2,335 research outputs found

    Analysis of environmental factors influence on endemic cholera risks in sub-Saharan Africa

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    The recurring cholera outbreaks in sub-Saharan Africa are of growing concern, especially considering the potential acceleration in the global trend of larger and more lethal cholera outbreaks due to the impacts of climate change. However, there is a scarcity of evidence-based research addressing the environmental and infrastructure factors that sustain cholera recurrence in Africa. This study adopts a statistical approach to investigate over two decades of endemic cholera outbreaks and their relationship with five environmental factors: water provision, sanitation provision, raising temperatures, increased rainfall and GDP. The analysis covers thirteen of the forty-two countries in the mainland sub-Saharan region, collectively representing one-third of the region's territory and half of its population. This breadth enables the findings to be generalised at a regional level. Results from all analyses consistently associate water provision with cholera reduction. The stratified model links increased water provision with a reduction in cholera risk that ranged from 4.2 % to 84.1 % among eight countries (out of 13 countries) as well as a reduction of such risk that ranged from 9.8 % to 68.9 % when there is increased sanitation provision, which was observed in nine countries (out of 13). These results indicate that the population's limited access to water and sanitation, as well as the rise in temperatures, are critical infrastructure and environmental factors contributing to endemic cholera and the heightened risk of outbreaks across the sub-Saharan region. Therefore, these are key areas for targeted interventions and cross-border collaboration to enhance resilience to outbreaks and lead to the end of endemic cholera in the region. However, it is important to interpret the results of this study with caution; therefore, further investigation is recommended to conduct a more detailed analysis of the impact of infrastructure and environmental factors on reducing cholera risk

    Genomic epidemiology of Vibrio cholerae reveals the regional and global spread of two epidemic non-toxigenic lineages

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    Non-toxigenic Vibrio cholerae isolates have been found associated with diarrheal disease globally, however, the global picture of non-toxigenic infections is largely unknown. Among non-toxigenic V. cholerae, ctxAB negative, tcpA positive (CNTP) isolates have the highest risk of disease. From 2001 to 2012, 71 infectious diarrhea cases were reported in Hangzhou, China, caused by CNTP serogroup O1 isolates. We sequenced 119 V. cholerae genomes isolated from patients, carriers and the environment in Hangzhou between 2001 and 2012, and compared them with 850 publicly available global isolates. We found that CNTP isolates from Hangzhou belonged to two distinctive lineages, named L3b and L9. Both lineages caused disease over a long time period with usually mild or moderate clinical symptoms. Within Hangzhou, the spread route of the L3b lineage was apparently from rural to urban areas, with aquatic food products being the most likely medium. Both lineages had been previously reported as causing local endemic disease in Latin America, but here we show that global spread of them has occurred, with the most likely origin of L3b lineage being in Central Asia. The L3b lineage has spread to China on at least three occasions. Other spread events, including from China to Thailand and to Latin America were also observed. We fill the missing links in the global spread of the two non-toxigenic serogroup O1 V. cholerae lineages that can cause human infection. The results are important for the design of future disease control strategies: surveillance of V. cholerae should not be limited to ctxAB positive strains

    Effects of climate change on the epidemiology of flood-related waterborne disease: A Systematic Literature Review

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    Natural disasters, such as flooding related to extreme precipitation, can lead to many adverse health effects (i.e. waterborne disease). Several outbreaks of waterborne disease have been linked to extreme precipitation, and gastrointestinal infection has been shown to increase after floods. Climate change is likely to lead to a higher frequency of waterborne disease through increases in extreme precipitation and associated flooding affecting water and sanitation infrastructure. This review sought to answer 2 research questions: 1. Has the epidemiology of waterborne disease related to floods changed over time? 2. Can this difference be related to climate change? A literature search was conducted in MEDLINE and Embase for studies reporting on the epidemiology of waterborne disease related to flooding. Studies were screened against inclusion and exclusion criteria, with a total of 52 publications included. Studies of campylobacter, dermatitis, pink eye, and schistosomiasis reported an association between floods and an increase in infection, adenovirus 40/41 and astrovirus showed a significant decrease in risk of disease related to flooding, and cryptosporidium, Giardia, cholera, Escherichia coli, leptospirosis, salmonella, shigella, hepatitis A, rotavirus, sapovirus, and dysentery had mixed evidence. Several studies reported on disease outbreaks tied to a specific flood, but the majority were from events in the past 20 years. It is difficult to draw clear conclusions regarding how waterborne disease is or is not related to floods due to the varied comparisons and outcome definitions. Additionally, most studies were of recent events precluding an analysis of any change over time. Continued research on flood-associated waterborne disease will allow for future analysis of epidemiological changes in response to alterations in climate. In the meantime, public health officials in flood-prone areas should prepare for increases in waterborne disease by educating their constituents on flood safety and implementing interventions for prevention and treatment

    THE IMPACT OF CLIMATE CHANGE ON HUMAN AND NATIONAL SECURITY IN SIERRA LEONE

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    This study examines the impacts of climate change on human and national security to Sierra Leone from 2000–2022, focusing on physical and social dimensions. Using data from the government of Sierra Leone and international organizations, the research provides insights into Sierra Leone’s climate change vulnerabilities and adaptive capacities. The findings indicate that extreme weather events are becoming more frequent and severe. While it is uncertain if climate change is the direct cause, there is likely a connection. Climate change has led the country to experience a rising temperature of 0.18°C per decade since the 1960s, thus affecting Sierra Leone’s food security, increasing economic cost, displacing people, and increasing the possibility of conflict between farmers and herders. The research also shows that the Sierra Leone government has established various institutions and policies intended to reduce the impacts of climate change, with a focus on agricultural transformation, climate change awareness and preparedness, and healthcare resilience. Despite these efforts, challenges persist, including inadequate coordination and implementation gaps in certain adaptive programs. Recommendations are provided to enhance monitoring and evaluation, strengthen environmental conservation policies, and improve coordination among stakeholders to maximize the effectiveness and sustainability of climate change adaptation initiatives in Sierra Leone.Distribution Statement A. Approved for public release: Distribution is unlimited.Major, Sierra Leone Arm

    On the socio-economic impact of pandemics in Africa: Lessons learned from COVID-19, Trypanosomiasis, HIV, Yellow Fever and Cholera

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    Throughout history, nothing has killed more human beings than infectious diseases. Although, death rates from pandemics dropped globally by about 0.8 % per year, all the way through the 20th century, the number of new infectious diseases like Sars, HIV and Covid-19 increased by nearly fourfold over the past century. In Africa, there were reported a total of 4,522,489 confirmed COVID-19 cases and 119,816 death, as of 23 April 2021. The pandemic impacted seriously on the economic and social sectors in almost all African countries. It is threatening to push up to 58 m people into extreme poverty. However, apart from the African poor, the Covid pandemic also affects the growing African middle class, i.e. about 170 million out of Africa's 1.3 billion people currently classified as middle class. Nearly eight million of may be thrust into poverty because of the coronavirus and its economic aftermath. This setback will be felt for decades to come. Moreover, in recent African History also other infectouse diseases like the 1896-1906 Congo Basin Trypanosomiasis with a death-toll of over 500.000 as well as the 1900-1920 Uganda African trypanosomiasis epidemic with 200,000-300,000 death had tremendous negative impact on Africa's societies and economies. Actually, other pandemics, like Yellow Fever, Cholera, Meningitis and Measles - not to mention Malaria - contributed to long-lasting economic downturns and seriously affect the social wellbeing for decades.Im Laufe der Geschichte hat nichts mehr Menschen getötet als Infektionskrankheiten. Obwohl die Sterblichkeitsrate durch Pandemien im Laufe des 20. Jahrhunderts weltweit um etwa 0,8% pro Jahr gesunken ist, hat sich die Zahl der neuen Infektionskrankheiten wie Sars, HIV und Covid-19 im vergangenen Jahrhundert fast vervierfacht. In Afrika wurden zum 23. April 2021 insgesamt 4.522.489 bestätigte COVID-19-Fälle und 119.816 Todesfälle gemeldet. Die Pandemie hatte schwerwiegende Auswirkungen auf den wirtschaftlichen und sozialen Sektor in fast allen afrikanischen Ländern. Sie droht, bis zu 58 Millionen Menschen in extreme Armut zu treiben. Abgesehen von den afrikanischen Armen betrifft die Covid-Pandemie jedoch auch die wachsende afrikanische Mittelschicht, d. h. etwa 170 Millionen der 1,3 Milliarden Menschen in Afrika, die derzeit als Mittelschicht eingestuft sind. Fast acht Millionen von ihnen könnten aufgrund des Coronavirus und seiner wirtschaftlichen Folgen in Armut geraten. Dieser Rückschlag wird noch Jahrzehnte zu spüren sein. Darüber hinaus hatten in der jüngeren afrikanischen Geschichte auch andere Infektionskrankheiten wie die Trypanosomiasis (Schlafkrankheit) im Kongobecken von 1896-1906 mit einer Zahl von über 500.000 Todesopfern sowie die Trypanosomiasis-Epidemie in Uganda von 1900-1920 mit 200.000-300.000 Todesfällen enorme negative Auswirkungen auf die afrikanischen Gesellschaften und Volkswirtschaften. Tatsächlich haben andere Pandemien wie Gelbfieber, Cholera, Meningitis und Masern - ganz zu schweigen von Malaria - zu lang anhaltenden wirtschaftlichen Abschwüngen beigetragen und das soziale Wohlbefinden über Jahrzehnte hinweg ernsthaft beeinträchtigt.Au cours de l’histoire, rien n’a tué plus d’êtres humains que les maladies infectieuses et la fièvre hémorragique. Bien que les taux de mortalité dus aux pandémies aient chuté de près de 1% par an dans le monde, environ 0,8% par an, tout au long du XXe siècle, le nombre de nouvelles maladies infectieuses comme le Sars, le VIH et le Covid-19 a presque quadruplé par rapport au passé. En Afrique, on a signalé un total de 4 522 489 cas confirmés de COVID-19 et 119 816 décès, au 23 avril 2021. La pandémie a eu de graves répercussions sur les secteurs économique et social dans presque tous les pays africains. Il menace de pousser jusqu'à 58 millions de personnes dans l'extrême pauvreté. Cependant, outre les Africains pauvres, la pandémie de Covid affecte également la classe moyenne africaine en pleine croissance, c'est-à-dire environ 170 millions sur les 1,3 milliard d'africains actuellement classés dans la classe moyenne. Près de huit millions d'entre eux pourraient être plongés dans la pauvreté à cause du coronavirus et de ses conséquences économiques. Ce revers se fera sentir pendant des décennies. En outre, dans l'histoire récente de l'Afrique, d'autres maladies infectieuses comme la trypanosomiase du bassin du Congo de 1896 à 1906 avec un nombre des morts de plus de 500 000 ainsi que l'épidémie de trypanosomose africaine en Ouganda de 1900 à 1920 avec 200 000 à 300 000 décès ont eu un impact négatif considérable sur les sociétés et économies africaines. En fait, d'autres pandémies, comme la fièvre jaune, le choléra, la méningite et la rougeole - sans parler du paludisme - ont contribué à des ralentissements économiques durables et affectent gravement le bien-être social pendant des décennies

    The impact of flooding on aquatic ecosystem services

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    Flooding is a major disturbance that impacts aquatic ecosystems and the ecosystem services that they provide. Predicted increases in global flood risk due to land use change and water cycle intensification will likely only increase the frequency and severity of these impacts. Extreme flooding events can cause loss of life and significant destruction to property and infrastructure, effects that are easily recognized and frequently reported in the media. However, flooding also has many other effects on people through freshwater aquatic ecosystem services, which often go unrecognized because they are less evident and can be difficult to evaluate. Here, we identify the effects that small magnitude frequently occurring floods (\u3c 10-year recurrence interval) and extreme floods (\u3e 100-year recurrence interval) have on ten aquatic ecosystem services through a systematic literature review. We focused on ecosystem services considered by the Millennium Ecosystem Assessment including: (1) supporting services (primary production, soil formation), (2) regulating services (water regulation, water quality, disease regulation, climate regulation), (3) provisioning services (drinking water, food supply), and (4) cultural services (aesthetic value, recreation and tourism). The literature search resulted in 117 studies and each of the ten ecosystem services was represented by an average of 12 ± 4 studies. Extreme floods resulted in losses in almost every ecosystem service considered in this study. However, small floods had neutral or positive effects on half of the ecosystem services we considered. For example, small floods led to increases in primary production, water regulation, and recreation and tourism. Decision-making that preserves small floods while reducing the impacts of extreme floods can increase ecosystem service provision and minimize losses

    Surveillance and Response to Infectious Diseases and Comorbidities: An African and German Perspective

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    Cite: Academy of Science of South Africa (ASSAf), (2019). Surveillance and Response to Infectious Diseases and Comorbidities: An African and German Perspective [Available online] DOI http://dx.doi.org/10.17159/assaf.2019/0042The conference explored various topics pertaining to Infectious Diseases and Comorbidities. These included: antimicrobial resistance; one health; HIV; TB; Malaria; and HCV. The objectives of the symposium were to scientifically analyse challenges pertaining to infectious diseases and comorbidities as they relate to surveillance, responses and diagnostics; identify current and future research needs that can be employed to tacle emrging scientific challenges; Assess possible solutions to current challenges as they relate to surveillance and response to infectious diseases and morbidities and how these can be used to provide science advice to governments; and, exchange scientific information between young and senior scientists from the sub-Saharan Africa and Germany.Academy of Science of South Africa (ASSAf

    Cholera and Climate Change: Pursuing Public Health Adaptation Strategies in the Face of Scientific Debate

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    Climate change will affect the prevalence, distribution, and lethality of many diseases, from mosquito-borne diseases like malaria and dengue fever to directly infectious diseases like influenza to water-borne diseases like cholera and cryptosporidia. This Article focuses on one of the current scientific debates surrounding cholera and the implications of that debate for public health-related climate change adaptation strategies. Since the 1970s, Rita Colwell and her co-researchers have been arguing a local reservoir hypothesis for cholera, emphasizing that river, estuarine, and coastal waters often contain more dormant forms of cholera attached to copepods, a form of zooplankton. Under this hypothesis, climatically driven increases in sea surface temperatures, sea surface levels, and phytoplankton production—such as during El Niño years or because of climate change—can then spur cholera outbreaks in vulnerable coastal communities. As such, the local reservoir hypothesis has immediate implications for climate change public health adaptation strategies. In November 2017, however, two teams of scientists published genomic research in Science concluding that epidemic and pandemic cholera outbreaks in the Americas and Africa originate from Asia, suggesting that the local reservoir hypothesis needs modification. The two research articles also suggested a very different strategy for dealing with cholera in the Anthropocene—namely, genetic detection and intensely focused control efforts in Asia. This Article examines in more detail this emerging scientific debate about cholera reservoirs and the ultimate source(s) of cholera outbreaks and epidemics. It then explores the implications of that debate for climate change public health adaptation strategies, suggesting simultaneously that the cholera debate is one concrete example of how identifying the stakes at issue in different climate change adaptation strategies can help communities and nations to choose appropriate adaptation strategies despite scientific uncertainty

    Exploring disaster-related disease outbreaks and the impact of pre-existing vulnerabilities: focusing on cholera and Africa

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    Research into the links between infectious disease outbreaks and disasters has increased over time, with continued discussion regarding the rate and mechanisms for these links. Yet, significant discrepancies and research gaps remain globally in terms of the frequency, geography and characteristics of post-disaster disease outbreaks. Here, the aim was to address these gaps and discrepancies by exploring several disasters and their associated risk factors and further quantifying their impact. By increasing this understanding, this improves the extent to which disaster-related disease outbreaks can be prepared for, to prevent outbreaks from exacerbating and prolonging disaster recovery. To further understand these risk factors, disease outbreaks in drought and conflict settings were analysed and an overview of the research area was gained through the first global systematic review of the literature. Cholera was selected as a focus for the research here, due to it being a disease of global public health importance and potentially linked to drought and conflict. The area of study was predominately Africa (due to the relatively high cholera, conflict and drought burden) and was studied at several spatial scales, from national to administrative level 1. The research identified many important risk factors for cholera outbreaks in a disaster context. To help further identify areas for prioritisation both nationally and sub-nationally, drought-related cholera outbreaks were investigated, as droughts are a relatively understudied natural hazard. Generalised linear models were used to identify a potential relationship and the flexibility of the modelling approach allowed for multiple covariates to be tested. The lack of available water during a drought exacerbates risk factors relating to cholera transmission. However, increasing freshwater availability, improving access to sanitation, poverty elimination and emissions reductions could help to offset cholera risk in the future. Using random forest models, specific targets for these risk factors were further quantified for Nigeria. States with Multi Dimensional Poverty Index values over 0.38 and sanitation access below 54% were particularly at risk for cholera transmission, which includes most northern states in Nigeria. Conflict-related cholera outbreaks were analysed by applying the self-controlled case series in a new application. The modelling approach uses conditional logistic regression to understand the impact of an exposure (conflict) on an event (outbreak). Conflict had the most significant impact on cholera in the first week after the conflict and increased the risk of cholera outbreaks by as much as 3.6 times. The recently developed percentage attributable fraction equations were applied to these results and identified <20% of cholera outbreaks being attributable to conflict in Nigeria and the Democratic Republic of Congo (DRC). The research helped quantify a specific health effect of both the Boko Haram conflict in Nigeria and the civil unrest in eastern DRC. Disease, disasters and global change were brought together here beyond what has previously been done and the knowledge gained was applied to policy throughout. Furthermore, a variety of projections and scenarios were used to identify how potential future conditions could alter cholera transmission. The Global Task for Cholera Control have ambitious 2030 targets, that will be essential for global cholera eradication and are important to make sure governments are committed to overcoming challenges. Both disasters and cholera outbreaks are not new phenomenon and societies have always had to respond and adapt but marked differences in global inequity can prevent this. Giving people agency and empowerment to react to sudden changes and make informed decisions to protect their health will require long-term investment in sustainable development. Enhancing development has far-reaching impacts and is essential for controlling disease, both regionally and globally.Open Acces
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