HUMAN PARVOVIRUS В19: VIRUS CHARACTERISTICS, DISTRIBUTION AND DIAGNOSTICS OF PARVOVIRUS INFECTION

[Parvovirus B19 infection in HIV-infected patients]

Here we provide a review of the literature and a description of our own clinical case. The patient was a 32-year-old woman who had been infected with HIV for 6 years without antiretroviral therapy. The test results showed CD4 87 cells/l, viral load 3750 copies/ml. Normochromic normocytic anemia and reticulocytopenia developed soon. In the myelogram, all erythroblasts were 0.5%. The viral load of parvovirus B19 DNA according to PCR was more than 9 million IU/ml. Pure red cell aplasia associated with parvovirus B19 was diagnosed. We started antiretroviral therapy with efavirenz, lamevudine and tenofovir. In addition to blood transfusions, we administered intravenous donor immunoglobulin with a dose increase from 5000 mg to 20 000 mg per day. After discontinuing of intravenous immunoglobulins, the laboratory test results were stable over the next 5 months: hemoglobin was more than 115 g/L, reticulocytes more than 3%, in the myelogram all erythroblasts were 21%. However, the elimination of parvovirus B19 wasnt achieved. The maximum decrease in viral load for parvovirus B19 was down to 720 IU/ml. A typical feature of the case was the lack of pure red cell aplasia of the bone marrow with the existing viral load of parvovirus B19. HIV infection progressed: 44 cells/l, viral load not determined. The case ended lethally.

[Results of a study of parvovirus B19 (Parvoviridae, Parvovirinae, Erythroparvovirus, Primate erythroparvovirus 1) prevalence and circulation activity in socially significant categories of the population]

Currently, along with the increasing need of medical organizations for blood preparations, algorithms for laboratory testing of blood donors are not available for all infections with hemo-contact mechanism of transmission. A representative example is infection caused by parvovirus В19.

PURPOSE OF THE STUDY

The article presents the results of the original study, the purpose of which was to study the prevalence of antibodies to parvovirus B19 and the activity of the circulation of this virus in socially important categories of the population.

MATERIAL AND METHODS

The materials of the study were blood samples from blood donors of Saint Petersburg, as well as parvovirus В19 sequences isolated from DNA-positive plasma samples.

RESULTS AND DISCUSSION

According to the results of the laboratory examination, a high proportion of carriers of virus-specific IgG antibodies was found in studied group of donors, which confirms the previous infection of parvovirus B19 in them and illustrates the high prevalence of infection in this socially significant group. Based on the results of the blood preparations testing, the presence of parvovirus DNA В19 in a significant number of samples was determined by polymerase chain reaction method. This indicates an current parvovirus infection in the examined donors and points to a high epidemiological risk of the blood products obtained from them. Sequencing and phylogenetic analysis of a fragment of the VP1 gene demonstrated that the studied isolates belonged to А1 genotype and its subtype 1А2, which correlates with the genotypes of parvovirus В19 circulating in the European Union and Asia. In addition, two previously unknown В19 parvovirus isolates were isolated, the nucleotide sequences of which were deposited into the international GenBank database.

CONCLUSION

Based on the results of the study, it is justified to include testing of blood samples for markers of В19 parvovirus infection in existing algorithms of laboratory examination of donors, which will ensure prevention of hemo-contact infection of blood recipients with parvovirus В19.