MST-Department of Medical Laboratory Sciences

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Browsing MST-Department of Medical Laboratory Sciences by Subject "Blood Transfusion Centre"

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    Genotypic Characterization of Hepatitis B Virus among Voluntary Blood Donors in Nairobi Regional Blood Transfusion Centre, Kenya
    (Kenyatta University, 2021) Aluora, Okoti Patrick; George Gachara; Margaret Muturi
    Hepatitis B virus (HBV) is one of the smallest DNA viruses that infects humans. Because of its ability to cause hepatocellular carcinoma (HCC), liver cirrhosis and hepatitis, HBV is one of the global causes of a high morbidity and consequently mortality. Most studies on HBV in Kenya have focused on its sero-epidemiology. HBV genome is prone to mutations which can lead to occult HBV infection that has been linked to Cirrhotic liver development and HCC. The mutations can also lead to drug resistance among individuals. The genotypic diversity within HBV results to varied characteristics from one genotype to another. To screen for HBV, the Kenya national blood transfusion services (KNBTS) use the chemiluminescent microparticle immunoassay (CMIA) method to detect the Hepatitis B surface antigen (HBsAg). This is a serological test that does not show the actual HBV presence in the blood or its genotypic traits. Those who may present with false negative results remain at risk of disease progression in future whose consequences may be liver cirrhosis or HCC. These HBV false negative donors may as well pass the infection to the recipients of their blood and blood products. This study sought to determine the HBV genetic diversity in Nairobi blood transfusion center among the voluntary blood donors and their susceptibility to anti-HBV drugs in current usage. The prevalence of occult HBV, overt HBV and the correlation between HBV infection and the demographic factors were also determined. Testing samples were collected in vacutainers at the point of donation. The samples were transported to the lab in cooler boxes. Sera and plasma were separated from plain and EDTA vacutainers respectively. Serum was used for testing for the HBsAg using CMIA method while the circulating genotypes were analyzed from the HBV DNA extracted from the plasma. The extracted genetic material was then subjected to a nested polymerase chain reaction (PCR) for amplification and sequencing done using Sanger’s method. The Circulating genotypes and P and S gene mutations were analyzed from the resulting sequences. Data analysis involved bivariate statistical analysis. Where p value <0.05, this was used to indicate association between HBV infection and demographic factors. A prevalence of 2.3% (7/300) overt HBV infection and 2.4% (7/293) occult HBV infection was reported. HBV infection and age, particularly age between 19-28 years, were significantly associated. Nine samples had HBV DNA; 7 HBsAg negative samples and 2 HBsAg positive samples. Several mutations were described among the samples including in the “a” determinant segment of the MHR as well as outside the S gene’s “a” determinant region. Sub genotype A1 was exclusively described in this population. Mutations were as well described in the P gene with varied resistance to several ʟ-nucleoside drugs. Occult HBV infections prevalence is high in this population due to the circulating mutations; an evidence that S gene mutations affect HBsAg detection. The study recommends the revision of the testing platform currently in use to incorporate molecular testing.