In Vivo and In Vitro Survival Rates of Protoscoleces Kept at Different Constant Temperature

An experiment was conducted on the survival rate of protoscoleces derived from hydatid cyst brought from infected camels in Tambool area (North Eastern Sudan). The survival rate was studied in vivo and in vitro through exposure to different constant temperatures to measure their viability. The results revealed that the protoscoleces remained viable in vitro for 20 days at 4°C, 7 and 5 days at 25°C and 37°C, respectively, while at 45°C the protoscoleces were immediately dead. This means that the infection rate of hydatid cyst becomes high in relatively cold seasons (winter and autumn). In the in vivo study, each mouse (five groups, four mice in each) was inoculated intraperitoneally with 2000 protoscoleces exposed to the same different constant temperature, as previously used. 6 months later, the mice in different groups were sacrificed and necropsied to study the development of hydatid cyst inside. The results showed that the rate of development inside the mice was clear in the first and the second groups (4°C and 25°C), however, in the other 2 groups (37°C and 45°C), no sign of development of the cyst was observed, with the presence of few number of hooks compared to the control group, which showed significant difference in the development of hydatid cyst.