) test performed by plaque reduction method in chick embryo fibroblasts. The sensitivity of the test was influenced by the source of erythrocytes i.e., from the different sheep from which these were drawn. After standardization of the test, 16 human sera and 18 sera of immunized mice were assayed for antibodies against JE virus by N and IHA tests. There were no significant differences between titres of both human and mice sera determined by N and IHA tests (P greater than 0.05). The correlation coefficient between N and IHA titres for human sera was 0.60 (P less than 0.05) and for mice sera 0.82 (P less than 0.01). The IHA test has been found to be very simple, inexpensive, sensitive and reproducible.
authors: Central Research Institute, Kasauli.
authors: R K
authors: RK
authors: Gupta
authors: C N
authors: CN
authors: Misra
authors: V K
authors: VK
authors: Mehta
authors: V K
authors: VK
authors: Gupta
authors: L N
authors: LN
authors: Bhau
authors: G
authors: G
authors: Singh
authors: D
authors: D
authors: Gowal
authors: S N
authors: SN
authors: Saxena
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology*; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D006386:Hemagglutination Tests; D006801:Humans; D051379:Mice; D009500:Neutralization Tests; D011237:Predictive Value of Tests; D011817:Rabbits
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral