An investigation of families that included at least one person with acute toxoplasmosis revealed that more than half of the families also had at least one additional family member with the diseases.
“Family members frequently share common exposures to food or environmental sources potentially contaminated with Toxoplasma gondii,” researchers from Stanford University School of Medicine wrote in Emerging Infectious Diseases. “Identification of additional infections could lead to earlier implementation of appropriate interventions for person in certain high-risk groups, such as immunocompromised persons and pregnant women.”
The researchers conducted a retrospective cohort study in which they identified families that had an index patient diagnosed with T. gondii infection and had at least one additional household member that was tested for infection. From 1991 to 2010, there were 97,279 people tested for T. gondii infection. There were 107 people who had at least one household member with a diagnosis of acute toxoplasmosis and at least one household member who was tested for T. gondii infection.
The 107 people were grouped into 32 study families that were further categorized into groups. In group 1, families had an index patient and one or more other household member with acute or recent infection. Group 2 consisted of families with an index patient, one or more family members with chronic infection and no other members with acute or recent infection. Families in group 3 had one index patient and no other family members showed evidence of infection.
The prevalence of group 1 families was 56% vs. 16% of group 2 families and 28% of group 3 families. The immunoglobulin G and IgM titers of the index patients were not different across the three groups. In group 1 families, the additional family members with recent or acute infection had similar serologic profiles to the index patient.
“When a case of acute toxoplasmosis is diagnosed, screening of additional family members should be considered, especially if pregnant women or immunocompromised patients live in those households, so that appropriate preventive strategies and/or therapeutic interventions are applied,” the researchers wrote.
Disclosure: The researchers report no relevant financial disclosures.