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UNSW Embryology

Abnormal Development - Parvovirus

© Dr Mark Hill (2008)

Acknowledgements

Introduction

Human parvovirus B19 (Latin, parvo = poor), infection is also called "fifth disease" and occurs mainly in children. Pets (dogs and cats) have their own animal parvoviruses that do not infect humans.

Parvovirus B19 (B19V) is the only member of the Parvoviridae family known to cause disease in humans and is a single-strand 5,594 nucleotide DNA Class II virus (More? Genome). The virions have a diameter of 22-25 nm and are transmitted by respiratory secretions between humans and can also cross the placenta. Virus replication requires help from either host cells or other viruses.

Page Links: Introduction | Some Recent Findings | Fifth Disease | B19 | Genome | Hydrops Fetalis | Parvovirus B19 and pregnancy? | References | WWW Links | Glossary

Fifth Disease

The term "fifth disease" arose due to this being the fifth in a group of once-common childhood diseases (the other four are measles, rubella, scarlet fever and Dukes' disease) that all have similar rashes.

B19

Yvonne Cossart

Professor Yvonne Cossart (University of Sydney, Bosch Professor of Infectious Diseases)

Yvonne Cossart coined the nomenclature "B19", from the well on a microtitre plate where the virus antigen was first discovered in blood (Cossart etal., 1975). Microtitre plates are generally organised by rows (alphabetically) and columns (numerically).

"A parvovirus-like antigen has been found in sera of nine healthy blood-donors and two patients. Its pathogenicity is unknown, but 30% of adults possess specific antibody. The new agent can be confused with hepatitis-B antigen both morphologically and serologically." Cossart YE, Field AM, Cant B, Widdows D. Parvovirus-like particles in human sera. Lancet. 1975 Jan 11;1(7898):72-3.

Parvovirus Genome

The complete genomic sequence of Human parvovirus B19 is now known and is a single-stranded DNA virus 5,594 nucleotides in length.

Lineage: Viruses; ssDNA viruses; Parvoviridae; Parvovirinae; Erythrovirus; Human parvovirus B19

Links: Parvovirus B19 Sequence | Parvovirus B19 Genome | The Universal Virus Database - Parvovirus B19

Hydrops Fetalis

"Parvovirus B19 infection in a pregnant woman, followed by transplacental transmission to the fetus, can lead to miscarriage or hydrops fetalis. Parvovirus infects the fetal liver, the site of erythrocyte production during early development. The swollen appearance in hydrops is the result of severe anemia and perhaps also myocarditis, both of which contribute to congestive heart failure. Thrombocytopenia may accompany severe anemia. Seroprevalence data indicate that about half of pregnant women are susceptible to parvovirus infection.

...The estimated risk of transplacental infection among women who are infected with parvovirus B19 during pregnancy is 30 % , with a 5 - 9 % risk of fetal loss. Infection during the second trimester poses the greatest risk of hydrops fetalis. Parvovirus B19 probably accounts for 10 - 20 % of all cases of nonimmune hydrops fetalis.

... The risk of infection is highest in epidemic years and is correlated with the extent of contact the pregnant woman had with children.

Most parvovirus B19 infections during pregnancy do not lead to loss of the fetus."

(Above text extract from review: Young NS, Brown KE. Parvovirus B19. N Engl J Med. 2004 Feb 5;350(6):586-97.)

"...Studies showed that the hepatic period of hematopoietic activity was correlated with the critical period of maternal infection, which suggested that B19 might have affinity for erythroid lineage cells at the stage of hematopoiesis."

(Text extract from review: Yaegashi N. Pathogenesis of nonimmune hydrops fetalis caused by intrauterine B19 infection. Tohoku J Exp Med. 2000 Feb;190(2):65-82.)

NSW Health

Parvovirus B19 and pregnancy?

"Usually there is no serious complication for a pregnant woman or her baby following exposure to a person with fifth disease. About 50 per cent of women are already immune to parvovirus B19, and these women and their babies are protected from infection and illness. Even if a woman is susceptible and gets infected with parvovirus B19, she usually experiences only a mild illness. Likewise, her unborn baby usually does not have any problems attributable to parvovirus B19 infection.

Sometimes, however, parvovirus B19 infection will cause the unborn baby to have severe anemia and the woman may have a miscarriage. This occurs in less than five per cent of all pregnant women who are infected with parvovirus B19 and occurs more commonly during the first half of pregnancy.

There is no evidence that parvovirus B19 infection causes birth defects or mental retardation.

There is no universally recommended approach to monitor a pregnant woman who has a documented parvovirus B19 infection. Some doctors treat a parvovirus B19 infection in a pregnant woman as a low-risk condition and continue to provide routine prenatal care. Other physicians may increase the frequency of doctor visits and perform blood tests and ultra-sound examinations to monitor the health of the unborn baby. The benefit of these tests in this situation, however, is not clear.

If the unborn baby appears to be ill, there are special diagnostic and treatment options available, and your obstetrician will discuss these options with you and their potential benefits and risks."

(Text extract from: NSW Health (Australia) Parvovirus B19 and Fifth Disease, also available as PDF document in several languages)

References

Reviews | Articles | Search NCBI Bookshelf | Search PubMed

Reviews

Lopez-Bueno A, Villarreal LP, Almendral JM. Parvovirus variation for disease: a difference with RNA viruses? Curr Top Microbiol Immunol. 2006;299:349-70.

Young NS, Brown KE. Parvovirus B19. N Engl J Med. 2004 Feb 5;350(6):586-97.

Heegaard ED, Brown KE. Human parvovirus B19. Clin Microbiol Rev. 2002 Jul;15(3):485-505.

Yaegashi N. Pathogenesis of nonimmune hydrops fetalis caused by intrauterine B19 infection. Tohoku J Exp Med. 2000 Feb;190(2):65-82.

Articles

Chow SS, Craig ME, Jacques CF, Hall B, Catteau J, Munro SC, Scott GM, Camaris C, McIver CJ, Rawlinson WD. Correlates of placental infection with cytomegalovirus, parvovirus B19 or human herpes virus 7. J Med Virol. 2006 Jun;78(6):747-56.

Mendelson E, Aboudy Y, Smetana Z, Tepperberg M, Grossman Z. Laboratory assessment and diagnosis of congenital viral infections: Rubella, cytomegalovirus (CMV), varicella-zoster virus (VZV), herpes simplex virus (HSV), parvovirus B19 and human immunodeficiency virus (HIV). Reprod Toxicol. 2006 May;21(4):350-82.

Krishnamurti L, Lanford L, Munoz R. Life threatening parvovirus B19 and herpes simplex virus associated acute myocardial dysfunction in a child with homozygous sickle cell disease. Pediatr Blood Cancer. 2006 May 12

Cossart YE, Field AM, Cant B, Widdows D. Parvovirus-like particles in human sera. Lancet. 1975 Jan 11;1(7898):72-3.

Search NCBI Bookshelf: Bookshelf - Parvovirus | Medical Microbiology - Parvovirus

Medical Microbiology Parvovirus

Search PubMed: Search May 2006 "Human Parvovirus" 3,269 reference articles of which 510 were reviews. Search term = Human Parvovirus

WWW Links

CDC Publications (USA) Parvovirus B19 Infection and Pregnancy | Parvovirus B19 (Fifth Disease)

NSW Public Health Bulletin (Australia) FactSheet: Parvovirus B19 and 'fifth disease' | FactSheet: Parvovirus B19 and 'fifth disease' (Volume 11 Number 5 (May 2000) page 83) (PDF document)

Victorian Infectious Disease Reference Laboratory Parvovirus B19

International Committee on Taxonomy of Viruses Parvovirus B19

Glossary of Terms

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

Other Infections

Below is a list of some known maternal (then fetal) infections that impact upon neurological development.

Only a very brief overview is given, for more details see Abnormal Development Notes or the listed internal and external links.

Cytomegalovirus

Viral infection causes systemic infection and extensive brain damage and cell death by necrosis.

NCBI Bookshelf (external link) Medical Microbiology: Cytomegalovirus | Search Medical Microbiology "Cytomegalovirus"

Herpes Simplex Virus

Viral infection causes systemic infection and extensive brain damage and cell death by necrosis.

NCBI Bookshelf (external link) Search Medical Microbiology "Herpes Simplex Virus"

Purulent Meningitus

Bacterial infection by E. coli or streptocci B. can cause vascular thrombosis involving choroid plexus which can effect CSF flow, and can cause hydrocephalus.

NCBI Bookshelf (external link) Search Medical Microbiology "Purulent Meningitus"

Toxoplasmosis

Toxoplasma infection causes random necrosis throughout the brain and can cause hydrocephalus.

NCBI Bookshelf (external link) Medical Microbiology: 84. Toxoplasma Gondii | Figure 84-1. Girl with hydrocephalus due to congenital toxoplasmosis. | Search Medical Microbiology "Toxoplasmosis"

Australian NHMRC Recommendations

The Australian NHMRC (1988) recommends neonates be assessed for follow-up care under the following conditions.

(see the NHMRC WWW Page)

Congenital abnormalities

These developmental abnormalities usually involve only small DNA mutations affecting individual or a few genes, two exceptions are the major chromosomal abnormalities usualy trisomy; trisomy 21 (Down syndrome) and trisomy 18 (Edwards syndrome) (also trisomy 9, 13, 15). Note that the occurance of chromosomal abnormalities also increases with increasing maternal age. There are many pamphlets providing information about prenatal diagnosis (see NSW State Health Publication Checking your baby's health before birth).

Finally

Each section of the notes covering early development and specific systems contain references to specific abnormalities (on Page 2 of each notes section). The best source for Australian statistical data is the Australian Institute of Health and Welfare National Perinatal Statistics Unit, UNSW which publishes "Congenital Malformations Australia" every 2 years. Be aware that some congenital abnormalities, by their nature, affect multiple systems. In the USA, the Center for Disease Control (CDC) keeps and publishes relevant statistical information. A very difficult issue in abnormal development are the many different Ethical implications.

This current page is a link to Normal and Abnormal Development and Population Data.

Where to Next?

You should look at normal development. Development Notes

Alternatively, go on to look at Systematic Development of organs and tissues.

Quick Links

Finally

For those wanting to see dynamic processes of development (and have a reasonably quick connection) then the Movies pages are good for watching changes occur.

Other Embryos

The study of human development has relied extensively on studying the process in other model animals. For those wanting to see the process of development in other species then the other embryos pages are a good start.

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