Clostridium Tetani and Tetanus

Tetanus is acquired through exposure to the environmental spore-forming Gram-positive bacillus Clostridium tetani, which may infect human wounds and cause disease by production of an exotoxin (tetanospasmin). There is no human-to-human transmission. The disease occurs worldwide and it is sporadic in high-income countries with universal access to well-accepted immunization programs. It is more common in agricultural regions and in low-income countries where contact with animal excreta is more likely and immunization programs are inadequate. Neonatal tetanus (NNT) following unclean deliveries and poor postnatal hygiene is still responsible for the majority of tetanus cases and deaths; the majority of NNT occurs in poor Asian and African countries, whereas in high-income countries the disease is extremely rare. Three forms of clinical disease can be distinguished: the most common form is generalized tetanus, whereas local tetanus and cephalic tetanus are rare. Neonatal tetanus (NNT) is a form of generalized tetanus in newborns. The case fatality rate of tetanus is high, 3%–95% depending on age, immune- and immunization-status, form of disease, and availability of proper medical care. The efficacy of tetanus toxoid vaccines was never formally studied, but cases in adequately vaccinated subjects are extremely rare and impact data (e.g. for NNT) convincingly show high vaccine effectiveness. WHO estimates that in 2018, 25,000 newborns died from NNT, an 88% reduction from the situation in 2000.

Gestion des déchets ménagers dans le quartier Mambanda (Douala-Cameroun) : Quelles stratégies durables?

L’urbanisation est l’une des grandes caractéristiques du monde contemporain. Elle génère des effets sur l’environnement et le cadre de vie perceptibles à travers la gestion des déchets. En effet, l’urbanisation s’accompagne d’une croissance de la population urbaine qui à son tour induit une production sans cesse importante de déchets, souvent mal gérés. Cette réflexion vise à cerner les problèmes liés aux différentes pratiques de gestion des déchets ménagers dans le quartier Mambanda de la ville de Douala. L’étude s’appuie sur une approche à la fois qualitative et quantitative qui intègre les recherches documentaires, les observations de terrain et les entretiens avec les acteurs-clé du terrain. Les résultats de l’étude montrent que les déchets solides, liquides et gazeux produits dans le quartier Mambanda sont constitués essentiellement des restes de nourriture, d’eaux usées domestiques et résiduaires, des eaux vannes, des déjections humaines et animales… Les populations, l’Etat et les sociétés privées (Hysacam, CIPRE, associations…) sont les acteurs qui se déploient sur le terrain pour gérer ces déchets qui sont généralement déversés dans les rues, les caniveaux, les cours d’eaux, les champs, les drains et les bacs à ordures. La mauvaise gestion des déchets entraine, dans la plupart des cas, la dégradation de l’environnement et du cadre de vie des populations et par conséquent impacte la santé des populations qui y vivent. Ainsi, la forte implication des populations dans le processus de gestion des déchets (campagnes d’éducation à l’hygiène, création et entretien du réseau d’évacuation…) est la meilleure stratégie durable pour une gestion efficace de ces déchets. Urbanization is one of the great characteristics of the contemporary world. It generates perceptible effects on the environment and the living environment through waste management. Indeed, urbanization is accompanied by a growth of the urban population which in turn induces an ever-increasing production of waste, which is often poorly managed. This reflection aims to identify the problems related to the different household waste management practices in the Mambanda district of the city of Douala. The study is based on a qualitative and quantitative approach that integrates documentary research, observations and interviews with key players in the field.The results of the study show that the solid, liquid and gaseous waste produced in the Mambanda district consists mainly of food scraps, domestic and waste water, human and animal excreta. The populations, the State and private companies (Hysacam, CIPRE, associations, etc.) are the actors who are deployed in the field to manage this waste which is generally dumped in the streets, gutters, rivers, fields. , drains and garbage bins. Poor waste management leads, in most cases, to the degradation of the environment and the living environment of the populations. Thus, the strong involvement of the population in the waste management process (hygiene education campaigns, creation and maintenance of the disposal network, etc.) is the best sustainable strategy for effective waste management.

Vermicomposting: A Valorization Alternative for Corn Cob Waste

As vermicomposting has become a viable alternative for the valorization of organic waste; the objectives of this research were to (1) assess the feasibility of said process for corn cob waste (corn cobs and corn husks) and (2) evaluate the operation conditions for the biodegradation of different mixtures with load material (LM). LM did not include animal excreta as a nitrogen source, a practice widely used in a range of studies. The experiment consisted of an initial phase of pre-composting in order to obtain a partially stabilized substrate. Subsequently, four separate mixtures were made consisting of corn cob waste mixed with consistent load material (LM) containing vegetable waste and eggshells (CR, M1, M2, M3) to obtain a balance substrate able to facilitate degradation using Eisenia fetida earthworms. The following parameters were analyzed during the control process: temperature, pH, humidity, organic material (OM), total organic carbon (TOC), total nitrogen (TN) and carbon/nitrogen (C/N) ratio. The analysis of the final values of the stabilized mixtures showed that vermicomposting is indeed a feasible alternative for the degradation of corn cob waste for use as a soil improver.

Greenhouse Gases from Agriculture

The rapidly changing global climate due to increased emission of anthropogenic greenhouse gases (GHGs) is leading to an increased occurrence of extreme weather events such as droughts, floods, and heatwaves. The three major GHGs are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The major natural sources of CO2 include ocean–atmosphere exchange, respiration of animals, soils (microbial respiration) and plants, and volcanic eruption; while the anthropogenic sources include burning of fossil fuel (coal, natural gas, and oil), deforestation, and the cultivation of land that increases the decomposition of soil organic matter and crop and animal residues. Natural sources of CH4 emission include wetlands, termite activities, and oceans. Paddy fields used for rice production, livestock production systems (enteric emission from ruminants), landfills, and the production and use of fossil fuels are the main anthropogenic sources of CH4. Nitrous oxide, in addition to being a major GHG, is also an ozone-depleting gas. N2O is emitted by natural processes from oceans and terrestrial ecosystems. Anthropogenic N2O emissions occur mostly through agricultural and other land-use activities and are associated with the intensification of agricultural and other human activities such as increased use of synthetic fertiliser (119.4 million tonnes of N worldwide in 2019), inefficient use of irrigation water, deposition of animal excreta (urine and dung) from grazing animals, excessive and inefficient application of farm effluents and animal manure to croplands and pastures, and management practices that enhance soil organic N mineralisation and C decomposition. Agriculture could act as a source and a sink of GHGs. Besides direct sources, GHGs also come from various indirect sources, including upstream and downstream emissions in agricultural systems and ammonia (NH3) deposition from fertiliser and animal manure.

Microbial electrolysis cells for electromethanogenesis: Materials, configurations and operations

Anaerobic digestion is a traditional method of producing methane-containing biogas by utilizing the methanogenic conversion of organic matter like agricultural waste and animal excreta. Recently, the application of microbial electrolysis cell (MECs) technology to a traditional anaerobic digestion system has been extensively studied to find new opportunities in increasing wastewater treatability and methane yield and producing valuable chemicals. The finding that both anodic and cathodic bacteria can synthesize methane has led to the efforts of optimizing multiple aspects like microbial species, formation of biofilms, substrate sources and electrode surface for higher production of the combustible compound. MECs are very fascinating because of its ability to uptake a wide variety of raw materials including untreated wastewater (and its microbial content as biocatalysts). Extensive work in this field has established different systems of MECs for hydrogen production and biodegradation of organic compounds. This review is dedicated to explaining the operating principles and mechanism of the MECs for electromethanogenesis using different biochemical pathways. Emphasis on single- and double-chambered MECs along with reactor components is provided for a comprehensive description of the technology. Methane production using hydrogen evolution reaction and nanocatalysts has also been discussed.

Vermicompost an Alternative in the Treatment of Organic Solid Waste, in Zones Altoandinas, Tarma, Junin 2019

In the present investigation, the weight, growth, adaptability and production of humus of a calf foot of Californian red worm (Eisenia foetida) fed with compost (made from animal excreta and organic waste) and organic remains were evaluated. The evaluation was carried out in Tarma, Junín Region. A breeding ground was built with 3.2 m3 cement bricks (6.10 m long  1.05 m wide and 0.50 m high); with a 5 cm thick screed with a 2” PVC drain pipe with a west-east slope, raised by the west side at 15°. A population of 10,000 individuals (10 kilograms) was sown, a sample of 370 individuals was extracted by applying a Simple Random Sampling (MAS) whose average weight and length was 0.3 g and 30 mm. they were fed for 3 months (90 days), the calf was divided into 21 sampling points from which 383 worms were weighed and measured whose average weight and length were 0.38 g and 33.24 mm (3.32 cm). Data were taken every day at 2:00 pm, hydrogen potential (pH) and humidity (soil peach meter), substrate temperature (digital thermometer), ambient temperature (thermohygrometer) were recorded. The average weight of the worms varied from 0.30-0.38 g, the average length varied from 30-33.24 mm. The presence of tiny heels and worms demonstrated their adaptability. The production of humus was 3 tons, the efficiency of the breeding stock was 93.75%. The final substrate had an average of 6.72 pH, 13.61°C temperature, 69.86% humidity and 19.5°C ambient temperature. Consequently, vermicompost is an alternative in the treatment of organic solid waste to be developed in high Andean areas.

Holistic solution to an old "mystery": the global role of antibiotic consumption patterns in the spread of certain non-contagious diseases in EU countries

The discovery and extensive utilization of antibiotics are highly contributed to the considerable lengthening life expectancy of human beings. Antibiotics, mixed with animal fodder, produced considerable growth promoting effect and hence, extended the indications of antibiotics at a much higher level. The indiscriminate use of antibiotics quickly resulted in the emergence of poly-resistant pathogens and the extensive antibiotic pollution of the environment, particularly of the surface water and rivers trough human and animal excreta. Along with extensive and ever increasing antibiotic consumption/pollution, the pandemic-like spreading of certain non-contagious diseases like obesity, diabetes (Type 1-2 T1DM, T2DM), Alzheimer disease (AD), Parkinson disease, multiple sclerosis (MS) etc. started unfolding, which was called as a slow moving disaster, without having any appropriate explanation of the phenomenon. The parallel appearance of those “pandemics”, which appeared simultaneously with the extensive antibiotic consumption, might indicate some kind of association. As far as several publications have reported the crucial role of altered gut flora in the development of metabolic disorders (diabetes, obesity) and neurodegenerative diseases alike (PD, AD, MS), it might be suspected that antibiotics, acting through the modification of microbiome, could influence the morbidity (prevalence) of those, non-infectious diseases. This concept, described below, might serve as a unified explanation, not excluding other, contributing causative factors, for the phenomenon, outlined above.

Coronavirus testing indicates transmission risk increases along wildlife supply chains for human consumption in Viet Nam, 2013-2014

Outbreaks of emerging coronaviruses in the past two decades and the current pandemic of a novel coronavirus (SARS-CoV-2) that emerged in China highlight the importance of this viral family as a zoonotic public health threat. To gain a better understanding of coronavirus presence and diversity in wildlife at wildlife-human interfaces in three southern provinces in Viet Nam 2013-2014, we used consensus Polymerase Chain Reactions to detect coronavirus sequences. In comparison to previous studies, we observed high proportions of positive samples among field rats (34.0%, 239/702) destined for human consumption and insectivorous bats in guano farms (74.8%, 234/313) adjacent to human dwellings. Most notably among field rats, the odds of coronavirus RNA detection significantly increased along the supply chain from field rats sold by traders (reference group; 20.7% positivity, 39/188) by a factor of 2.2 for field rats sold in large markets (32.0%, 116/363) and 10.0 for field rats sold and served in restaurants (55.6%, 84/151). Coronaviruses were detected in the majority of wildlife farms (60.7%, 17/28) and in the Malayan porcupines (6.0%, 20/331) and bamboo rats (6.3%, 6/96) that are farmed. We identified six known coronaviruses in bats and rodents, clustered in three Coronaviridae genera, including the Alpha-, Beta-, and Gammacoronaviruses. Our analysis also suggested either mixing of animal excreta in the environment or interspecies transmission of coronaviruses, as both bat and avian coronaviruses were detected in rodent feces in the trade. The mixing of multiple coronaviruses, and their apparent amplification along the wildlife supply chain into restaurants, suggests maximal risk for end consumers and likely underpins the mechanisms of zoonotic spillover to people.

Environmental and management drivers of alpine grassland vegetation types

Current vegetation of alpine grasslands has been shaped by the combination of natural ecological factors (such as climate, soil, topography) and human activities, mainly represented by animal grazing and agricultural practices. An assessment of these factors can explain the present composition of plant communities and help to evaluate the future development of rangeland vegetation. Nowadays, the analysis of the botanical composition of grasslands is of a major importance in order to propose appropriate management plans for the sustainable exploitation of pastoral resources and their future conservation. The main purpose of this work was to assess the relevance of ecological and management factors in alpine grasslands in an area located in eastern Italy, currently used for extensive grazing, and to describe the main factors that affect the characteristics of pasture types. To this aim, about 900 ha of alpine grasslands were surveyed in Val Visdende (northern Veneto, province of Belluno, Italy) by means of 189 linear transects. Some environmental variables (altitude, slope, aspect) and factors related to management (pastoral value, animal excreta, distance from night barns) were collected for each botanical transect. Landolt indicators were calculated in order to evaluate the ecological space occupied by each type. This assessment made it possible to identify the most relevant grassland communities (namely nutrient poor, shrub encroached, nutrient rich and humid pastures) occurring in the studied area, the effectiveness of ecological indicators to describe and to differentiate vegetation groups and the effect of animal management and ecological factors in the discrimination of grassland types.