Erythema Infectiosum is disease caused by Human Parvovirus B19. Human Parvovirus B19 is of the family Parvoviridae and is not the same type of parvovirus that infects canines. This virus is species specific and only infects humans (1). Yvonne Cossart and a fellow worker in England first discovered the Human Parvovirus in 1975 (2). When viewing samples of blood, a Parvovirus like particle was contained in sample number B19, later discovered as the etiological agent of Erythema Infectiosum. Erythema Infectiosum is also known as 5th Disease because in 1905 Erythema Infectiosum was the 5th disease on a list of diseases (3).
5th Disease is transmitted to other individuals through person to person contact, through fomites, or through droplets (4). It is not known however, which of these modes of transmission is the primary mode. Fluids from the mouth or throat transmit the disease to others by coughing or sneezing or from sharing utensils or glasses (4). Transfusion of blood can also carry the disease and on some occasions, from pregnant women to their fetuses (1).
The disease most commonly infects children, but can also infect older teens and adults with slightly different symptoms. In children the disease begins with a mild fever, headache, mild respiratory symptoms, like stuffy or runny nose, very similar to the common cold (4,5). Then 6-11 days later a rash will appear, beginning on the face. After a few days the rash will spread to the trunk and extremities. The child will experience splotchy red skin over the entire body, which can appear as welps. Sometimes the rash will itch for older children and adults and the joints might ache and possibly swell for adults as well. One to three weeks after the rash appears it will clear up and disappear. Some types of stimuli can aggravate the rash like sunlight, stress, heat or exercise (1,5).
The disease can be tested for in a few different ways including a blood test and nucleic acid hybridization. A doctor can usually diagnose it as 5th disease simply by the characteristic rash and other previous signs, but a blood test would have to be done to confirm it (6,7). If IgM antibody to B19 is detected in the blood, this suggests the person has had a recent infection of Human Parvovirus B19. In nucleic acid hybridization Human Parvovirus B19 can be identified in serum, leukocytes, respiratory secretions and tissue specimens. Sometimes light and electron microscopy can aid in diagnoses of the virus (1).
The virus infects and lyses erythroid precursor cells and normal red blood cell production is interrupted (1). People with normal hematopoiesis show red blood cell aplasia that clinically is inapparent. However, with those with anemia or immune disease, the disease can be much more serious. The virulence of the virus is due mostly to the fact that it can go undetected (8). The disease is only contagious before the rash appears and once it is present the virus can not be transmitted to others. Therefore it is masked as a simple cold during its contagious time and then about 20% of the people that carry the virus never experience a rash, unaware they have it, and transmitting it to many
others.
Treatment for the disease is very minor. Normally for the symptoms experienced at the beginning of infection like fever and stuffy nose, over the counter medications are sufficient (3). However, there is no cure for the virus since it can not be treated with antibiotics and no treatment is known for the rash (4,5).
5th Disease can not be prevented since there is no vaccine, although one is being experimented with (1). The disease must just run its natural course and since it is not normally a serious disease, this is usually not a problem (4). However, if the person infected does have immune problems or anemia, the doctor should be seen immediately to start treatment. No studies have been done to examine whether decontaminating toys or washing hands would decrease the spread of the disease, but it is hypothesized that this would help in preventing it (1).
1. [Anonymous]. Current Trends Risks Associated with Human Parvovirus B19 Infection. 2/17/89. Website:http://www.cdc.gov/mmwr/preview/mmwrhtml/0001348.htm. Visited 11/29/00.
2. [Anonymous]. Human Parvovirus B19 (B19V) Introduction. 2000. Website: http://www.biotrin.ie/lab/parvo/page1.html. Visited 12/1/00.
3. Tortora, Gerard J., Funke, Berdell R., & Case, Christine L. Microbiology: An Introduction. California: Addison Wesley; 1998. P. 572.
4. [Anonymous]. Fifth Disease. Website: http://www.lambtonhealth.on.ca/cdci/5th_disease.htm. Visited 11/29/00.
5. [Anonymous]. Fifth Disease. 2000. Website: http://kidshealth.org/parent/infections/sin/fifth_prt.htm. Visited 11/30/00.
6. [Anonymous]. Fifth Disease. 2000. Website: http://www.cdc.gov/ncidod/diseae/parvovirus/B19.htm. Visited 11/29/00.
7. Jensen, Inge Panum. Parvovirus B19 Infections. 1997. Website: http://www.ssi/dk/en/epi-nyt.uk/1997/uge24a.txt. Visited 11/29/00.
8. [Anonymous]. Viral Diseases. 2000. Wesbsite: http:// www.fiu.edu/~sully/micro/spring2000/viraldiseases.html