الفهرس 
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Abstract
Toxoplasmosis is parasitic zoonosis of worldwide distribution caused by the intracellular protozoa Toxoplasma gondii. This parasite infects most mammals (including humans), which are intermediary hosts. On one hand, Cats play animportant role in the epidemiology of the disease, as they are the definitive hosts allowing the sexual phase of the parasite in their gastrointestinal tract. That is why cats are the only source of environmental pollution with oocysts.Hence, Infection rates in cats are considered to be the best monitoring tool of the level of T. gondii in the environment. Infection in cats frequently takes place as subclinical or asymptomatic disease and is very rare to develop evident clinical signs. Several previous surveys have been conducted worldwide, which come with the fact that the prevalence of toxoplasmosis in cats reported worldwide ranges from 60 to 90%.On the other hand, toxoplasmosis in human is one of the multiple etiologies of threatened abortion or neonatal complications in humans. As a result, studying the seroprevalence of toxoplasmosis among household cats and aborted women were an important aspect of the current study. In addition to studying the hematological and biochemical changes accompany to the infection in examined cats.This study concerned mainly with the following aspects: 4.Theestimation of toxoplasmosis seroprevalence in household cats in Sohag Governorate in Egypt by using serological tests (latex and rapid tests) and confirmation of Toxoplasma infection in cats usingmolecular methods (conventional PCR)5.Studying the hematological and biochemical changes that accompany to the infection in cats through complete blood picture and liver function tests.6. Study of the prevalence of antibodies to T. gondii (IgG, IgM) among aborted women using the ELISA test. And try to clarify the relationship between household cats and human toxoplasmosis. This study was carried out on 80 randomly household cats,which were admitted to Animal Health Research Institute pet clinic in Sohagby their owners for health check-ups. Cats were of different breeds (domestic shorthairedcats,Turkish, Persian and Siamese), different agegroups (6 months to 7 years), and of both sexes. The assessment of the possible risk factors (sex, age, diet, hunting behaviour of household cats) was made through a questionnaire survey to each owner.On one hand, a total of 80 Cat’s blood samples were collected through puncturethe jugular vein, and deposited in two vacutainer tubes. One with EDTA anticoagulant for complete blood picture analysis, while the other tube was without anticoagulant for serum collection for serological testing. All serum samples were tested for the presence of T. gondii IgG and IgM antibodies by”Latex and rapid tests”; also were evaluated to assess liver functions and activity of enzymes (ALT,AST). After that, the 11 Cats’ blood samplesthat have been proven positive using both rapid and latex tests were subjected to molecular diagnosis using conventional PCR to detect the B1 gene of T.gondii.On the other hand, a total of 88 sera samples were collected from women and examined by ELISAtest for detection of T.gondii antibodies. The serum samples included 77of aborted womencollected from Governmental Hospital and private clinics in Sohag Governorate. These women have been givenquestionnaire about age to establish whither any relationship was between age group and toxoplasma infection. The other 11 samples were collected from female pet owners to assess any linkage between cat rearing and Toxoplasma infection.Finally, our results can be summarized in the following:1-The percentage of T.gondii infection in household cats were 31.25% ,18.75% and 13.75% by using cat rapid test ,latex test and both tests respectively2- Cats’ sera examination revealed that the percent of infection in the examined cats varied with the different risk factors, as following:a) Age: the percent of serological prevalence of T. gondiiincreased bythe age of the cats using rapid, latexandboth tests togetherUsing rapid test, the infection rates recorded were (7.14%) for cats ”<1 year”, and (48.4%) for cats”>2 years” by rapid test. By latex test, the infection rates recorded were (0%) for cats ” 1 year”, and (33.3%) for cats ”1-2 year”. Lastly, the infection rates recorded were (0%) for cats ”<1 year ”and (21.6 %) for cats ”>2year” by both latex and rapid tests.
b) Sex: The infection percentagewas higher in male cats than in female ones.By rapid test, male cats had 38%, while female ones had 25%. Likewise, male cats had 28%, while female ones had 11% by latex test c) Breed: Siamese cats recorded the highest rate of infection (83.3%) among the other studied breeds by using the rapid test, followed by Persian, domestic short hair and Turkish cats by (28.8%, 22.2% and 16.7%) respectively. Similarly,using the latex test, Siamese cats ranked first (66.7%) compared with the other breads, followed by Persian by (18.6%), Turkish and domestic short hair by (0%).The reason may be that all examined Siamese cats came to the clinic during our investigation were accidently adult (> 6 years), and this is consistent with what we have just mentioned above that the percent of infection increases in older cats. On the other hand, these variations in seropositivity percent among different breeds may be due to genetic susceptibility or differences in strength of the measurable humoral immunity.3-The hematological examination showed leukocytosis in seropositive cats by both rapid and latex testthe value was (16.78 ± 7.80) when compared to seronegative ones (control) (10.69 ± 3.37). It also showed monocytosis in seropositive cats by latex test, where the value was (6.75±9.54) when compared to control (2.16 ± 1.71). While other hematological parameters did not show remarkable change.4-The liver function tests of seropositive cats showed only a significant increase in ALT activity (64.15 ± 30.57) using both rapid and latex test compared to control (53.94 ± 35.15). AST activity increased in seropositive cats (41.29 ± 28.06) by using rapid test compared to seronegative control (32.72 ± 28.17); however, it was not statistically significant. 5- The molecular investigation using conventional PCR for eleven cats, which were proven positive by both latex and rapid testsdisplayed negative forToxoplasma gene (B1 gene).This is most likely because the clearance time for Toxoplasma DNA from the blood with acute toxoplasmic lymphadenopathy was estimated to be 5.5- 13 weeks and owing to the parasite leave the blood and localized in organs forming latent stage (bradyzoites).6- Prevalence of T. gondiiantibodies in aborted women sera was (57%) by using ELISA test, which can be classified into (37.5%) IgG, (13%) IgM and (6%) for both IgG and IgM. 7- Prevalence of T. gondii antibodies in female cat owners (using ELISA test) was 18.18% forIgG. 8- Statistically, no relationship was detected between age groups of aborted women and toxoplasma infection (p=0.935 for IgG, and p=0.478 for IgM).9-There was no match between seropositivity ofcats (using rapid and latex tests) and detection ofT.gondii antibodies in their owner’s sera(using ELISA test). This may be due to exposure to other sources of infection otherwise direct contact with cats, such as consumption of undercookedmeat, or oocyst contaminated food.