Abnormal Development - TORCH Infections: Difference between revisions
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Virus particles measure 42nm in overall diameter and contain a 27nm diameter DNA-based core. | Virus particles measure 42nm in overall diameter and contain a 27nm diameter DNA-based core. | ||
[[File: | [[File:Hepatitis_B_virus.jpg|400px]] | ||
===Hepatitis Transmission Risk to the Fetus=== | ===Hepatitis Transmission Risk to the Fetus=== |
Revision as of 10:38, 25 October 2012
Educational Use Only - Embryology is an educational resource for learning concepts in embryological development, no clinical information is provided and content should not be used for any other purpose. |
Introduction
Materal effects should really be called environmental (in contrast to genetic) removing the association of mother with the deleterious agent. Accepting this caveat, there are several maternal effects from lifestyle, environment and nutrition that can be prevented or decreased by change which is not an option for genetic effects.
Infections, collectively grouped under the acronym TORCH for Toxoplasmosis, Other organisms (parvovirus, HIV, Epstein-Barr, herpes 6 and 8, varicella, syphilis, enterovirus) , Rubella, Cytomegalovirus and Hepatitis. See related pages on Maternal Hyperthermia and Bacterial infections.
Finally, when studying this topic remember the concept of "critical periods" of development that will affect the overall impact of the above listed factors. This can be extended to the potential differences between prenatal and postnatal effects, for example with infections and outcomes.
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 | ||
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Some Recent Findings
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Toxoplasmosis
The causal agent of Toxoplasmosis is the protist Toxoplasma 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.
Toxoplasmosis lifecycle | Toxoplasma tachyzoites |
Recent findings suggest that pre-pregnancy immunization against toxoplasmosis may not protect against reinfection by atypical strains.
Other Organisms
A general term covering a ranges of viruses: parvovirus, HIV, Epstein-Barr, herpes 6 and 8, varicella, syphilis, enterovirus.
<pubmed>20539252</pubmed>
Links: Abnormal Development - Viral Infection
Rubella
Rubella virus (Latin, rubella = little red) is also known as "German Measles" due to early citation in German medical literature. Infection during pregnancy can cause congenital rubella syndrome (CRS) with serious malformations of the developing fetus. This association between infection and abnormal development was first identified in 1941.[3]The type and degree of abnormality relates to the time of maternal infection.
Infant rubella virus | Rubella virus (electron micrograph |
Cytomegalovirus
Human cytomegalovirus (HCMV, Greek, cyto = "cell", megalo = "large") or Human Herpesvirus 5 (HHV-5) is a member of the herpes virus family. A viral infection that causes systemic infection and extensive brain damage and cell death by necrosis. HCMV infection is ranked as one of the most common infections in adults, with the seropositive rates ranging from 60–99% globally. In Western countries, adults with advanced AIDS prior to the introduction of highly active antiretroviral therapy (HAART) this virus also a cause of blindness (CMV retinitis) and death in patients.
- Links: Cytomegalovirus
Hepatitis
Hepatitis (inflammation of the liver) is caused in humans by one of 7 viruses (A, B, C, D, E) with the 2 additional F has not been confirmed as a distinct genotype; and G is a newly described flavivirus.
"All of these viruses can cause an acute disease with symptoms lasting several weeks including yellowing of the skin and eyes (jaundice); dark urine; extreme fatigue; nausea; vomiting and abdominal pain. It can take several months to a year to feel fit again." (CDC text).
Virus particles measure 42nm in overall diameter and contain a 27nm diameter DNA-based core.
Hepatitis Transmission Risk to the Fetus
- Hepatitis A - Fetal transmission of virus occurs with extreme rarity.
- Hepatitis B - Can occur as a consequence of intrapartum exposure, transplacental transmission, and breastfeeding.
20%–30% of HBsAg-positive/HbeAg-negative women will transmit virus to their infants. 90% of HBsAg- and HBeAg-positive women will transmit virus to their infants. Immunoprophylaxis at birth with both HBIG and Hepatitis B vaccine within 12 hours of birth decreases the risk of transmission. Passive (HBIG) and active immunization is 85%–95% effective in preventing neonatal HBV infection.
- Hepatitis C - The overall risk of transmission is approximately 5%–10% with unknown maternal viral titers.
All pregnant women with HCV should have viral titers performed.
Data: Hepatitis and reproduction[4]
References
Reviews
<pubmed>12150751</pubmed> <pubmed>10073308</pubmed> <pubmed>10073301</pubmed> <pubmed>8198407</pubmed>
PMID1972489
Articles
<pubmed>20476874</pubmed> <pubmed>20348511</pubmed> <pubmed>18455090</pubmed> <pubmed>17657031</pubmed> <pubmed>16231309</pubmed>
Search Pubmed
June 2010 "TORCH Infections" All (183) Review (37) Free Full Text (18)
Search Pubmed: TORCH Infections | maternal infections | teratogens
Glossary Links
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Cite this page: Hill, M.A. (2024, April 27) Embryology Abnormal Development - TORCH Infections. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Abnormal_Development_-_TORCH_Infections
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G