Serape valence OF Avian Influenza Type A in Khartoum North and The Effect OF Different Treatments on Sera Using The Indirect Elisa

Abstract

A serological survey was carried out to investigate the presence of avian influenza type A antibodies in Khartoum North. A total of 210 serum samples were collected from different layer chicken farms in Khartoum North in the last third of 2010. The sera were examined for avian influenza type A antibodies using indirect ELISA. The results showed that (3.3%) of the sera were positive to influenza type A antibodies. The second part of the study was designed to know whether temperature, freezing/thawing cycle will have any impact on AI antibodies when tested using indirect ELISA. Testing sera were incubated at different temperatures (37ºC & 45ºC for overnight) or treated with three cycles of freezing and thawing or kept in refrigerator at 4ºC for 15 days. The results showed that certain temperature (37° C for overnight and two weeks refrigerating at 4ºC time had no effect on the testing results of ELISA. In addition, testing results for serum samples which had been incubated at 45° C overnight and freezing and thawing for three cycles showed that two negative sera in each group changed to false positive. Therefore, it is recommended to store serum samples at appropriate temperatures (4° C for up to 14 days and -20° C for more than two weeks) to avoid the appearance of false results when tested. And also recommend monitoring the disease situation in the country through regular surveillance.