الفهرس 
Parvovirus B19Only 14 pages are availabe for public view
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Abstract
Human parvovirus B19 is a small non-enveloped DNA virus
belonging to the genus Erythrovirus, Family Parvoviridae. Although, it
generally causes self-limiting conditions in healthy people, B19V
infections may have a different outcome in patients with inherited
haemolytic anaemia. In such high-risk individuals, the high-titer replication
may result in bone marrow suppression, triggering a life threatening drop
of hemoglobin values leading to profound anaemia & may be aplastic crisis. There is a vicious circle between parvovirus B19 infections and the occurance of aplastic crisis.
The objective of this study was to detect parvovirus B19 DNA and its IgG antibodies in the serum of children with chronic haemolytic anaemia and in apparently healthy children in Benha University Hospitals.
This study was carried out in Medical Microbiology and Immunology Department, Benha Faculty of Medicine. It was conducted on 80 children. Forty of them with chronic haemolytic anaemia, were subdivided into 2 groups: group (Ia) included 20 patients without history of aplastic crisis& group (Ib) included 20 patients with a history of aplastic crisis. The other 40 children, age and sex-matched with apparently healthy children, represented the control group (group II). All patients were subjected to full history taking, clinical examination and laboratory investigations. Parvovirus B19 IgG was measured using anti-parvovirus B19 ELISA kits, and the parvovirus B19 DNA was detected by using nested-polymerase chain reaction.
In the present study; males with chronic haemolytic anaemia
without history of aplastic crisis (60%) and with a history of aplastic crisis
(70%) were more than females in both groups. The highest mean age
was in chronic anaemia patients with a history of aplastic crisis 7.2
±2.9.
In the present study, children with splenectomy were (55% in
group Ia and 80% in group Ib) more than those with splenomegaly in both
groups.
According to the current study, there were statistical significant differences (p=0.061) between three groups regarding IgG positivity, the prevalence of anti-parvovirusB19 IgG in children with chronic haemolytic anaemia without history of aplastic crisis was 50% and the prevelance in children with chronic haemolytic anaemia with a history of aplastic crisis was 45%. In apparently healthy children in this study, anti-parvovirus B19 IgG antibodies were 17.5%. There were no statistical significant differences (p=0.91) between different types of anaemia regarding prevalence of anti-parvovirus B19 IgG.
In the present study; there was a significant positive correlation between level of anti-parvovirus B19 IgG with age (r=0.228, P value = 0.04) ,a highly significant positive correlation with frequency of blood transfusion (r=0.472 , P value = 0.000) , mean corpuscular hemoglobin concentration (MCHC) (r=0.313 , P value = 0.005), red cell distribution width (RDW) (r=0.297 , P value = 0.008) , white blood cells count (WBCs) (r= 0.299 , P value = 0.007) and platelets count (r=0.337 , P value = 0.002). There was a highly significant negative correlations between the level of anti-parvovirus B19 IgG with hemoglobin level (Hb) (r=-0.319, P value = 0.004) and red blood cells count (RBCs) (r=-0.286, P value = 0.01). However, There was insignificant correlation with age of starting blood transfusion (r=0.078, P value = 0.63), mean corpuscular volume (MCV) (r=0.199, P value = 0.07) and mean corpuscular hemoglobin (MCH) (r=0.109, P value = 0.33).
In group Ia; DNA was detected in 2 patients (10%). Sex patients in group Ib out of 20 (30%) had detectable DNA. While in control group; no detectable DNA. There were highly statistical significant differences among the three groups (P value=0.001).
There were no statistical significant differences in number of PCR positive patients among different types of anaemia.
from this study, it was concluded that:
1) All children with chronic haemolytic anaemias should be screened for the presence of parvovirus B19.
2) Direct detection of DNA by PCR needs to be performed along with serology in these children for a more reliable diagnosis of
parvovirus B19 infection.
3) Measures to avoid iatrogenic and nosocomial transmission have to be implemented including screening of donated blood for parvovirus B19 especially blood given to patients with hematological disorders.