Molecular and phylogenetic analyses of human Parvovirus B19 isolated from Brazilian patients with sickle cell disease and β‐thalassemia major and healthy blood donors

Abstract

Human Parvovirus B19 (B19V) is a recognized cause of life-threatening conditions among patients with hemoglobinopathies. This study investigates B19V infection in patients with sickle cell disease and β-thalassemia using different experimental approaches. A total of 183 individuals (144 with sickle cell disease and 39 with β-thalassemia major) and 100 healthy blood donors were examined for B19V using anti-B19V IgG enzyme immunoassay, quantitative PCR, DNA sequencing, and phylogenetic analysis. Viremia was documented in 18.6% of patients and 1% of donors, and was generally characterized by low viral load (VL); however, acute infections were also observed. Anti-B19V IgG was detected in 65.9% of patients with sickle cell disease and in 60% of donors, whereas the patients with thalassemia exhibited relatively low seroreactivity. The seroprevalence varied among the different age groups. In patients, it progressively increased with age, whereas in donors it reached a plateau. Based on partial NS1 fragments, all isolates detected were classified as subgenotype 1A with a tendency to elicit genetically complex infections. Interestingly, quasispecies occurred in the plasma of not only patients but also donors with even higher heterogeneity. The partial NS1 sequence examined did not exhibit positive selection. Quantitation of B19V with a conservative probe is a technically and practically useful approach. The extensive spread of B19V subgenotype 1A in patients and donors and its recent introduction into the countryside of the São Paulo State, Brazil were demonstrated; however, it is difficult to establish a relationship between viral sequences and the clinical outcomes of the infection.

Prevalence and Viral Load of Human Parvovirus B19 (B19V) Among Blood Donors in South-East Brazil

“…This result is not divergent from our previous observations, where B19V DNA was detected at the same percentage in an almost the same number of tested blood donors [2]. This prevalence is also similar to the data obtained in the USA (0.88 %) [8].…”

“…Clinical manifestations of B19V infection in children and adults may include erythema infectiosum (fifth disease) or arthropathy, nevertheless, great proportion of the infected individuals remain asymptomatic [1]. Therefore, in the general population B19V infections among blood donors can be considered a normal event and many of them have asymptomatic course [2,3]. A peculiar characteristic of B19V infection is that not always the virus is cleared and in many cases it can establish persistency in different body tissues [4].…”

“…Viral DNA was extracted from 140 ll of plasma using the QIAamp Viral RNA Mini Kit (QIAGEN, São Paulo, Brazil), extracting simultaneously viral RNA and DNA, following the manufactureŕs instructions. B19V detection and VL quantitation was performed using a previously described TaqMan Ò real-time PCR with sensitivity 10 B19V DNA copies/reaction and a wide order of magnitude [2]. In brief, the 25 ll volume reactions were run in duplicates using standard reaction conditions as implied by 7500 Real-Time PCR system (Life Technologies, São Paulo, Brazil).…”

Human parvovirus B19 in patients with beta thalassemia major from Tehran, Iran

“…Genotype III has been largely limited to Ghana, France, Brazil, and tropical areas in Africa [23]. For example, in one study in Brazil, the phylogenetic analysis demonstrated that all B19 isolates from patients with hemoglobinopathies were genotype I, confirming its widespread prevalence [24]. The connection between B19 genotypes and infection outcomes in patients with hemoglobinopathies is not yet known.…”

“…Of 183 patients, 144 and 39 patients were diagnosed with anemia and beta-thalassemia, respectively. The prevalence of parvovirus B19 DNA in 28 patients with sickle cell anemia and six beta-thalassemia patients were 19.4% and 15.3%, respectively [24]. In a survey of patients five to 25 years of age in Iran from 2004–2005, parvovirus B19 IgG antibodies were detected in 83.5% of men and 88% of women.…”