Abnormal Development - Toxoplasmosis

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Toxoplasma tachyzoites

The causal agent of Toxoplasmosis is the protist Toxoplasma gondii (T. gondii). This unicellular eukaryote is a member of the phylum Apicomplexa which includes other parasites responsible for a variety of diseases (malaria, cryptosporidiosis). The diagnosis and timing of an infection are diagnostically based on serological tests. During a period of acute maternal infection, transplacental transmission can occur, and the rate of congenital toxoplasmosis with risk for severe fetal varies from 15 to 68%, depending on gestational age and the transmission rate is highest in the later stages of pregnancy. The congenital disease is characterized by a wide range of clinical manifestations (neurological, ophthalmological, and systemic involvement).

Toxoplasma gondii was initially described in 1908 in Tunis by Nicolle and Manceaux (1908) and in Brazil by Splendore (1908).[1] More recently, every 3 years experts from many areas meet at the "International Congress on Congenital Toxoplasmosis" (last held in 2010 Marseille France).

A recent survey identified a low infection knowledge among doctors and nurses providing prenatal care in an endemic region.[2]

Recent findings suggest that pre-pregnancy immunization against toxoplasmosis may not protect against reinfection by atypical strains.

Environmental Links: Introduction | low folic acid | iodine deficiency | Nutrition | Drugs | Australian Drug Categories | USA Drug Categories | thalidomide | herbal drugs | Illegal Drugs | smoking | Fetal Alcohol Syndrome | TORCH | viral infection | bacterial infection | fungal infection | zoonotic infection | toxoplasmosis | Malaria | maternal diabetes | maternal hypertension | maternal hyperthermia | Maternal Inflammation | Maternal Obesity | hypoxia | biological toxins | chemicals | heavy metals | air pollution | radiation | Prenatal Diagnosis | Neonatal Diagnosis | International Classification of Diseases | Fetal Origins Hypothesis
Abnormality Links: abnormal development | abnormal genetic | abnormal environmental | Unknown | teratogens | ectopic pregnancy | cardiovascular abnormalities | coelom abnormalities | endocrine abnormalities | gastrointestinal abnormalities | genital abnormalities | head abnormalities | integumentary abnormalities | musculoskeletal abnormalities | limb abnormalities | neural abnormalities | neural crest abnormalities | placenta abnormalities | renal abnormalities | respiratory abnormalities | hearing abnormalities | vision abnormalities | twinning | Developmental Origins of Health and Disease |  ICD-11
Historic Embryology  
1915 Congenital Cardiac Disease | 1917 Frequency of Anomalies in Human Embryos | 1920 Hydatiform Degeneration Tubal Pregnancy | 1921 Anencephalic Embryo | 1921 Rat and Man | 1966 Congenital Malformations

Some Recent Findings

  • Toxoplasmosis and horse meat, france[3] "Toxoplasma gondii parasites are obligate intracellular apicomplexans that can infect virtually all warm-blooded animals; felids are definitive hosts. The most common sources of human infection are ingestion of tissue cysts in undercooked meat or of food or water contaminated with oocysts shed by felids and transplacental transmission. Acquired toxoplasmosis in immunocompetent humans is frequently asymptomatic but is associated with cervical or occipital lymphadenopathy in approximately 10% of patients. Severe or fatal outcomes for immunocompetent patients have been attributed to the virulence of specific T. gondii genotypes (1). We describe 3 cases of toxoplasmosis caused by atypical strains probably acquired by from ingestion of raw horse meat imported from Canada and Brazil."
  • Seroprevalence of TORCH infections in women of childbearing age in Croatia.[4] "During 2005-2009, a seroepidemiological study was carried out in Croatia to define the population susceptible to common TORCH agents among pregnant and non-pregnant women of childbearing age. The IgG seroprevalence was 29.1% forT. gondii, 94.6% for rubella, 75.3% for cytomegalovirus (CMV), 78.7% for herpes simplex virus type 1 (HSV-1), and 6.8% for HSV-2. Acute toxoplasmosis and CMV infection (positive IgM antibodies with low IgG avidity) were documented in 0.25% and 0.09% women, respectively. IgM prevalence was 1.2% for both HSV-1 and HSV-2. None of the participants showed acute rubella infection. Seropositivity to T. gondii and HSV-2 varied significantly between age groups (p = 0.001 and p = 0.036, respectively). Women residing in rural regions showed a significantly higher seroprevalence rate for T. gondii, CMV, and HSV-1 than urban women (T. gondii: 44.0% vs. 25.4%, p < 0.001; CMV: 85.0% vs. 73.1%, p = 0.018; HSV-1: 86.0% vs. 76.4%, p = 0.041)."

Toxoplasmosis Lifecycle

Toxoplasmosis lifecycle

Toxoplasma Tachyzoites

Toxoplasma tachyzoites

European Congenital Toxoplasmosis Surveillance

See the recent 2008 article.[5]

  • Denmark - neonatal screening programme based on neonatal Guthrie card testing for toxoplasma-specific IgM was implemented in 1999 but discontinued on 31 July, 2007.
  • France - a surveillance system for congenital toxoplasmosis was initiated in May 2007.
  • Germany - congenital toxoplasmosis cases have been notifiable since 2001 implemented under the Protection Against Infection Act.
  • Italy - surveillance is confined to a regional programme in the Campania region initiated in 1997.
  • Bulgaria, Cyprus, Czech Republic, England and Wales, Estonia, Ireland, Latvia, Lithuania, Malta, Poland, Scotland, and Slovakia - surveillance (congenital or not), as defined by the European Union (symptomatic toxoplasmosis cases serologically confirmed) is considered a notifiable disease and subject to continuous data collection.

Ocular Toxoplasmosis

Clinical episodes of ocular toxoplasmosis can represent either acquire toxoplasmosis after birth or a reactivation of an infection that was acquired in utero.

Ocular toxoplasmosis is the commonest identifiable cause of posterior uveitis.

Links: PubMed Health - Uveitis


  1. Weiss LM & Dubey JP. (2009). Toxoplasmosis: A history of clinical observations. Int. J. Parasitol. , 39, 895-901. PMID: 19217908 DOI.
  2. da Silva LB, de Oliveira Rde V, da Silva MP, Bueno WF, Amendoeira MR & de Souza Neves E. (2011). Knowledge of toxoplasmosis among doctors and nurses who provide prenatal care in an endemic region. Infect Dis Obstet Gynecol , 2011, 750484. PMID: 21747644 DOI.
  3. Pomares C, Ajzenberg D, Bornard L, Bernardin G, Hasseine L, Darde ML & Marty P. (2011). Toxoplasmosis and horse meat, France. Emerging Infect. Dis. , 17, 1327-8. PMID: 21762609 DOI.
  4. Vilibic-Cavlek T, Ljubin-Sternak S, Ban M, Kolaric B, Sviben M & Mlinaric-Galinovic G. (2011). Seroprevalence of TORCH infections in women of childbearing age in Croatia. J. Matern. Fetal. Neonatal. Med. , 24, 280-3. PMID: 20476874 DOI.
  5. Bénard A, Petersen E, Salamon R, Chêne G, Gilbert R & Salmi LR. (2008). Survey of European programmes for the epidemiological surveillance of congenital toxoplasmosis. Euro Surveill. , 13, . PMID: 18445459


Montoya JG & Remington JS. (2008). Management of Toxoplasma gondii infection during pregnancy. Clin. Infect. Dis. , 47, 554-66. PMID: 18624630 DOI.

Montoya JG & Liesenfeld O. (2004). Toxoplasmosis. Lancet , 363, 1965-76. PMID: 15194258 DOI.

Jones J, Lopez A & Wilson M. (2003). Congenital toxoplasmosis. Am Fam Physician , 67, 2131-8. PMID: 12776962

Stegmann BJ & Carey JC. (2002). TORCH Infections. Toxoplasmosis, Other (syphilis, varicella-zoster, parvovirus B19), Rubella, Cytomegalovirus (CMV), and Herpes infections. Curr Womens Health Rep , 2, 253-8. PMID: 12150751


da Silva LB, de Oliveira Rde V, da Silva MP, Bueno WF, Amendoeira MR & de Souza Neves E. (2011). Knowledge of toxoplasmosis among doctors and nurses who provide prenatal care in an endemic region. Infect Dis Obstet Gynecol , 2011, 750484. PMID: 21747644 DOI.

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Search Pubmed: Toxoplasmosis | Maternal Toxoplasmosis

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Cite this page: Hill, M.A. (2019, September 20) Embryology Abnormal Development - Toxoplasmosis. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Abnormal_Development_-_Toxoplasmosis

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© Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G