Investigation into pregnancy and toxoplasma gondii infection in Libya

Toxoplasma gone/// is a parasite discovered in 1908 by Nicolle and Manceaux; they found a protozoan in tissue of a hamster-like rodent in laboratory of the Charles Nicolle at the Pasteur Institute in Tunisia. It is an obligate intracellular protozoan parasite, capable of infecting most species of warm-blooded vertebrates including mammals and birds. This infection is world-wide and one third of the human population is infected chronically. Toxoplasmosis is an important disease and a causative agent that is responsible for abortion in human and farm animals. T. gondii can be transmitted in three ways: via cat faeces, eating raw meat and congenital transmission (mother to child). To investigate transmission routes and prevalence of T. gondii in human in Libya a set of human tissues samples (umbilical cord) were collected at birth using suitable ethical procedures. One hundred fifty three umbilical cord samples were collected from volunteer subjects in Misurata Central Hospital and Alsaed Hospital in Libya for subsequent DNA extraction and testing for T.gondii infection. The clinical records from these subjects were analysed for factors such as mother age, number of previous children, number of previous miscarriages, pregnancy success and number of current miscarriages. The aim of this thesis was to determine the frequency of congenital transmission of T. gondii in humans and to use clinical records to investigate pregnancy success in Libya. One hundred and fifty mothers were recruited to the study producing 153 children, of these a ratio of male to female of 1.22:1, giving a slightly higher bias than the Libyan average (1.05:1). Mother's ages ranged from 18-45 with an average age of 28 years. The sample contained mothers having their first child to those who had 11 children. The pregnancy success of this cohort was 8 deaths per 145 live births (55.1/1000 live births) which is higher than the Libyan national average (21.9/1000) and the UK national average of 4.93/1000. Overall, the samples set did not appear biased when compared with Libyan national statistics. Miscarriage was analysed with respect to various parameters. As has previously been reported, success of pregnancy declined with increasing with age although this was more marked in mothers older than 38. There was no significant association between miscarriage in the current pregnancy with miscarriage in previous pregnancies (P = 0.96). Interestingly, there was a higher frequency of miscarriage in male than in female children although this was not quite significant (P = 0.062). Of the umbilical cord samples tested for T. gondii 2.01% were infected, giving an overall rate of congenital transmission rate of 2.01%. This is much higher than reported studies using serology, where values of less than 1 per 1000 live births are commonly reported. However, it is lower than a previous study from Libya based on PCR detection (20.1%). Toxoplasma strain typing was carried out on the positive samples and types I and III were found. Toxoplasma infection was not apparent in any of the current miscarried children and there was no association of current infection with miscarriages during previous pregnancies