Water-borne pathogens

Origin of the Water-Borne Pathogens and Faecal Indicators Present... 

This review mostly summarizes the scientific information available in developed countries, where the prevalence of diseases associated with water use is kept under very acceptable levels. However, there are reasons to think that the situation might worsen as a consequence of the effects of the climatic change, the increase of population in certain areas and the deterioration of sanitation infrastructures. It may be necessary to take new measures to maintain the present situation. Better knowledge of the water-borne pathogens, where they originate, how they persist or replicate in the environment, how they survive water treatments, and how they are transported in water and soil, will allow us to take the necessary measures to prevent the effects of water scarcity as well as the effects of extreme climatic events foreseen for the future by the experts in climatic change [13]. 

The most important pathogens causing faecal-oral water-borne diseases, with the exception of helmints (Ascaris, Trichurus, Taenia, etc.) are compiled in Table 2. These, virtually absent in the developed countries, are stiU highly prevalent in developing countries, though without causing serious illness [8]. 

Abundant literature on the increase of the densities of faecal pathogens and indicators in water sources during dry and rainy periods and the significant effect of rain in water-borne infectious disease outbreaks exist and prove all these assertions. 

Increased amounts of faecal-oral water-borne pathogens (virus, bacteria and protozoa) and microbial indicators (bacterial and viral) have been reported in groundwater bodies [18], karst springs [19, 20], surface freshwater [21-26], marine waters used for bathing [27-29] and shellfish growing [30] as well as tap water [31]. 

The biological contamination and the hardness of underground water are the two very serious problems of water. Dissolved salts deteriorate water quality and may cause diseases related to joints and bones, while infected water may cause many water-borne diseases such as cholera, dysentery, typhoid etc. Ultrasound may disinfect the potable water by blasting off micro organisms such as zooplanktons, phytoplanktons, pathogenic bacteria and produce germ-free water in few minutes of... 

The FDA, USDA, and EPA have established methods and standards for detecting food- and water-borne pathogens these methods are available on the agencies websites [4—81. Many of the procedures for microbe identification rely on culturing the sample for subsequent identification by multiple tests such as colony characteristics, selective growth conditions, and biochemical assays for metabolites. Such traditional methods take upward of 24 h and remain the standard against which new... 

By sterilisation is understood the destruction of all organisms4 in the water, whether pathogenic or not. In the absence of suitable mechanical filters or in cases of doubt as to the efficiency of the filters in removing pathogenic germs, sterilisation should be resorted to, for this is the only sure method of preventing the spread of water-borne diseases. 

Technical solutions have been developed to a number of important environmental problems. One of the most important contributions to human health has been the chemical purification of drinking water, which has nearly eliminated water-borne diseases in developed countries.2 Disinfection with chlorine and ozonation have been used to eliminate pathogens, and advances in membrane science have enabled removal of various substances from water. Many of the technical solutions have been developed in response to unexpected problems created by other technical advances. 

Cases and deaths from selected water-borne infectious diseases in the Mediterranean countries are summarized in Table 4.5. Microorganisms which can be pathogenic to man and which are transmitted by contaminated water are discussed below. 

A Comparison of Insulator-Based Dielectrophoretic Devices for the Monitoring and Separation of Water-Borne Pathogens as a Function of Microfabrication Technique, Chapter 9... 

Salmonella is an important food and water-borne pathogen associated with acute gastrointestinal illnesses around the world. The infective dose can be as low as 15-20 cells, depending on the age, health status of the host and differences between Salmonella strains. It is estimated that over 4 million cases of Salmonella infections and one thousand deaths occur in the United States (1). 

The three most common sources of these biohazards are (1) those rising from microbial decomposition, (2) those associated with certain environments (water-borne, food-bome), and (3) those present in individuals infected with the pathogen. 

Water-borne pathogens Cryptosporidium, oholera Baoteria 176... 

Commonly implicated water-borne pathogens include Vibrio cholerae, Cryptosporidium parvum and hepatitis A. The pathophysiology and clinical presentation of these, and numerous other examples, are well described in the wider literature. However, they are also relevant from a biological weapons perspective due to the capacity to cause widespread illness by their intentional release into water supplies. Natural epidemics also occur sporadically throughout the world. Most UK cases are imported by infected travellers. 

---