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Background:Serologic assays can monitor population exposure to pathogens and immunity to vaccine-preventable diseases; the multiplex bead assay (MBA) can test for multiple analytes simultaneously.Intervention:Specimens collected during the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS) were used to estimate the seroprevalence of diseases of public health importance, and specimens collected from special studies were used to estimate the seroprevalence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to improve the surveillance programmes. In 2019, Luminex MAGPIX® instruments were installed at the MBA laboratory in the National Reference Laboratory, Nigeria Centre for Disease Control and Prevention, in Abuja, Nigeria. Dried blood spot specimens from the NAIIS, stored with consent for future testing, were prioritised for testing. Between 2019 and 2022, the National Reference Laboratory MBA laboratory conducted antibody and antigen assays for an estimated 130 000 NAIIS participants, completed two rounds of coronavirus disease 2019 (COVID-19) serosurveys, and validated SARS-CoV-2 serological assays for use in Nigeria.Lessons learnt:The data generated by the MBA laboratory supported funding requests for childhood immunisation and the application of the National Malaria Elimination Programme Global Fund. The MBA results strengthened the National HIV Serial Rapid Testing Algorithm. During the COVID-19 pandemic, the laboratory validated a SARS-CoV-2 MBA, which measured antibodies against three antigens. This multi-target assay was used to complete two additional rounds of the COVID-19 household serosurvey in Nigeria.Recommendations:This strategy of investing in MBA laboratory capacity building could serve as a model for other nations seeking to fortify their public health infrastructure.What this study adds:Nigeria’s integrated disease surveillance capability was boosted through MBA technology.

Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates. Data on geographically restricted SARS-CoV-2 variants is lacking in some regions. In this nationwide effort including 18 public health labs, the authors used genomic epidemiology and travel data to understand the origin and spread of 2 variants of interest that predominated during the second wave of the pandemic in Nigeria.

Background: Serologic assays can monitor population exposure to pathogens and immunity to vaccine-preventable diseases; the multiplex bead assay (MBA) can test for multiple analytes simultaneously. Intervention: Specimens collected during the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS) were used to estimate the seroprevalence of diseases of public health importance, and specimens collected from special studies were used to estimate the seroprevalence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to improve the surveillance programmes. In 2019, Luminex MAGPIX® instruments were installed at the MBA laboratory in the National Reference Laboratory, Nigeria Centre for Disease Control and Prevention, in Abuja, Nigeria. Dried blood spot specimens from the NAIIS, stored with consent for future testing, were prioritised for testing. Between 2019 and 2022, the National Reference Laboratory MBA laboratory conducted antibody and antigen assays for an estimated 130 000 NAIIS participants, completed two rounds of coronavirus disease 2019 (COVID-19) serosurveys, and validated SARS-CoV-2 serological assays for use in Nigeria. Lessons learnt: The data generated by the MBA laboratory supported funding requests for childhood immunisation and the application of the National Malaria Elimination Programme Global Fund. The MBA results strengthened the National HIV Serial Rapid Testing Algorithm. During the COVID-19 pandemic, the laboratory validated a SARS-CoV-2 MBA, which measured antibodies against three antigens. This multi-target assay was used to complete two additional rounds of the COVID-19 household serosurvey in Nigeria. Recommendations: This strategy of investing in MBA laboratory capacity building could serve as a model for other nations seeking to fortify their public health infrastructure. What this study adds: Nigeria’s integrated disease surveillance capability was boosted through MBA technology.

Three amino acid mutations have been identified in the isolated YG1 strain of severe fever thrombocytopenia syndrome virus (SFTSV), Gn (Y328H) accounts for 26.9% of the virus in patients’ blood, Gc (R624W) and L (N1891K) those are minor. To investigate viral properties caused by each mutation, we rescued viruses with one–three mutations. Mutations Y328H and R624W in GP increased the cell fusion activity and plaque size. Theses enhancement was more pronounced for both Y328H and R624W. The pseudotyped vesicular stomatitis virus coated with the SFTSV GP Y328H mutant showed lower infectivity in Vero E6 cells, which was compensated for by the additional R624W mutation. In the process of adaptation for virus with Y328H, the R624W mutation may be acquired. Moreover, only the viruses with the N1891K mutation in L showed significant CPE and the CPE was inhibited by the pan-caspase inhibitor, suggesting that caspase-dependent cell death occurred. Programmed cell death associated molecules caspase-1 and caspase-3 were induced in both CPE inducing and wild-type virus-infected cells. Furthermore, infection with the wild-type virus suppressed actinomycin D-induced cell death. These results suggest that SFTSV infected cells initiate programmed cell death, whereas wildt-ype virus may inhibit cell death. Furthermore, the N1891K mutation in L virus was outcompeted by a 10-fold less wild-type virus in Vero E6 cells indicating that it was not advantageous for viral survival in Vero E6 cells. Thus the quasispecies composition of SFTSV appeared to be influenced by propagative environment.

Avian hepatitis E virus (aHEV) is associated with hepatitis-splenomegaly syndrome, big liver and spleen disease and hepatic rupture haemorrhage syndrome. However, the knowledge about aHEV in commercial layer chickens in Nigeria is scarce. In this study, 460 serum samples obtained from 36 apparently healthy commercial layer chicken flocks in three states (Ogun, Osun and Oyo States) of southwestern Nigeria were analysed by enzyme linked immunosorbent assay for the presence of anti-aHEV immunoglobulin Y (IgY) antibodies. In total, the overall seroprevalence of anti-aHEV antibodies was 14.6%. The serological analysis revealed that 75% of the flocks examined were positive for anti-aHEV IgY antibodies from chickens of various ages in all three states. The percentage of the seropositive chickens in the three states varied from flock to flock ranging from 60% to 88.8% and seropositive chickens were detected at any age (24–52 weeks of age) without significant differences between the age groups. This is the first report assessing the presence of aHEV antibodies in chickens from Nigeria. The detection of anti-aHEV antibodies in commercial layer chickens in this study emphasizes the importance of serosurveillance in disease monitoring due to the economic threat posed by aHEV as a result of decreased egg production and increased mortality in affected commercial layer chicken farms. However, further studies are essential to reveal the clinical implications and to assess the real burden of aHEV in Nigeria.

The COVID-19 global pandemic is being driven by evolving SARS-CoV-2 variants with consequential implications on virus transmissibility, host immunity, and disease severity. Continuous molecular and genomic surveillance of the SARS-CoV-2 variants is therefore necessary for public health interventions toward the management of the pandemic. This study is a retrospective analysis of COVID-19 cases reported in a Nigerian tertiary institution from July to December 2021. In total, 705 suspected COVID-19 cases that comprised 547 students and 158 non-students were investigated by real time PCR (RT-PCR); of which 372 (~52.8%) tested positive for COVID-19. Using a set of selection criteria, 74 (~19.9%) COVID-19 positive samples were selected for next generation sequencing. Data showed that there were two outbreaks of COVID-19 within the university community over the study period, during which more females (56.8%) tested positive than males (47.8%) (p<0.05). Clinical data together with phylogenetic analysis suggested community transmission of SARS-CoV-2 through mostly asymptomatic and/or pre-symptomatic individuals. Confirmed COVID-19 cases were mostly mild, however, SARS-CoV-2 delta (77%) and omicron (4.1%) variants were implicated as major drivers of respective waves of infections during the study period. This study highlights the importance of integrated surveillance of communicable disease during outbreaks.

Owing to its high mortality rate, viral hepatitis is a major public health problem, especially in low-income countries. In Africa, hepatitis B virus (HBV) and hepatitis E virus (HEV) are highly endemic, and HBV/HEV coinfections, which are associated with more severe liver disease and poor outcomes, are common. HEV genotypes 1 and 2 have been associated with large human outbreaks, while 3 is known to circulate in pigs and sporadically in humans. In this study, the prevalence of HBV and HEV among individuals with acute or chronic liver diseases in Osun State, Southwest Nigeria, was analyzed. One hundred plasma samples from liver disease patients attending Ladoke Akintola University Teaching Hospital were analyzed for the presence of anti-HEV antibodies and hepatitis B surface antigen (HBsAg) via ELISA, and HEV RNA and HBV DNA were analyzed via RT‒PCR. Virus genotyping was performed by sequencing and subsequent phylogenetic analysis. Overall, 50 individuals (50%) were positive for HBsAg, of which 14 (28%) also tested positive for HBV DNA. Two individuals (2%) had occult HBV infection. Most HBV strains were genotype E, except for two genotype A (A2 and A3). Anti-HEV antibodies were detected in eight individuals (8%), with one (1%) being positive for anti-HEV IgM and seven (7%) for anti-HEV IgG. Nine (9%) samples had detectable HEV RNA, with one being HEV-3; a rare occurrence in Nigeria. Coinfection with HBV/HEV was detected in seven (7%) individuals. The prevalence of HEV in Nigeria is low, but considering the high prevalence of HBV and the possible complications due to HEV coinfection or superinfection, HEV screening and HBV vaccination targeting high-risk populations are emphasized.

Hepatitis B virus (HBV) infection remains a major global health concern, with a high burden in countries like Nigeria. This study aimed to investigate the molecular epidemiology of HBV by identifying circulating genotypes and detecting antiviral-resistant mutations in samples from selected communities in Enugu and Nasarawa States, Nigeria. Sample (plasma and serum) quality was evaluated after prolonged storage under freeze-thaw conditions using Qubit 4 fluorometer and Nanodrop One spectrophotometer. High-quality samples underwent molecular characterization and Sanger sequencing for HBV-positive cases. Of the 67 samples analyzed, seven were sequenced: two from Enugu and four from Nasarawa belonged to genotype E, while one from Nasarawa was genotype A. No antiviral resistance mutations were identified. This study provides valuable molecular data contributing to our understanding of HBV epidemiology in Nigeria.

Background The help-seeking interval and primary-care interval are points of delays in breast cancer presentation. To inform future intervention targeting early diagnosis of breast cancer, we described the contribution of each interval to the delay and the impact of delay on tumor progression. Method We conducted a multicentered survey from June 2017 to May 2018 hypothesizing that most patients visited the first healthcare provider within 60 days of tumor detection. Inferential statistics were by t-test, chi-square test, and Wilcoxon-Signed Rank test at p -value 0.05 or 95% confidence limits. Time-to-event was by survival method. Multivariate analysis was by logistic regression. Results Respondents were females between 24 and 95 years ( n  = 420). Most respondents visited FHP within 60 days of detecting symptoms (230 (60, 95% CI 53–63). Most had long primary-care (237 of 377 (64 95% CI 59–68) and detection-to-specialist (293 (73% (95% CI 68–77)) intervals. The primary care interval (median 106 days, IQR 13–337) was longer than the help-seeking interval (median 42 days, IQR 7–150) Wilcoxon signed-rank test p  = 0.001. There was a strong correlation between the length of primary care interval and the detection-to-specialist interval (r = 0.9, 95% CI 0.88–0.92). Patronizing the hospital, receiving the correct advice, and having a big tumor (> 5 cm) were associated with short intervals. Tumors were detected early, but most became advanced before arriving at the specialist clinic. The difference in tumor size between detection and arriving at a specialist clinic was 5.0 ± 4.9 cm (95% CI 4.0–5.0). The hazard of progressing from early to locally advanced disease was least in the first 30 days (3%). The hazard was 31% in 90 days. Conclusion Most respondents presented early to the first healthcare provider, but most arrived late at a specialist clinic. The primary care interval was longer than the help-seeking interval. Most tumors were early at detection but locally advanced before arriving in a specialist clinic. Interventions aiming to shorten the primary care interval will have the most impact on time to breast cancer presentation for specialist oncology care in Nigeria.