Handling toxoplasmosis in pregnancy: the Verona experience

Abstract number: 1134_01_189

a Beccara L., Nicolini G., Tonolli E., Danzi M.C., Concia E.

Background:  

Assessing seroprevalence of the infection from Toxoplasma gondii is of pivotal importance to estimate the risk for mothers of becoming infected with toxoplasmosis during pregnancy. Informing non-immune women about which behaviours should be avoided in order not to get infected is therefore important. Even more important is to devise early diagnosis techniques in order to treat the mother and possibly the foetus and to monitor the newborn in the case of an infection: avoiding risk behaviours is sometimes not sufficient to avoid the infection.

Objective:  

The aim of this study was to estimate: i) the prevalence of antibodies against Toxoplasma gondii in pregnant women in Verona; ii) the incidence of primary infection during pregnancy; iii) the prevalence of congenital toxoplasmosis. By means of procedure we wanted to test: i) the validity of the pre-birth monthly screening in women susceptible to infection as a function of seroprevalence; ii) the feasibility of an early diagnosis; iii) the validity of the diagnostic-therapeutic iter for women with an acute infection.

Methods:  

Seroprevalence was prospectively analysed in 1801 pregnant women visited at the general hospital during 2001: assays were performed to detect immunoglobulins IgG, IgM, IgA and IgG avidity antibodies. In case of positive IgM a second serum sample was requested and processed in parallel with the first one. Determination of IgG avidity antibodies allowed us to define three stages of infection: acute, possible and past. Congenital infection was determined prenatally by PCR in amniotic fluid and/or postnatally by serology and clinic of the newborn in 27 acute infection cases screened between 1999 and October 2004.

Results:  

Seroprevalence of toxoplasmic infection in pregnant women in Verona was 17.5%. The incidence of primary infection in pregnancy was 4.7/1000 susceptible pregnant women. All women with serological evidence of toxoplasmosis during pregnancy were given spiramicin to stop placental infection. Transmission was 7.4%. No children showed clinical signs of congenital toxoplasmosis.

Discussion:  

Our seroprevalence figures (17.5%) are very low and justify the screening of all pregnant women. Monthly screening of susceptible pregnant women has allowed us to early recognise an occurred infection in the mother. This way we could put in action prevention and therapy strategies against the foetus infection, which occurred only in the 7.4% of the studied cases.