Vertically transmitted infection 1

Vertically transmitted infection

Perinatal infectionClassification and external resources

Micrograph of cytomegalovirus (CMV) infection of the placenta (CMV placentitis), a vertically transmitted infection. The characteristic largenucleus of a CMV infected cell is seen off-centre at the bottom-right of the image. H&E stain.

ICD-10 P35 [1]-P39 [2]

ICD-9 771 [3]

A vertically transmitted infection is an infection caused by bacteria, viruses or, in rare cases, parasites transmitteddirectly from the mother to an embryo, fetus or baby during pregnancy or childbirth. It can occur when the mothergets an infection as an intercurrent disease in pregnancy.Nutritional deficiencies may exacerbate the risks of perinatal infection.

ClassificationThe transmission can also be called mother-to-child transmission.A vertically transmitted infection can be called a perinatal infection if it is transmitted in the perinatal period, whichis the period starting at a gestational age of 22[4] to 28[5] weeks (with regional variations in the definition) and ending7 completed days after birth.The term congenital infection can be used if the vertically transmitted infection persists after childbirth.

ExamplesSeveral vertically transmitted infections are included in the TORCH complex, which stands for:1. T – Toxoplasmosis / Toxoplasma gondii2. O – Other infections (see below)3. R – Rubella4. C – Cytomegalovirus5. H – Herpes simplex virus-2 or neonatal herpes simplexThe "other agents" under O include:•• Coxsackievirus• Chickenpox (caused by varicella zoster virus)•• Parvovirus B19•• Chlamydia

Vertically transmitted infection 2

•• HIV•• Human T-lymphotropic virus•• SyphilisHepatitis B may also be classified as a vertically transmitted infection, but the hepatitis B virus is a large virus anddoes not cross the placenta, hence it cannot infect the fetus unless there have been breaks in the maternal-fetalbarrier, such as can occur in bleeding during childbirth or amniocentesis.[6]

The TORCH complex was originally considered to consist of the four conditions mentioned above, with the "TO"referring to "Toxoplasma". The four-term form is still used in many modern references, and the capitalization"ToRCH" is sometimes used in these contexts. The acronym has also been listed as TORCHES, forTOxoplasmosis, Rubella, Cytomegalovirus, HErpes simplex, Syphilis.A further expansion of this acronym, CHEAPTORCHES, was proposed by Ford-Jones and Kellner in 1995:• C – Chickenpox and shingles• H – Hepatitis B, C, (D), E• E – Enteroviruses• A – AIDS (HIV infection)• P – Parvovirus B19• T – Toxoplasmosis / Toxoplasma gondii• O – Other (Group B Streptococcus, Listeria, Candida, Lyme disease)• R – Rubella• C – Cytomegalovirus• H – Herpes simplex• E – Everything else sexually transmitted (Gonorrhea, Chlamydia, Ureaplasma urealyticum, Human

papillomavirus)• S – Syphilis

Signs and symptomsThe signs and symptoms of a vertically transmitted infection depend on the individual pathogen. It may cause subtlesigns such as a influenza-like illness and may not even be noticed by the mother during the pregnancy. In such cases,the effects may be seen first at birth.Symptoms of a vertically transmitted infection may include fever and poor feeding. The newborn is often small forgestational age. A petechial rash on the skin may be present, with small reddish or purplish spots due to bleedingfrom capillaries under the skin. An enlarged liver and spleen (hepatosplenomegaly) is common, as is jaundice.However, jaundice is less common in Hepatitis B because a newborn's immune system is not developed well enoughto mount a response against liver cells, as would normally be the cause of jaundice in an older child or adult. Hearingimpairment, eye problems, mental retardation, autism, and death can be caused by vertically transmitted infections.The mother often has a mild infection with few or no symptoms.It is possible for genetic conditions (Aicardi-Goutieres syndrome) to present in a similar manner.

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CausesThe main routes of transmission of vertically transmitted infections are across the placenta (transplacental) andacross the female reproductive tract during childbirth:

TransplacentalThe embryo and fetus have little or no immune function. They depend on the immune function of their mother.Several pathogens can cross the placenta and cause (perinatal) infection. Often microorganisms that produce minorillness in the mother are very dangerous for the developing embryo or fetus. This can result in spontaneous abortionor major developmental disorders. For many infections, the baby is more at risk at particular stages of pregnancy.Problems related to perinatal infection are not always directly noticeable.

During childbirthBabies can also become infected by their mother during birth. Some infectious agents may be transmitted to theembryo or fetus in the uterus, while passing through the birth canal or even shortly after birth. The distinction isimportant because when transmission is primarily during or after birth, medical intervention can help preventinfections in the infant.During birth, babies are exposed to maternal blood and body fluids without the placental barrier intervening and tothe maternal genital tract. Because of this, blood-borne microorganisms (Hepatitis B, HIV), organisms associatedwith sexually transmitted disease (e.g., Gonorrhoea and Chlamydia), and normal fauna of the genito-urinary tract(e.g., Candida) are among those commonly seen in infection of newborns.

Pathophysiology

Virulence versus symbiosisIn the spectrum of optimal virulence, vertical transmission tends to evolve benign symbiosis. It is therefore a criticalconcept for evolutionary medicine. Because a pathogen's ability to pass from parent to child depends significantly onthe hosts' ability to reproduce, pathogens' transmissibility tends to be inversely related with their virulence. In otherwords, as pathogens become more harmful to and thus decrease the reproduction rate of their host organism, they areless likely to be passed on to the hosts' offspring, since there will be fewer offspring.Although AIDS is sometimes transmitted through perinatal transmission, its virulence can be accounted for by thefact that its primary mode of transmission is not vertical. Moreover, medicine has further decreased the frequency ofvertical transmission of AIDS. The incidence of perinatal AIDS cases in the United States has declined as a result ofthe implementation of recommendations on HIV counselling and voluntary testing practices and the use ofzidovudine therapy by providers to reduce perinatal HIV transmission.The price paid in the evolution of symbiosis is, however, great: for many generations, almost all cases of verticaltransmission will continue to be pathological—in particular if there are any other routes of transmission. It takesmany generations of random mutation and selection to evolve symbiosis. During this time, the vast majority ofvertical transmission cases will exhibit the initial virulence.[citation needed]

In Dual Inheritance Theory, vertical transmission refers to the passing of cultural traits from parents to children.

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DiagnosisWhen physical examination of the newborn shows signs of a vertically transmitted infection, the examiner may testblood, urine, and spinal fluid for evidence of the infections listed above. Diagnosis can be confirmed by culture ofone of the specific pathogens or by increased levels of IgM against the pathogen.

Treatment and prevention

Micrograph of a pap test showing changes(upper-right of image) associated with herpes

simplex virus, a vertically transmitted infection.

Some of the vertically transmitted infections, such as toxoplasmosisand syphilis, can be effectively treated with antibiotics if the mother isdiagnosed early in her pregnancy. Many of the viral verticallytransmitted infections have no effective treatment, but some, notablyrubella and varicella-zoster, can be prevented by vaccinating themother prior to pregnancy.

If the mother has active herpes simplex (as may be suggested by a paptest), delivery by Caesarean section can prevent the newborn fromcontact, and consequent infection, with this virus.

It has been suggested that IgG2 antibody can play crucial role inprevention of intrauterine infections and currently extensive research isgoing on for developing IgG2 based therapies for treatment andvaccination.[7]

Prognosis

Each type of vertically transmitted infection has a different prognosis. The stage of the pregnancy at the time ofinfection also can change the effect on the newborn.

Additional images

CMV placentitis. CMV placentitis.

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References[1] http:/ / apps. who. int/ classifications/ icd10/ browse/ 2010/ en#/ P35[2] http:/ / apps. who. int/ classifications/ icd10/ browse/ 2010/ en#/ P39[3] http:/ / www. icd9data. com/ getICD9Code. ashx?icd9=771[4] Definitions and Indicators in Family Planning. Maternal & Child Health and Reproductive Health. (http:/ / test. cp. euro. who. int/ document/

e68459. pdf) By European Regional Office, World Health Organization. Revised March 1999 & January 2001. In turn citing: WHO Geneva,WHA20.19, WHA43.27, Article 23

[5][5] Singh, Meharban (2010). Care of the Newborn. p. 7. Edition 7. ISBN 9788170820536[6] Hepatitis B (http:/ / www. who. int/ csr/ disease/ hepatitis/ whocdscsrlyo20022/ en/ index1. html) by World Health Organization (WHO),

retrieved November, 2011[7] • Syal K* and Karande AA. IgG2 Subclass Isotype Antibody and Intrauterine Infections. Current Science Vol. 102, No. 11, 10 June 2012.

Article Sources and Contributors 6

Article Sources and ContributorsVertically transmitted infection  Source: http://en.wikipedia.org/w/index.php?oldid=597568411  Contributors: Arcadian, Arthena, DadaNeem, Emble64, Facts707, Herbee, KillerChihuahua,Kirtimaansyal, LT910001, Lucien504, Mikael Häggström, Qetuth, SingleIntegral, TenPoundHammer, Una Smith, Wouterstomp, 3 anonymous edits

Image Sources, Licenses and ContributorsFile:CMV placentitis1_mini.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:CMV_placentitis1_mini.jpg  License: Creative Commons Attribution-Sharealike 3.0  Contributors:NephronImage:Herpes simplex virus pap test.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Herpes_simplex_virus_pap_test.jpg  License: Creative Commons Attribution-Sharealike 3.0 Contributors: NephronImage:CMV_placentitis1.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:CMV_placentitis1.jpg  License: Creative Commons Attribution-Sharealike 3.0  Contributors: NephronImage:CMV_placentitis2.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:CMV_placentitis2.jpg  License: Creative Commons Attribution-Sharealike 3.0  Contributors: Nephron

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