Human parvovirus B19: a review of clinical and epidemiological aspects in Brazil

Since the first evidence of human parvovirus B19 (B19V) infection in late 80s, several studies have been conducted to clarify the spectrum of clinical diseases in Brazil. B19V infection is prevalent in the general population and has exhibited a cyclical pattern of occurrence every 4–5 years, with the predominance of genotype 1 over 3b. During epidemic periods the wide range of clinical conditions, such as ertythema infectiosum, arthropathy, transient aplastic crisis, nonimmune hydrops fetalis and B19V-hepatitis were diagnosed. However, many infections are likely asymptomatic or have a self-limiting clinical course and are not readly diagnosed. Besides, the similarity of the symptoms of ertythema infectiosum to other rash diseases and the broadly circulation of arboviruses makes differential diagnosis more difficult. In this article, we provide a historical comprehensive overview of the research on parvovirus B19 conducted in Brazil, with a focus on the clinical and epidemiological aspects of the infection.

Leukoerythroblastosis as an Unusual Presentation of Parvovirus B19 Infection in a Sickle Cell Patient

Parvovirus B19 infection in pediatrics most commonly causes fifth disease, a mild viral illness. Hematologic manifestations include severe anemia, especially in patients with chronic hemolytic anemias or who are immunocompromised. Because of the shortened life span of erythrocytes in patients with sickle cell disease, parvovirus infection can cause transient aplastic crisis which can be life-threatening. However, leukocytosis and thrombocytosis are rarely seen. We report leukoerythroblastosis as an unusual presentation of acute parvovirus B19 infection in a previously splenectomized 12-year-old boy with sickle cell disease.

Parvovirus B19

Parvovirus B19 (B19V) is a small DNA virus that replicates in erythroid progenitor cells, with virus-induced cytotoxicity stopping red cell production. It only infects humans, is endemic in most places, and is transmitted predominantly by the respiratory route. In healthy people it causes the rash illness, erythema infectiosum, also known as ‘fifth disease’ or ‘slapped cheek disease’, associated with minimal drop in haemoglobin, but in patients with increased red cell turnover (e.g. haemolytic anaemia or haemoglobinopathy), it causes transient aplastic crisis; in immunocompromised patients it causes chronic anaemia; and following maternal infection it leads to hydrops fetalis or fetal loss. Treatment is supportive in most instances, but reduction in iatrogenic immunosuppression and/or intravenous immunoglobulin may be appropriate in some cases. No vaccine is available.

Observations on human parvovirus B19 infection diagnosed in 2011

Introduction: The incidence of human parvovirus B19 infection is unknown. Aim: A retrospective analysis of clinical and laboratory findings was carried out in patients diagnosed with human parvovirus B19 infection in 2011 in a virologic laboratory of a single centre in Hungary. Methods: Clinical and laboratory data of patients with proven human parvovirus B19 infection were analysed using in- and out-patient files. Results: In 2011, 72 patients proved to have human parvovirus B19 infection with the use of enzyme immunoassay. The clinical diagnoses of these patients were as follows: human parvovirus B19 infection (30.6%), transient aplastic crisis (16.7%), arthritis (8.3%) and acute hepatitis (4.1%). Symptoms of each of the four phases of the infection occurred in various combinations with the exception of the monophase of cheek exanthema. This occurred without the presence of other symptoms in some cases. Leading symptoms and signs were exanthema (in 74.6% of cases), haematological disorders (in 69% of cases), fever (in 54.9% of cases) and arthritis (in 33.8% of cases). Several atypical dermatological symptoms were also observed. Acute arthritis without exanthema was noted in 8 patients. Of the 72 patients with proven human parvovirus B19 infection there were 7 pregnant women, and one of them had hydrops foetalis resulting spontaneous abortion. In 16 patients (22.5%) human parvovirus B19 IgG was undetectable despite an optimal time for testing. Conclusion: The observations of this study may contribute to a better recognition of clinical symptoms of human parvovirus B19 infection. Orv. Hetil., 2012, 153, 1948–1957.