La transmisión acelerada del virus covid-19 a escala mundial y la declaración de pandemia por parte de la OMS alertó a los países del planeta sobre la adopción de medidas para impedir su propagación y proteger la salud de los seres humanos. En el presente artículo se pretende dar a conocer si el covid-19 se transmite a través del agua residual y si su detección es útil para determinar su infectividad o capacidad de producir enfermedad, o si se puede usar como herramienta de vigilancia epidemiológica. La falta de conocimiento de este nuevo virus y la necesidad de una pronta mitigación de su esparcimiento han impulsado a los investigadores a conocer su estructura, origen, forma de transmisión, forma de reproducción, factores ambientales que influyen en su persistencia y técnicas de detección en muestras de agua. | The accelerated transmission of the covid-19 virus worldwide and the declaration of a pandemic by WHO alerted the countries around the world to adopt security measures to prevent its spread and protect the health of human beings. This article aims to divulge whether covid-19 is transmitted through wastewater and if its detection is useful to determine its infectivity disease production capacity or if it can be used as an epidemiological surveillance tool. The lack of knowledge of this new virus and the need for timely mitigation of its spread has motivated researchers to know about its structure, origin, way of transmission, way of replication, environmental factors that influence its persistence, and detection techniques in water samples. | Bióloga de la Pontificia Universidad Javeriana, especialista en Microbiología de la Universidad de los Andes, coordinadora del Laboratorio de Ingeniería Ambiental y profesora titular de la Escuela Colombiana de Ingeniería. [email protected]

This publication provides guidance to water-sector decision makers and planners on how to deal with the quality dimension of groundwater resources management in the World Bank's client countries. There is growing evidence of increasing pollution threats to groundwater and some well-documented cases of irreversible damage to important aquifers. This guide has been produced in the belief that groundwater pollution hazard assessment must become an essential part of environmental best practice for water supply utilities. The guide is particularly relevant for the World Bank's Latin American and Caribbean Region, where many countries have initiated major changes to modernize their institutional and legal framework for water resources management, but may not yet have considered groundwater at the same level as surface water, because of lack of awareness and knowledge of groundwater issues and policy options.

A toxoplasmose é uma zoonose causada pelo protozoário Toxoplasma gondii, que tem como hospedeiros definitivos os felídeos e diversas espécies animais como hospedeiros intermediários. No hospedeiro definitivo ocorre o ciclo intestinal, a qual resulta na produção de oocistos eliminados nas fezes. Nos hospedeiros intermediários, incluindo o homem, ocorre o ciclo extra-intestinal, formando cistos teciduais. Os felídeos eliminam pelas fezes milhões de oocistos não esporulados durante a primo-infecção, sendo esta fase auto-limitante. A esporulação ocorre no ambiente em três a cinco dias, quando em temperatura ótima. Mesmo que os felinos domésticos tenham um importante papel na manutenção no ciclo de vida do toxoplasma, o contato direto com os gatos não é elo importante da transmissão. Os casos humanos estão frequentemente associados ao consumo de alimentos: de origem vegetal ou água contaminados com oocistos eliminados por felídeos ou produtos de origem animal com presença de cistos. A toxoplasmose tem grande importância em saúde pública, pois é uma das zoonoses mais difundidas no mundo. Diversos animais (cerca de 30 espécies de aves e 300 de mamíferos), assim como humanos, podem sofrer a infecção. A soroprevalência em humanos é elevada, pois estima-se que até um terço das pessoas do mundo sejam soropositivas, apresentando a forma de infecção crônica assintomática. A primo-infecção de gestantes representa grande risco, podendo ocorrer a transmissão fetal que leva a lesões no sistema nervoso central, devido ao tropismo do protozoário por esse tecido, podendo ser fatal. Também é um problema para pacientes com imunocomprometimento severo, nos quais causa sintomas graves. A doença ocular é provavelmente a manifestação sintomática, potencialmente grave, mais comum em toxoplasmose aguda pós-natal. A retinocoroidite toxoplasmática pode ser devido a doença congênita ou adquirida pós-natal e pode estar associada com a infecção aguda ou reativação. Mesmo assim, a toxoplasmose é considerada uma zoonose ainda negligenciada no Brasil, é preocupante o fato de não existir uma política pública que faça com que os médicos dediquem mais atenção a essa doença. Apenas recentemente a toxoplasmose congênita tornou-se um agravo de notificação obrigatória. Principalmente considerando que sua transmissão através do consumo de alimentos e água contaminados estiveram associados a surtos envolvendo grande número de acometidos no país. | Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii, which has felids as the definitive host; and several animal species as intermediary hosts. The intestinal cycle occurs in the definitive host, which results in the production of oocysts eliminated in the feces. In the intermediary hosts, including man, the extra intestinal cycle occurs by forming tissue cysts. Felids eliminate millions of non-sporulated oocysts in the feces during the primary infection, and this phase is self-limiting. Sporulation occurs in the environment in 3 to 5 days, when at optimum temperature. Even though domestic cats play an important role in maintaining the toxoplasma life cycle, direct contact with cats is not an important link in transmission. Human cases are often associated with the consumption of food: vegetables or water contaminated with oocysts eliminated by felids or products of animal origin with the presence of cysts. Toxoplasmosis is of great importance in public health, since it is one of the most widespread zoonosis in the world. Several animals (about 30 species of birds and 300 of mammals), as well as humans, can suffer from the infection. Seroprevalence in humans is high, and it is estimated that up to a third of the global population may be seropositive and present an asymptomatic chronic infection. The primary infection of pregnant women represents a great risk, and transmission to the fetus may occur, which leads to lesions in the central nervous system, due to the tropism of the protozoan for this tissue. This infection form can be fatal. It is also a hazard for immunocompromised patients, in which it causes severe symptoms. Eye disease is probably the most common potentially severe symptomatic manifestation in acute postnatal toxoplasmosis. Toxoplasmic retinochoroiditis can be due to a congenital or acquired postnatal disease and can be associated with an acute infection or reactivation. In spite of that, toxoplasmosis is a zoonosis still neglected in Brazil, it is worrying that there is no public policy that makes doctors pay more attention to this disease. It is only recently that congenital toxoplasmosis has become a disease of mandatory notification. Especially considering that its transmission through the consumption of contaminated food and water has been associated with outbreaks involving a large number of people affected in the country.

The quality of drinking water is a crucial aspect for the health and well-being of any community, especially in the rural peripheral areas of Quevedo canton, Ecuador, where the drinking water supply infrastructure is deficient and exposure to contaminants is high. In our study we aim to conduct a comprehensive analysis of drinking water quality. Five representative localities in Quevedo canton were selected for the evaluation of microbial load and analysis of total coliforms, soil texture, soil pH, and the content of nitrates, nitrites, copper, and chromium in the water. Our results showed significant variations in water and soil quality among the localities. The microbial load and total coliform counts were highest in SCR 3, indicating a possible local contamination source. The soil texture varied, with a predominance of sandy texture in SCR 2 and SCR 3, which af fects water retention and nutrient availability.Soil pH values ranged from 6.0 to 7.0, with SCR 3 presenting the lowest pH. Nitrate concentration was highest in SCR 2 (20 mg L-1), while nitrites were highest in ESP 2 (0.12 mg L-1). Copper levels varied, being highest in AGR (18 mg L-1), lastly, hexavalent chromium levels were highest in SCR 2 (0.075 mg L-1). These variations in water and soil quality have significant implications for public health and agricultural productivity. Sources of contamination were identified in our study, hence, we propose mitigation measures to improve water quality, promote public health, and support sustainable agricultural development in the rural communities of Quevedo. | La calidad del agua potable es un aspecto crucial para la salud y el bienestar de cualquier comunidad, especialmente en las zonas rurales periféricas del cantón Quevedo, Ecuador, donde la infraestructura de abastecimiento de agua potable es deficiente y la exposición a contaminantes es alta. Este estudio tiene como objetivo realizar un análisis integral de la calidad del agua potable. Para ello, se seleccionaron cinco localidades representativas del cantón Quevedo para la evaluación de la carga microbiana y el análisis de coliformes totales, textura del suelo, pH del suelo, y contenido de nitratos, nitritos, cobre y cromo en el agua. Los resultados mostraron variaciones significativas en la calidad del agua y del suelo entre las localidades. La carga microbiana y el conteo de coliformes totales fueron más altos en SCR 3, indicando una posible fuente de contaminación local. La textura del suelo varió, con predominancia arenosa en SCR 2 y SCR 3, lo cual afecta la retención de agua y la disponibilidad de nutrientes. Los valores de pH del suelo oscilaron entre 6.0 y 7.0, con SCR 3 presentando el pH más bajo. La concentración de nitratos fue más alta en SCR 2 (20 mg L-1), mientras que los nitritos fueron más elevados en ESP 2 (0.12 mg L-1). Los niveles de cobre variaron, siendo más altos en AGR (18 mg L-1), y los niveles de cromo hexavalente fueron más altos en SCR 2 (0.075 mg L-1). Estas variaciones en la calidad del agua y del suelo tienen implicaciones significativas para la salud pública y la productividad agrícola. Se identificaron fuentes de contaminación y se propusieron medidas de mitigación para mejorar la calidad del agua, promover la salud pública y apoyar el desarrollo agrícola sostenible en las comunidades rurales de Quevedo.

El agua es catalogada como uno de los principales vehículos de transmisión de enfermedades: la mayoría de los patógenos intestinales se transmiten por está vía, habitan el tracto gastrointestinal del ser humano y son eliminados posteriormente en las heces. En este artículo se muestran las enfermedades de origen hídrico más recurrentes con sus respectivos agentes acusantes, se definen microorganismos emergentes, microorganismos oportunistas, grupo coliforme como grupo indicador de contaminación, se presenta la Escherichia coli como la bacteria de origen fecal de mayor impacto en salud pública y algunos factores que influyen en la persistencia de los microorganismos en el agua. | Water is one of the most important vehicles of diseases transmission; the intestinal pathogens are transmitted in this way. They live un humans' gastrointestinal track; and later they are eliminated in the feces. This paper shows the main waterborn diseases and their causing agents, and defines emergent microorganisms, opportunistic microorganisms, and the coliform group, which indicates contamination. The paper also shows that Escherichia coli is a bacteria of fecal origin that impacts public health and some factors that influence the persistence of microorganisms in water.