An Approach to Reaeration Coefficient Modeling in Local Surface Water Quality Monitoring

Reaeration coefficient (k2) for River Atuwara, Ogun State, Nigeria was calculated from dissolved oxygen and biochemical oxygen demand data collected over period of 3 months covering the two prevailing climatic seasons in the country. Both the Akaike and Bayesian information criteria were used in the selection and analysis of ten models to identify the most suitable reaeration coefficient (k2) model for Atuwara River. Models that passed the confidence limit were subjected to model evaluation using measures of agreement between observed and predicted data such as percent bias, Nash–Sutcliffe efficiency, and root mean square observation standard deviation ratio. The used approach yield better results than empirical models developed for local conditions while it is also useful in conserving scarce resources

An Approach to Reaeration Coefficient Modeling in Local Surface Water Quality Monitoring

Reaeration coefficient (k2) for River Atuwara, Ogun State, Nigeria was calculated from dissolved oxygen and biochemical oxygen demand data collected over period of 3 months covering the two prevailing climatic seasons in the country. Both the Akaike and Bayesian information criteria were used in the selection and analysis of ten models to identify the most suitable reaeration coefficient (k2) model for Atuwara River. Models that passed the confidence limit were subjected to model evaluation using measures of agreement between observed and predicted data such as percent bias, Nash–Sutcliffe efficiency, and root mean square observation standard deviation ratio. The used approach yield better results than empirical models developed for local conditions while it is also useful in conserving scarce resources

Knowledge of blood donation among adults in north-central Nigeria

Background: About half of the population in Nigeria is medically fit for blood donation but only four in one thousand are voluntary donors. The low level of blood donation has been attributed to poor knowledge, misconceptions, myths, bias, poverty, fear, malnutrition among the population. Therefore, this study assessed the knowledge of blood donation among adults in two selected North Central States of Nigeria.Methods: It was a descriptive cross-sectional study. A total of 3104 respondents comprising of adults between 18 and 60 years were involved in the study. A multistage sampling technique was used and the research tool was interviewer-administered questionnaire. The data generated were entered into the computer and subjected to appropriate statistical analysis using EPI INFO computer software package (version 3.5.3). Pearson Chi Square (χ2) was used to test statistical significance and p-value was set at < 0.05.Results: Majority of the respondents 2565 (82.5%) knew that blood donation save lives. More than three-quarters, 2468 (79.5%), knew where to go for voluntary blood donation. About one-third, (37.1%), demonstrated good knowledge of voluntary blood donation. Older respondents (>60 years) had poor knowledge of blood transfusion compared with younger age groups (p<0.001). Respondents’ occupation and educational status were significantly associated with knowledge of blood transfusion (p<0.001)Conclusion: Periodic awareness programme on voluntary blood donation in rural and urban areas across Nigeria is needed. In addition, sensitization of the informal sector on the significance of non-remunerated voluntary blood donation should be given priority.Keywords: Knowledge, Blood, Donation, North-Central, Nigeri

Determinants of voluntary blood donation among adults in communities of north central region of Nigeria

Objective: The collection of blood from voluntary, non-remunerated blood donors is an important measure for ensuring the safety, quality, availability and accessibility of blood. The study assessed factors affecting voluntary blood donation in North-central zone, Nigeria.Methods: The study design was descriptive cross-sectional, data was collected using a pre-tested interviewer administered questionnaire from 3104 respondents using multistage sampling technique. Data was analyzed using EPI INFO computer software package (version 3.5.3). Level of significance was pre-determined at p-value < 0.05 at a confidence level of 95%.Results: Respondents with good knowledge of voluntary blood donation had better practice of voluntary blood donation. Younger age groups were 8 times more likely to donate blood voluntarily than older respondents. Yoruba ethnic groups are 1.5 times more likely to donate blood than other ethnic groups.Conclusion: For Nigeria and other developing countries at large to achieve 100% voluntary blood donation drive by year 2020, it is critical to change the blood donation culture from replacement to that of volunteerism through more effective communication and mobilization of donors. These efforts must be rendered more methodical and accomplished through a wider range of strategies.Keywords: Determinants, voluntary, blood, donation, Nigeri

Epidemiological profile of the Ebola virus disease outbreak in Nigeria, July-September 2014

Introduction: In July 2014, Nigeria experienced an outbreak of Ebola virus disease following the introduction of the disease by an ill Liberian Traveler. The Government of Nigeria with the support of Technical and Development Partners responded quickly and effectively to contain the outbreak. The epidemiological profile of the outbreak that majorly affected two States in the country in terms of person, place and time characteristics of the cases identified is hereby described. Methods: Using field  investigation technique, all confirmed and probable cases were identified, line-listed and analysed using Microsoft Excel 2007 by persons, time and place. Results: A total of 20 confirmed and probable cases; 16 in Lagos (including the index case from Liberia) and 4 in Port Harcourt were  identified. The mean age was 39.5 ± 12.4 years with over 40% within the age group 30-39 years. The most frequent exposure type was direct physical contact in 70% of all cases and 73% among health care workers. The total case-fatality was 40%; higher among healthcare workers (46%) compared with non-healthcare workers (22%). The epidemic curve initially shows a typical common source outbreak, followed by a propagated pattern. Conclusion: Investigation revealed the size and spread of the outbreak and provided information on the characteristics of persons, time and place. Enhanced surveillance measures, including contact tracing and follow-up proved very useful in early case detection and containment of the outbreak

Possible Impact of Co-infections of Tuberculosis and Malaria on the CD4+ Cell Counts of HIV Patients in Nigeria

Background: This study focused on evaluating the possible impact of co-infections of tuberculosis and malaria on the CD4+ cell counts in HIV infected subjects. Methods: This is a cross sectional study. The subjects were drawn from three hospitals and a blood bank in LagosState. After due consent, blood samples were obtained from 69 subjects with single infections (HIV, TB, and Malaria), 34 subjects with multiple infections (HIV/Malaria, HIV/TB, Malaria/TB, HIV/TB/Malaria) and 24 blood donors (controls). The CD4+ cell counts of all the 127 blood samples were estimated using a FACS count. Results: Data obtained were analysed and a comparison of the results showed that the median CD4+ counts in all groups of subjects with HIV infections (whether single or co-infection) were similar and significantly lower than the median counts for the healthy control group as well as groups without HIV infection (malaria, TB and malaria/TB). Conclusion: Overall data further confirmed the progressive depletion of CD4+ cells in HIV infection while co-infections with TB and malaria did not have any impact on the CD4+ cells of HIV infected subjects. A larger prospective study is needed.Fond: Cette \ue9tude a \ue9t\ue9 consacr\ue9e \ue1 l'\ue9valuation de l'impact possible de co-infections de tuberculose et le paludisme sur les comptes de cellule CD4+ des sujets infect\ue9s du VIH. M\ue9thode: Ceci est une \ue9tude transversale. Les sujets ont \ue9t\ue9 choisis de trois diff\ue9rents h\uf4pitaux et une banque du sang dans l'Etat de Lagos. Apr\ue8s le consentement n\ue9cessaire, les \ue9chantillons de sang ont \ue9t\ue9 obtenus de 69 sujets avec les mono-infections (VIH, TB, et le Paludisme), 34 sujets avec les infections multiples (le VIH/PALUDISME, LE VIH/TB, LE Paludisme/TB, VIH/TB/le Paludisme) et 24 donneurs de sang (les contr\uf4les). les comptes de cellule CD4+ de tous les 127 \ue9chantillons de sang ont \ue9t\ue9 estim\ue9s utilisant une compte FACS. R\ue9sultats: les donn\ue9es obtenues ont \ue9t\ue9 analys\ue9es et une comparaison des r\ue9sultats a d\ue9montr\ue9 que le m\ue9dian des comptes CD4+ dans tous les groupes de sujets avec les infections de VIH (soit mono ou co-infection) \ue9taient similaires et significativement plus bas que les comptes m\ue9dianes pour le groupe de contr\uf4le sain de m\ueame que les groupes sans l'infection de VIH (le paludisme, TB et le paludisme/TB). Conclusion: les donn\ue9es g\ue9n\ue9rales ont confirm\ue9 le plus l'\ue9puisement progressif des cellules CD4+ dans l'infection de VIH pendant que les co-infections avec TB et le paludisme n'ont pas eu aucun impact sur les cellules CD4+ des sujets infect\ue9s de VIH. Une plus profonde \ue9tude sera n\ue9cessaire

The practice of hepatocellular cancer surveillance in Nigeria

Background: Hepatocellular cancer is a disease of global and public health importance due to the widespread distribution of risk factors and associated high case fatality. Hepatocellular Cancer (HCC) in Sub-Saharan Africa is commonly seen among the younger age groups (<45 years) who present mostly in the terminal stage, when the disease is not amenable to any curative therapy. Hepatocellular Carcinoma surveillance employs the use of simple, cheap and readily available investigations, to detect early curable cancer in individuals with risk factors for HCC.Objectives:The aim of this study is to assess the practice of hepatocellular cancer screening among physicians.Methodolgy:This is a nationwide online survey carried out among physicians who care for patients with HCC. A questionnaire was sent out via a web link to all consenting doctors in Nigeria. The responses were collated in a cloud-based application and data was analysed using Epi-info version 20.Results:Atotal of 218 respondents, 142 were males (65.1 %) with a mean age of 37.6 ± 5.7 years. The modal age group was 31-40 years 153 (69.5%). The main factors considered as a hindrance to surveillance were; the cost of the tests (57.7%), failure of return of patients (50.5%) and not being aware of a surveillance program (45.2 %). The majority of the respondents were Gastroenterologists and Family Physicians. 54% of the gastroenterologists and 64% of the family physicians have never offered HCC surveillance to their patients.Conclusion:This survey highlights a knowledge gap in HCC surveillance among physicians. There is a need to make HCCsurveillance a daily routine among patients at risk by all physicians. Keywords: Surveillance, Hepatocellular Carcinoma, HBV, HCV, Cancer screening

Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND: Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. METHODS: The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. FINDINGS: Globally, 18·7% (95% uncertainty interval 18·4–19·0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58·8% (58·2–59·3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48·1 years (46·5–49·6) to 70·5 years (70·1–70·8) for men and from 52·9 years (51·7–54·0) to 75·6 years (75·3–75·9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49·1 years (46·5–51·7) for men in the Central African Republic to 87·6 years (86·9–88·1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216·0 deaths (196·3–238·1) per 1000 livebirths in 1950 to 38·9 deaths (35·6–42·83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5·4 million (5·2–5·6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult males, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. INTERPRETATION: This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950–2019: a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2•72 (95% uncertainty interval [UI] 2•66–2•79) in 2000 to 2•31 (2•17–2•46) in 2019. Global annual livebirths increased from 134•5 million (131•5–137•8) in 2000 to a peak of 139•6 million (133•0–146•9) in 2016. Global livebirths then declined to 135•3 million (127•2–144•1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2•1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27•1% (95% UI 26•4–27•8) of global livebirths. Global life expectancy at birth increased from 67•2 years (95% UI 66•8–67•6) in 2000 to 73•5 years (72•8–74•3) in 2019. The total number of deaths increased from 50•7 million (49•5–51•9) in 2000 to 56•5 million (53•7–59•2) in 2019. Under-5 deaths declined from 9•6 million (9•1–10•3) in 2000 to 5•0 million (4•3–6•0) in 2019. Global population increased by 25•7%, from 6•2 billion (6•0–6•3) in 2000 to 7•7 billion (7•5–8•0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58•6 years (56•1–60•8) in 2000 to 63•5 years (60•8–66•1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019. Interpretation: Over the past 20 years, fertility rates have been dropping steadily and life expectancy has been increasing, with few exceptions. Much of this change follows historical patterns linking social and economic determinants, such as those captured by the GBD Socio-demographic Index, with demographic outcomes. More recently, several countries have experienced a combination of low fertility and stagnating improvement in mortality rates, pushing more populations into the late stages of the demographic transition. Tracking demographic change and the emergence of new patterns will be essential for global health monitoring. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens