Less Common Protozoan and Helminth Infections

Parasitic infections are highly prevalent in many developing areas of the world and may be common among pregnant women in developed countries. The placenta serves as an effective barrier, even in infections such as malaria and schistosomiasis in which systemic involvement and hematogenous spread are common. Although transplacental infections of the fetus are uncommon, the prevalence of parasitic infections among infants younger than 1 month is high in developing countries, and infections occur primarily through transmission during or shortly after birth.