Performance evaluation of SARS-CoV-2 rapid diagnostic tests in Nigeria: A cross-sectional study.

The COVID-19 pandemic challenged health systems globally. Reverse transcription polymerase chain reaction (RT-PCR) is the gold standard for detecting the presence of SARS-CoV-2 in clinical samples. Rapid diagnostic test (RDT) kits for COVID-19 have been widely used in Nigeria. This has greatly improved test turnover rates and significantly decreased the high technical demands of RT-PCR. However, there is currently no nationally representative evaluation of the performance characteristics and reliability of these kits. This study assessed the sensitivity, specificity, and predictive values of ten RDT kits used for COVID-19 testing in Nigeria. This large multi-centred cross-sectional study was conducted across the 6 geo-political zones of Nigeria over four months. Ten antigen (Ag) and antibody (Ab) RDT kits were evaluated, and the results were compared with RT-PCR. One thousand, three hundred and ten (1,310) consenting adults comprising 767 (58.5%) males and 543 (41.5%) females participated in the study. The highest proportion, 757 (57.7%), were in the 20-39 years' age group. In terms of diagnostic performance, Lumira Dx (61.4, 95% CI: 52.4-69.9) had the highest sensitivity while MP SARS and Panbio (98.5, 95% CI: 96.6-99.5) had the highest specificity. For predictive values, Panbio (90.7, 95% CI: 79.7-96.9) and Lumira Dx (81.2, 95% CI: 75.9-85.7) recorded the highest PPV and NPV respectively. Ag-RDTs had better performance characteristics compared with Ab-RDTs; however, the sensitivities of all RDTs in this study were generally low. The relatively high specificity of Ag-RDTs makes them useful for the diagnosis of infection in COVID-19 suspected cases where positive RDT may not require confirmation by molecular testing. There is therefore the need to develop RDTs in-country that will take into consideration the unique environmental factors, interactions with other infectious agents, and strains of the virus circulating locally. This may enhance the precision of rapid and accurate diagnosis of COVID-19 in Nigeria.

Post-tuberculosis respiratory impairment in Gambian children and adolescents: A cross-sectional analysis.

BACKGROUND: Although post-tuberculosis lung disease (PTLD) is a known consequence of pulmonary tuberculosis (pTB), few studies have reported the prevalence and spectrum of PTLD in children and adolescents. METHODS: Children and adolescent (≤19 years) survivors of pTB in the Western Regions of The Gambia underwent a respiratory symptom screening, chest X-ray (CXR) and spirometry at TB treatment completion. Variables associated with lung function impairment were identified through logistic regression models. RESULTS: Between March 2022 and July 2023, 79 participants were recruited. The median age was 15.6 years (IQR: 11.8, 17.9); the majority, 53/79 (67.1%), were treated for bacteriologically confirmed pTB, and 8/79 (10.1%) were children and adolescents living with HIV. At pTB treatment completion, 28/79 (35.4%) reported respiratory symptoms, 37/78 (47.4%) had radiological sequelae, and 45/79 (57.0%) had abnormal spirometry. The most common respiratory sequelae were cough (21/79, 26.6%), fibrosis on CXR (22/78, 28.2%), and restrictive spirometry (41/79, 51.9%). Age at TB diagnosis over ten years, undernutrition and fibrosis on CXR at treatment completion were significantly associated with abnormal spirometry (p = .050, .004, and .038, respectively). CONCLUSION: Chronic respiratory symptoms, abnormal CXR, and impaired lung function are common and under-reported consequences of pTB in children and adolescents. Post-TB evaluation and monitoring may be necessary to improve patient outcomes.

Childhood TB sequel: evaluating respiratory function after treatment for pulmonary tuberculosis in a prospective cohort of Gambian children - a study protocol.

BACKGROUND: 1.2 million children under 15 years are estimated to have developed tuberculosis (TB) in 2021. 85% of paediatric patients achieve successful treatment outcomes if treated for the first episode of TB. However, despite so-called successful treatment, TB leaves many survivors with permanently destroyed or damaged lungs. Data from prospective paediatric cohorts to establish the burden and evolution of post-TB lung disease (PTLD) are still absent. The Childhood TB Sequel study aims to describe respiratory consequences associated with pulmonary TB in Gambian children, describe the evolution of these sequelae, and determine associated epidemiological risk factors. METHODS: We aim to recruit up to 80 subjects aged 19 years and below who have recently completed treatment for pulmonary TB. Recruitment started in April 2022 and is expected to continue until June 2024. Clinical assessment, chest X-ray, and comprehensive lung function assessment are carried out at treatment completion and again six and 12 months later. DISCUSSION: The Childhood TB Sequel study will address existing research gaps to enhance our knowledge and understanding of the burden of PTLD in Gambian children. The study will also contribute to formulating a plan for post-TB evaluation and long-term follow-up strategies. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05325125, April 13, 2022.

Seroprevalence of anti-SARS-CoV-2 specific antibodies in vaccinated and vaccine naïve adult Nigerians.

BACKGROUND: Reports on the evaluation of immune responses to different COVID-19 vaccines are limited. Similarly, effects of age and gender have not been well explored as variables that could impact on the vaccine-induced antibody response. Therefore, seroprevalence of anti-SARS-CoV-2 specific antibodies in vaccinated and vaccine naïve adult Nigerians was determined in this study. METHODOLOGY: A total of 141 adults were enrolled into this study. Presence or absence of SARS-CoV-2 infection was confirmed by real-time reverse-transcriptase polymerase-chain reaction (RT-PCR) assay on nasopharyngeal and oropharyngeal swab specimens. Anti-SARS-CoV-2 Specific IgG and IgM antibodies were qualitatively detected using a Rapid Diagnostic Test kit. RESULTS: Pre-vaccination, 77% of the study participants had never had PCR-confirmed COVID-19 test yet 66.7% of them were seropositive for SARS-CoV-2 antibodies. Of 111 COVID-19 vaccinated participants, 69.2% and 73.8% of them had SARS-CoV-2 specific IgG post-first and second doses of COVID-19 vaccine respectively. However, 23.1% and 21.4% of the participants who have had first and second doses respectively had no detectable anti-SARS-CoV-2 antibodies. The proportion of participants with SARS-CoV-2 specific IgG was insignificantly higher in those between the ages of 18-40 years and 41-59 years compared with individuals aged ≥60 years. No significant association was observed between gender and seropositivity for SARS-CoV-2 antibodies. CONCLUSION: There is high SARS-CoV-2 antibody seroprevalence among Nigerian adults who never had PCR-confirmed COVID-19. Also, there is the need for anti-SARS-CoV-2 antibodies screening post vaccination as this could be essential in achieving herd immunity. Age and gender do not seem to have significant association with seropositivity.

Assessment of thyroid function of newly diagnosed SARS-CoV-2 infected patients in Nigeria.

INTRODUCTION: the outbreak and rapid spread of the novel SARS-CoV-2, the causative agent of the coronavirus disease 2019 (COVID-19), has evolved into an unprecedented global pandemic. The infection impairs several human organs and systems, however, it is not clear how it affects thyroid function. The study therefore aimed at measuring plasma levels of thyroid hormones and Hs-CRP in COVID-19 patients and apparently healthy uninfected controls to assess the possible effect of SAR-CoV-2 infection on thyroid function. METHODS: in this cross-sectional study carried out between May-August 2020, 90 consenting participants comprising 45 COVID-19 patients and 45 apparently healthy uninfected controls were recruited. Plasma FT3, FT4, TSH and Hs-CRP were measured using Enzyme Linked Immunosorbent Assay (ELISA) method. Data was analysed using SPSS version 20 and statistical significance set at p < 0.05. RESULTS: the mean plasma FT3 and TSH concentrations were significantly higher in COVID-19 patients compared to controls (p < 0.001, p < 0.001 respectively). Euthyroidism was observed in all uninfected controls, whereas 35 (77.8%) COVID-19 patients were euthyroid. Sick euthyroid and subclinical hypothyroidism was observed in 7 (15.6%) and 3 (6.7%) COVID-19 patients, respectively. CONCLUSION: though there was a preponderance of euthyroidism among COVID-19 patients, significantly higher mean plasma levels of TSH and FT3, sick euthyroid syndrome and subclinical hypothyroidism observed among some COVID-19 patients may be indicative of disease-related thyroid function changes. Hence, there is need to pay attention to thyroid function during and after treatment of COVID-19.

Sars-Cov-2 Infection Screening Using Two Serological Testing Methods.

The challenges associated with adequate deployment of nucleic acid amplification tests (NAATs) in developing countries underscores the important role of simple but sensitive and specific serological testing kits in COVID-19 diagnosis. Presently, there are a number of point-of-care tests for Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) screening. However, the reliability of these test kits is poorly documented and hence, needs to be ascertained. This study was therefore designed to determine the sensitivity and specificity of two serological test kits for COVID-19 screening with the view to providing necessary information on the suitability of their deployment as routine test kits for SARS-CoV-2 in Nigeria. Forty-seven (47) asymptomatic adults who had been tested for SARS-CoV-2 with the real-time reverse-transcriptase polymerase-chain reaction (RT-PCR) were enrolled into this study. Blood samples were obtained for qualitative determination of serum IgM and IgG antibodies to the S-antigen of SARS-CoV-2 using a commercially available IgM and IgG Rapid Diagnostic Test (RDT) and enzyme linked immunosorbent assay (ELISA). The association between the test kits (ELISA and RDT) and PCR in diagnosing COVID-19 was determined using the Fisher's Exact test at P<0.05. The sensitivity and specificity of the test kits were determined using ROC while the Positive Predictive Value (PPV), Negative Predictive Value (NPV), Positive Likelihood Ratio (PLR), Negative Likelihood Ratio (NLR), Diagnostic Odds Ratio (DOR) and accuracy were calculated as appropriate. Twenty-eight (59.6%) of the study participants had positive PCR result. ELISA and RDT identified 20 (42.6%) and 13 (27.7%) participants respectively as having anti- SARS COV-2 specific antibodies. ELISA had a better sensitivity performance, NPV, PLR, DOR and accuracy than the RDT while the RDT had a better specificity performance than ELISA. The proportion of participants with anti-SARS-CoV-2 IgM antibody identified using ELISA was significantly higher compared with RDT. In contrast, the proportion of participants with positive anti- SARS COV-2 IgG antibody identified using RDT was significantly higher compared with ELISA. ELISA has a better sensitivity for detecting anti-SARS-CoV-2 Spike-protein specific antibodies than the RDT. However, combination of RDT and ELISA for the detection of anti-SARS-COV-2 antibodies might be useful for population COVID-19 screening.

Zinc, lead, and cadmium levels in serum and milk of lactating women in Ibadan, Nigeria.

Zinc (Zn) is known to interact with lead (Pb) and cadmium (Cd) reversing their toxicity and reducing their concentrations. However, lactating women are at high risk of developing Zn deficiency, which may result in Pb and Cd intoxication or increased exposure of breast-fed infants to Pb and Cd from breast milk. The aim of this study was to determine Zn, Pb, and Cd concentrations and examine their relationship in serum and breast milk of lactating women in Ibadan, Nigeria. Ninety-two lactating women were recruited into this study. Anthropometric measurements were assessed by standard methods while serum and breast milk concentrations of Zn, Pb, and Cd were assessed by atomic absorption spectrophotometry. Data analyzed statistically by Student's t test, Pearson's correlation coefficient, and a multiple regression model were significant at p < 0.05. Zn deficiency was observed in 12 (17.1%) of lactating women. Breast milk levels of Zn, Pb, and Cd were significantly higher than their levels in serum, whereas the ratios Zn:Pb and Zn:Cd in milk were significantly less than serum ratios. Significant negative correlation was observed between milk Pb and serum Zn:Pb while milk Cd correlated positively with milk Zn. Significant positive correlations were observed between serum Zn and serum Zn:Pb, serum Zn and serum Zn:Cd, as well as serum Zn:Cd and serum Zn:Pb. Serum Cd and serum Zn were significantly negatively related. Significant negative correlations between serum Pb and serum Zn:Pb as well as milk Zn:Pb. Serum Cd and serum Zn:Pb as well as serum Zn:Cd correlated negatively. Milk Cd and Zn/Cd positively related with milk Pb while milk Zn was a negatively related with milk Pb in a multiple regression model ( R2 = 0.333; p = 0.023). Breast milk may be contaminated by toxic metals. However, Zn supplementation in deficient mothers may protect maternal and infant health.

Thyroid function in multidrug-resistant tuberculosis patients with or without human immunodeficiency virus (HIV) infection before commencement of MDR-TB drug regimen.

BACKGROUND: Mycobacterium tuberculosis and human immunodeficiency virus (HIV) are known to cause abnormal thyroid function. There is little information on whether HIV infection aggravates alteration of thyroid function in patients with MDR-TB. OBJECTIVES: This study was carried out to determine if HIV co-infection alters serum levels of thyroid hormones (T3, T4) and thyroid stimulating hormone (TSH) in patients with MDR-TB patients and to find out the frequency of subclinical thyroid dysfunction before the commencement of MDR-TB therapy. METHODS: This observational and cross-sectional study involved all the newly admitted patients in MDR-TB Referral Centre, University College Hospital, Ibadan, Nigeria between July 2010 and December 2014. Serum levels of thyroid stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were determined using ELISA. RESULTS: Enrolled were 115 patients with MDR-TB, out of which 22 (19.13%) had MDR-TB/HIV co-infection. Sick euthyroid syndrome (SES), subclinical hypothyroidism and subclinical hyperthyroidism were observed in 5 (4.35%), 9 (7.83%) and 2 (1.74%) patients respectively. The median level of TSH was insignificantly higher while the median levels of T3 and T4 were insignificantly lower in patients with MDR-TB/HIV co-infection compared with patients with MDRT-TB only. CONCLUSION: It could be concluded from this study that patients with MDR-TB/HIV co-infection have a similar thyroid function as patients having MDR-TB without HIV infection before commencement of MDR-TB drug regimen. Also, there is a possibility of subclinical thyroid dysfunction in patients with MDR-TB/HIV co-infection even, before the commencement of MDR-TB therapy.

Innate Cellular Immunity in Newly Diagnosed Pulmonary Tuberculosis Patients and During Chemotherapy.

BACKGROUND: Leukocyte migration (LM) and intracellular killing aspects of the innate immune response play important roles in protection against and containment and cure of Mycobacterium tuberculosis infection, and thus may be exploited as immunotherapeutic targets to improve the management and treatment outcomes of patients with tuberculosis (TB). OBJECTIVES: The aim of this study was to assess LM and mediators of intracellular killing in patients with TB at the time of diagnosis and during anti-TB chemotherapy and compare them with apparently healthy controls. METHODS: We recruited 24 patients who were newly diagnosed with pulmonary TB and 20 apparently healthy individuals. Blood was drawn from patients with TB at the time of diagnosis, and after 2, 4, and 6 months of anti-TB chemotherapy and control. In vitro percentage LM (%LM) upon stimulation with Bacillus Calmette-Guérin vaccine, percentage nitroblue tetrazolium (%NBT) reduction, plasma concentrations of hydrogen peroxide (H2O2), and nitric oxide (NO) were assessed in both groups. FINDINGS: Percentage NBT was significantly reduced in patients with TB at 2 months of anti-TB chemotherapy compared with patients at diagnosis and in healthy controls, whereas %LM was significantly increased in patients at 4 months of anti-TB chemotherapy compared with patients at diagnosis and controls. Mean plasma H2O2 and NO were significantly reduced in patients at diagnosis and throughout the period of anti-TB chemotherapy compared with the control group. Significant decreases were demonstrated in mean plasma H2O2 and NO in patients at 2 and 4 months of anti-TB chemotherapy, respectively, compared with patients at diagnosis. There was significant positive correlation between %NBT with plasma H2O2 and NO, but %LM was negatively correlated with plasma H2O2 in this group. CONCLUSION: The intracellular killing aspect of innate cellular immunity is deficient in patients with TB, especially 2 to 4 months after commencement of treatment. Therefore, measures (eg, arginine supplementation) to improve intracellular killing in these patients is advocated. Moreover, %LM assay with Bacillus Calmette-Guérin vaccine as an antigen may be used to differentiate those newly diagnosed patients from those on anti-TB chemotherapy.