Human parvovirus B19 is the causative agent of erythema infectiosum (rubella). The disease, which in itself is harmless, poses a potentially serious risk to the fetus in pregnant women. It is usually transmitted from person to person through virus-containing droplets that are transmitted when sneezing or coughing and through swab infections. In adults and children, the pathogen causes symptoms such as moderate fever, headache, runny nose or rash on the arms, legs and trunk. Children develop the characteristic redness of their cheeks. There is no specific antiviral therapy; it can only be treated symptomatically. Once you contract the virus, you are immune for life.