10 research outputs found

    Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State, Nigeria

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    <p>Abstract</p> <p>Background</p> <p>The control of urinary schistosomiasis in Ogun State, Nigeria remains inert due to lack of reliable data on the geographical distribution of the disease and the population at risk. To help in developing a control programme, delineating areas of risk, geographical information system and remotely sensed environmental images were used to developed predictive risk maps of the probability of occurrence of the disease and quantify the risk for infection in Ogun State, Nigeria.</p> <p>Methods</p> <p>Infection data used were derived from carefully validated morbidity questionnaires among primary school children in 2001–2002, in which school children were asked among other questions if they have experienced "blood in urine" or urinary schistosomiasis. The infection data from 1,092 schools together with remotely sensed environmental data such as rainfall, vegetation, temperature, soil-types, altitude and land cover were analysis using binary logistic regression models to identify environmental features that influence the spatial distribution of the disease. The final regression equations were then used in Arc View 3.2a GIS software to generate predictive risk maps of the distribution of the disease and population at risk in the state.</p> <p>Results</p> <p>Logistic regression analysis shows that the only significant environmental variable in predicting the presence and absence of urinary schistosomiasis in any area of the State was Land Surface Temperature (LST) (B = 0.308, p = 0.013). While LST (B = -0.478, p = 0.035), rainfall (B = -0.006, p = 0.0005), ferric luvisols (B = 0.539, p = 0.274), dystric nitosols (B = 0.133, p = 0.769) and pellic vertisols (B = 1.386, p = 0.008) soils types were the final variables in the model for predicting the probability of an area having an infection prevalence equivalent to or more than 50%. The two predictive risk maps suggest that urinary schistosomiasis is widely distributed and occurring in all the Local Government Areas (LGAs) in State. The high-risk areas (≥ 50% prevalence) however, are confined to scatter foci in the north western part of the State. The model also estimated that 98.99% of schools aged children (5–14 years) are living in areas suitable for urinary schistosomiasis transmission and are at risk of infection.</p> <p>Conclusion</p> <p>The risk maps developed will hopefully be useful to the state health officials, by providing them with detailed distribution of urinary schistosomiasis, help to delineate areas for intervention, assesses population at risk thereby helping in optimizing scarce resources.</p

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

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    Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Baseline and recurrent exposure to the standard dose of artemisinin-based combination therapies (ACTs) induces oxidative stress and liver damage in mice (BALB/c)

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    Abstract Background In malaria-endemic countries, repeated intake of artemisinin-based combination therapies (ACTs) is rampant and driven by drug resistance, improper usage, and easy accessibility. Stress effects and potential liver toxicity due to the frequent therapeutic use of ACTs have not been extensively studied. Here, we investigated the effects of repeated treatment with standard doses of the commonly used ACTs artemether/lumefantrine (A/L) and artesunate-amodiaquine (A/A) on oxidative stress and liver function markers in male mice (BALB/c). Methods Forty Five mice were divided into three groups: control, A/L, and A/A. The drugs were administered three days in a row per week, and the regimen was repeated every two weeks for a total of six cycles. The levels of oxidative stress and liver function markers were measured in both plasma and liver tissue after initial (baseline) and repeated exposures for the second, third, and sixth cycles. Results Exposure to A/L or A/A caused a significant (p < 0.001) increase in plasma malondialdehyde (MDA) levels after the first and repeated exposure periods. However, Hepatic MDA levels increased significantly (p < 0.01) only after the sixth exposure to A/A. Following either single or repeated exposure to A/L or A/A, plasma and liver glutathione peroxidase (GPx) and catalase (CAT) activities, plasma aspartate and alanine transaminase, alkaline phosphatase activity, and bilirubin levels increased, whereas total plasma protein levels decreased significantly (p < 0.001). Varying degrees of hepatocyte degeneration and blood vessel congestion were observed in liver tissues after a single or repeated treatment period. Conclusion Irrespective of single or repeated exposure to therapeutic doses of A/L or A/A, plasma oxidative stress and liver damage were observed. However, long-term repeated A/A exposure can led to hepatic stress. Compensatory processes involving GPx and CAT activities may help reduce the observed stress

    The Effects of Frequent Therapeutic Administration of Artesunate-amodiaquine and Artemether-lumefantrine on Haematological Markers in BALB/c Mice

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    Artemisinin Combination Therapy (ACT) is readily available in malaria-endemic nations, leading to repeated drug usage by undiagnosed persons. Repeated use of ACT therapy by non-infected individuals may affect blood cells. This study explored how repeated artesunate-amodiaquine (A/A) and artemether-lumefantrine (A/L) treatment in non-infected mice affected haematological markers. 100 male BALB/c mice were randomly divided into 5 groups: non-infected and Plasmodium berghei NK65 infected treated with A/L and A/A 1X, 2X, 3X, 4X, 5X, and 6X, and the control group. Packed cell volume (PCV), Haemoglobin (Hb), and red blood cell (RBC) were reduced (p>0.05) non-significantly in the non-infected group treated with A/L or A/A six times compared to the control and infected groups. WBC rose in infected and non-infected mice treated with A/L or A/A 1X, 2X, 3X, and 6X, with a substantial rise in non-infected mice treated with A/L (p < 0.01) and A/A (p < 0.001) three times. WBC mainly rose due to lymphocytes, although neutrophils decreased. Repeated therapeutic use of A/L and A/A without infection may cause a haematological change. Continuous efforts are needed to educate the public about screening for malaria parasites before using drugs

    Risk map of suitable areas for urinary schistosomiasis transmission in Ogun State based on predicted probability of 0

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    75.<p><b>Copyright information:</b></p><p>Taken from "Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State, Nigeria"</p><p>http://www.biomedcentral.com/1471-2334/8/74</p><p>BMC Infectious Diseases 2008;8():74-74.</p><p>Published online 31 May 2008</p><p>PMCID:PMC2438363.</p><p></p

    Risk model map of presence of high-risk schools for urinary schistosomiasis in Ogun State as observed and predicted through logistic regression

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    <p><b>Copyright information:</b></p><p>Taken from "Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State, Nigeria"</p><p>http://www.biomedcentral.com/1471-2334/8/74</p><p>BMC Infectious Diseases 2008;8():74-74.</p><p>Published online 31 May 2008</p><p>PMCID:PMC2438363.</p><p></p

    Risk model map of presence of urinary schistosomiasis in Ogun State as observed and predicted through logistic regression

    No full text
    <p><b>Copyright information:</b></p><p>Taken from "Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State, Nigeria"</p><p>http://www.biomedcentral.com/1471-2334/8/74</p><p>BMC Infectious Diseases 2008;8():74-74.</p><p>Published online 31 May 2008</p><p>PMCID:PMC2438363.</p><p></p

    Impact of the COVID-19 pandemic on patients with paediatric cancer in low-income, middle-income and high-income countries: a multicentre, international, observational cohort study

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    OBJECTIVES: Paediatric cancer is a leading cause of death for children. Children in low-income and middle-income countries (LMICs) were four times more likely to die than children in high-income countries (HICs). This study aimed to test the hypothesis that the COVID-19 pandemic had affected the delivery of healthcare services worldwide, and exacerbated the disparity in paediatric cancer outcomes between LMICs and HICs. DESIGN: A multicentre, international, collaborative cohort study. SETTING: 91 hospitals and cancer centres in 39 countries providing cancer treatment to paediatric patients between March and December 2020. PARTICIPANTS: Patients were included if they were under the age of 18 years, and newly diagnosed with or undergoing active cancer treatment for Acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, Wilms' tumour, sarcoma, retinoblastoma, gliomas, medulloblastomas or neuroblastomas, in keeping with the WHO Global Initiative for Childhood Cancer. MAIN OUTCOME MEASURE: All-cause mortality at 30 days and 90 days. RESULTS: 1660 patients were recruited. 219 children had changes to their treatment due to the pandemic. Patients in LMICs were primarily affected (n=182/219, 83.1%). Relative to patients with paediatric cancer in HICs, patients with paediatric cancer in LMICs had 12.1 (95% CI 2.93 to 50.3) and 7.9 (95% CI 3.2 to 19.7) times the odds of death at 30 days and 90 days, respectively, after presentation during the COVID-19 pandemic (p<0.001). After adjusting for confounders, patients with paediatric cancer in LMICs had 15.6 (95% CI 3.7 to 65.8) times the odds of death at 30 days (p<0.001). CONCLUSIONS: The COVID-19 pandemic has affected paediatric oncology service provision. It has disproportionately affected patients in LMICs, highlighting and compounding existing disparities in healthcare systems globally that need addressing urgently. However, many patients with paediatric cancer continued to receive their normal standard of care. This speaks to the adaptability and resilience of healthcare systems and healthcare workers globally

    Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

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    Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality
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