Is the incidence of congenital toxoplasmosis declining?

Prenatal infection with the protozoan parasite Toxoplasma gondii can cause con-genital toxoplasmosis (CT), an often fatal or lifelong-disabling condition. Several studies of human populations have reported temporal decreases in seroprevalence, suggesting declining CT incidence. However, the consistency of this trend among diverse populations remains unclear, as does its implication for prenatal screening programmes, the major intervention against CT. Using temporally resolved data on the seroprevalence of T. gondii in various countries, we discuss how the parasite's changing epidemiology may affect trends in CT incidence in varying and counterin-tuitive ways. We argue that parasite stage-specific serology could be helpful for un-derstanding underlying causes of secular changes in seroprevalence. Furthermore, we highlight the importance of updating cost-effectiveness estimates of screening programmes, accounting for neuropsychiatric sequelae.

Automated summary

Several studies have suggested a decline in the incidence of congenital toxoplasmosis due to decreasing seroprevalence of Toxoplasma gondii. However, the consistency of this trend across different populations and its implications for prenatal screening programs remain unclear. This study explores how the changing epidemiology of the parasite may affect trends in congenital toxoplasmosis incidence and emphasizes the importance of updating cost-effectiveness estimates of screening programs to account for neuropsychiatric sequelae.