Challenges in conducting population-based seroepidemiology survey of COVID-19 in Lagos State, Nigeria.

Population-based study is known to be a very essential type of study during and after a pandemic or epidemic, as it provides crucial information on the incidence, prevalence, and risk factors of the disease in question. There has been limited information about the challenges faced in conducting such surveys in Nigeria. In this paper, we will share our experience, and describe the challenges faced in conducting a population-based seroepidemiological study of COVID-19 in Lagos, Nigeria. Some challenges were peculiar to specific Local Government Areas (LGAs) while others were general. The challenges include general misconceptions of community members about health research, difficulties in mapping houses, planning for data collection, standardizing data collection, working in hard-to-reach communities when resources were limited as well as difficulty in collection of blood and naso-oropharyngeal swabs. Ways of overcoming these problems, lessons learnt, and recommendations are hereby discussed.

Sensitivity and Specificity of Rapid Diagnostic Tests for Hepatitis C Virus With or Without HIV Coinfection: A Multicentre Laboratory Evaluation Study.

BACKGROUND: Hepatitis C virus (HCV) screening is critical to HCV elimination efforts. Simplified diagnostics are required for low-resource settings and difficult-to-reach populations. This retrospective study assessed performance of rapid diagnostic tests (RDTs) for detection of HCV antibodies. METHODS: Two lots of 13 RDTs were evaluated at 3 laboratories using archived plasma samples from 4 countries (Nigeria, Georgia, Cambodia, and Belgium). HCV status was determined using 3 reference tests according to a composite algorithm. Sensitivity and specificity were evaluated in HIV-infected and HIV-uninfected populations. Operational characteristics were also assessed. RESULTS: In total, 1710 samples met inclusion criteria. In HIV-uninfected samples (n = 384), the majority of RDTs had sensitivity ≥98% in 1 or both lots and most RDTs had specificity ≥99%. In HIV-infected samples (n = 264), specificity remained high but sensitivity was markedly lower than in HIV-uninfected samples; only 1 RDT reached >95%. The majority of HIV-infected samples for which sensitivity was low did not have detectable HCV viral load/core antigen. Interreader variability, lot-to-lot variability, and rate of invalid runs were low for all RDTs (<2%). CONCLUSIONS: HCV RDTs should be evaluated in the intended target population, as sensitivity can be impacted by population factors such as HIV status. CLINICAL TRIALS REGISTRATION: NCT04033887.

Cross-Reactivity of Two SARS-CoV-2 Serological Assays in a Setting Where Malaria Is Endemic.

Accurate SARS-CoV-2 serological assays are critical for COVID-19 serosurveillance. However, previous studies have indicated possible cross-reactivity of these assays, including in areas where malaria is endemic. We tested 213 well-characterized prepandemic samples from Nigeria using two SARS-CoV-2 serological assays, Abbott Architect IgG and Euroimmun NCP IgG assay, both targeting SARS-CoV-2 nucleocapsid protein. To assess antibody binding strength, an avidity assay was performed on these samples and on plasma from SARS-CoV-2 PCR-positive persons. Thirteen (6.1%) of 212 samples run on the Abbott assay and 38 (17.8%) of 213 run on the Euroimmun assay were positive. Anti-Plasmodium IgG levels were significantly higher among false positives for both Abbott and Euroimmun; no association was found with active Plasmodium falciparum infection. An avidity assay using various concentrations of urea wash in the Euroimmun assay reduced loosely bound IgG: of 37 positive/borderline prepandemic samples, 46%, 86%, 89%, and 97% became negative using 2 M, 4 M, 5 M, and 8 M urea washes, respectively. The wash slightly reduced avidity of antibodies from SARS-CoV-2 patients within 28 days of PCR confirmation; thereafter, avidity increased for all urea concentrations except 8 M. This validation found moderate to substantial cross-reactivity on two SARS-CoV-2 serological assays using samples from a setting where malaria is endemic. A simple urea wash appeared to alleviate issues of cross-reactivity.

Seroprevalence of SARS-CoV-2 IgG among healthcare workers in Lagos, Nigeria.

Healthcare workers (HCWs) are disproportionately infected with SARS-CoV-2 when compared to members of the general public; estimating the seroprevalence of SARS-CoV-2 antibody and SARS-CoV-2 infection rate among HCWs is therefore crucial. This study was carried out in four health facilities in Lagos Nigeria to determine the prevalence of IgG antibodies (seroprevalence) and SARS-CoV-2 active infection rate via a positive rtPCR result, the cross-sectional study was conducted between December 2020 and July 2021. Nasopharyngeal and blood samples were collected from HCWs and screened for SARS-CoV-2 infection using the rtPCR technique and antibody using the Abbott anti-SARS-CoV-2 IgG CMIA assay, respectively. Demographic and occupational exposures data were obtained and analysed using descriptive and inferential statistics, variables significant via inferential statistics were subjected to a multivariate analysis. A total of 413 participants were enrolled, with a mean age in years of 38.4±11.0. The seroprevalence was 30.9% (115/372) while 63/395 (15.9%) were actively infected with the virus. HCWs whose job role had direct contact with patients had a higher percentage of SARS-CoV-2 infection when compared with those not in direct contact, also being a health care worker was significantly associated with getting a positive COVID-19 PCR result. In conclusion the SARS-CoV-2 seroprevalence seen in this study was higher than national serosurvey estimates indicating HCWs are at higher risk of COVID-19 infection when compared to the general public. Vaccination and effective implementation of infection control measures are important to protect HCWs.

Comparison of one single-antigen assay and three multi-antigen SARS-CoV-2 IgG assays in Nigeria.

Objectives: Determining an accurate estimate of SARS-CoV-2 seroprevalence has been challenging in African countries where malaria and other pathogens are endemic. We compared the performance of one single-antigen assay and three multi-antigen SARS-CoV-2 IgG assays in a Nigerian population endemic for malaria. Methods: De-identified plasma specimens from SARS-CoV-2 RT-PCR positive, dried blood spot (DBS) SARS-CoV-2 RT-PCR positive, and pre-pandemic negatives were used to evaluate the performance of the four SARS-CoV-2 assays (Tetracore, SARS2MBA, RightSign, xMAP). Results: Results showed higher sensitivity with the multi-antigen (81% (Tetracore), 96% (SARS2MBA), 85% (xMAP)) versus the single-antigen (RightSign (64%)) SARS-CoV-2 assay. The overall specificities were 98% (Tetracore), 100% (SARS2MBA and RightSign), and 99% (xMAP). When stratified based on <15 days to ≥15 days post-RT-PCR confirmation, the sensitivities increased from 75% to 88.2% for Tetracore; from 93% to 100% for the SARS2MBA; from 58% to 73% for RightSign; and from 83% to 88% for xMAP. With DBS, there was no positive increase after 15-28 days for the three assays (Tetracore, SARS2MBA, and xMAP). Conclusion: Multi-antigen assays performed well in Nigeria, even with samples with known malaria reactivity, and might provide more accurate measures of COVID-19 seroprevalence and vaccine efficacy.

Seroprevalence of SARS-CoV-2 in four states of Nigeria in October 2020: A population-based household survey.

The observed epidemiology of SARS-CoV-2 in sub-Saharan Africa has varied greatly from that in Europe and the United States, with much lower reported incidence. Population-based studies are needed to estimate true cumulative incidence of SARS-CoV-2 to inform public health interventions. This study estimated SARS-CoV-2 seroprevalence in four selected states in Nigeria in October 2020. We implemented a two-stage cluster sample household survey in four Nigerian states (Enugu, Gombe, Lagos, and Nasarawa) to estimate age-stratified prevalence of SARS-CoV-2 antibodies. All individuals in sampled households were eligible for interview, blood draw, and nasal/oropharyngeal swab collection. We additionally tested participants for current/recent malaria infection. Seroprevalence estimates were calculated accounting for the complex survey design. Across all four states, 10,629 (96·5%) of 11,015 interviewed individuals provided blood samples. The seroprevalence of SARS-CoV-2 antibodies was 25·2% (95% CI 21·8-28·6) in Enugu State, 9·3% (95% CI 7·0-11·5) in Gombe State, 23·3% (95% CI 20·5-26·4) in Lagos State, and 18·0% (95% CI 14·4-21·6) in Nasarawa State. Prevalence of current/recent malaria infection ranged from 2·8% in Lagos to 45·8% in Gombe and was not significantly related to SARS-CoV-2 seroprevalence. The prevalence of active SARS-CoV-2 infection in the four states during the survey period was 0·2% (95% CI 0·1-0·4). Approximately eight months after the first reported COVID-19 case in Nigeria, seroprevalence indicated infection levels 194 times higher than the 24,198 officially reported COVID-19 cases across the four states; however, most of the population remained susceptible to COVID-19 in October 2020.

Validation of xMAP SARS-CoV-2 Multi-Antigen IgG assay in Nigeria.

OBJECTIVE: There is a need for reliable serological assays to determine accurate estimates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence. Most single target antigen assays have shown some limitations in Africa. To assess the performance of a multi-antigen assay, we evaluated a commercially available SARS-CoV-2 Multi-Antigen IgG assay for human coronavirus disease 2019 (COVID-19) in Nigeria. METHODS: Validation of the xMAP SARS-CoV-2 Multi-Antigen IgG assay was carried out using well-characterized SARS-CoV-2 reverse transcription polymerase chain reactive positive (97) and pre-COVID-19 pandemic (86) plasma panels. Cross-reactivity was assessed using pre-COVID-19 pandemic plasma specimens (213) from the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). RESULTS: The overall sensitivity of the xMAP SARS-CoV-2 Multi-Antigen IgG assay was 75.3% [95% CI: 65.8%- 82.8%] and specificity was 99.0% [95% CI: 96.8%- 99.7%]. The sensitivity estimate increased to 83.3% [95% CI: 70.4%- 91.3%] for specimens >14 days post-confirmation of diagnosis. However, using the NAIIS pre-pandemic specimens, the false positivity rate was 1.4% (3/213). CONCLUSIONS: Our results showed overall lower sensitivity and a comparable specificity with the manufacturer's validation. There appears to be less cross-reactivity with NAIIS pre-pandemic COVID-19 specimens using the xMAP SARS-CoV-2 Multi-Antigen IgG assay. In-country SARS-CoV-2 serology assay validation can help guide the best choice of assays in Africa.

SARS-COV-2 antibody responses to AZD1222 vaccination in West Africa.

Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies. Previous IgG anti-N positivity significantly increased post two-dose neutralizing antibody titres in both populations. Serological evidence of breakthrough infection was observed in 8/49 (16%). Neutralising antibodies were observed to wane in both populations, especially in anti-N negative participants with an observed waning rate of 20% highlighting the need for a combination of additional markers to characterise previous infection. We conclude that AZD1222 is immunogenic in two independent West African cohorts with high background seroprevalence and incidence of breakthrough infection in 2021. Waning titres post second dose indicates the need for booster dosing after AZD1222 in the African setting despite hybrid immunity from previous infection.

Validation of Commercial SARS-CoV-2 Immunoassays in a Nigerian Population.

Validated assays are essential for reliable serosurveys; however, most SARS-CoV-2 immunoassays have been validated using specimens from China, Europe, or U.S. populations. We evaluated the performance of five commercial SARS-CoV-2 immunoassays to inform their use in serosurveys in Nigeria. Four semiquantitative enzyme-linked immunosorbent assays (ELISAs) (Euroimmun anti-SARS-CoV-2 nucleocapsid protein [NCP] immunoglobulin G [IgG], Euroimmun spike SARS-CoV-2 IgG, Mologic Omega COVID-19 IgG, Bio-Rad Platelia SARS-CoV-2 Total Ab) and one chemiluminescent microparticle immunoassay (Abbott Architect SARS-CoV-2 IgG) were evaluated. We estimated the analytical performance characteristics using plasma from 100 SARS-CoV-2 PCR-positive patients from varied time points post-PCR confirmation and 100 prepandemic samples (50 HIV positive and 50 hepatitis B positive). The Bio-Rad assay failed the manufacturer-specified validation steps. The Euroimmun NCP, Euroimmun spike, and Mologic assays had sensitivities of 73.7%, 74.4%, and 76.9%, respectively, on samples taken 15 to 58 days after PCR confirmation and specificities of 97%, 100%, and 83.8%, respectively. The Abbott assay had 71.3% sensitivity and 100% specificity on the same panel. Parallel or serial algorithms combining two tests did not substantially improve the sensitivity or specificity. Our results showed lower sensitivity and, for one immunoassay, lower specificity compared to the manufacturers' results and other reported validations. Seroprevalence estimates using these assays might need to be interpreted with caution in Nigeria and similar settings. These findings highlight the importance of in-country validations of SARS-CoV-2 serological assays prior to use to ensure that accurate results are available for public health decision-making to control the COVID-19 pandemic in Africa. IMPORTANCE This study used positive and negative sample panels from Nigeria to test the performance of several commercially available SARS-CoV-2 serological assays. Using these prepandemic and SARS-CoV-2-positive samples, we found much lower levels of sensitivity in four commercially available assays than most assay manufacturer reports and independent evaluations. The use of these assays with suboptimal sensitivity and specificity in Nigeria or countries with population exposure to similar endemic pathogens could lead to a biased estimate of the seroprevalence, over- or underestimating the true disease prevalence, and limit efforts to stop the spread of SARS-CoV-2. It is important to conduct in-country validations of serological SARS-CoV-2 assays prior to their widespread use, especially in countries with limited representation in published assay validations.

Low level SARS-CoV-2 RNA detected in plasma samples from a cohort of Nigerians: Implications for blood transfusion.

The present global pandemic triggered by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has lingered for over a year in its devastating effects. Diagnosis of coronavirus disease 2019 (COVID-19) is currently established with a polymerase chain reaction (PCR) test by means of oropharyngeal-, nasopharyngeal-, anal-swabs, sputum and blood plasma. However, oral and nasal swabs are more commonly used. This study, therefore, assessed sensitivity and specificity of plasma as a diagnostic in comparison with a combination of oral and nasal swab samples, and the implications for blood transfusion. Oropharyngeal (OP) and nasopharyngeal (NP) swab samples were obtained from 125 individuals suspected to have COVID-19 and stored in viral transport medium (VTM) tubes. Ten millilitres of blood samples in EDTA were also obtained by venepuncture and spun to obtain plasma. Viral RNA was obtained from both swabs and plasma by manual extraction with Qiagen QIAamp viral RNA Mini Kit. Detection was done using a real time fluorescent RT-qPCR BGI kit, on a QuantStudio 3 real-time PCR instrument. Average age of study participants was 41 years, with 74 (59.2%) being male. Out of the 125 individuals tested for COVID-19, 75 (60%) were positive by OP/NP swab. However, only 6 (4.8%) had a positive plasma result for COVID-19 with median Ct value of 32.4. Sensitivity and specificity of RT-PCR SARS-CoV-2 test using plasma was 8% and 100% respectively. There was no false positive recorded, but 69 (55.2%) false negatives were obtained by plasma. SARS-CoV-2 viral RNA was detected, albeit low (4.8%) in plasma. Plasma is likely not a suitable biological sample to diagnose acute SARS-CoV-2 infection. The implication of transfusing blood in this era of COVID-19 needs further investigations.

The use of DIY (Do it yourself) sampling and telemonitoring model for COVID-19 qPCR testing scale up.

The first case of COVID-19 in Nigeria was recorded on February 27, 2020, being an imported case by an Italian expatriate, to the country. Since then, there has been steady increase in the number of cases. However, the number of cases in Nigeria is low in comparison to cases reported by other countries with similar large populations, despite the poor health system prevailing in the country. This has been mainly attributed to the low testing capacity in Nigeria among other factors. Therefore, there is a need for innovative ways to increase the number of persons testing for COVID-19. The aim of the study was to pilot a nasopharyngeal swab self-sample collection model that would help increase COVID-19 testing while ensuring minimal person-to-person contact being experienced at the testing center. 216 participants took part in this study which was carried out at the Nigerian Institute of Medical Research between June and July 2020. Amongst the 216 participants, 174 tested negatives for both self-collected samples and samples collected by Professionals, 30 tested positive for both arms, with discrepancies occurring in 6 samples where the self-collected samples were positive while the ones collected by the professionals were negative. The same occurred in another set of 6 samples with the self-collected samples being negative and the professional-collected sample coming out positive, with a sensitivity of 83.3% and a specificity of 96.7%. The results of the interrater analysis are Kappa = 0.800 (95% CI, 0.690 to 0.910) which implies an outstanding agreement between the two COVID-19 sampling methods. Furthermore, since p< 0.001 Kappa (k) coefficient is statistically different from zero, our findings have shown that self-collected samples can be reliable in the diagnosis of COVID-19.

Comparative performance of SARS-CoV-2 real-time PCR diagnostic assays on samples from Lagos, Nigeria.

A key element in containing the spread of the SARS-CoV-2 infection is quality diagnostics which is affected by several factors. We now report the comparative performance of five real-time diagnostic assays. Nasopharyngeal swab samples were obtained from persons seeking a diagnosis for SARS-CoV-2 infection in Lagos, Nigeria. The comparison was performed on the same negative, low, and high-positive sample set, with viral RNA extracted using the Qiagen Viral RNA Kit. All five assays are one-step reverse transcriptase real-time PCR assays. Testing was done according to each assay's manufacturer instructions for use using real-time PCR platforms. 63 samples were tested using the five qPCR assays, comprising of 15 negative samples, 15 positive samples (Ct = 16-30; one Ct = 35), and 33 samples with Tib MolBiol E-gene Ct value ranging from 36-41. All assays detected all high positive samples correctly. Three assays correctly identified all negative samples while two assays each failed to correctly identify one different negative sample. The consistent detection of positive samples at different Ct/Cq values gives an indication of when to repeat testing and/or establish more stringent in-house cut-off value. The varied performance of different diagnostic assays, mostly with emergency use approvals, for a novel virus is expected. Comparative assays' performance reported may guide laboratories to determine both their repeat testing Ct/Cq range and/or cut-off value.

Full length genomic sanger sequencing and phylogenetic analysis of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Nigeria.

In an outbreak, effective detection of the aetiological agent(s) involved using molecular techniques is key to efficient diagnosis, early prevention and management of the spread. However, sequencing is necessary for mutation monitoring and tracking of clusters of transmission, development of diagnostics and for vaccines and drug development. Many sequencing methods are fast evolving to reduce test turn-around-time and to increase through-put compared to Sanger sequencing method; however, Sanger sequencing remains the gold standard for clinical research sequencing with its 99.99% accuracy This study sought to generate sequence data of SARS-CoV-2 using Sanger sequencing method and to characterize them for possible site(s) of mutations. About 30 pairs of primers were designed, synthesized, and optimized using endpoint PCR to generate amplicons for the full length of the virus. Cycle sequencing using BigDye Terminator v.3.1 and capillary gel electrophoresis on ABI 3130xl genetic analyser were performed according to the manufacturers' instructions. The sequence data generated were assembled and analysed for variations using DNASTAR Lasergene 17 SeqMan Ultra. Total length of 29,760bp of SARS-CoV-2 was assembled from the sample analysed and deposited in GenBank with accession number: MT576584. Blast result of the sequence assembly shows a 99.97% identity with the reference sequence. Variations were noticed at positions: nt201, nt2997, nt14368, nt16535, nt20334, and nt28841-28843, which caused amino acid alterations at the S (aa614) and N (aa203-204) regions. The mutations observed at S and N-gene in this study may be indicative of a gradual changes in the genetic coding of the virus hence, the need for active surveillance of the viral genome.

Hepatitis C viral load and genotypes among Nigerian subjects with chronic infection and implication for patient management: a retrospective review of data.

INTRODUCTION: Hepatitis C Virus (HCV) is highly infectious with no currently available vaccine. Prior to treatment, it is recommended to confirm HCV infection with either quantitative or qualitative nucleic acid test. Access to these assays in Nigeria is limited but for effective management of patients, HCV viral load (VL) prior to therapy is required and genotype may be needed in some instances. This study aimed at reviewing the pattern of HCV viral load and genotype in the country, and its implication in patient management. METHODS: this was a retrospective study that involved data abstraction from an electronic database of an accredited laboratory between June 2013 and May 2017. De-linked data were abstracted from records of adult subjects with HCV VL and genotype results, these were analysed using Microsoft Excel 2010 and SPSS v20. RESULTS: within the study period, 346 subjects had baseline VL and 134 (38.7%) had genotype results available. Of these, 202/346 (58.4%) had detectable VL results with higher prevalence in males (64.7%) and ≥51years (42.5%) age group. The median VL among 202 subjects was 407,430 (IQR: 96,388 - 1,357,012) IU/mL. Distribution of genotypes showed that genotypes 1 and 4 had prevalence of 63.2% and 16.8% respectively. CONCLUSION: genotypes 1 and 4 have the highest prevalence. A greater proportion of subjects had VL values ≤800,000 IU/mL, an indication that they are more likely to respond well to available antiviral therapy hence, access to these antivirals will greatly improve management of HCV infection in Nigeria.

Implementation of a modified drive-through sampling strategy for SARS-CoV-2-the Nigerian experience.

INTRODUCTION: effective and safe means of sample collection is a crucial component of testing for Covid-19. Uptake of testing is key to containing and controlling the spread of the virus. Scientists have been working on various strategies that will increase the uptake of testing for COVID-19. One such method involves the use of the drive-through sampling strategy. METHODS: data was collected by both qualitative and quantitative methods. An eligibility form was filled online. While in-depth interviews were conducted for the qualitative aspect of the study. RESULTS: 2,600 visits were recorded at the website, 2300 (88.46%) participants successfully registered for the test. 57.4% were found eligible of which 78.0% presented for the test. This Consisted of 78.0% drive-through and 22.0% walk-in. The average time for transiting through the drive-through site was 19.2 ± 4.6minutes while that of the walk-in was 28 ± 9.2min. This difference was statistically significant (p<0.001). In the qualitative component, respondents opined that maximum safety measures were deployed to protect both participants and health workers. Most said that the turnaround time for the sampling process was short. CONCLUSION: the sampling strategy although largely successful, is largely dependent on Internet penetrability, thus this sampling modality will be best utilized as an adjunct to established models of sample collection.

Potential for false-positive HIV test results using rapid HIV testing algorithms.

Background: In order to scale up access to HIV counselling and testing in Nigeria, an HIV diagnostic algorithm based on rapid testing was adopted. However, there was the need to further evaluate the testing strategy in order to better assess its performance, because of the potential for false positivity. Objectives: The objective of this study was to compare positive HIV test results obtained from the approved rapid testing algorithm with results from western blot tests performed on samples from the same patient. Methodology: A retrospective review was conducted of HIV screening and confirmatory results for patients seen between 2007 and 2008. Rapid test and western blot results were extracted and compared for concordance. Discordant results were further reviewed using a combination of HIV-1 RNA viral load and CD4+ cell count test results and clinical presentation from medical records. Results: Analysis of 2228 western blot results showed that 98.3% (n = 2191) were positive for HIV-1, 0.4% (n = 8) were positive for HIV-2 and 0.3% (n = 7) were dual infections (positive for both HIV-1 and HIV-2); 0.6% (n = 13) were indeterminate and 0.4% (n = 9) were negative. Further investigation of the 13 indeterminate results showed nine to be HIV-1 positive and four to be HIV-negative, for a total of 13 negative results. The positive predictive value of the HIV counselling and testing algorithm was 99.4%. Conclusion: Using the rapid testing algorithm alone, false positives were detected. Therefore, effective measures such as training and retraining of staff should be prioritised in order to minimise false-positive diagnoses and the associated potential for long-term psychological and financial impact on the patients.

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.