Occult Hepatitis B virus infection in previously screened, blood donors in Ile-Ife, Nigeria: implications for blood transfusion and stem cell transplantation.

BACKGROUND: Hepatitis B virus (HBV) transmission through blood transfusion is reduced by screening for hepatitis B surface antigen (HBsAg). However this method cannot detect the presence of occult hepatitis B virus infection. This study sought to determine the prevalence of occult hepatitis B virus infection among blood donors in Ile-Ife, Nigeria. For the first time in Nigeria we employed an automated real-time PCR- method to investigate the prevalence of occult HBV in blood donors. METHODS: Blood donors screened with HBsAg immunochromatographic rapid test kits at the blood transfusion units of two hospitals and found to be negative were recruited into the study. Questionnaires to elicit risk factors for HBV infection were administered and then 10 ml of blood was collected from each donor. Plasma samples obtained from these HBsAg negative blood donors were screened again for HBsAg using an enzyme-linked immunosorbent assay (ELISA) method, and those found negative were screened for the presence of total antibody to the HBV core antigen (anti-HBc) using ELISA method. Those positive to anti-HBc were then tested for HBV DNA, using an automated real-time PCR method. RESULTS: Five hundred and seven blood donors found HBsAg negative by immunochromatographic rapid test kits at both blood transfusion units, were tested for HBsAg using ELISA and 5 (1 %) were HBsAg positive. The 502 found negative were tested for anti-HBc and 354 (70.5 %) were found positive implying previous exposure to HBV and 19 (5.4 %) of the 354 anti-HBc positive had HBV DNA signifying occult HBV infection. No risk factors were found to be associated with the presence of HBV DNA among those who tested positive. CONCLUSION: Occult HBV infection exists in blood donors in Ile-Ife, Nigeria and the use of HBsAg alone for screening prospective donors will not eliminate the risk of HBV transmission in blood transfusion or stem cell transplantation.

Detection of High-Risk Human Papillomavirus Genotypes Among HIV-Infected Women in Four States in Nigeria.

Introduction The World Health Organization states that almost all cervical cancer cases are linked to infection with high-risk human papillomaviruses transmitted through sexual contact. Implementing effective surveillance and preventive measures would enable the prevention of most cervical cancer cases, especially in HIV-infected women. Every year, about 12,000 women in Nigeria are diagnosed, with almost 8,000 deaths. HPV cervical cancer testing capacity is low in Nigeria. Testing scale-up and sensitization efforts across health facilities, including cervical tissue sample collection, are needed to reduce the cases of cervical cancer. This study aimed to assess the genotype-specific prevalence of clinically relevant high-risk HPV among women living with HIV in Nigeria. Methods A descriptive, cross-sectional study was conducted among adult HIV-infected women attending health facilities in four Nigerian states. From August to October 2022, cervical tissue was collected into PCR cell media, transported to the Nigerian Institute of Medical Research, and assayed for HPV presence and genotype using the Cobas 6800 System (Roche Diagnostics). Statistical analysis was conducted with Stata 2. Results A total of 4423 cervical swab samples were tested. The ages of women ranged from 18 to 72 years (mean 36.61±8.61). In our study, we found that 16.3% of participants tested positive for HPV. Among the high-risk HPV genotypes detected, HPV16 was present in 1.44% of participants, HPV18 in 1.29%, and other high-risk HPV (OHR-HPV) in 11.35%. Additionally, co-infections were observed, with 0.98% of participants testing positive for both HPV16 and OHR-HPV, 1.12% for HPV18 and OHR-HPV, and 0.12% for HPV16, HPV18, and OHR-HPV concurrently. However, 7.4% of the total results were deemed invalid. Conclusion OHR-HPV is prevalent among HIV-infected women across the north and west geopolitical zones of Nigeria. Policies and interventions geared towards curtailing the incidence of cervical cancer are fervently solicited.

Laboratory Optimization Tweaks for Sanger Sequencing in a Resource-Limited Setting.

Despite various challenges that hinder the implementation of high-tech molecular methods in resource-limited settings, we have been able to implement and achieve International Organization for Standardization 15189:2012 accreditation for genotypic HIV drug resistance testing in our facility. At the Center for Human Virology and Genomics, Nigerian Institute of Medical Research, Nigeria has recorded a high sequencing success rate and good quality sequence data. This was achieved by optimizing laboratory processes from 2008 to the current date. We have optimized sample preparation, RT-PCR, several post-PCR processes, and the cycle sequencing to improve the sensitivity of amplification even with limited plasma samples and low viral copy numbers. The optimized workflow maximizes output, minimizes reagent wastage, and achieves substantial cost savings without compromising the quality of the sequence data. Our performance at our last external quality assurance program is a testimonial to the efficiency of the workflow. For the 5-sample panel, each with 67-68 mutation points evaluated, we scored 100% for all 5 specimens. Our optimized laboratory workflow is thus documented to support laboratories and to help researchers achieve excellent results the first time and eliminate contamination while minimizing the wastage of costly sequencing reagents.

Comparison of the COBAS/Ampliprep Taqman and Amplicor HIV-1 monitor tests in Lagos, Nigeria.

BACKGROUND: The use of real-time Polymerase chain reaction (PCR) technology options is increasing in resource-limited settings because they are faster, improve assay sensitivity, have higher throughput, larger dynamic ranges and reduced rates of contamination. In 2010, UNAIDS ranked Nigeria as the second highest population of people living with HIV and AIDS (2.98 million people) in the world. OBJECTIVE: The objective of this study was to compare the analytical performances of the Amplicor HIV-1 Monitor (version 1.5) and the COBAS Ampliprep/Taqman (version 2.0) used in monitoring HIV disease progression in HIV-infected individuals. METHOD: In a cross-sectional study, HIV-1 RNA values obtained with the Amplicor HIV-1 monitor version 1.5 were compared with those of the COBAS/Ampliprep TaqMan HIV-1 version 2.0 in a routine clinical setting. Between May and November 2011, 176 plasma samples collected were analysed in parallel using both techniques. Data analysis was done using statgraphics Centurion XVI and Medcalc version 12.0. RESULT: The correlation coefficient for the two assays was 0.83 and the level of agreement using a Bland-Altman plot was 94.2%. CONCLUSION: These findings suggest that the results from the two methods were comparable, hence the COBAS/Ampliprep Taqman version 2.0 is recommended for high-volume laboratories.

Experience of quality management system in a clinical laboratory in Nigeria.

ISSUES: Quality-management systems (QMS) are uncommon in clinical laboratories in Nigeria, and until recently, none of the nation's 5 349 clinical laboratories have been able to attain the certifications necessary to begin the process of attaining international accreditation. Nigeria's Human Virology Laboratory (HVL), however, began implementation of a QMS in 2006, and in 2008 it was determined that the laboratory conformed to the requirements of ISO 9001:2000 (now 2008), making it the first diagnostic laboratory to be certified in Nigeria. The HVL has now applied for the World Health Organization (WHO) accreditation preparedness scheme. The experience of the QMS implementation process and the lessons learned therein are shared here. DESCRIPTION: In 2005, two personnel from the HVL spent time studying quality systems in a certified clinical laboratory in Dakar, Senegal. Following this peer-to-peer technical assistance, several training sessions were undertaken by HVL staff, a baseline assessment was conducted, and processes were established. The HVL has monitored its quality indicators and conducted internal and external audits; these analyses (from 2007 to 2009) are presented herein. LESSONS LEARNED: Although there was improvement in the pre-analytical and analytical indicators analysed and although data-entry errors decreased in the post-analytical process, the delay in returning laboratory test results increased significantly. There were several factors identified as causes for this delay and all of these have now been addressed except for an identified need for automation of some high-volume assays (currently being negotiated). Internal and external audits showed a trend of increasing non-conformities which could be the result of personnel simply becoming lax over time. Application for laboratory accreditation, however, could provide the renewed vigour needed to correct these non-conformities. RECOMMENDATION: This experience shows that sustainability of the QMS at present is a cause for concern. However, the tiered system of accreditation being developed by WHO-Afro may act as a driving force to preserve the spirit of continual improvement.