Incidence of congenital toxoplasmosis among infants born to HIV-coinfected mothers: case series and literature review

Abstract

Introduction: There is a paucity of data on the occurrence of congenital toxoplasmosis in children born to mothers dually infected with HIV and Toxoplasma gondii.

Objective: To evaluate aspects of the mother-infant pairs associated with vertical transmission of toxoplasmosis in women co-infected with HIV in a referral center for perinatally acquired infections in Belo Horizonte, Brazil.

Methods: Descriptive study of HIV vertically exposed children, with congenital toxoplasmosis, followed at a referral center (cohort/Belo Horizonte). Prenatal and post-natal variables for the mother-infant pairs were evaluated. A literature review with no filtering for time and language was performed to identify reports of congenital toxoplasmosis in HIV vertically exposed children.

Results: Among 2007 HIV vertically exposed children evaluated in the period from 1998 to 2011, 10 cases of congenital toxoplasmosis were identified (incidence: 0.5%, 95% confidence interval: 0.24-0.91). In searching the literature 22 additional cases in 17 reports were found. Combining the findings of our cohort with other reported cases, 50% (16/32) of congenital toxoplasmosis in HIV vertically exposed children were from Brazil. The cases of congenital toxoplasmosis in HIV vertically exposed children identified in Brazil occurred mainly in the post-Highly Active Antiretroviral Therapy era (p=0.002) and presented a lower death rate (p=0.003) than those from other countries. In the cohort/Belo Horizonte, HIV infection was identified mainly during gestation; T. gondii vertical transmission was observed in pregnant women with CD4(+)>500 cells/mm(3) and latent toxoplasmosis. High rates of ocular lesions (87.5%) and central nervous system involvement (70%) were detected.

Conclusions: The risk of vertical transmission of T. gondii in HIV-infected women is low and has been usually associated with maternal immunosuppression and elevated viral load. However, our findings of congenital toxoplasmosis in children born to HIV-infected mothers with latent toxoplasmosis and not immunosuppressed emphasize the need for careful follow-up in these cases.

Keywords: Co-infection; Congenital toxoplasmosis; HIV.