Title of Thesis
Seroprevalence and Polymorphism of Toxoplasma
Gondii in Local Isolates
Department of Zoology / University of the
|Number of Pages|
|Keywords (Extracted from title, table of contents and
abstract of thesis)|
Seroprevalence, Polymorphism, Toxoplasma, Gondii,
Toxoplasmosis Latex, Local, Isolates, Gynaecology, Polymerases Chain
Seroprevalance of toxoplasmosis in women, butchers, dogs and cats was recorded during November. 2002 to March, 2004. The results are presented in four parts. Part I deals with seroprevalence of Toxoplasma gondii in women. A total of 850 women (history of abortion n=425 and normal parturition n=425) serum samples were collected from the labour room, Gynaecology wards of four different hospitals of Lahore. The serum samples were screened for anti-Toxoplasma antibodies at screening dilutions of 1: 16, 1:128 and 1:256 by using commercial kit "Toxoplasmosis Latex". The women ages ranging from 20 to above 40 years were included. The age group of 31-35 years and above showed the highest percentage seropositivity (75%) followed by the age group of 20-25 years (68.18%) and the least percentage (44.4%) in the age group of 26-30 years. The higher seropositivity (75%) was found from the 8'h gestation onwards. Furthermore, amongst the 425 cases with known history of abortion, 340 (80%) showed seropositivity compared to 187 (44%) with history of normal parturition. Of the 850 women screened. 374 families were known to have cats as pets. The percentage seropositivity increased drastically (86.4%) in women belonging to families which were keeping cats as companion animals. The results also revealed that most abortions took place in the last trimester. The prevalence was highest in the autumn season and lowest in winter. It was also noted that women from rural areas were commonly affected.
Part II deals with Seroprevalance of Toxoplasma gondii infection in butchers. A total of 425 butchers were examined for toxoplasmosis. Out of these, 16.94% were found to be positive for toxoplasmosis. Butchers ranging from 51-60 (n=70) years of age and above exhibited highest seropositivity (20.35%) whereas the lowest prevalence (11.76%) was recorded in butchers from the age group of 3140 years (n=68). Prevalence was higher in weak butchers than in healthy ones. Highest prevalence was noted during autumn while the lowest was observed during spring. Infection was also higher in older butchers as compared to the younger ones.
Part III deals with the serological survey for Toxoplasma gondii in dogs. A total of 305 dogs were examined. 143 of them were found to be seropositive. seroprevalence of Toxoplasma gondii in canines was inversely related to the age. i.e. 52% at 7 months or less and 32.5% at 4 years and above. There significant difference between the exotic (39.44%) and local breeds (57.80%). Infection rate was found to be much higher in stray dogs as well as in dogs from rural areas. Amongst the 120 bitches of different age groups 80 had a previous history of abortion. Prevalence was highest in autumn season (63.88%).
Part IV deals with the seroprevalence of Toxoplasma gondii in cats. A total of 120 cats were examined out of which 71 (59.1%) were found positive. Prevalence was the highest (76%) in the age group of 4 years and above, whereas the lowest (40%) was recorded in the age of group of six months or less. The prevalence in relation to breed indicated that the highest (67.5%) was noted in local breeds and the lowest (51.4%) in Persian breed. Prevalence in relation to the sex indicated that the highest (80%) was noted in females as compared to males (24.4%). Infection rate in cats was the highest in autumn as well as in cats belonging to rural areas.
A total of 250 serum samples were analyzed for anti Toxoplasma antibodies. From the total, 100 serum samples of pregnant and aborted women were collected at random, whereas 150 samples were taken from butchers, canines and felines. On the basis of serological examination of serum samples, Toxoplasma gondii positive at 1/16 dilution (Group A), positive at 1/256 (Group B) and in normal cases (Group N) of women, butchers, dogs and cats were subjected to biochemical analysis.
Although there was significant difference (P<0.01) for serum enzymes, however there was no significant difference (P>0.01) for serum electrolytes among all the three treatment groups of women, butchers, dogs and cats.
Thus the results showed that the serum enzymes were affected by Toxoplasma gondii but serum electrolytes remained unaffected during Toxoplasma gondii infection in women, butchers and cats.
In the present study, Polymerase Chain Reaction (PCR) based on the amplification of repetitive BI gene of Toxoplasma gondii was applied. 100 samples of amniotic fluid suspected for toxoplasmosis were included in the study. Out or these, 35% specimens of amniotic fluid were positive for Toxoplasma gondii by PCR. The same samples were processed for genotyping and as a result two different genotypes were distinguished, one with a single nucleic acid hand and Elie other with two bands.
The PCR results in the present study were in good correlation with the serological data of these patients. All of them presented a high level of titers in LAT. the gold standard. The result demonstrated that PCR analysis of samples of patients suspected for toxoplasmosis is a promising diagnostic method that enables an early and direct detection of parasitic DNA. This helps in curtailing this drastic malady at an early stage and will help in devising strategies for minimizing losses due to this disease.