You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Cats are a major reservoir of the disease known as toxoplasmosis and they can be responsible for the transmission of Toxoplasma organisms to humans through contaminated faeces.  However, a recent study suggests that cats are not the main source of infection

Toxoplasmosis is most serious in pregnant women because the infection can spread to the baby - and does so in about 25% of cases in which a pregnant woman contracts the disease. In a large survey of 1000 pregnant women in Europe* it was found that the main source of infection with Toxoplasma was eating undercooked meat - beef, lamb or pork. The risk of contracting toxoplasmosis from meat was 5 times as great as contracting it from contaminated soil (which can be contaminated with the cat  faeces containing the infective stage of toxoplasma organisms - called oocysts).

Nevertheless, pregnant women should wash their hands after handling cats, and should wear protective clothing (eg gloves) when emptying cat litter trays. Direct contact with cat faeces or contaminated soil (eg in garden beds where cats may defaecate) should be avoided.

Reference 

*Cook et al (2000) British Medical Journal 312: 142-147

Updated October 2013