|Electron micrograph of Parvoviruses in blood|
|Group:||Group II (ssDNA)|
|Species:||Human parvovirus B19|
The B19 virus, generally referred to as parvovirus B19 or sometimes erythrovirus B19, was the first (and until 2005 the only) known human virus in the family of parvoviruses, genus erythrovirus; it measures only 23–26 nm in diameter. B19 virus is most known for causing disease in the pediatric population; however, it can also affect adults. It is the classic cause of the childhood rash called fifth disease or erythema infectiosum, or "slapped cheek syndrome." 
The virus was discovered by chance in 1975 by Australian virologist Yvonne Cossart. It gained its name because it was discovered in well B19 of a large series of microtiter plates labelled in this way.
Erythroviruses belong to the Parvoviridae family of small DNA viruses. It is a non-enveloped, icosahedral virus that contains a single-stranded linear DNA genome. Approximately equal proportions of DNA of positive and negative sense are found in separate particles. At each end of the DNA molecule there are palindromic sequences which form "hairpin" loops. The hairpin at the 3' end serves as a primer for the DNA polymerase. It is classified as erythrovirus because of its capability to invade red blood cell precursors in the bone marrow. Three genotypes (with subtypes) have been recognised.
In humans the P antigen (also known as globoside) is the cellular receptor for parvovirus B19 virus that causes Erythema infectiosum (fifth disease) in children. This infection is sometimes complicated by severe aplastic anemia caused by lysis of early erythroid precursors.
The virus is primarily spread by infected respiratory droplets; blood-borne transmission, however, has been reported. The secondary attack risk for exposed household persons is about 50%, and about half of that for classroom contacts.
Symptoms begin some six days after exposure (between 4 and 28 days, with the average being 16 to 17 days) and last about a week. Infected patients with normal immune systems are contagious before becoming symptomatic, but probably not after then. Individuals with B19 IgG antibodies are generally considered immune to recurrent infection, but reinfection is possible in a minority of cases. About half of adults are B19-immune due to a past infection.
Parvovirus B19 causes an infection in humans only. Cat and dog parvoviruses do not infect humans. There is no vaccine available for human parvovirus B19, though attempts have been made to develop one.
Role in disease
Fifth disease or erythema infectiosum is only one of several expressions of Parvovirus B19. The associated bright red rash of the cheeks gives it the nickname "slapped cheek syndrome". Any age may be affected, although it is most common in children aged six to ten years. It is so named because it was the fifth most common cause of a pink-red infection associated rash to be described by physicians (many of the others, such as measles and rubella, are rare now) .
Once infected, patients usually develop the illness after an incubation period of four to fourteen days. The disease commences with high fever and malaise, when the virus is most abundant in the bloodstream, and patients are usually no longer infectious once the characteristic rash of this disease has appeared. The following symptoms are characteristic:
- A usual brief viral prodrome with fever, headache, nausea, diarrhea.
- As the fever breaks, a red rash of the cheeks forms, with relative pallor around the mouth ("slapped cheek rash"), sparing the nasolabial folds, forehead, and mouth.
- "Lace-like,(reticular)" red rash on trunk or extremities then follows the facial rash. Infection in adults usually only involves the reticular rash, with multiple joint pain predominating.
- Exacerbation of rash by sunlight, heat, stress.
Teenagers or young adults may develop the so-called "Papular Purpuric Gloves and Socks Syndrome".
The rash of fifth disease is typically described as "slapped cheeks", with erythema across the cheeks and
Parvovirus B19 is a cause of chronic anemia in individuals who have AIDS. It is frequently overlooked. Treatment with erythropoetin or intravenous immunoglobulin have been helpful in some patients. The parvovirus infection may trigger an inflammatory reaction in AIDS patients who have just begun antiretroviral therapy.
In adults (and perhaps some children), parvovirus B19 can lead to a seronegative arthritis which is usually easily controlled with analgesics. Women are approximately twice as likely as men to experience arthritis after parvovirus infection. Possibly up to 15% of all new cases of arthritis are due to parvovirus, and a history of recent contact with a patient and positive serology generally confirms the diagnosis. This arthritis does not progress to other forms of arthritis. Typically joint symptoms last 1–3 weeks, but in 10–20% of those affected, it may last weeks to months.
Although most patients have an decrease of erythropoiesis (production of red blood cells) during parvovirus infection, it is most dangerous in patients who have sickle cell anemia or hereditary spherocytosis, and are therefore heavily dependent on erythropoiesis due to the reduced lifespan of the red cells. This is termed "aplastic crisis" (also called reticulocytopenia). It is treated with blood transfusion.
Parvovirus infection in pregnant women is associated with hydrops fetalis due to severe fetal anemia, sometimes leading to miscarriage or stillbirth. The risk of fetal loss is about 10% if infection occurs before pregnancy week 20 (especially between weeks 14 and 20), but minimal after then. Routine screening of the antenatal sample would enable the pregnant mother to determine the risk of infection. Knowledge of her status would allow the mother to avoid the risk of infection. The risk to the fetus will be reduced with correct diagnosis of the anemia (by ultrasound scans) and treatment (by blood transfusions). There is some evidence that intrauterine Parvovirus B19 infection leads to developmental abnormalities in childhood.
At the moment, there are no treatments that directly target the Parvovirus B19 virus. Intravenous immunoglobulin therapy (IVIG) therapy has been a popular alternative because doctors can administer it without stopping chemotherapy drugs like MEL-ASCT. Also, the treatment's side effects are rare as only 4 out of 133 patients had complications (2 had acute renal failure and 2 had pulmonary edema) even though 69 of the patients had organ transplants and 39 of them were HIV positive. This is a large improvement over administering Rituximab. The monoclonal antibody against the CD20 protein has been shown to cause acute hepatitis, neutropenia via Parvovirus B19 reactivations, and even persistent Parvovirus B19 infection. However, it is important to note that IVIG therapy is not perfect as 34% of treated patients will have a relapse after 4 months.
- Servey JT, Reamy BV, Hodge J (February 2007). "Clinical presentations of parvovirus B19 infection". Am Fam Physician 75 (3): 373–376. PMID 17304869.
- Kahn JS, Kesebir D, Cotmore SF, et al. (July 2008). "Seroepidemiology of human bocavirus defined using recombinant virus-like particles". J. Infect. Dis. 198 (1): 41–50. doi:10.1086/588674. PMID 18491974.
- Vafaie J, Schwartz RA (2004). "Parvovirus B19 infections". Int J Dermatol 43 (10): 747–749. doi:10.1111/j.1365-4632.2004.02413.x. PMID 15485533.
- Sabella C, Goldfarb J (October 1999). "Parvovirus B19 infections". Am Fam Physician 60 (5): 1455–60. PMID 10524489. Retrieved 2009-11-06.
- Heegaard ED, Brown KE (2002). "Human parvovirus B19". Clin. Microbiol. Rev. 15 (3): 485–505. doi:10.1128/CMR.15.3.485-505.2002. PMC 118081. PMID 12097253.
- Cossart YE, Field AM, Cant B, Widdows D (1975). "Parvovirus-like particles in human sera". Lancet 1 (7898): 72–73. doi:10.1016/S0140-6736(75)91074-0. PMID 46024.
- Brown KE (2004). "Variants of B19". Dev Biol (Basel) 118: 71–77. PMID 15645675.
- G. Siegl and P. Cassinotti, Parvoviruses Chapter 14, Topley and Wison's Microbiology and Microbial Infections, Vol. 1, Virology, 1998 pp. 261-280
- Molenaar-de Backer MW, Lukashov VV, van Binnendijk RS, Boot HJ, Zaaijer HL (2012) Global co-existence of two evolutionary lineages of parvovirus B19 1a, different in genome-wide synonymous positions. PLoS One 7(8):e43206
- Pattison JR, Patou G (1996). Parvoviruses. In: Barron's Medical Microbiology (Barron S et al., eds.) (4th ed.). Univ of Texas Medical Branch. ISBN 0-9631172-1-1.
- Young NS, Brown KE (February 2004). "Parvovirus B19". N Engl J Med 350 (6): 586–597. doi:10.1056/NEJMra030840. PMID 14762186.
- Corcoran A, Doyle S (2004). "Advances in the biology, diagnosis and host-pathogen interactions of parvovirus B19". J Med Microbiol 53 (Pt 6): 459–75. doi:10.1099/jmm.0.05485-0. PMID 15150324.
- Lehmann HW, von Landenberg P, Modrow S (2003). "Parvovirus B19 infection and autoimmune disease". Autoimmun Rev 2 (4): 218–223. doi:10.1016/S1568-9972(03)00014-4. PMID 12848949.
- Servey JT, Reamy BV, Hodge J (February 2007). "Clinical presentations of parvovirus B19 infection". Am Fam Physician 75 (3): 373–376. PMID 17304869. Retrieved 2009-11-06.
- Ballou WR, Reed JL, Noble W, Young NS, Koenig S (2003). "Safety and immunogenicity of a recombinant parvovirus B19 vaccine formulated with MF59C.1". J Infect Dis 187 (4): 675–8. doi:10.1086/368382. PMID 12599085.
- Lamont RF, Sobel JD, Vaisbuch E, Kusanovic JP, Mazaki-Tovi S, Kim SK, Uldbjerg N, Romero R (January 2011). "Parvovirus B19 infection in human pregnancy". BJOG : an International Journal of Obstetrics and Gynaecology 118 (2): 175–86. doi:10.1111/j.1471-0528.2010.02749.x. PMC 3059196. PMID 21040396.
- Santonja C, Nieto-González G, Santos-Briz Á, Gutiérrez Zufiaurre Mde L, Cerroni L, Kutzner H, Requena L (December 2011). "Immunohistochemical detection of parvovirus B19 in "gloves and socks" papular purpuric syndrome: direct evidence for viral endothelial involvement. Report of three cases and review of the literature". The American Journal of Dermatopathology 33 (8): 790–5. doi:10.1097/DAD.0b013e318221bc41. PMID 22024574.
- Doldan Silvero AM, Acevedo-Gadea CR, Pantanowitz L, Dezube BJ, Johari V (June). "Images in HIV/AIDS. Unsuspected parvovirus B19 infection in a person with AIDS". The AIDS Reader 19 (6): 225–227.
- Fjaerli, H. O.; Vogt, H.; Bruu, A. L. (1991). "Human parvovirus B19 as the cause of aplastic crisis in hereditary spherocytosis". Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke 111 (22): 2735–2737. PMID 1658972.
- Beland, S. S.; Daniel, G. K.; Menard, J. C.; Miller, N. M. (1997). "Aplastic crisis associated with parvovirus B19 in an adult with hereditary spherocytosis". The Journal of the Arkansas Medical Society 94 (4): 163–164. PMID 9308316.
- Ergaz Z, Ornoy A (May 2006). "Parvovirus B19 in pregnancy". Reprod. Toxicol. 21 (4): 421–35. doi:10.1016/j.reprotox.2005.01.006. PMID 16580942.
- Nagel, Hélène T. C. MD; de Haan, Timo R. MD; Vandenbussche, Frank P. H. A. MD, PhD; Oepkes, Dick MD, PhD; Walther, Frans J. MD, PhD (2007). "Long-Term Outcome After Fetal Transfusion for Hydrops Associated With Parvovirus B19 Infection". Obstetrics & Gynecology 109 (1): 42–47. doi:10.1097/01.AOG.0000249611.67873.94 (inactive 2010-03-17). PMID 17197586. Retrieved 2010-01-30.
- Bassols, A. C. (2008). "Parvovirus B19 and the New Century". Clinical Infectious Diseases 46 (4): 537–539. doi:10.1086/526523. PMID 18194096.
- Katragadda, L.; Shahid, Z.; Restrepo, A.; Muzaffar, J.; Alapat, D.; Anaissie, E. (2013). "Preemptive intravenous immunoglobulin allows safe and timely administration of antineoplastic therapies in patients with multiple myeloma and parvovirus B19 disease". Transplant Infectious Disease: n/a. doi:10.1111/tid.12067. PMID 23578205.
- Crabol, Y.; Terrier, B.; Rozenberg, F.; Pestre, V.; Legendre, C.; Hermine, O.; Montagnier-Petrissans, C.; Guillevin, L.; Mouthon, L.; Groupe d'experts de l'Assistance Publique-Hôpitaux de Paris; Loic, G.; Annette, B.; Alain, F.; Bertrand, F.; Bertrand, G.; Amelie, L.; Isabelle, L.; Catherine, M.-P.; Luc, M.; Eric, O.; Nathalie, P.; Helene, S.; Tarek, S.; Hopital Ambroise, P.; Jean-Marie, L. P.; Bruno, F.; Bernard, C.; Thomas, P.; Francois, D.; Loic, G. et al. (2012). "Intravenous Immunoglobulin Therapy for Pure Red Cell Aplasia Related to Human Parvovirus B19 Infection: A Retrospective Study of 10 Patients and Review of the Literature". Clinical Infectious Diseases 56 (7): 968–977. doi:10.1093/cid/cis1046. PMID 23243178.
- Yang, S. H.; Lin, L. W.; Fang, Y. J.; Cheng, A. L.; Kuo, S. H. (2011). "Parvovirus B19 infection-related acute hepatitis after rituximab-containing regimen for treatment of diffuse large B-cell lymphoma". Annals of Hematology 91 (2): 291–294. doi:10.1007/s00277-011-1238-8. PMID 21538062.
- Klepfish, A.; Rachmilevitch, E.; Schattner, A. (2006). "Parvovirus B19 reactivation presenting as neutropenia after rituximab treatment". European Journal of Internal Medicine 17 (7): 505–507. doi:10.1016/j.ejim.2006.05.002. PMID 17098597.
- Hartmann, J. T.; Meisinger, I.; Kröber, S. M.; Weisel, K.; Klingel, K.; Kanz, L. (2006). "Progressive bicytopenia due to persistent parvovirus B19 infection after immunochemotherapy with fludarabine/cyclophosphamide and rituximab for relapsed B cell lymphoma". Haematologica 91 (12 Suppl): ECR49. PMID 17194655.