Risk factors for Toxoplasma gondii infection in the United States.
BACKGROUND
Toxoplasmosis can cause severe ocular and neurological disease. We sought to determine risk factors for Toxoplasma gondii infection in the United States.


METHODS
We conducted a case-control study of adults recently infected with T. gondii. Case patients were selected from the Palo Alto Medical Foundation Toxoplasma Serology Laboratory from August 2002 through May 2007; control patients were randomly selected from among T. gondii-seronegative persons. Data were obtained from serological testing and patient questionnaires.


RESULTS
We evaluated 148 case patients with recent T. gondii infection and 413 control patients. In multivariate analysis, an elevated risk of recent T. gondii infection was associated with the following factors: eating raw ground beef (adjusted odds ratio [aOR], 6.67; 95% confidence limits [CLs], 2.09, 21.24; attributable risk [AR], 7%); eating rare lamb (aOR, 8.39; 95% CLs, 3.68, 19.16; AR, 20%); eating locally produced cured, dried, or smoked meat (aOR, 1.97; 95% CLs, 1.18, 3.28; AR, 22%); working with meat (aOR, 3.15; 95% CLs, 1.09, 9.10; AR, 5%); drinking unpasteurized goat's milk (aOR, 5.09; 95% CLs, 1.45, 17.80; AR, 4%); and having 3 or more kittens (aOR, 27.89; 95% CLs, 5.72, 135.86; AR, 10%). Eating raw oysters, clams, or mussels (aOR, 2.22; 95% CLs, 1.07, 4.61; AR, 16%) was significant in a separate model among persons asked this question. Subgroup results are also provided for women and for pregnant women.


CONCLUSIONS
In the United States, exposure to certain raw or undercooked foods and exposure to kittens are risk factors for T. gondii infection. Knowledge of these risk factors will help to target prevention efforts.
Jones
Jeffrey L
JL
Division of Parasitic Diseases, National Center for Zoonotic, Vectorborne, and Enteric Diseases, Coordinating Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. jlj1@cdc.gov
Dargelas
Valerie
V
Roberts
Jacquelin
J
Press
Cindy
C
Remington
Jack S
JS
Montoya
Jose G
JG
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D016022:Case-Control Studies; D002371:Cat Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology / Q000635:transmission; D002415:Cats; D017281:Cost of Illness; D005260:Female; D016266:Food Parasitology; D006801:Humans; D006920:Hygiene; D008460:Meat / Q000469:parasitology; D008875:Middle Aged; D008892:Milk / Q000469:parasitology; D015999:Multivariate Analysis; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012737:Sex Factors; D012758:Shellfish / Q000469:parasitology; D014122:Toxoplasma / Q000276:immunology; D014123:Toxoplasmosis / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology* / Q000635:transmission; D014124:Toxoplasmosis, Animal / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission; D014125:Toxoplasmosis, Congenital / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D014481:United States / Q000453:epidemiology; D055815:Young Adult
D000913:Antibodies, Protozoan