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Parvovirus Matthew Ward Maria De Arcos November 20, 2012 Parvovirus B19 (fifth disease) The first epidemic of this virus was in 1886. People named it the fifth disease, because it was the fifth disease known to caused a rash in children. 1. Measles 2. Scarlet fever 3. German measles 4. Duke's disease 5. Fifth disease (parvovirus B19) Parvovirus B19 was accidentally discovered in well 19 of plate B in England in 1974 while performing a screening test for Hepatitis B on a healthy blood donor. It was finally accepted in 1975. It infects mainly children who are at elementary level, but it can also infect adults. It has the highest incidence between winter and spring B19 Parvovirus Family: Parvoviridae Genus: Erythrovirus small ssDNA non-enveloped two capsids autonomous( doesn't require co-infection to cause infection) only infects human human is the natural host • • • • • • • It replicates in the nucleus of replicating erythroid cells (pronormoblast) in the bone marrow causing a cytopathic effect. It binds to the receptor Gb4Cer and co-receptor Ku80 of the pronormoblast. -"Infected cells contain enlarged cell nuclei with chromatin displaced to the marginal area." -Incubation time: 4-14 days -Can be asymptomatic or symptomatic Symptoms First symptoms: • Fever • Runny nose • Headache • Tiredness Secondary symptoms: • Rash: the rash starts on the face giving the appearance of “slapped cheeks” and later it may spread to the arms, legs, chest, back or buttocks . • Joint pain and swelling: known as polyarthropathy syndrome and is usually prominent in adult women • Temporary anemia -The interruption of the red cell maturation leads to reticulocytopenia in healthy individuals that last for about a week -The virus can cause Transient aplastic crisis in those individuals who are immunocompromised. -After the first sign of symptoms the immune system will develop IgM against the virus that could last between 8-10 weeks -IgG will also be developed lasting a lifetime. Case Study • Mrs. Doe brought her daughter to the pediatrician with the complaint of a rash. The daughter’s face appeared as if it had been slapped, but she had no fever or other notable symptoms. On questioning, Mrs. Doe reported that her daughter had had a mild cold within the previous 2 weeks and that she, herself, was currently having more joint pain than usual and was very tired. 1. What features of this history indicate a parvovirus B19 etiology? • • Parvovirus B19 only infects humans There were several symptoms that indicated a parvovirus B19 infection -Rash on cheeks -Had a mild “cold” recently -The mother was experiencing joint pain and fatigue • • • • Parvovirus causes erythema (reddening of the skin) on the cheeks, forehead, mouth, upper lip and nose The disease begins with cold-like symptoms prior to the rash Adults may develop seronegative arthritis resulting in joint pain Parvovirus infection can cause temporary anemia resulting in fatigue 2. Was the child infectious at presentation? If not, when was she contagious? • • • • • The child was not infectious at presentation Individuals are not contagious when the characteristic rash symptom becomes present However, the infection is contagious before this, such as during the “cold symptoms” stage The contagious period is variable, and is usually between four and twenty-eight days 3. What caused the symptoms? • • Viremia occurs during the first week of infection causing symptoms of malaise and fever The rash is thought to be immunologically mediated. It corresponds to the appearance of immunoglobulin M (IgM) in the serum. Recurrence of the rash may be provoked by sunlight, stress, or exercise. • • Parvovirus causes stiffness, and inflammation/swelling of joints. This causes arthropy in adults. Parvovirus can cause temporary anemia, resulting in weariness http://www.stanford.edu/group/virus/par vo/2005/B19.html http://www.humpath.com/IMG/jpg/parvo_inclusion_ 12_1.jpg 4. Were the symptoms of the mother and daughter related? • • • • Yes, the symptoms of the mother and daughter were very likely related Adults do not develop the characteristic rash that young children do Instead, many adults develop joint pain and may develop prolonged fatigue Child and mother contact is a common method of spread of the disease 5. What underlying condition would put the daughter at increased risk for serious disease after B19 infection? The mother? • There are several underlying conditions that would put individuals at an increased risk for serious disease after B19 infection o -Weak/compromised immune system o -Blood disorder such as sickle cell anemia o -Pregnancy • • • Individuals with weak immune systems are at risk for extended and severe symptoms of infection In individuals with chronic red blood cell disorders, such as sickle cell disease, infection may result in severe anemia, in which there is a deficiency of red blood cells or hemoglobin in the blood, resulting in pallor and fatigue Parvovirus B19 can cause a miscarriage in pregnant women by causing anemia in the unborn child 6. Why is quarantine a poor means of limiting the spread of B19 parvovirus? • • Quarantine is a poor means of limiting the spread of the disease because the characteristic symptoms do not appear while the disease is contagious During the contagious period, an individual may have cold-like symptoms, or may be asymptomatic References 1. Corcoran A., Doyle S. (2004). Advances in the biology, diagnosis and host-pathogen interactions of parvovirus B19. J Med Microbiol. 53(6) pp. 459-475. 2. Broliden K., Tolfvenstam T., Norbeck O. (2006). Clinical aspects of parvovirus B19 infection. J Intern Med. 260(4). pp. 285-304. 3. Servey J.T., Reamy B.V., Hodge J. (2007). Clinical presentations of parvovirus B19 infection. Am Fam Physician.75(3). pp.373-376. 4. Matano S, Kinoshita H, Tanigawa K, Terahata S, Sugimoto T. (2003). Acute parvovirus B19 infection mimicking chronic fatigue syndrome. Intern Med. 42(9). pp. 903-905. 5. Sabella C, Goldfarb J. (1999). Parvovirus B19 infections. Am Fam Physician. 60(5). pp.1455-1460. 6. Mayo Clinic http://www.mayoclinic.com/health/parvovirus-infection 1. National Center for Biotechnology Information http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001972/