Molecular characterization of non-aureus staphylococci and Mammaliicoccus from Hipposideros bats in Southwest Nigeria.

Bats are not only ecologically valuable mammals but also reservoirs of zoonotic pathogens. Their vast population, ability to fly, and inhabit diverse ecological niches could play some role in the spread of antibiotic resistance. This study investigated non-aureus staphylococci and Mammaliicoccus colonization in the Hipposideros bats at Obafemi Awolowo University, Ile-Ife, Nigeria. Pharyngeal samples (n = 23) of the insectivorous bats were analyzed, and the presumptive non-aureus staphylococcal and Mammaliicoccus isolates were confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The isolates were characterized based on antibiotic susceptibility testing and whole-genome sequencing (WGS). Six bacterial genomes were assembled, and three species were identified, including Mammaliicoccus sciuri (n = 4), Staphylococcus gallinarum (n = 1), and Staphylococcus nepalensis (n = 1). All the isolates were resistant to clindamycin, while the M. sciuri and S. gallinarum isolates were also resistant to fusidic acid. WGS analysis revealed that the M. sciuri and S. gallinarum isolates were mecA-positive. In addition, the M. sciuri isolates possessed some virulence (icaA, icaB, icaC, and sspA) genes. Multi-locus sequence typing identified two new M. sciuri sequence types (STs) 233 and ST234. The identification of these new STs in a migratory mammal deserves close monitoring because previously known ST57, ST60, and ST65 sharing ack (8), ftsZ (13), glpK (14), gmk (6), and tpiA (10) alleles with ST233 and ST234 have been linked to mastitis in animals. Moreover, the broad host range of M. sciuri could facilitate the dispersal of antibiotic resistance genes. This study provides evidence of the importance of including migratory animals in monitoring the development and spread of antibiotic resistance.

Transport fare and road traffic crashes in Nigeria: insights from a geographical analysis.

Road traffic crashes (RTCs) are significantly high in Nigeria with serious social and health consequences. While existing studies on RTCs have mainly focused on the effect of socio-economic, environmental, human and mechanical factors to address the high rates, the relationship between road transport fares and RTCs has been glossed over in literature. Thus, this study examines the influence of road transport fares and other covariates on RTCs. Data on RTCs and the predictors between 2017 and 2022 were obtained from the records of the National Bureau of Statistics and the Federal Road Safety Corps. Spatial statistical techniques were used for the data analysis. RTCs vary across the country, and Northern Nigeria is the hot spot. Results from the spatial analysis show that road transport fares, population density, and illiteracy rate are significant predictors of RTCs. The study recommends striking a balance between fare affordability, the quality of service provided, and the implementation of effective transportation strategies.

Adaptive immune cells are necessary for SARS-CoV-2-induced pathology.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the ongoing global pandemic associated with morbidity and mortality in humans. Although disease severity correlates with immune dysregulation, the cellular mechanisms of inflammation and pathogenesis of COVID-19 remain relatively poorly understood. Here, we used mouse-adapted SARS-CoV-2 strain MA10 to investigate the role of adaptive immune cells in disease. We found that while infected wild-type mice lost ~10% weight by 3 to 4 days postinfection, rag-/- mice lacking B and T lymphocytes did not lose weight. Infected lungs at peak weight loss revealed lower pathology scores, fewer neutrophils, and lower interleukin-6 and tumor necrosis factor-α in rag-/- mice. Mice lacking αß T cells also had less severe weight loss, but adoptive transfer of T and B cells into rag-/- mice did not significantly change the response. Collectively, these findings suggest that while adaptive immune cells are important for clearing SARS-CoV-2 infection, this comes at the expense of increased inflammation and pathology.

Age-dependent acquisition of pathogenicity by SARS-CoV-2 Omicron BA.5.

Pathology studies of SARS-CoV-2 Omicron variants of concern (VOC) are challenged by the lack of pathogenic animal models. While Omicron BA.1 and BA.2 replicate in K18-hACE2 transgenic mice, they cause minimal to negligible morbidity and mortality, and less is known about more recent Omicron VOC. Here, we show that in contrast to Omicron BA.1, BA.5-infected mice exhibited high levels of morbidity and mortality, correlating with higher early viral loads. Neither Omicron BA.1 nor BA.5 replicated in brains, unlike most prior VOC. Only Omicron BA.5-infected mice exhibited substantial weight loss, high pathology scores in lungs, and high levels of inflammatory cells and cytokines in bronchoalveolar lavage fluid, and 5- to 8-month-old mice exhibited 100% fatality. These results identify a rodent model for pathogenesis or antiviral countermeasure studies for circulating SARS-CoV-2 Omicron BA.5. Further, differences in morbidity and mortality between Omicron BA.1 and BA.5 provide a model for understanding viral determinants of pathogenicity.

Crosstalk between hypoxic cellular micro-environment and the immune system: a potential therapeutic target for infectious diseases.

There are overwhelming reports on the promotional effect of hypoxia on the malignant behavior of various forms of cancer cells. This has been proposed and tested exhaustively in the light of cancer immunotherapy. However, there could be more interesting functions of a hypoxic cellular micro-environment than malignancy. There is a highly intricate crosstalk between hypoxia inducible factor (HIF), a transcriptional factor produced during hypoxia, and nuclear factor kappa B (NF-κB) which has been well characterized in various immune cell types. This important crosstalk shares common activating and inhibitory stimuli, regulators, and molecular targets. Impaired hydroxylase activity contributes to the activation of HIFs. Inflammatory ligands activate NF-κB activity, which leads to the expression of inflammatory and anti-apoptotic genes. The eventual sequelae of the interaction between these two molecular players in immune cells, either bolstering or abrogating functions, is largely cell-type dependent. Importantly, this holds promise for interesting therapeutic interventions against several infectious diseases, as some HIF agonists have helped prevent immune-related diseases. Hypoxia and inflammation are common features of infectious diseases. Here, we highlighted the role of this crosstalk in the light of functional immunity against infection and inflammation, with special focus on various innate and adaptive immune cells. Particularly, we discussed the bidirectional effects of this crosstalk in the regulation of immune responses by monocytes/macrophages, dendritic cells, neutrophils, B cells, and T cells. We believe an advanced understanding of the interplay between HIFs and NF-kB could reveal novel therapeutic targets for various infectious diseases with limited treatment options.

Usutu virus: An emerging flavivirus with potential threat to public health in Africa: Nigeria as a case study.

Usutu virus (USUV) is an arthropod-borne virus (arbovirus) of the flaviviridae family (genus Flavivirus) which belong to the Japanese encephalitis virus complex. Culex mosquitoes have been implicated in the transmission of this pathogen. The major susceptible hosts of USUV are migratory birds, thereby potentiating its ability to spread from one region to another globally. Nigeria has the largest economy in Africa with a significant percentage of the gross domestic product relying on the agricultural and animal production industry. This review explores the zoonotic potentials of the virus in Africa, especially Nigeria, with special focus on the devastating sequelae this might lead to in the future if necessary precautionary policies are not enacted and adopted to bolster the surveillance system for mosquito-borne viruses.

Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria.

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.

Is there a relationship between internet access and COVID-19 mortality? Evidence from Nigeria based on a spatial analysis.

With over 6.5 million deaths due to COVID-19, it has become an issue of global health concern. Early findings have identified several social determinants of deaths from COVID-19. However, very few studies have been done on the relationship between internet access and COVID-19 mortality in the context of developing countries. Using geospatial methods, this study examines the relationship between internet access and COVID-19 mortality disparity in Nigeria. In contrast to the widely reported relationship in the literature that internet access lowers the risk of COVID-19 mortality, the current study finds that geographical locations with the highest internet access are the hotspots of COVID-19 mortality in Nigeria, especially some parts of southwest Nigeria. In addition, findings show that population density and unemployment are risk factors of COVID-19 mortality. The study recommends educating the population on the use of online health information and the need to adhere strictly to non-pharmaceutical and vaccination interventions to reduce the number of deaths caused by the virus.

Detection of Alpha- and Betacoronaviruses in Frugivorous and Insectivorous Bats in Nigeria.

The rise of bat-associated zoonotic viruses necessitates a close monitoring of their natural hosts. Since the detection of severe acute respiratory syndrome coronavirus (SARS-CoV), it is evident that bats are vital reservoirs of coronaviruses (CoVs). In this study, we investigated the presence of CoVs in multiple bat species in Nigeria to identify viruses in bats at high-risk human contact interfaces. Four hundred and nine bats comprising four bat species close to human habitats were individually sampled from five states in Nigeria between 2019 and 2021. Coronavirus detection was done using broadly reactive consensus PCR primers targeting the RNA-dependent RNA polymerase (RdRp) gene of CoVs. Coronavirus RNA was detected in 39 samples (9.5%, CI 95%: [7.0, 12.8]), of which 29 were successfully sequenced. The identified CoVs in Nigerian bats were from the unclassified African alphacoronavirus lineage and betacoronavirus lineage D (Nobecovirus), with one sample from Hipposideros ruber coinfected with alphacoronavirus and betacoronavirus. Different bat species roosting in similar or other places had CoVs from the same genetic lineage. The phylogenetic and evolutionary dynamics data indicated a high CoV diversity in Nigeria, while host switching may have contributed to CoV evolution. Robust sentinel surveillance is recommended to enhance our knowledge of emerging and re-emerging coronaviruses.

A Geographical Analysis of the African COVID-19 Paradox: Putting the Poverty-as-a-Vaccine Hypothesis to the Test.

The poverty-as-a-vaccine hypothesis came to light following the wide circulation of the controversial British Broadcasting Corporation (BBC) World Service post on the internet and social media. It was a theoretical response to what this paper has termed as "the African COVID-19 paradox" or what some have characterised as the "African COVID-19 anomaly" whose thesis is though Africa is the poorest continent in the world, yet it has some of the lowest COVID-19 infection and mortality rates globally. This paradoxical profile apparently contradicts earlier and grim projections by several international bodies on the fate of Africa in this global health crisis. Given this background, we specifically tested the validity of the hypothesis from a geographic perspective within the spatial framework of Africa. Data came from secondary sources. Evidence truly points out a significant negative relationship between COVID-19 and poverty in Africa and thus statistically supports the poverty-as-a-vaccine hypothesis. However, this does not confirm that poverty confers immunity against COVID-19 but it implicitly shows there are complex factors responsible for the anomaly. The main conclusion of the paper is that poverty has no protective immunity against COVID-19 in Africa and is therefore not tenable.

Geographical patterns and effects of human and mechanical factors on road traffic crashes in Nigeria.

Road traffic crashes (RTCs) remain an issue of global concern particularly in Nigeria where over 80 percent of these crashes are accounted by human and mechanical factors (HM). Many geographic studies on RTCs, fatality and injury have largely focused on the spatial clustering and associative analysis of risk factors; with little known about the relative contribution of HM factors within the spatial context. Hence, this study applied a spatial approach to the effect of HM factors on RTCs, fatality and injury across the regions of Nigeria. The data for this study were obtained from the National Bureau of Statistics for the year 2017-2019 and were analysed using spatial analysis techniques such as Global Moran's I and spatial regression model. There was evidence of geographic clustering of RTCs, fatality and injury in Nigeria. On one hand, route violation and sleeping on steering were significant predictors in southern Nigeria while tyre burst was significant at the national level, in the north and rural areas. The use of mobile phone while driving was a significant predictor at the national level. On the other hand, overloading was associated with RTCs and injuries at the national level and northern Nigeria. Speed violation was a prominent risk factor across the country. The study, based on observed regional differentials, argues that extant laws and regulations on traffic safety should be strictly enforced to curtail RTCs in the country.

A retrospective cross-national examination of COVID-19 outbreak in 175 countries: a multiscale geographically weighted regression analysis (January 11-June 28, 2020).

OBJECTIVE: This study retrospectively examined the health and social determinants of the COVID-19 outbreak in 175 countries from a spatial epidemiological approach. METHODS: We used spatial analysis to examine the cross-national determinants of confirmed cases of COVID-19 based on the World Health Organization official COVID-19 data and the World Bank Indicators of Interest to the COVID-19 outbreak. All models controlled for COVID-19 government measures. RESULTS: The percentage of the population age between 15-64 years (Age15-64), percentage smokers (SmokTot.), and out-of-pocket expenditure (OOPExp) significantly explained global variation in the current COVID-19 outbreak in 175 countries. The percentage population age group 15-64 and out of pocket expenditure were positively associated with COVID-19. Conversely, the percentage of the total population who smoke was inversely associated with COVID-19 at the global level. CONCLUSIONS: This study is timely and could serve as a potential geospatial guide to developing public health and epidemiological surveillance programs for the outbreak in multiple countries. Removal of catastrophic medical expenditure, smoking cessation, and observing public health guidelines will not only reduce illness related to COVID-19 but also prevent unecessary deaths.