ABSTRACT
Early detection of human Parvovirus B19 and better understanding of the pathology of the infection will help at reducing the burden of the disease in sickle cell disease patients. Infection by viruses such as human parvovirus B19 amongst others are widely reported as contributing to high morbidity and mortality among sickle cell disease patients worldwide. Three genotypes of B19V with their subtypes are in existence: genotype 1 (subtype 1A and 1B), genotype 2 (A6 and Lali-like) and genotype 3 (subtypes 3A and 3B). The aim of this study was to determine the epidemiological and molecular characterization of human parvovirus B19 as well as evaluate some haematological profile of sickle cell disease patients in Edo State that are infected with human Parvovirus B19.
A total of 400 participants consisting of 300 sickle cell disease patients (134 males and 166 females) and 100 apparently healthy participants (38 males and 62 females) with haemoglobin genotype AA that served as controls were enrolled for this study. The age of the participants ranged from 1 to 54 years. Venous blood of about 8mls was collected from each participant and used to detect human parvovirus B19 using enzyme linked immunosorbent assay (ELISA) by SERION ELISA classic parvovirus B19 IgG and IgM, Partec Gmbh, Wuzburg, Germany, full blood count was also estimated using Sysmex KX-21N haematology auto-analyzer. B19V genomic DNA was extracted from IgM positive samples using a previously described method for DNA extraction. The extracted DNA was used as a template for the detection of parvovirus B19 DNA in a nested PCR procedure. PCR products positive after the agarose gel electrophoresis were purified and sequenced for genotype analysis. The results of the sequences were read by CLC main workbench 5.5 programs and the consensus sequences were aligned with MEGA version 5.2 using the Clustal Wallis algorithm method against parvovirus B19 reference sequences obtained from Genbank (using the BLAST Database program maintained by the National Centre for Biotechnology Information (to find close evolutionary relatives). Paired distances were also calculated.
An overall prevalence of B19V IgM of 27.3% and B19V IgG of 34.7% was observed in this study. Age, educational levels and seasonal variation significantly influenced the prevalence of B19V infection among SCD patients (P<0.0001, P=.0.033 and P=0.007 respectively). Also, gender, marital status, family type, location of residence and religion did not significantly affect the prevalence of B19V infection among SCD patients (P=0.870, P=0.540, P=0.856, P= 0.556 and P=0.617). There was no statistical significance difference between socio demographic and associated risk factors and B19V infection among the study participants. This study found no significant relationship between the haematological profile (History of blood transfusion, Platelet count and PCV) of SCD patients and B19V infection (P=0.580, P= 0.931 and P=0.116). The level of Knowledge, Attitude and Practice of SCD was low among our study population.Two genotypes of B19V were recovered – genotype 1 (54.5%) and genotype 3 (45.5%) among SCD patients. Subtype 1A of genotype 1 was identified in our study.Strict compliance with standard quality assurance procedures in screening of whole blood and pooled plasma before transfusion to SCD patients, as well as more awareness as to how SCD is acquired is stongly advocated. Establishment of designated training and genetic counseling centers on SCD with adequate resource staff will prove effective in improving public health knowledge about SCD especially among the trait carriers.
