Clinical and Health Affairs
Toxoplasmosis Prevention Knowledge among Pregnant Women in Minnesota
By Folashade Ogunmodede, M.B.B.S., M.P.H., Joni Scheftel, D.V.M., M.P.H., Jeffrey L. Jones, M.D., M.P.H., and Ruth Lynfield, M.D.
ABSTRACT
Congenital toxoplasmosis causes blindness and mental retardation. In the United States, up to 85% of women of childbearing age are susceptible to infection with the Toxoplasma gondii parasite, which causes toxoplasmosis. Up to 50% of T. gondii infections are transmitted by ingesting undercooked meat, making toxoplasmosis one of the most clinically significant food-borne diseases in pregnant women. This article describes the results of a 2003 survey of pregnant Minnesota women through which we determined their knowledge of toxoplasmosis and ways to prevent it during pregnancy. Fewer than half of respondents had heard about toxoplasmosis, although higher education levels were significantly associated with knowledge about the disease.
Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii and is endemic throughout the world. Ingestion of tissue cysts in undercooked meat and oocysts in contaminated soil are the primary sources of infection, although transmission from pregnant women to the fetus also occurs.1,2 In the United States, up to 85% of women of childbearing age are susceptible to infection by T. gondii, the remainder being immune because of prior exposure. This makes toxoplasmosis one of the most clinically significant food-borne infections to occur during pregnancy.3,4
Between 400 and 4,000 cases of congenital toxoplasmosis are diagnosed each year in the United States.5 Congenital toxoplasmosis can cause blindness, deafness, and mental retardation. Many cases could be prevented by taking simple precautions during pregnancy. Cooking meat until it reaches the appropriate internal temperature, keeping uncooked and cooked foods separate, and thoroughly washing hands and utensils with soap and water after any contact with raw meat can prevent many types of food-borne illness. Additional precautions for pregnant women specific to toxoplasmosis prevention include not changing the cat litter box, not bringing a new cat into the home, and avoiding stray cats.5
In 2003, the Minnesota Department of Health surveyed pregnant women in the state to estimate their baseline knowledge of and preventive behaviors regarding T. gondii infection, and to determine whether knowledge and behavior were dependent on factors such as age, race, level of education, residence in a rural or urban location, the trimester of pregnancy, or the number of pregnancies a woman had experienced. In conjunction with the survey, we developed an educational brochure about toxoplasmosis and prevention of T. gondii infection. The brochure targets pregnant women and immunocompromised persons.
Methods
The Minnesota Department of Health administered a written questionnaire to pregnant women across the state. A geographic sampling scheme ensured that women from all regions of the state were represented. Participants included women who were enrolled in the Women, Infants, and Children (WIC) nutritional programs in St. Louis, Itasca, Clay, Steele, Blue Earth, Cottonwood-Jackson, Kandiyohi, Pine, Mille Lacs, Dakota, and Washington counties, as well as women who were patients at 3 large multispecialty clinics: MeritCare in Bemidji, CentraCare in St. Cloud, and Allina Medical Clinic in Woodbury. The questionnaire was brief, and it was completed during either a WIC visit or a prenatal exam. Respondents were anonymous. Questions focused on the women’s knowledge of toxoplasmosis and risk factors for T. gondii transmission as well as their understanding of ways to prevent infection during pregnancy. Caregivers from the public health agencies and clinics were encouraged to provide their pregnant patients with the Department of Health’s toxoplasmosis brochure and other information about toxoplasmosis after they completed the survey. Data were analyzed using simple random sampling techniques, and proportions were compared with the chi-square test.
Results
We received 322 completed surveys from respondents ages 15 to 42 years (mean 25.3 years); 46% were in their first pregnancy. The gestational age of the fetus ranged from 4 to 40 weeks (mean 21 weeks). The majority of respondents were white (84%), non-Hispanic (89%), and U.S.-born (95%). Almost half (46%) had a high school education or less.
One hundred thirty-four (42%) respondents had heard of toxoplasmosis; of those, 89 (66%) had read about it in books and magazines on childbirth, 84 (63%) had heard about it from a medical professional, and 47 (35%) had learned about it from friends and family members. Only 3% of respondents said they had heard about toxoplasmosis from a government agency (Table).
When asked specifically about the risk factors for T. gondii infection, 200 (62%) knew they could get toxoplasmosis by changing cat litter, but only 74 (24%) knew they could get it by eating undercooked pork, and only 84 (26%) knew they could become infected by gardening without gloves. Similarly, 184 (57%) knew T. gondii is shed in the feces of cats, but only 84 (26%) knew it could be found in raw or undercooked meat. Only 97 (30%) knew toxoplasmosis could be prevented by cooking meat thoroughly. Most of the respondents reported very good hand-washing practices; 229 (72%) said they routinely wash their hands after changing cat litter; 262 (81%) after gardening; and 300 (93%) after handling raw meat. Respondents older than 25 years of age were significantly more likely to have heard of toxoplasmosis (p=0.009) and were more likely to know of the association with cat feces (p=0.01), undercooked meat (p=0.02), and gardening (p=0.01) than those age 25 and younger. Women with higher levels of education (college versus high school) were significantly more likely to have heard of toxoplasmosis (p=0.007) and understand the risks associated with changing cat litter (p<0.001), gardening without gloves (p<0.001), and eating undercooked pork (p=0.03). There were no significant differences in knowledge levels by race, number of pregnancies, trimester of pregnancy, or area of residence.
Discussion
The results of our survey demonstrate a relatively low level of knowledge about toxoplasmosis risk factors and prevention among pregnant women. Respondents in all age groups and with all levels of education were generally aware of the association between T. gondii and cats. However, the role of undercooked meat in T. gondii transmission and the risk of exposure to oocyst-contaminated soil by gardening without gloves were not understood as well. Older and more educated respondents were significantly more likely to know of these risk factors than those who were younger and less educated. Jones, et al. conducted a similar study of pregnant women across the United States in 2002. That study also demonstrated increasing knowledge of the risk factors for T. gondii infection with increasing age and an increased level of education.6 This study also showed that knowledge does not necessarily correlate with behavior. Although respondents showed a limited knowledge about what could expose them to T. gondii, the majority indicated that they practiced appropriate hygienic behavior.
It is interesting to note from our survey that pregnant women are more likely to get T. gondii-related information from print media and their health care providers than from any other source. Studies from Europe found that primary prevention is the most cost-effective method of preven- ting congenital toxoplasmosis. Researchers have demonstrated the effectiveness of a prenatal education program in Canada for preventing congenital toxoplasmosis.7,8 Therefore, providers who care for pregnant women or women who are thinking of becoming pregnant should routinely offer them information about toxoplasmosis prevention. MM
This study was supported in part with funding provided through a cooperative agreement with the Centers for Disease Control and Prevention as part of the Emerging Infections Program Network. We would like to thank the nursing staff from the participating local public health agencies and prenatal clinics for their assistance with data collection. Finally, we would like to thank Brenda Jewel, Elizabeth Pretzel, Lenette Bauer, and Marilyn Grant for their work on the questionnaire, brochure, and data entry.
Folashade Ogunmodede is an epidemiologist in the Acute Disease Investigation and Control Section, Joni Scheftel is the state public health veterinarian, and Ruth Lynfield is medical director of the Division of Infectious Disease Epidemiology, Prevention and Control. All work for the Minnesota Department of Health. Jeffrey Jones is medical epidemiologist in the Division of Parasitic Diseases of the National Center for Infectious Diseases, at the Centers for Disease Control and Prevention in Atlanta.
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