Abnormal Development - TORCH Infections: Difference between revisions

From Embryology
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==Hepatitis==
==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.
| [[File:Hepatitis_B_virus.jpg|400px]]
| 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).
"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.
Virus particles measure 42nm in overall diameter and contain a 27nm diameter DNA-based core.
 
|}
[[File:Hepatitis_B_virus.jpg|400px]]


===Hepatitis Transmission Risk to the Fetus===
===Hepatitis Transmission Risk to the Fetus===
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Data: Hepatitis and reproduction<ref><pubmed>19007636</pubmed></ref>
Data: Hepatitis and reproduction<ref><pubmed>19007636</pubmed></ref>
:'''Links:''' [[Abnormal_Development_-_Hepatitis_Virus|Hepatitis Virus]]


==References==
==References==

Revision as of 11:40, 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

Toxoplasmosis lifecycle

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.

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


Viral Links: viral infection | TORCH | cytomegalovirus | hepatitis | HIV | parvovirus | polio | rubella virus | chickenpox | Lymphocytic Choriomeningitis Virus | Zika virus | human papillomavirus | rotavirus | West Nile virus | varicella virus | vaccination | zoonotic infection | environment
Historic Embryology - Viral 
1941 Rubella Cataracts | 1944 Rubella Defects
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

  • Seroprevalence of TORCH infections in women of childbearing age in Croatia.[1] "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)."
  • Routine TORCH screening is not warranted in neonates with subependymal cysts.[2] "Congenital infections are associated with a wide variety of clinical symptoms, including subependymal cysts (SEC). ...The co-occurrence of TORCH congenital infections in infants with SEC is rare. Routine TORCH screening in neonates with SEC does not seem warranted."

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
Toxoplasmosis lifecycle Toxoplasma tachyzoites

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


Links: Abnormal Development - Toxoplasmosis

Other Organisms

A general term covering a ranges of viruses: parvovirus, HIV, Epstein-Barr, herpes 6 and 8, varicella, syphilis, enterovirus.

Human immunodeficiency virus

<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.jpg Rubella virus.jpg
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.

Cytomegalovirus.jpg

Links: Cytomegalovirus

Hepatitis

Hepatitis B virus.jpg 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]


Links: Hepatitis Virus

References

  1. <pubmed>20476874</pubmed>
  2. <pubmed>20227842</pubmed>
  3. <pubmed>1879476</pubmed>
  4. <pubmed>19007636</pubmed>

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

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, March 28) Embryology Abnormal Development - TORCH Infections. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Abnormal_Development_-_TORCH_Infections

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G