Toxoplasmosis is a common zoonotic infection caused by the protozoan Toxoplasma gondii. Humans are typically infected by ingesting oocysts that contaminate water or food, or by eating undercooked meat that contains tissue cysts.^1,2 In immunocompetent individuals, the infection is often asymptomatic, but it can cause serious disease in immunocompromised people and during pregnancy.^3,4 Primary maternal infection exposes the foetus to vertical (maternal–foetal) transmission, and may lead to severe complications, including neurological and ocular damage, and even death in utero, especially in early infection.^5,6 Diagnosis relies mainly on serological measurement of T. gondii-specific IgG and IgM; IgG-avidity testing and, where indicated, amniotic-fluid polymerase chain reaction (PCR) help to refine the timing of infection.^7,8,9,10,11 In the absence of pre-existing IgG, pregnant women remain susceptible throughout pregnancy. Although serological screening is recommended as part of antenatal care in several countries, including Côte d’Ivoire, its implementation remains uneven, depending on the context and the resources available.^12,13 In Africa, toxoplasmosis seroprevalence, typically measured by anti-toxoplasma IgG seropositivity, varies widely among pregnant women, with rates of 44.4% in Cotonou,¹⁴ 36.1% in rural Benin,¹³ and 51% in Morocco.¹⁵ In Côte d’Ivoire, data are scarce, with the most recent study in Abidjan reporting a seroprevalence rate of 48%,¹⁶ underlining the high level of endemicity. However, these data appear outdated and require re-evaluation, particularly owing to the continued presence of environmental and dietary risk factors. This study was therefore designed to estimate the seroprevalence of toxoplasmosis and to describe IgG/IgM serological profiles in pregnant women attending the University Hospital of Cocody.

The results of this study show an overall IgG seroprevalence of 49.0% among pregnant women. This rate is comparable to those reported in Côte d’Ivoire in Abidjan (48%),¹⁶ and in Daloa (54.16%),¹⁸ as well as in Benin in Cotonou (44.4%),¹⁴ and in rural areas (36.1%),¹³ indicating sustained T. gondii endemicity in West Africa. Similar rates have also been observed in other tropical contexts, such as Mayotte¹⁹ and Morocco.¹⁵ At the individual level, previous infection (IgG⁺/IgM⁻) is generally considered reassuring for the current pregnancy. However, the significant proportion of women with positive IgM (9.5%), including 5.5% with IgG⁻/IgM⁺ and 4.0% with IgG⁺/IgM⁺, is of concern. These serological profiles reflect recent or current infection, with a risk of foetal transmission, particularly during the first two trimesters.^6,20 In the absence of an IgG-avidity test, it remains difficult to distinguish acute infection, reinfection or persistence of IgM.^9,10 However, several authors recommend that, in cases of IgM positivity, treatment with spiramycin be initiated early, accompanied by close ultrasound monitoring, even in the absence of confirmation by IgG-avidity testing.¹²

Furthermore, a substantial proportion of women with no infection (IgG⁻/IgM⁻; 45.5%) constitutes a susceptible group lacking protective IgG. Although exposure pathways were not assessed in this study, targeted antenatal counselling on food and environmental hygiene, including thorough cooking of meat, remains essential to prevent primary infection during pregnancy. In a highly endemic context such as Côte d’Ivoire,^3,21 this risk must be considered actively. Evidence indicates that the risk of vertical transmission rises with advancing gestation, from 10% – 15% in the first trimester to more than 60% in the third, although the most severe clinical forms of congenital toxoplasmosis are linked to early infections.²²

Cross-analysis between pregnancy trimesters and serological profiles showed that IgM-positive cases occurred in all trimesters, with a higher proportion in the first (17.6%) than in the second (8.2%) and third (7.4%). Although this difference did not reach statistical significance (χ² = 2.99; df = 2; p = 0.22), the pattern is consistent with a higher risk of primary infection in early pregnancy, a critical period for the foetus. These results, although observed in the absence of ultrasound or neonatal confirmation, underscore the need for increased vigilance from the first trimester, including, where possible, amniotic-fluid PCR when a recent infection is suspected.^11,12,23 Our work is a seroprevalence study based on laboratory data; the assessment of clinical management and obstetric or neonatal outcomes was not part of the present analysis.

Furthermore, our study revealed late initiation of toxoplasmosis screening among pregnant women. Only 17.2% were screened in the first trimester, compared with 43.8% and 39.0% in the second and third trimesters, respectively. This delay limits opportunities for early diagnosis and, where indicated, timely preventive measures. In Côte d’Ivoire, first trimester screening is recommended, but uptake is constrained by out-of-pocket payment, as the test is not covered routinely. This financial barrier delays early screening and supports consideration of measures to improve affordability, for example, through targeted fee exemptions or inclusion of toxoplasmosis serology in the essential antenatal-care package.

The main limitation of this study lies in its retrospective design without longitudinal follow-up. Seroconversions and pregnancy outcomes (confirmation of foetal infection or neonatal serology) could not be documented.^24,25 In addition, clinical management data (e.g. treatment initiation) and obstetric or neonatal outcomes were not recorded in the laboratory registers and were therefore unavailable for analysis, which, together with the absence of IgG-avidity testing and amniotic-fluid PCR, limits precise dating of infection phases and the clinical interpretation of the findings.^11,12 Although IgG titres were recorded in the laboratory registers, they were not analysed here because their interpretation remains difficult without avidity testing; however, prior reports suggest that very high IgG titres may indicate long-standing immunity.^10,16

Despite these limitations, our results support strengthening prenatal monitoring practices: the implementation of systematic screening from the first trimester, serological testing in cases of seronegativity or clinical doubt, and better interpretation of serological profiles. Countries such as France have demonstrated that early treatment with spiramycin reduces the foetal transmission rate significantly from more than 30% to less than 5%.²³ In Côte d’Ivoire, although national recommendations exist, their application remains inconsistent. It is therefore essential to train medical personnel in serological interpretation, to make IgG-avidity and PCR testing available, to raise awareness among pregnant women about preventive measures, and to ensure access to specific treatments.