When immunocompetent people become infected with the parasite Toxoplasma gondii, the disease is generally asymptomatic. However, transplacental transmission of T. gondii may lead to severe congenital infection including in utero abortion, foetal death, or neurological or ocular damage of the foetus. France has had a national programme to prevent congenital toxoplasmosis since 1978. However, although estimated seroprevalence in pregnant women has fallen from 84% in the 1960s to 44% in 2003, no reliable data have been available on the annual number of cases of congenital toxoplasmosis or the severity of infection. In 2006, the French National Institute for Public Health Surveillance (Institut de Veille Sanitaire) and the National Reference Centre for Toxoplasmosis recommended that a national laboratory-based surveillance system be used for the surveillance of the disease. In 2007, 31 laboratories reported at least one congenital case through the surveillance system, giving a total of 272 cases. A total of 11 terminations of pregnancy were reported (six abortions and five foetal deaths). Of the live-born cases, 206 were asymptomatic, 28 were symptomatic and seven had a severe form of the disease. As there were 818,700 births in France and French overseas departments in 2007, the overall prevalence of congenital toxoplasmosis observed that year was 3.3 (95% confidence interval (CI): 2.9 to 3.7) per 10,000 live births and the incidence rate of the disease at birth was 2.9 (95% CI: 2.5 to 3.2) per 10,000 live births; the estimated incidence rate of symptomatic congenital toxoplasmosis was 0.34 (95% CI: 0.2 to 0.5) cases per 10,000 live births.

Several recent outbreaks of toxoplasmosis were related to drinking water. We propose a strategy for Toxoplasma oocyst detection as part of an approach to detecting multiple waterborne parasites, including Giardia and Cryptosporidium spp., by the U.S. Environmental Protection Agency method with the same sample. Water samples are filtered to recover Toxoplasma oocysts and purified on a sucrose density gradient. Detection is based on PCR and mouse inoculation (bioassay) to determine the presence and infectivity of recovered oocysts. In an experimental seeding assay with 100 liters of deionized water, a parasite density of 1 oocyst/liter was successfully detected by PCR in 60% of cases and a density of 10 oocysts/liter was detected in 100% of cases. The sensitivity of the PCR assay varied from less than 10 to more than 1000 oocysts/liter, depending on the sample source. PCR was always more sensitive than mouse inoculation. This detection strategy was then applied to 139 environmental water samples collected over a 20-month period. Fifty-three samples contained PCR inhibitors, which were overcome in 39 cases by bovine serum albumin addition. Among 125 interpretable samples, we detected Toxoplasma DNA in 10 cases (8%). None of the samples were positive by mouse inoculation. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method.

The foodborne disease burden (FBDB) related to 26 major biological hazards in France was attributed to foods and poor food-handling practices at the final food preparation step, in order to develop effective intervention strategies, especially food safety campaigns. Campylobacter spp. and non-typhoidal Salmonella accounted for more than 60% of the FBDB. Approximately 30% of the FBDB were attributed to 11 other hazards including bacteria, viruses and parasites. Meats were estimated as the main contributing food category causing (50–69%) (CI90) of the FBDB with (33–44%), (9–21%), (4–20%) (CI90) of the FBDB for poultry, pork and beef, respectively. Dairy products, eggs, raw produce and complex foods caused each approximately (5–20%) (CI90) of the FBDB. When foods are contaminated before the final preparation step, we estimated that inadequate cooking, cross-contamination and inadequate storage contribute for (19–49%), (7–34%) and (9–23%) (CI90) of the FBDB, respectively; (15–33%) (CI90) of the FBDB were attributed to the initial contamination of ready-to-eat foods—without any contribution from final food handlers. The thorough implementation of good hygienic practices (GHPs) at the final food preparation step could potentially reduce the FBDB by (67–85%) (CI90) (mainly with the prevention of cross-contamination and adequate cooking and storage).

Toxoplasma gondii is a cosmopolitan protozoan parasite which affects approximately 30% of the population worldwide. The drugs currently used against toxoplasmosis are few in number and show several limitations, such as drug intolerance, poor bioavailability, or drug resistance mechanism developed by the parasite. Thus, it is important to find new compounds able to inhibit parasite invasion or proliferation. In this study, the 400 compounds of the open-access Pathogen Box, provided by the Medicines for Malaria Venture (MMV) foundation, were screened for their anti- Toxoplasma gondii activity. A preliminary in vitro screening performed over 72 h by an enzyme-linked immunosorbent assay (ELISA) revealed 15 interesting compounds that were effective against T. gondii at 1 μM. Their cytotoxicity was estimated on Vero cells, and their 50% inhibitory concentrations (IC ₅₀ ) were further calculated. As a result, eight anti- Toxoplasma gondii compounds with an IC ₅₀ of less than 2 μM and a selectivity index (SI) value of greater than 4 were identified. The most active was MMV675968, showing an IC ₅₀ of 0.02 μM and a selectivity index value equal to 275. Two other compounds, MMV689480 and MMV687807, also showed a good activity against T. gondii , with IC ₅₀ s of 0.10 μM (SI of 86.6) and 0.15 μM (SI of 11.3), respectively. Structure-activity relationships for the eight selected compounds also were discussed on the basis of fingerprinting similarity measurements using the Tanimoto method. The anti- Toxoplasma gondii compounds highlighted here represent potential candidates for the development of new drugs that could be used against toxoplasmosis.

Background: Toxoplasmosis during pregnancy can result in congenital anomalies or fetal death. Universal antenatal screening is recommended in France, a strategy in place since the 1970s. Aim: We determined the seroprevalence of toxoplasmosis among pregnant women participating in the 2016 national perinatal survey (ENP), compared results with previous ENPs, and investigated factors associated with Toxoplasma gondii infection. Methods: Using the 2016 ENP data, which contain sociodemographic and clinical information from all women giving birth during a one week period, we calculated adjusted prevalence ratios (aPR) by sociodemographic factors. Using available data from prior ENPs (1995, 2003 and 2010), we calculated age-standardised seroprevalences and aPRs for French women. Results: In 2016, seroprevalence was 31.3% overall. Among French women, associations with increasing age (aPR: 1.54; 95% CI: 1.39–1.70), residence in Paris (aPR: 1.19; 95% CI: 1.08–1.31) or south-western regions (aPR: 1.19; 95% CI: 1.08–1.31), and higher professional status (aPR: 1.12; 95%CI 1.04–1.21) were observed. An association with increasing age was also evident among women from North Africa and sub-Saharan Africa. Age-standardised seroprevalence decreased from 55.0% in 1995 to 33.7% in 2016. Among French women, significant associations with age, Paris and south-west regions persisted across all ENPs. Conclusion: Higher prevalences in older women may reflect a higher past risk of exposure while persistent geographical differences may reflect dietary or environmental differences. Toxoplasma seroprevalence among pregnant women continues to fall and will impact screening effectiveness. This warrants a comprehensive review to determine the appropriate future of prevention in France.