Table 4.
Summary of Within-Family Cluster Demographics and Risk Factors
| Year | Strain | State of Residence | SES Scorea | Ethnicity | Maternal Risk Factors | Maternal Illness | Infant Illness | Parityb | Other Notes |
|---|---|---|---|---|---|---|---|---|---|
| 1995 | ND | NJ | 1 | Non-Hispanic | Cat exposure, sandbox exposure | Adenopathy | Jaundice | 1 | Father developed adenopathy after infection |
| 1996 | NE-II | NY | 1 | Non-Hispanic | Cat exposure, sandbox exposure | PPc | Rash, chorioretinitis, thrombocytopenia, petechiae | 1 | Extended maternal exposure to aerosolized excreta from wild cats in pregnancy; brother was recently infected during this time; maternal grandmother was chronically infected during this time |
| 1997 | NE-II | FL | 4 | Non-Hispanic | Cat exposure, exposure to raw or undercooked meat, gardening | PP | Jaundice, hypothermia, chorioretinitis, blindness, seizures, hydrocephalus, cerebrospinal fluid pleocytosis | 1 | Mother prepared raw deer and pork during pregnancy |
| 2000 | IId | Canada | 2 | Non-Hispanic | Cat exposure, sandbox exposure | Fever, nausea, myalgia, PPROMc | Jaundice, hydrocephalus, chorioretinitis, respiratory distress | 1 | No clear risk factors other than a single exposure to cats at a sandbox in the 1st trimester |
| 1996 | ND | OH | 2 | Hispanic | Cat exposure, sandbox exposure, gardening | Adenopathy, URIc | Hepatosplenomegaly | 1 | No clear risk factors other than a single exposure to cats at a playground in the 2nd trimester |
| 2012 | ND | KS | 1 | Non-Hispanic | Cat exposure, exposure to raw or undercooked meat | Fever, myalgia | Intracranial calcifications | 3 | Mother consumed venison tartare during pregnancy; father and other community members became ill after consuming venison tartare; father had eye disease at examination after infection |
Abbreviations: ND, not determined; NE-II, nonexclusively type II; PP, placenta previa; PPROM, preterm premature rupture of membranes; SES, socioeconomic status; URI, upper respiratory tract infection.
a SES was calculated according to the Hollingshead 4-factor socioeconomic score.
b Parity number refers to the parity of the mother at the time of her acute primary infection, which occurred during the gestational period of her congenitally infected child. Parity was evaluated because if the families already have toddler-aged children who play in sandboxes, the risk of exposure to the oocyst form of the parasite may increase for mothers, fathers, and other children. Parity at the time of acute maternal infection was therefore also reviewed as a possible risk factor for the 6 mothers in within-family clusters.
c Not known to be an associated symptom of Toxoplasma infection.
d Exclusively type II.