الفهرس 
Historical Background of EchinococcusOnly 14 pages are availabe for public view
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Abstract
Cystic echinococcosis (CE), the metacestode stage of Echinococcus granulosus, is a worldwide cyclozoonotic disease of public health importance in livestock raising countries. Human CE is believed to be endemic in Egypt. To date, ten genotypes (G1-G10) of CE have been identified. The present study aimed to detect the G6 genotype of CE in different isolates of human and livestock animals and to probe the CE patients’ sera for this genotype as an approach of molecular diagnosis of CE. Two human groups included in the study; group I (CE cases) which was subdivided into group I-A (hepatic CE), group I-B (pulmonary CE) and group I-C (multi-organ CE); group II (control subjects) that included group II-A (patients with other parasitic diseases), group II-B (patients with space occupying lesions) and group II-C (healthy individuals). Animal hydatid isolates were collected from camels and pigs. DNA extraction was done from protoscolices in fertile hydatids, and from HCF as well as germinal layer in sterile cysts. Hot-Start specific G6 polymerase chain reaction PCR was done for all human and animal isolates (PCRp) and revealed that all isolates (100%) under the study were of G6 genotype (camel strain) which has its impact on immunodiagnosis, vaccination and control programmes. Indirect haemagglutination test (IHAT) and PCR were done for sera (PCRs) of all the studied human groups and compared as regard sensitivity and specificity. The G6 genotype of CE was detected in concentrated serum samples of all CE cases and gave true negative results in all control groups. Therefore, PCR for G6 in serum (PCRs) showed 100% sensitivity and 100% specificity, whereas IHAT showed 61.29% sensitivity and 95.92% specificity. Subsequent DNA sequencing of the amplified DNA fragments was done in forward and reverse directions. Comparison of the Egyptian G6 strain nucleotide sequence with that of the Argentinean reference strain (provided from WHO reference laboratory) and with the Iranian G6 strain deposited on the GenBank, revealed 100% homology. However, Egyptian G6 showed 99% when compared with the Kenyan G6 strain in one nucleotide which may its impact on the degree of infectivity of the G6 strain to human.