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Mass balance equations can be used to quantify the level of fossil carbon dioxide (CO2)ff at a given site by using samples of tree leaves or tree rings. These sites are often densely populated and highly industrialized areas. In this case, in addition to the natural carbon dioxide level of the site, there are several other components that are added to it. The approaches we propose in this paper are based on the isotopic fractionation of carbon and the laws of matter conservation. Mathematical equations are derived from this and we propose approaches to establish them. Our method has allowed us to come to the conclusion of the relationship that is already found in literature. But we term this relationship in another way by introducing the fraction of carbon modern F and the proportion of CO2 derived from fossil fuels, which will be noted (S)ff for the following. As an indicator of the Suess Effect, we have calculated these values in our different sites. Wooded areas sites which are located in urban areas have higher value of proportion of fossil fuel (S)ff .

Data on influenza vaccine immunogenicity in children are limited from tropical developing countries. We recently reported significant, moderate effectiveness of a trivalent inactivated influenza vaccine (IIV) in a controlled, cluster-randomized trial in children in rural Senegal during 2009, a year of H3N2 vaccine mismatch (NCT00893906). We report immunogenicity of IIV3 and inactivated polio vaccine (IPV) from that trial. We evaluated hemagglutination inhibition (HAI) and polio antibody titers in response to vaccination of three age groups (6 through 35 months, 3 through 5 years, and 6 through 8 years). As all children were IIV naive, each received two vaccine doses, although titers were assessed after only the first dose for subjects aged 6 through 8 years. Seroconversion rates (4-fold titer rise or increase from

The advent of the COVID-19 pandemic and the dynamics of its spread is unprecedented. Therefore, the need for a vaccine against the virus is huge. Researchers worldwide are working around the clock to find a vaccine. Experts estimate that a fast-tracked vaccine development process could speed a successful candidate to market in approximately 12-18 months. The objective of this review was to describe the coronavirus vaccines candidates in development and the important considerations. The review was conducted through a thematic analysis of the literature on COVID-19 vaccines in development. It only included data until the end of June 2020, 6 months after the emergence of the COVID-19. Different approaches are currently used to develop COVID-19 vaccines from traditional live-attenuated, inactivated, subunit vaccines, to more novel technologies such as DNA or mRNA vaccines. The race is on to find both medicines and vaccines for the COVID-19 pandemic. As with drugs, vaccine candidates go through pre-clinical testing first before they go through the three phases of clinical trials in humans. Of the over 130 vaccine candidates, 17 are in clinical trials while others are expected to move to clinical testing after the animal studies.

Background The population effects of influenza vaccination in children have not been extensively studied, especially in tropical, developing countries. In rural Senegal, we assessed the total (primary objective) and indirect effectiveness of a trivalent inactivated influenza vaccine (IIV3). Methods In this double-blind, cluster-randomized trial, villages were randomly allocated (1:1) for the high-coverage vaccination of children aged 6 months through 10 years with either the 2008–09 northern hemisphere IIV3 or an inactivated polio vaccine (IPV). Vaccinees were monitored for serious adverse events. All village residents, vaccinated and unvaccinated, were monitored for signs and symptoms of influenza illness using weekly home visits and surveillance in designated clinics. The primary outcome was all laboratory-confirmed symptomatic influenza. Results Between 23 May and 11 July 2009, 20 villages were randomized, and 66.5% of age-eligible children were enrolled (3918 in IIV3 villages and 3848 in IPV villages). Follow-up continued until 28 May 2010. There were 4 unrelated serious adverse events identified. Among vaccinees, the total effectiveness against illness caused by the seasonal influenza virus (presumed to all be drifted A/H3N2, based on antigenic characterization data) circulating at high rates among children was 43.6% (95% confidence interval [CI] 18.6–60.9%). The indirect effectiveness against seasonal A/H3N2 was 15.4% (95% CI -22.0 to 41.3%). The total effectiveness against illness caused by the pandemic influenza virus (A/H1N1pdm09) was -52.1% (95% CI -177.2 to 16.6%). Conclusions IIV3 provided statistically significant, moderate protection to children in Senegal against circulating, pre-2010 seasonal influenza strains, but not against A/H1N1pdm09, which was not included in the vaccine. No indirect effects were measured. Further study in low-resource populations is warranted. Clinical Trials Registration NCT00893906.

International audience; This study contributes to the literature about the effects of space and place on health by introducing a socio-territorial approach to urban health disparities in West Africa. It explores how urban spaces, specifically neighbourhoods, are shaped by social and economic relations and strategies of territorial control. We examine the potential influence of socio-territorial processes on vulnerability to disease, access to medical care, healthscapes, and illness experiences. Our research was conducted in Senegal and relied on a mixed methods design. We identified four neighbourhoods that represent the socio-spatial heterogeneity of the city of Saint-Louis and utilized the following methods: geographic and anthropological field research, household surveys, health knowledge and behaviour surveys, clinical exams, and illness interviews. Our results highlight the socio-territorial processes at work in each neighbourhood, clinical findings on three health measures (overweight, high blood pressure, and hyperglycaemia) and health experiences of individuals with hypertension or type II diabetes. We found significant differences in the prevalence of the three health measures in the study sites, while experiences managing hypertension and diabetes were similar. We conclude that a socio-territorial approach offers insight into the complex constellation of forces that produce health disparities in urban settings.

La vaccination est incontestablement l’une des interventions de santé publique les plus efficaces et les plus rentables qui soient. Les vaccins continuent de révolutionner notre capacité à prévenir les maladies et à améliorer la santé. Avec toutes les avancées technologiques, nous sommes en mesure d’étendre les avantages des vaccins à plus de gens et de fournir une meilleure protection contre les maladies infectieuses mortelles. Toutefois, avec le développement incessant de nouvelles souches microbiennes à travers le monde, la recherche en vaccinologie se doit d’innover continuellement. D’énormes progrès ont été réalisés pour améliorer la couverture vaccinale et introduire de nouveaux vaccins en Afrique. De nouveaux types de vaccins associés à des outils de vectorisation, d’administration et de délivrance spécifiques mais aussi des adjuvants susceptibles de moduler finement la réponse immunitaire sont attendus dans le futur. En Afrique, il est nécessaire de développer une approche régionale afin de répondre efficacement aux nombreux défis. Une meilleure information, la formation des personnels de santé en vaccinologie et des recherches bien ciblées sont les clés des futurs accomplissements dans le domaine.

Invasive species are considered as one of the most environmental challenges of the 21st century. They constitute the second cause of biodiversity loss and lead to high economic disruption and public health. Despite significant, financial and human investments made by countries and world conservation of biodiversity agencies, there are not strategies that lead to appropriate measures for sustainable management and control. The objective of this study is to assess the state of knowledge on invasive plants in West Africa and to promote knowledge and exchange information. It contributes also to establish in Western African region, a coordinated early warning system through a network of intervention. The paper discusses concepts and bio-ecology of invasive plants, gives precise indications on their diversity and distribution. To achieve the objectives, a literature review was carried out to collect data on invasive species from Western African countries. Therefore, different information sources included floras, database and collection were consulted. The results how that in West Africa, the information collected on invasive plants indicate that 113 invasive species are reported, distributed in 94 genera and 43 families. The most represented families are Poaceae (17 species) and Leguminosae (16 species). They are followed by Cyperaceae (9 species) and Asteraceae (6 species). Euphorbiaceae, Solanaceae and Nympheaceae have 4 species each one. The most common invasive species in West African countries are present in, at least, eight countries. They are: Chromolaena odorata, Eichhornia crassipes, Salvinia molesta, Typha domingensis and Pistia stratiotes. Depending on data availability, the presence and importance of invasive plants vary from one country to another. It must be noticed that there are few data related to Cape Verde, Guinea Bissau and Nigeria. Recommendations were formulated to improve knowledge and sustainable management of invasive plants in West Africa. The expected results of this work should improve the understanding of issues related to invasive species at national and regional levels

Since the initial reports of a link between Zika and microcephaly, researchers across the world began working toward understanding the virus. In a short amount of time, Zika has become a household name, prompting worldwide concern. The virus is spread rapidly by mosquito bites. We currently do not have a vaccine for Zika. But with the recent findings, vaccine companies are mobilizing their resources to expedite efforts to shave years off the typical decade-long process of vaccine development. The Pan African Medical Journal 2016;24

Influenza is one of the major infectious disease threats to the world New Global Burden of Disease estimates attribute nearly of all cause mortality during the first five years of life to influenza In tropical developing countries the pattern of influenza circulation may differ markedly from those in temperate developed settings Of influenza deaths are estimated to occur in low and middle income countries Studies on seasonal influenza occurrence morbidity and mortality in sub Saharan Africa published from January st to December st were reviewed in order to assess the burden of seasonal influenza in the Region The starting date of January st has been selected because of the increasing number and quality of studies in later years Relevant studies were identified using combinations of Medical Subject Headings MeSH and text terms as follows ldquo influenza rdquo AND ldquo Africa rdquo OR ldquo Africa rdquo AND ldquo pneumonia rdquo OR ldquo acute respiratory infection rdquo OR ldquo influenza rdquo AND each individual sub Saharan African country The study seems to show that seasonal influenza could have a greater toll on morbidity and mortality in Africa compared with more developed continents considering the frequency of predisposing factors such as HIV and TB and the absence of influenza vaccination programs in most of the African countries Available data suggest both the respiratory disease and influenza associated mortality may be increased in low income settings such as sub Saharan Africa

Background Group A meningococci are the source of major epidemics of meningitis in Africa. An affordable, highly immunogenic meningococcal A conjugate vaccine is needed. Methods We conducted two studies in Africa to evaluate a new MenA conjugate vaccine (PsA-TT). In study A, 601 children, 12 to 23 months of age, were randomly assigned to receive PsA-TT, a quadrivalent polysaccharide reference vaccine (PsACWY), or a control vaccine (Haemophilus influenzae type b conjugate vaccine [Hib-TT]). Ten months later, these children underwent another round of randomization within each group to receive a full dose of PsA-TT, a one-fifth dose of PsACWY, or a full dose of Hib-TT, with 589 of the original participants receiving a booster dose. In study B, 900 subjects between 2 and 29 years of age were randomly assigned to receive PsA-TT or PsACWY. Safety and reactogenicity were evaluated, and immunogenicity was assessed by measuring the activity of group A serum bactericidal antibody (SBA) with rabbit complement and performing an IgG group A-specific enzyme-linked immunosorbent assay. Results In study A, 96.0% of the subjects in the PsA-TT group and 63.7% of those in the PsACWY group had SBA titers that were at least four times as high as those at baseline; in study B, 78.2% of the subjects in the PsA-TT group and 46.2% of those in the PsACWY group had SBA titers that were at least four times as high as those at baseline. The geometric mean SBA titers in the PsA-TT groups in studies A and B were greater by factors of 16 and 3, respectively, than they were in the PsACWY groups (P

New Global Burden of Disease estimates attribute nearly 2% of all-cause mortality during the first five years of life to influenza. Of influenza deaths, 99% are estimated to occur in low and middle income countries. Effective influenza vaccines have been available for decades, but their use in sub-Saharan Africa has been limited. Lack of data on seasonal influenza in the region has left questions regarding risk groups and disease burden largely unanswered. Sub-Saharan African countries have limited expertise with data on influenza epidemiology and with influenza vaccines. Such regional capacity must be strengthened if countries are to make the best evidencebased decisions about influenza vaccine use and to maintain a sense of program ownership. A regionalization of efforts would be the most realistic and feasible approach for future influenza vaccine policy consideration as it would leverage individual country strengths and capacities. The pathway for influenza vaccine introduction in sub-Saharan Africa could be as follows: (i) strengthening laboratory capacity and influenza surveillance; (ii) conduct of research studies, such as burden studies, in a few key countries; (iii) improved communication of data; (iv) development of policy strategies; (v) building vaccine production capacity; (vi) identification of financing and development of political will; (vii) and reliance on well-informed technical advisory committees. Additional concerns regarding influenza vaccine implementation include capacity to administer vaccine outside of existing routine immunization systems, program sustainability, and the importance of local and regional program control. Successful introduction of sustained influenza vaccination programs into the sub-Saharan African region will require adherence to a clear plan that includes strong evidence-based decision-making processes, evidence of operational feasibility, and assurances of sustainability.

Chikungunya is a mosquito-borne disease caused by an alphavirus from the Togaviridae family. The Chikungunya virus (CHIKV) is transmitted by the Aedes mosquitoes. The usual clinical signs of chikungunya are non-specific flu-like symptoms, a distinctive rash and severe joint pains. The disease shares some clinical signs with dengue and can be misdiagnosed in areas where dengue is endemic. There is no vaccine nor a specific antiviral treatment for CHIKV. CHIKV was initially seen in the early 1950s at the boundary of Tanzania and Mozambique. For the past 5 decades, CHIKV was limited to sub-Saharan Africa in addition to Southeast Asia. The situation worsened when CHIKV re-emerged in Kenya in 2004 and reached several other countries in and around the Indian Ocean. The epidemic swiftly reached regions like India and Southeast Asia and transmission of CHIKV was reported for the first time in Europe in 2007 in Italy. The purpose of this review is to summarize CHIKV outbreaks that have been reported in the 15-year period from 2000 to 2015 to show that periodic outbreaks have occurred not only in Asia and Africa, but in Europe and the Americas. It is evident that CHIKV is not restricted to a single region but has become a global public health challenge. As many citizens from non-endemic countries visit areas endemic for CHIKV fever, medical professionals must learn to recognize such cases among travelers returning from such areas with non-specific symptoms such as fever, arthralgia and skin eruptions. In endemic areas for mosquito-borne diseases, clinicians must be educated about the recognition, diagnosis and timely reporting of chikungunya virus disease cases.

This study contributes to the literature about the effects of space and place on health by introducing a socio-territorial approach to urban health disparities in West Africa. It explores how urban spaces, specifically neighbourhoods, are shaped by social and economic relations and strategies of territorial control. We examine the potential influence of socio-territorial processes on vulnerability to disease, access to medical care, healthscapes, and illness experiences. Our research was conducted in Senegal and relied on a mixed methods design. We identified four neighbourhoods that represent the socio-spatial heterogeneity of the city of Saint-Louis and utilized the following methods: geographic and anthropological field research, household surveys, health knowledge and behaviour surveys, clinical exams, and illness interviews. Our results highlight the socio-territorial processes at work in each neighbourhood, clinical findings on three health measures (overweight, high blood pressure, and hyperglycaemia) and health experiences of individuals with hypertension or type II diabetes. We found significant differences in the prevalence of the three health measures in the study sites, while experiences managing hypertension and diabetes were similar. We conclude that a socio-territorial approach offers insight into the complex constellation of forces that produce health disparities in urban settings.

Influenza viruses cause annual epidemics of respiratory tract disease that affect all age groups. Many developing countries do not have an influenza surveillance system or adequate laboratory capacity for virus detection. The objective of this study was to describe the influenza surveillance systems in the different countries in the tropics and to identify outstanding research needs. A questionnaire was designed and sent to 52 NICs and MoHs in the different countries in tropical Asia and Africa to gather information on the surveillance systems, sentinel sites, specimen and data collection, and laboratory testing. Replies were received from 32 NICs and MoHs (61.5% response) – 17 were located in tropical Asia and 15 in Africa. There are 20 WHO recognized NICs in tropical Asia and 14 in tropical Africa, all with virus isolation and polymerase chain reaction (PCR) testing capacity. Of the Asian countries, only Hong Kong and Singapore reported that the patient population from the sites represents the broader community. In tropical Africa, only Senegal has sentinel sites distributed all over the country contributing to the geographic representativeness of the surveillance system. The rest of the countries in Africa have just established their influenza surveillance system in the past decade and are working toward geographic expansion of the ILI and SARI sites. Limited laboratory capacity or infrastructure to perform influenza surveillance makes difficult to justify the importance of influenza vaccine or other influenza control measures as a strategy for improving population health in the tropical region.Key words: Tropical region, influenza surveillance, epidemics of respiratory

Background In this study, we suggested characterizing the vasodilator effects and the phytochemical characteristics of a plant with food usage also used in traditional treatment of arterial high blood pressure in Senegal. Methods Vascular effects of crude extract of dried and powdered calyces of Hibiscus sabdariffa were evaluated on isolated thoracic aorta of male Wistar rats on organ chambers. The crude extract was also enriched by liquid-liquid extraction. The various cyclohexane, dichloromethane, ethyl acetate, butanol extracts obtained as well as the residual marc were subjected to Sephadex LH-20 column chromatography. The different methanolic eluate fractions were then analyzed by Thin Layer (TLC) and High Performance Liquid Chromatography (HPLC) and their vascular effects also evaluated. Results The H. Sabdariffa crude extract induced mainly endothelium-dependent relaxant effects. The endothelium-dependent relaxations result from NOS activation and those who not dependent to endothelium from activation of smooth muscle potassium channels. The phytochemical analysis revealed the presence of phenolic acids in the ethyl acetate extract and anthocyans in the butanolic extract. The biological efficiency of the various studied extracts, in term of vasorelaxant capacity, showed that: Butanol extract > Crude extract > Residual marc > Ethyl acetate extract. These results suggest that the strong activity of the butanolic extract is essentially due to the presence of anthocyans found in its fractions 43-67. Conclusion These results demonstrate the vasodilator potential of hibiscus sabdariffa and contribute to his valuation as therapeutic alternative.