Is Parvovirus B19 Infection A Serious Problem & Can It Be Reversed?

Parvovirus b19 is a widespread infection with varying immunological and hematological manifestations in the affected individuals.(1)

Parvovirus b19 is known to cause prolonged epidemics of erythema infectiosum, especially in school-aged children.(2)

Is Parvovirus B19 Infection A Serious Problem?

Human parvovirus b19 leads to an acute infection that is usually self-limiting and mostly asymptomatic. The most common manifestation is erythema infectiosum, which is also known as the fifth disease characterized by mild symptoms of fever, malaise and myalgia, followed by a biphasic rash. The affected individual will present with a bright red malar eruption on the cheeks that is known as the ‘slapped cheek syndrome’ with circumoral pallor. This rash is followed by a maculopapular rash on the extremities and trunk, which fades to a reticular appearance and often recurs, transiently for weeks. In adult women, the parvovirus b19 infection causes polyarthralgia or arthritis that mostly affects the peripheral joints lasting around 1-3 weeks or more.(2)

Can Parvovirus B19 Infection Be Reversed?

The parvovirus primarily infects the erythroid precursors that lead to hemolytic anemia, which is a subclinical condition that can be spontaneously reversed in normal people. In people with increased red cell turnover, as seen in the case of sickle cell anemia, the virus can lead to an acute plastic crisis. This condition can be life-threatening, but due to the normal defense mechanism can be limited in most cases. However, in individuals who are immunocompromised, the virus can cause chronic infection along with pancytopenia or red cell aplasia. In the case of fetal infection, it is usually benign and self-limiting, but in a few cases, severe anemia and hydrops fetalis can occur in the second semester.(2)

Most cases of erythema infectiosum resolve on its own, requiring no treatment, while some patients with b19 induced arthralgia to need symptomatic treatment with anti-inflammatory drugs. The transient aplastic crisis due to b19 parvovirus can be managed by bringing the hemoglobin level to optimal concentrations by erythrocyte transfusion. In pregnant seronegative women, the infection should be monitored by ultrasound examinations conducted weekly along with cardiocentesis and intrauterine transfusions. This is an effective therapy that has successfully lowered cases of hydrops fetalis. Effective therapy for persistent b19 infection requires the use of immunoglobulin infusion that is capable of neutralizing antibodies in the majority of the adult population exposed to the virus.(1)

Prevention of b19 parvovirus infection can be initiated by universal testing of the virus with b19 screening of blood components for children, especially with malignancies to bring down cases of death. Also, the assaying of b19 is essential to diagnose cases of ALL and HIV to avoid subsequent diagnostic uncertainty in immunocompromised patients.(1)

Epidemiology And Risk Factors For Parvovirus B19 Infection

The parvovirus b19 is caused by the respiratory route, which leads to the onset of a rash immediately after contracting the infection. The incubation period for the infection is one to three weeks. The epidemics caused due to parvovirus b19 occur over extended periods. There is some evidence from recent studies in Victoria that states the two-yearly epidemic periods alternate with endemic periods of a similar period.

Young children are the most commonly affected age group, but it can also affect around 30-50% of adults. The highest number of infections can be seen in the age group of 5-9 years while 60% of women in the childbearing age of 20-39 years were immune to the virus.(2)

The rate at which the virus is going to infect children is directly proportional to the degree of exposure to the virus. The risk is greatest in women who have an infected child at home, i.e., in 50% of cases. In pregnant women, the fetal risk is limited to the first half of pregnancy. Fetal loss can occur if the mother is infected with the virus in the first 20 weeks. In approximately 3% of maternal infections between 9 to 20 weeks, fetal complications can be seen in the form of hydrops fetalis due to severe anemia and cardiac failure. Chronic congenital anemia has also been reported in children who have undergone intrauterine transfusion for hydrops fetalis.(1)

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