الفهرس 
The HCV life cycleOnly 14 pages are availabe for public view
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Abstract
HCV infection is the most common cause of chronic liver diseases (CLD) worldwide and can lead to cirrhosis and HCC. HCV infection has emerged as major public health problem in Egypt where the overall predicted number of truly infected individuals is more than five million. A potential risk factor can be identified in approximately 90% of people with HCV infection. In the remaining 10%, no recognized source of infection can be identified.
Laboratory diagnostic tests for HCV infection include serological assays for antibodies and molecular techniques for detecting virus particles. The main screening tests for anti-HCV include EIAs where the third generation of EIA (EIA-3) has specificity greater than 99%. However, despite improved sensitivity compared to EIA2 assays, EIA3 assays may miss a few RNA-positive patients.
In resource-challenged countries, the expense of currently available ELISA for blood screening results in a lack of or inconsistent testing of blood donations. In addition, transfusion services and laboratories are hampered by the generally poor specificity of anti-HCV screening assays. In settings where few blood donations are collected and equipment is unavailable or even when money is available to purchase the necessary equipment, the fluctuation of the power supply and the difficulties in maintaining and repairing equipment present yet another level of obstacles that cannot be under-estimated. These constraints carry us to identify diagnostic test kits that are rapid, sensitive, specific and affordable.
Rapid tests provide a flexible, practical, technically undemanding, relatively inexpensive approach to ensuring a safer blood supply and suitable in geographic areas with limited laboratory infrastructure.
The aim of the present study was to evaluate the effectiveness of rapid tests for the detection of HCV antibodies. This study was carried out through the period from July 2009 to February 2010. It included 100 blood donors (50 anti-HCV positive and 50 anti-HCV negative according to ELISA results) who attended the Blood Bank of the Medical Research Institute in Alexandria. The anti-HCV results of attendees were taken from blood bank records, and the samples were retested by ELISA technique to obtain the absorbance values. After taking the donor’s consent a thorough history taking was done including the important personal data (e.g. age, sex …) (Appendix 1) and were subjected to collection of blood sample which was tested for:
1- HCV antibodies by third-generation ELISA (Dialab HCV Ab ELISA test).
2- HCV antibodies by three rapid diagnostic tests:
• Indirect solid-phase EIA HCV test (Immunocomb II HCV )
• Immuno-chromatographic HCV test (ACON HCV one step test device)
• Flow-through HCV test (4th Generation HCV TRI-DOT )
3- HCV RNA by nested PCR technique.
The study revealed the following results:
1. The sensitivity of 98% and specificity of 100% were found with ACON HCV one step test device and 4th generation HCV TRI-DOT compared to third generation ELISA for detection HCV antibodies.
2. The sensitivity of 96% and specificity of 100% of ImmunoComb® II HCV compared to third generation ELISA for detection HCV antibodies
3. The sensitivity of 100% and specificity of 77% of third generation ELISA to detect the HCV antibodies compared to RT-PCR results
4. The sensitivity of 97% and specificity of 77% were found with ACON HCV one step test device and 4th generation HCV TRI-DOT to detect the HCV antibodies compared to RT-PCR results
5. The sensitivity of 97% and specificity of 78.5% of ImmunoComb® II HCV to detect the HCV antibodies compared to RT-PCR results
6. By simple logistic regression analysis among blood donors, age, residence and contact with anti-HCV positive family member were statistically significant( p< 0.05) risk factors associated with HCV seropositivity
7. By simple logistic regression analysis among blood donors, gender, marital status, surgery, accidental exposure to blood, antibilharzial treatment by injection and parenteral treatment(injection or infusion) were risk factors associated with HCV seropositivity but the difference was statistically insignificant( p>0.05)
8. By stepwise logistic regression analysis among blood donors, age(OR : 4.6 95% CI:1.7-11.9 ), accidental exposure to blood(OR : 6.4; 95% CI: 1.3–33.1) and contact with anti-HCV positive family member(OR : 10.8; 95% CI : 1.9–62.1) remained independently predictive for HCV seropositivity .
from the study it could be concluded that:
1. The performance of the three investigated rapid tests is comparable to the third generation ELISA with regards to sensitivity and specificity.
2. Sensitivity of the third generation ELISA was 100% compared to qualitative PCR
3. Age, accidental exposure to blood and contact with anti-HCV positive family member are statistically significant risk factors associated with anti-HCV seropositivity