Search tips
Search criteria 


Logo of springeropenLink to Publisher's site
Maternal and Child Health Journal
Matern Child Health J. 2006 September; 10(Suppl 1): 189–193.
Published online 2006 June 3. doi:  10.1007/s10995-006-0092-0
PMCID: PMC1592156

Toxoplasmosis, Cytomegalovirus, Listeriosis, and Preconception Care


Toxoplasma gondii (T. gondii), cytomegalovirus (CMV), and Listeria monocytogenes (L. monocytogenes) can all negatively affect pregnancy outcomes. Preconception counseling about such effects can reduce the risks posed by these pathogens. Informing women of childbearing age about these pathogens and how to prevent their negative effects can help women make informed decisions about prevention. This brief summarizes some basic information about these infections and provides some web sites and articles for further information about how to prevent them within the context of preconception care.

Toxoplasmosis is a disease caused by Toxoplasma gondii (T. gondii), a protozoan parasite mainly transmitted to humans via three routes: a) ingestion of raw or undercooked contaminated meat; b) exposure to T. gondii oocysts (a form of the organism passed in cat feces), through cat litter or soil (e.g., from gardening or unwashed fruits or vegetables), or contaminated water; and c) congenital in which maternal infection is passed transplacentally via blood to the fetus [1]. Congenital infection leads to stillbirth and severe neurological illness in some instances, although the majority of infected newborns are asymptomatic at birth and some develop sequelae such as mental retardation, blindness, and epilepsy later in life [2]. Extrapolation from regional studies suggests that ~400–4,000 cases of congenital toxoplasmosis occur each year in the United States [2].

Adults with normal immune function who are infected with T. gondii are usually asymptomatic or have self-limited symptoms (e.g., fever, malaise, and lymphadenopathy) [1]. Once infected, these individuals usually develop an immune response against toxoplasmosis [3, 4]. A recent study based on the National Health and Nutrition Survey conducted from 1988–1994 (NHANES III) reported that, among women aged 15–44 years, seroprevalence of T. gondii antibodies was 15%, suggesting that ~85% of women of childbearing age are susceptible to T. gondii infection [5].

Three principal interventions are presently used to reduce morbidity and mortality from congenital toxoplasmosis: a) education about how to prevent infection (especially during pregnancy); b) prenatal and newborn screening to identify and treat congenital infection; and c) animal rearing and production methods designed to reduce T. gondii contamination of meat. Of the three, education about how to prevent infection is applicable to adolescents and women in the preconception period. Education programs during pregnancy have been associated with improved knowledge and behavior and a reduction in infection rates [69]. Toxoplasma infection can be prevented by one or more of the following: a) cooking meat to a sufficient temperature to kill Toxoplasma; b) peeling or thoroughly washing fruits and vegetables before eating; c) cleaning cooking surfaces and utensils after they have contacted raw meat, poultry, or unwashed fruits or vegetables; d) pregnant women avoiding changing cat litter or using gloves, then washing hands thoroughly; and e) not feeding raw or undercooked meat to cats and keeping cats inside to prevent acquisition of Toxoplasma by eating infected prey [2].

Although prenatal and newborn screening programs have been evaluated, they are controversial because of the lack of proven efficacy of treatment, side effects of treatment, and potential complications of invasive procedures such as amniocentesis to evaluate fetal infection [1023]. Animal rearing and production methods to reduce T. gondii contamination of meat are effective and have been associated with a reduction in the prevalence of T. gondii in important meat sources such as pork [24]; however the need for improvement in producers’ knowledge and production practices is acknowledged [25]. Education about toxoplasmosis is an important component of preconception care that can be integrated with information about other diseases that affect women.

Human cytomegalovirus (CMV) is the largest DNA virus belonging to the herpesvirus family. Humans are the only reservoirs for the human herpesviruses, and they can transmit these agents through direct contact with infected blood, tissues, bodily fluids, feces, and fomites [26]. A pregnant woman infected with CMV can transmit this virus to her unborn fetus, which can cause damage to the central nervous system, hematopoietic system, kidneys, endocrine glands, gastrointestinal tract, lungs, and liver. Long-term sequelae include cerebral palsy, mental retardation, and hearing loss [26, 27]. The birth prevalence rate of congenital CMV infection varies between ~0.6–1.5% [2830] in the United States, making it the most commonly transmitted virus in utero [26, 31] and a major cause of cerebral palsy, mental retardation, and hearing loss among children [27, 31].

CMV infects almost all humans at some point in their lives. Adults with normal immune function infected with CMV are usually asymptomatic or might experience mild flu-like symptoms, or even mononucleosis with symptoms such as malaise, persistent fever, myalgia, and cervical lympadenopathy [26, 31]. Once a human is infected, the virus passes into a latent state [26]. Although the virus can be reactivated, it is usually kept under control, because adults with normal immune function usually retain lifelong immunity against CMV.

Primary CMV infection of women during pregnancy or periconceptionally results in transmission to the fetus transplacentally in ~30–40% of maternal infections [26, 3234]. Preexisting maternal immunity strongly reduces the risk of transmission to the fetus [34]. However, approximately 10–15% of newborns with congenital CMV will be symptomatic and from ~6–25% of those born without symptoms will develop late sequelae [35].

The most common means for women to be infected with CMV is by exposure to toddlers who shed large amounts of the virus in their saliva and urine for many months following their first (usually asymptomatic) infection [26, 3640]. Daycare providers and pregnant women who have a toddler of their own are at high risk for infection [4146]. Sexual transmission, blood transfusion, and organ transplantation are other means by which CMV is transmitted [26]. It is important to counsel all women about safe sex practices.

Currently, there are no vaccines available for preventing CMV infection, although some promising advances have been made [47, 48]. It is, therefore, extremely important to provide women of childbearing age with information about how they can prevent CMV infection before conception. The most effective means for preventing CMV infection is handwashing [26, 4953]. Education about careful hygiene and frequent handwashing, especially after contact with the saliva and urine of young children, and careful disposal of diapers, tissues, and other contaminated items can reduce the transmission of CMV. Avoiding sharing drinking glasses and eating utensils with young children can also prevent transmission. This is especially true for women who work in daycare settings and for those who are pregnant [26, 4954].

As some studies suggest that CMV infection prior to conception can result in congenital CMV infection [26, 30, 55], counseling all women of childbearing age about how to prevent transmission preconceptionally could significantly reduce the incidence of congenital CMV infection.

Listeriosis is an invasive foodborne infection caused by the motile, gram-positive bacterium Listeria monocytogenes (L. monocytogenes). The disease affects primarily pregnant women, newborns, and adults with weakened immune systems [56]. Maternal infection during pregnancy is usually a self-limited, nonspecific acute febrile illness of the third trimester. In contrast to the maternal illness, fetal and neonatal infection is severe and frequently fatal. Infection in the fetus and newborn occurs by transplacental transmission or possibly from exposure to L. monocytogenes in the perinatal period. The effects of intrauterine infection on the fetus and neonate include preterm labor, amnionitis, spontaneous abortion, still birth, and early-onset of the neonatal sepsis syndrome, evident at birth or shortly thereafter. Late-onset neonatal disease is likely due to infection at or around the time of birth, and presents as meningitis at one to several weeks of age [57].

Listeriosis is a rare disease; the incidence rate in 10 states participating in the Foodborne Diseases Active Surveillance Network (FoodNet) was 2.7 cases per 1,000,000 population in the year 2004 [58]. However, the incidence rate in susceptible subgroups is much higher. The rate among neonates younger than 28 days of age in FoodNet sites was 52.8 per 100,000 population in the year 2000 (CDC unpublished data). More importantly, listeriosis has a very high case fatality rate (20–30% in neonates) and is responsible for an estimated 500 deaths each year in the United States [59].

The food items implicated in outbreaks of listeriosis include ready-to-eat meats, such as turkey delicatessen meat [60], meat paté [61], pork tongue in jelly [62], hot dogs [63], and dairy products made from unpasteurized milk, in particular fresh soft cheeses [64].

Primary prevention for listeriosis focuses on improvements in food processing and on consumer education. Substantial efforts by the food industry and food regulatory agencies have been directed toward reducing the likelihood that high risk foods will be contaminated with L. monocytogenes [65]. Despite this, pregnant women, immunocompromised persons, and the elderly should be advised to avoid paté, fresh soft cheeses made from unpasteurized milk and to cook ready-to-eat foods such as hotdogs, delicatessen meats, and left over foods until steaming [66]. Information regarding these foods at high risk of contamination with Listeria can be incorporated into preconception care dietary recommendations.

For more information

CDC web sites

Toxoplasmosis: toxoplasmosis/default.htm


Listeria: listeriosis_g.htm

Publications for practitioners

Disclaimer: These references are included for information only. CDC has no control over the information in these articles. Views and opinions of these organizations are not necessarily those of CDC, the Department of Health and Human Services (HHS), or the U.S. Public Health Service (PHS).

American College of Obstetricians and Gynecologists. Perinatal viral and parasitic infections. ACOG Practice Bulletin 2000;20.

Brundage, SC. Preconception health care. American Family Physician. 2002 June; 65(12):2507–14.

Hanlin RB. Congenital infections and preconception counseling. J S C Med Assoc. 2002 Oct;98(6):277–80.


The findings and conclusions in this report have not been formally disseminated by the Centers for Disease Control and Prevention and should not be construed to represent any agency determination or policy.

Contributor Information

Danielle S. Ross, vog.cdc@3ssord.

Jeffery L. Jones, vog.cdc@senoJLJ.

Michael F. Lynch, vog.cdc@1hcnyLM.


1. Jones JL, Lopez A, Wilson M, Schulkin J, Gibbs R. Congenital toxoplasmosis: Review. Obstet Gynecol Surv 2001 May;56(5):296–305. [PubMed]
2. Lopez A, Dietz VJ, Wilson M, Navin TR, Jones JL. Preventing congenital toxoplasmosis. MMWR Recomm Rep 2000 Mar;49(RR-2):59–68. [PubMed]
3. Kravetz JD, Federman DG. Toxoplasmosis in pregnancy. Am J Med 2005 Mar;118(3):212–6. [PubMed]
4. Remington JS, McLeod R, Thulliez R, Desmonts G. Toxoplasmosis. In: Remington JS, Klein JO, editors. Infectious diseases of the fetus and newborn infants. 5th ed. Philadelphia: Saunders, 2001. p. 205–346.
5. Jones JL, Kruszon-Moran D, Wilson M, McQuillan G, Navin T, McAuley JB. Toxoplasma gondii infection in the United States: Seroprevalence and risk factors. Am J Epidemiol 2001 Aug;154(4):357–65. [PubMed]
6. Breugelmans M, Naessens A, Foulon W. Prevention of toxoplasmosis during pregnancy-an epidemiologic survey over 22 consecutive years. J Perinat Med 2004;32(3):211–4. [PubMed]
7. Pawlowski ZS, Gromadecka-Sutkiewicz M, Skommer J, Paul M, Rokossowski H, Suchocka E, Schantz PM. Impact of health education on knowledge and prevention behavior for congenital toxoplasmosis: The experience in Poznan, Poland. Health Educ Res 2001 Aug;16(4):493–502. [PubMed]
8. Carter AO, Gelmon SB, Wells GA, Toepell AP. The effectiveness of a prenatal education programme for the prevention of congenital toxoplasmosis. Epidemiol Infect 1989 Dec;103(3):539– 45. [PMC free article] [PubMed]
9. Stray-Pedersen B. Prevention of congenital toxoplasmosis in Norway. Arch Pediatr 2003;10:23–4. [PubMed]
10. Gilbert R, Gras L. Effect of timing and type of treatment on the risk of mother to child transmission of Toxoplasma gondii. BJOG 2003 Feb;110(2):112–20. [PubMed]
11. Wallon M, Liou C, Garner P, Peyron F. Congenital toxoplasmosis: systematic review of evidence of efficacy of treatment in pregnancy. BMJ 1999 Jun;318(7197):1511–4. [PMC free article] [PubMed]
12. Olliaro P. Congenital toxoplasmosis. Clin Evid 2002 Jun;(7):623–6. [PubMed]
13. Gilbert RE, Gras L, Wallon M, Peyron F, Ades AE, Dunn DT. Effect of prenatal treatment on mother to child transmission of Toxoplasma gondii: Retrospective cohort study of 554 mother-child pairs in Lyon, France. Int J Epidemiol 2001 Dec;30(6):1303–8. [PubMed]
14. Thulliez P. Commentary: Efficacy of prenatal treatment for toxoplasmosis: a possibility that cannot be ruled out. Int J Epidemiol 2001 Dec;30(6):1315–6. [PubMed]
15. Foulon W, Villena I, Stray-Pedersen B, Decoster A, Lappalainen M, Pinon JM, Jenum PA, Hedman K, Naessens A. Treatment of toxoplasmosis during pregnancy: a multicenter study of impact on fetal transmission and children's sequelae at age 1 year. Am J Obstet Gynecol 1999 Feb;180(2 Pt 1):410–5. [PubMed]
16. Eskild A, Oxman A, Magnus P, Bjorndal A, Bakketeig LS. Screening for toxoplasmosis in pregnancy: What is the evidence of reducing a health problem? J Med Screen 1996;3(4):188–94. [PubMed]
17. Miron D, Raz R, Luder A. Congenital toxoplasmosis in Israel: to screen or not to screen. Isr Med Assoc J 2002 Feb;4(2):119– 22. [PubMed]
18. Mittendorf R, Pryde P, Herschel M, Williams MA. Is routine antenatal toxoplasmosis screening justified in the United States? Statistical considerations in the application of medical screening tests. Clin Obstet Gynecol 1999 Mar;42(1):163–73; quiz 174–5. [PubMed]
19. Bader TJ, Macones GA, Asch DA. Prenatal screening for toxoplasmosis. Obstet Gynecol 1997 Sep;90(3):457–64. [PubMed]
20. Gilbert RE, Peckham CS. Congenital toxoplasmosis in the United Kingdom: to screen or not to screen? J Med Screen 2002;9(3):135–41. [PubMed]
21. Peyron F, Wallon M. Options for the pharmacotherapy of toxoplasmosis during pregnancy. Expert Opin Pharmacother 2001 Aug;2(8):1269–74. [PubMed]
22. Ricci M, Pentimalli H, Thaller R, Rava L, Di Ciommo V. Screening and prevention of congenital toxoplasmosis: an effectiveness study in a population with a high infection rate. J Matern Fetal Neonatal Med 2003 Dec;14(6):398–403. [PubMed]
23. Guerina NG, Hsu HW, Meissner HC, Maguire JH, Lynfield R, Stechenberg B, Abroms I, Pasternack MS, Hoff R, Eaton RB, et al. Neonatal serologic screening and early treatment for congenital Toxoplasma gondii infection. The New England Regional Toxoplasma Working Group. N Engl J Med 1994 Jun;330(26):1858–63. [PubMed]
24. Weigel RM, Dubey JP, Siegel AM, Hoefling D, Reynolds D, Herr L, Kitron UD, Shen SK, Thulliez P, Fayer R, et al. Prevalence of antibodies to Toxoplasma gondii in swine in Illinois in 1992. J Am Vet Med Assoc 1995 Jun;206(11):1747–51. [PubMed]
25. Bahnson PB, Michalak MM, Miller GY. Pork producers’ attitudes, knowledge, and production practices that relate to on-farm food safety. J Food Prot 2001 Dec;64(12):1967–72. [PubMed]
26. Stagno S. Cytomegalovirus. In: Remington JS, Klein JO, editors. Infectious diseases of the fetus and newborn infant. Philadelphia: WB Saunders Company; 2001. p. 389–424.
27. Demmler G. Summary of a workshop on surveillance for congenital cytomegalovirus disease. Rev Infect Dis 1991;13:315– 29. [PubMed]
28. Stagno S, Dworsky ME, Torres J, Mesa T, Hirsh T. Prevalence and importance of congenital cytomegalovirus infection in three different populations. J Pediatr 1982 Dec;101(6):897– 900. [PubMed]
29. Kenneson, A. Review and meta-analysis of the epidemiology of congenital cytomegalovirus infection. presentation at Centers for Disease Control and Prevention: “New Directions in Prevention and Screening: Congenital CMV Infection.” Atlanta, GA, August 30, 2005.
30. Stagno S, Pass RF, Cloud G, Britt WJ, Henderson RE, Walton PD, Veren DA, Page F, Alford CA. Primary cytomegalovirus infection in pregnancy. Incidence, transmission to fetus, and clinical outcome. JAMA 1986 Oct;256(14):1904–8. [PubMed]
31. Britt WJ, Alford CA. Cytomegalovirus. 3rd ed. Fields B, Knipe D, Howley P, editors. Fields Virology. Vol. 3. Philadelphia: Lippincott-Raven Publishers; 1996. p. 2493–523.
32. Cannon MJ, Pellet PE. Risk of congenital cytomegalovirus infection. CID 2005;40:1701–2. [PubMed]
33. Revello MG, Zavattoni M, Baldanti F, Sarasini A, Paolucci S, Gerna G. Diagnostic and prognostic value of human cytomegalovirus load and IgM antibody in blood of congenitally infected newborns. J Clin Virol 1999;14(1):57–66. [PubMed]
34. Fowler KB, Stagno S, Pass RF. Maternal immunity and prevention of congenital cytomegalovirus infection. JAMA 2003 Feb;289(8):1008–11. [PubMed]
35. Boppana SB, Fowler KB, Pass RF, Rivera LB, Bradford RD, Lakeman FD, Britt WJ. Congenital cytomegalovirus infection: association between virus burden in infancy and hearing loss. J Pediatr 2005;146:817–23. [PubMed]
36. Taber LH, Frank AL, Yow MD, Bagley A. Acquisition of cytomegaloviral infections in families with young children: a serological study. J Infect Dis 1985 May;151(5):948–52. [PubMed]
37. Yeager AS. Transmission of cytomegalovirus to mothers by infected infants: another reason to prevent transfusion-acquired infections. Pediatr Infect Dis 1983 Jul;2(4):295–7. [PubMed]
38. Dworsky ME, Welch K, Cassady G, Stagno S. Occupational risk for primary cytomegalovirus infection among pediatric health-care workers. N Engl J Med 1983 Oct;309(16):950–3. [PubMed]
39. Yow MD, White NH, Taber LH, Frank AL, Gruber WC, May RA, et al. Acquisition of cytomegalovirus infection from birth to 10 years: a longitudinal serologic study. J Pediatr 1987 Jan;110(1):37–42. [PubMed]
40. Pass RF, Hutto C, Lyon MD, Cloud G. Increased rate of cytomegalovirus infection among day care center workers. Pediatr Infect Dis J 1990 Jul;9(7):465–70. [PubMed]
41. Pass RF, Kinney JS. Child care workers and children with congenital cytomegalovirus infection. Pediatrics 1985 May;75(5): 971–3. [PubMed]
42. Pass RF. Day care centers and transmission of cytomegalovirus: New insight into an old problem. Seminars in Pediatric Infectious Diseases 1990;1(2):245–51.
43. Pass RF, Hutto C. Group day care and cytomegaloviral infections of mothers and children. Rev Infect Dis 1986 Jul;8(4):599– 605. [PubMed]
44. Pass RF, Hutto SC, Reynolds DW, Polhill RB. Increased frequency of cytomegalovirus infection in children in group day care. Pediatrics 1984 Jul;74(1):121–6. [PubMed]
45. Pass RF, Hutto C, Ricks R, Cloud GA. Increased rate of cytomegalovirus infection among parents of children attending day-care centers. N Engl J Med 1986 May;314(22):1414–8. [PubMed]
46. Pass RF, Little EA, Stagno S, Britt WJ, Alford CA. Young children as a probable source of maternal and congenital cytomegalovirus infection. N Engl J Med 1987 May;316(22):1366–70. [PubMed]
47. Plotkin SA. Is there a formula for an effective CMV vaccine? J Clin Virol 2002;25:S13–S21. [PubMed]
48. Arvin AM, Fast P, Myers M, Plotkin S, Rabinovich R. Vaccine development to prevent cytomegalovirus disease: report from the National Vaccine Advisory Committee. Clin Infect Dis 2004 Jul;39(2):233–9. [PubMed]
49. Cannon MJ, Davis KF. Washing our hands of the congenital cytomegalovirus disease epidemic. BMC Public Health 2005 Jun;5(1):70. [PMC free article] [PubMed]
50. Onorato IM, Morens DM, Martone WJ, Stansfield SK. Epidemiology of cytomegaloviral infections: recommendations for prevention and control. Rev Infect Dis 1985 Jul;7(4):479–97. [PubMed]
51. Finney JW, Miller KM, Adler SP. Changing protective and risky behaviors to prevent child-to-parent transmission of cytomegalovirus. J Appl Behav Anal 1993;26(4):471–2. [PMC free article] [PubMed]
52. Adler SP, Finney JW, Manganello AM, Best AM. Prevention of child-to-mother transmission of cytomegalovirus by changing behaviors: a randomized controlled trial. Pediatr Infect Dis J 1996 Mar;15(3):240–6. [PubMed]
53. American College of Obstetricians and Gynecologists. Perinatal viral and parasitic infections. ACOG Practice Bulletin 2000;20.
54. Adler SP, Finney JW, Manganello AM, Best AM. Prevention of child-to-mother transmission of cytomegalovirus among pregnant women. J Pediatr 2004 Oct;145(4):485–91. [PubMed]
55. Fowler KB, Stagno S, Pass RF. Interval between births and risk of congenital cytomegalovirus infection. Clin Infect Dis 2004 Apr;38(7):1035–7. [PubMed]
56. Schuchat A, Swaminathan B, Broome CV. Epidemiology of human listeriosis. Clin Microbiol Rev 1991 Apr;4(2):169–83. [PMC free article] [PubMed]
57. Gellin BG, Broome CV. Listeriosis. JAMA 1989 Mar;261(9): 1313–20. [PubMed]
58. CDC. Preliminary FoodNet data on the incidence of infection with pathogens transmitted commonly through food-10 sites, United States, 2004. MMWR 2005;54:352–6. [PubMed]
59. Mead PS, Slutsker L, Dietz V, McCaig LF, Bresee JS, Shapiro C, et al. Food-related illness and death in the United States. Emerg Infect Dis 1999 Sep–1999 Oct;5(5):607–25. [PMC free article] [PubMed]
60. Gottlieb SL, Newbern EC, Griffin PM, Graves LM, Hoekstra RM, Baker NL, et al. Multistate outbreak of listeriosis linked to turkey deli meat and subsequent changes in US regulatory policy. Clin Infect Dis 2006 Jan;42(1):29–36. [PubMed]
61. McLauchlin J, Hall SM, Velani SK, Gilber RJ. Human Listeriosis and paté: A possible association. BMJ 1991 Sep;303(6805):773–5. [PMC free article] [PubMed]
62. Jacquet C, Catimel B, Brosch R, Buchrieser C, Dehaumont P, Goulet V, Lepoutre A, Veit P, Rocourt J. Investigations related to the epidemic strain involved in the French listeriosis outbreak in 1992. Appl Environ Microbiol 1995 Jun;61(6):2242–6. [PMC free article] [PubMed]
63. Mead PS, Dunne EF, Graves L, Wiedmann M, Patrick M, Hunter S, et al. Nationwide outbreak of listeriosis due to contaminated meat. Epidemiol Infect 2005 Dec;1:1–8. [PubMed]
64. Centers for Disease Control and Prevention. Outbreak of listeriosis associatred with homemade Mexocan style cheese-Update. North Carolina, October 2000–January 2001. MMWR 2001;50(26):560–2. [PubMed]
65. FDA/CDC. Reducing the risk of Listeria monocytogenes: Food and Drug Administration/Centers for Disease Control and Prevention. Update of the Listeria Action Plan is available at
66. Information regarding listeriosis is available at http://www.cdc. gov/ncidod/dbmd/diseaseinfo/listeriosis_g.htm.

Articles from Springer Open Choice are provided here courtesy of Springer