Toxoplasma gondii (T.gondii), an obligate intracellular parasite found in many species throughout the world, causes a variety of clinical syndromes in human and animals 1. Toxoplasmosis during pregnancy can cause congenital infection and manifest as mental retardation and blindness in the infant. The severity of fetal disease varies inversely with the gestational age at which maternal infection occurs 2.

Seroprevalence estimated for human population varies greatly among different countries, among different geographical areas within one country, and among different ethnic groups living in the same area 2. Seroprevalence of T.gondii infection in women at childbearing age is found to be between 4%-100%. Incidence of primary maternal infection during pregnancy varies in a range of 1 to 310 per 10.000 pregnancies in the populations in Europe, Asia, Australia, and the Americas 2. The serological screening of pregnant women for toxoplasmosis and the follow-up until delivery are not routine procedures in Turkey. In a few studies performed in our country, seroprevalence of T.gondii infection in women at childbearing age is found to be between 19.2% to 85%; and it is estimated that incidence of congenital toxoplasmosis is 0.1% 345.

Major routes of infection are: a) ingestion of oocysts through close contact with infected cat or cat's faeces, b) ingestion of water or food contaminated with the oocysts, c) eating raw or undercooked meat from infected animals that contain the tissue cysts, d) transplantation of infected organs, and e) congenital infection 1. The following risk factors have also been identified in recent epidemiological studies: owning cats 6, eating raw or uncooked pork, lamb, mutton, beef, game or mincemeat products 678910, eating raw or unwashed vegetables or fruits 8, frequent consumption of raw vegetables outside the home 6, travelling outside of Europe, the United States and Canada 7, having poor hand hygiene 6, washing kitchen knives infrequently 8, cleaning the cat litter box 8, contact with soil 7, a history of working in soil-related occupations 11. Similarly, outbreaks of toxoplasmosis have been reported to be related with eating raw or uncooked pork, lamb, mutton or beef products 12 and additionally, with oocyst contaminated water 13 or soil 14.

The aims of the present study were to determine the prevalence of toxoplasmosis in pregnant women at the first trimester of their pregnancy and to follow up the seroconversion for the next two trimesters, and to identify the risk factors and possible contamination routes in the Aydin province, Turkey.

There were 389 pregnant women at the beginning of the study. The mean age of the women was 24.28 ± 4.56 years. The mean gestation week was 9.85 ± 2.21. The means of total number of pregnancies, total abortion and stillbirth, and total live births were 2.01 ± 1.37, 0.36 ± 0.80 and 0.65 ± 0.82, respectively.

The seroprevalence of Toxoplasma specific IgG was 30.1% among pregnant women at the first trimester of their pregnancy (n = 389). During the follow-up during pregnancy, we could reach 257 (66.1 %) women in the second trimester and 124 (31.9%) women in the third trimester. No Toxoplasma specific IgM in total 770 serum samples of three trimesters was detected.

Socio-demographic characteristics and obstetrical history are given in Table 1. Risk factors related to eating preferences and hygienic habits are given in Table 2.

Seroprevalence of T.gondii infection range between 15%-77% in different countries 911. In the current study, the seroprevalence of Toxoplasma specific IgG was 30.1% in pregnant women at the first trimester. In outpatient women at childbearing age it is found to be between 21.8% to 85% in our country 420212223. The only population-based study that could be reached was performed in a village. In that study, the seroprevalence of toxoplasmosis was found to be 30% in 600 people aged 7–50 years 24. Latter seroprevalence is similar with the current study.

As in the study of Bobic et al. (1998) that have found that prevalence increases as the age increases 9, age effect was observed in the current study. The reason might be increasing risk of exposure with age.

In the current study, no statistical meaningful difference was observed between urban and rural areas for toxoplasmosis seroprevalence. Baril et al.(1999) 6 have found similar results with the current study; however, Ades et al (1993) 25 have found higher seroprevalences in urban areas. There is a need to assess the nature of infection chain for Aydin.

Seroprevalence was found to be changed according to usage of different drinking water sources in the current study. The highest prevalence (33.7%) was in the people using general network water, followed by uncontrolled water sources (30.7%). The municipal network water in Aydın is collected to processing pools from open springs next to a few villages. The high seroprevalence in general network water users may be in accordance with the latest articles that have showed the presence of oocysts in chlorinated network water. A study is needed to investigate oocysts in domestic and outdoor life for those whose water sources are the same. Lower prevalences in bottled water users might be explained in that the containers are filled soon after the water surfaces. Oocyst form of T.gondii seems to be the major factor in the infection of water resources. Bowie et al (1997) assessed an outbreak in the western Canadian province of British Columbia and found that a municipal water system that used unfiltered, chloraminated surface water had been the likely cause of the large community-wide outbreak of toxoplasmosis 26.

Frequent consumption and type of meat (pig, sheep and goat) were identified as the principle risk factor in several recent studies of T.gondii infections in humans 678927. No relation was observed between seroprevalence and type of meat consumed in the current study. In Turkey, beef and lamb are commonly used, especially mixed together. Pork is never used due to religious ban. However, it is known that pork is mixed with other type of meat and served without knowledge of consumers.

The cooking temperature of meat is an important issue in the infection of T.gondii. Thorough cooking is always preferred in Turkey. However, raw meat is also consumed in traditional cuisine as "cig kofte" which is a mixture of raw meats. In the current study, no statistical difference was observed between T.gondii prevalence, and cooking preferences and consumption of raw meat.

The association of cats and human toxoplasmosis is difficult to assess by epidemiological surveys because soil, not the cats, is the main culprit. Oocysts are not found on cat fur 28 and are often buried in soil along with cat faeces, and soil contact is universal and difficult to avoid 29. In Turkey, cats and dogs are commonly stray animals. There is always a possibility that oocysts of the stray cats may gain infectious ability outside the animal. In the current study, the number of cat owners was just a few, and no relation was detected.

In the previous studies, lower educational level, soil-related occupations 11, eating raw or unwashed vegetables or fruits, cleaning the cat litter box 8, having poor hand hygiene 68, eating raw vegetables outside the home 6, contact with soil 7, travelling outside of Europe, the United States and Canada 7 were all found as risk factors for toxoplasmosis. These factors were assessed in the current study; however, no relation was found.

The importance of the current study is that it is one of the few – to our knowledge only one -population based studies performed in Turkey. However, there are some restrictions in the study. First of all, dye test could not be used as a gold standard. In order to overcome this restriction, different test were used together. Secondly, although health centers as primary care units cover all the population which they are responsible for, and the data obtained from them is the most appropriate for population-based studies, there may be a few women that could not be reached. Maybe one of the most important restrictions is that the assessment of risk factors was done according to information given by the patient. Some issues such as hygienic behaviour might be misrepresented as higher because of shaming or other factors. However, an improvement in the quality of data was attempted by using district midwifes who were familiar and trusted by the women during data collection.

In conclusion, 69.9 % of pregnant women in the first trimester in the Aydin Province-Turkey, are susceptible to acute infection, and no Toxoplasma specific IgM was detected during the follow-up of pregnant women for three trimesters. This may be due to lower ratios of serum assessment in the second (66.1 %) and in the third (31.9%) trimesters. At the current moment, there is no legal obligation for education about means of minimizing exposure to T.gondii. in our country. Health authorities, especially primary health care givers should be sensitive to the importance of the issue. Hygiene of water supplies is also important. Future studies on possibility of contamination of network water by oocysts should be performed and used for prevention activities. The data found in the current study point out that due to a high risk of toxoplasmosis in pregnant women, a debate on developing a general screening program for toxoplasmosis in pregnancy in Turkey should be begun.

The author(s) declare that they have no competing interests.

SE planned the research; performed parasitic examinations and contributed discussing the results and writing manuscript. PO performed the sampling and statistical analyzes and contributed discussing the results and writing manuscript. MT participated in initial study design, and revised the manuscript. HY participated in initial study design, and revised the manuscript. All authors read and approved the final manuscript.