Age-dependent susceptibilities of Bulinus truncatus snails to an aqueous extract of Pulicaria crispa (Forssk.) Oliv. (Asteraceae) leaves.

This study was carried out to investigate the potential use of the herb Pulicaria crispa in the biological control of different developmental stages of Bulinus truncatus, a major snail intermediate host of urinary schistosomiasis. Age-dependent susceptibilities of mature adult snails, immature snails, juveniles, and one-day old egg masses to aqueous extracts of Pulicaria crispa leaves collected from Khartoum (Sudan) and Riyadh (Saudi Arabia) was determined and compared. The results show the juvenile snails are the most susceptible, followed in descending order by one-day old egg masses, immature snails, and mature adult snails. The P. crispa sample collected from Riyadh was significantly more potent against B. truncatus than that collected from Khartoum, as indicated by the least (LC50) and (LC90) values for all B. truncatus ages.

Seroprevalence of Toxoplasma gondii in household and stray cats of Riyadh, Saudi Arabia.

This study was undertaken to determine the seroprevalence of Toxoplasma gondii in cats in the area of Riyadh, Saudi Arabia. We examined 200 serum samples collected from stray and household cats for T. gondii antibodies by ELISA. The overall seroprevalence was 26%. Seroprevalence was significantly higher (p < 0.05) in stray cats (39%) compared with household cats (13%). The prevalence in male and female cats was 31.4% and 20.4%, respectively. The seroprevalence increased with age and was higher in cats over 6 years of age (43%) as opposed to cats less than 4 years old (33%). Seropositivity varied according to the breed. The highest was recorded among cats of American breed (38.5%), followed by Persian (27%), Himalayan (21%), Bengali (11.5%), and Siamese (2%). Antibodies were not reported from the Turkish breed. Overall seroprevalence among cats did not vary significantly with season or with the localities within the Riyadh municipality. We also examined 100 faecal samples from stray and household cats by flotation technique, which revealed an overall prevalence of 12% of T. gondii oocycts.