Fecal Coliform Contamination Research Articles

Guidelines for Greywater Re‐Use: Health Issues

ABSTRACTThis paper discusses the potential threat to health associated with the microbial contamination of grey‐water. Although it has been shown that greywater may contain large numbers of potentially pathogenic microorganisms, the incidence of disease is dependent upon more than just the concentration of organisms. Other factors include the degree of exposure and the health and age of affected individuals. Proposed guidelines for the re‐use of greywater focus upon faecal coliform contamination and suggest limits based upon the end use of recycled water.The paper (a) proposes modifications to the guidelines to better represent the delicate balance between protection of public health and the levels of risk posed by greywater re‐use within the context of everyday human activity, and (b) attempts to identify areas where there is either an expectation for responsibility or a personal acceptance of responsibility with regard to public or personal health.

A massive epidemic of multidrug-resistant typhoid fever in Tajikistan associated with consumption of municipal water.

From 1 January through 30 June 1997, 8901 cases of typhoid fever and 95 associated deaths were reported in Dushanbe, Tajikistan. Of 29 Salmonella serotype Typhi isolates tested, 27 (93%) were resistant to ampicillin, chloramphenicol, nalidixic acid, streptomycin, sulfisoxazole, tetracycline, and trimethoprim-sulfamethoxazole. In a case-control study of 45 patients and 123 controls, Salmonella Typhi infection was associated with drinking unboiled water (matched odds ratio, 7; 95% confidence interval, 3-24; P<.001). Of tap water samples, 97% showed fecal coliform contamination (mean level, 175 cfu/100 mL). Samples taken from water treatment plants revealed that fecal coliform contamination occurred both before and after treatment. Lack of chlorination, equipment failure, and back-siphonage in the water distribution system led to contamination of drinking water. After chlorination and coagulation were begun at the treatment plants and a water conservation campaign was initiated to improve water pressure, the incidence of typhoid fever declined dramatically.

Fiji's Great Astrolabe Lagoon: baseline study and management issues for a pristine marine environment

The Great Astrolabe Lagoon ( 18°45′ S, 178°32′ E ), located some 70 km south of Suva, the capital of Fiji, is a marine environment in relatively pristine condition, impacted only by low human populations on small islands. The Great Astrolabe Reef which encloses the Lagoon is a barrier reef composed of oceanic ribbon reefs. A baseline study of the Lagoon was carried out in 1989–92 which consisted of two components: (1) biological monitoring of permanent reef transects, and (2) water and sediment quality monitoring. Twelve study sites encompassing different habitats were visited regularly during the study period. Substrate cover, hard coral cover, plant cover and counts of selected motile invertebrates were taken. Fish counts were also conducted. The water quality studies included temperature, dissolved oxygen and nutrients, trace metal analyses and microbiological examination of edible bivalves. Sediment samples were also analysed for a range of macro- and micro-elements. The reefs that were relatively inaccessible to the local villagers were found to be in a healthier state than those in close proximity to the islands. There were several problems encountered in the reef monitoring studies which exemplify the constraints of conducting research in a relatively isolated location. Water analyses indicated that the Lagoon is relatively free from pollution with pH, dissolved oxygen, temperature and salinity data close to open ocean values. Apart from nitrate, all nutrient values were below detection limits. Nitrate values averaged 0.74 μmol/L, but varied from 0.2 to 1.9 μmol/L. Data for trace metals in water were consistent with no contamination. Shellfish samples showed no contamination by trace metals and minimal faecal coliform contamination. Sediments showed no contamination by trace metals and were dominated by high magnesium calcite and aragonite, with minor amounts of low magnesium calcite. There are increasing pressures on this area, both from local residents who wish to move to a more cash oriented economy through increased fishing and tourism, and from external tourism interests. The Lagoon has also been suggested as a marine national park. Some of the management issues associated with these alternatives are discussed.

RT-PCR evaluation of viral contamination in five shellfish beds over a 21-month period

Five shellfish beds were sampled for 21 months and evaluated for microbial contamination. Viral extraction was performed on dissected tissues and the clinically most important enteric viruses (hepatitis A virus, small round structured virus, rotavirus and enterovirus) were searched for by RT-PCR and hybridization. Among the 104 samples analysed, 66% were contaminated by at least one virus and 34% were negative for any virus. The two sites regularly contaminated by faecal coliforms had the highest percentage of viral contamination and HAV was detected only in these sites. However, sampling sites meeting the criteria for commercialisation showed occasional viral contamination and viruses were detected in samples with no faecal coliform contamination.

RT-PCR evaluation of viral contamination in five shellfish beds over a 21-month period

Five shellfish beds were sampled for 21 months and evaluated for microbial contamination. Viral extraction was performed on dissected tissues and the clinically most important enteric viruses (hepatitis A virus, small round structured virus, rotavirus and enterovirus) were searched for by RT-PCR and hybridization. Among the 104 samples analysed, 66% were contaminated by at least one virus and 34% were negative for any virus. The two sites regularly contaminated by faecal coliforms had the highest percentage of viral contamination and HAV was detected only in these sites. However, sampling sites meeting the criteria for commercialisation showed occasional viral contamination and viruses were detected in samples with no faecal coliform contamination.

Fecal Coliform Contamination in Child Day-Care Centers

Enteropathogens associated with outbreaks of diarrhea in child day-care centers can be spread by the fecal-oral route through hands or environmental objects that are contaminated. The purpose of this study was to determine the prevalence of fecal coliform contamination in day-care centers. During a 6-month period, on four separate occasions, cultures were taken from environmental surfaces and the hands of children and teachers at six licensed day-care centers. Fecal coliforms were recovered from 64 (9.5%) of the 675 surfaces sampled. Recovery rate was not influenced by the socioeconomic status of the clientele, time of year, or presence of children who were not toilet trained. All children wore paper diapers. Recovery rates did differ significantly for different areas: the kitchen showed a relatively high recovery rate (19%), and toys and toilets showed remarkably low rates (2% and 4%, respectively). Centers with formal hand-washing procedures had lower recovery rates than those without such practices. We also demonstrated a high recovery rate from hands of staff (16%); 6% of cultures taken from children's hands were positive. Contamination of hands and classroom objects is a potential source for transmitting enteric diseases among children in day-care centers.

Bacteriological study of cooked ogi (fermented cereal weaning food) and its potential safety in a rural Nigerian community

Thirty households with children receiving the fermented cereal food ogi were selected randomly from Ajara, a rural community in Lagos State, Nigeria. Eighty-one samples of ogi were collected from these households at the time of administration to the children. The degree of bacteriological contamination and pH values of the cooked ogi samples were determined. The mean pH was 3·6 ± 0·2. Faecal coliform contamination levels of 3 to ≥/2400/ml were recorded in 26 (31·3%)of the 81 ogi samples. Levels of faecal coliforms increased significantly ( P < 0·025) during storage of cooked samples for 9 h. The high contamination rate is unacceptable and is a potential health hazard. Although fermenting food like ogi, resulting in a low pH, may reduce bacterial contamination, hygienic practices during handling and preparation should be emphasized as adjuncts in intervention for control of diarrhoeal disease in developing countries.

Waterborne Giardia cysts and Cryptosporidium oocysts in the Yukon, Canada.

Several outbreaks of waterborne giardiasis have occurred in southern Canada, but nothing has been reported from the Canadian North. The objective of this study was to collect information relevant to waterborne giardiasis and cryptosporidiosis in the Yukon including epidemiological data and analyses of water, sewage, and animal fecal samples. Remote, pristine water samples were found to be contaminated with Giardia cysts (7 of 22 or 32%) but not with Cryptosporidium oocysts. Giardia cysts were found in 21% (13 of 61) of animal scats, but no Cryptosporidium oocysts were observed (small sample size). Whitehorse's drinking water was episodically contaminated with Giardia cysts (7 of 42 or 17%) and Cryptosporidium oocysts (2 of 42 or 5%). Neither were found in Dawson City's water supply. The only water treatment in the Yukon is chlorination, but contact times and free chlorine residuals are often too low to provide adequate protection by disinfection. Raw sewage samples from the five largest population centers in the Yukon contained 26 to 3,022 Giardia cysts and 0 to 74 Cryptosporidium oocysts per liter. Treated sewage from Whitehorse contained fewer Giardia cysts but more Cryptosporidium oocysts on average. Both were detected in Lake Laberge, downstream of Whitehorse, which has a history of fecal coliform contamination. Daily monitoring of raw sewage from the suburbs of Whitehorse showed a summertime peak of Giardia cysts and occasional Cryptosporidium oocysts after springtime contamination of drinking water. Despite this evidence, epidemiological data for the Yukon showed an endemic infection rate of only 0.1% for giardiasis (cryptosporidiosis is not notifiable).(ABSTRACT TRUNCATED AT 250 WORDS)

Application of phage typing to the identification of sources of groundwater contamination

Phage typing of Escherichia coli populations was used as a “fingerprinting” tool to identify the source(s) of fecal coliform contamination of a drinking water well, PW- 12. Group discriminate analysis was used to evaluate the data and determine the relative distance of population centroids from the centroid of the PW- 12 population. The phage typing patterns were compared to serological results and correlations noted. Phage typing patterns were shown to be stable following 32-days incubation of E. coli isolates in garden soil, tap water and neutralized tertiary effluent, with and without the presence of autochthonous flora.

Activity of fecal coliform bacteria measured by 4-methylumbelliferyl-ß-D-glucuronide substrate in the northern Adriatic Sea with special reference to marine snow

Activity of fecal coliform bacteria measured by 4-methylumbelliferyl-ß-D-glucuronide substrate in the northern Adriatic Sea with special reference to marine snow

The Effect of Diaper Type and Overclothing on Fecal Contamination in Day-care Centers

Fecal coliform contamination of environmental surfaces and hands in the day-care center is common. This study evaluated the effect of two diaper types on fecal contamination. Ten rooms in four day-care centers containing 141 children were studied in a prospective, randomized, crossover study. A total of 2946 samples were cultured during the 9-week study. Fecal coliforms were isolated from 307 inanimate objects (15%), 73 toy balls (46%), and 131 hands (17%). The number of contaminated inanimate objects was significantly less in rooms where paper diapers were worn when compared with that in rooms where double cloth diapers with plastic overpants were worn and in rooms where clothes were worn over diapers. Inanimate object cultures had more contamination in rooms in which diarrhea had occurred. Containment of feces by overclothes and diaper type may be important in decreasing transmission of enteric pathogens in day-care environments.

Environmental Contamination in Child Day-Care Centers

Enteropathogens associated with outbreaks of diarrhea in day-care centers are spread by the fecal-oral route through contaminated hands or environmental objects. This prospective study was undertaken to determine the prevalence of fecal coliform contamination in day care. Ten rooms in six centers housing 121 children less than 2 years of age were studied for 13 weeks (February to May 1988). Inanimate objects (n = 1,275), toy balls (n = 724), and hands (n = 954) were cultured 1-3 times per week. Fecal coliform contamination was common and was greater (p less than 0.05) for objects, toy balls, and hands of children in toddler compared with infant rooms. In five rooms in which clothes were worn over diapers, there was a significantly lower prevalence of fecal coliform contamination of toy balls (p less than 0.005), inanimate objects (p less than 0.05), and hands (p less than 0.001) when compared with rooms in which overclothes were not worn. Occurrence of diarrhea was significantly associated with increased contamination of hands (p = 0.001). Stool and environmental isolates from individual rooms had the same plasmid patterns, which were unique to each center. In summary, fecal coliform contamination of environmental objects and hands of children and caregivers in day-care centers is common; toy balls can serve as sentinels of contamination; fecal coliform contamination can be significantly decreased by use of overclothes; and Escherichia coli strains from stool showed the same plasmid patterns.

Patterns of Fecal Coliform Contamination in Day‐Care Centers

During a six-month period, on four separate occasions, six licensed day-care centers had cultures taken from environmental surfaces as well as the hands of children and teachers. Fecal coliforms were recovered from 64 (9.5%) of the 675 surfaces sampled. Recovery rate was not influenced by a center's socioeconomic status, time of year, or presence of children who were not toilet trained. Recovery rates did differ significantly in different areas, with the kitchen showing a relatively high recovery rate (19%), and toys and toilets showing remarkably low rates (2% and 4%). Centers with formal hand-washing procedures had lower recovery rates than those without such practices. We also demonstrated a high recovery rate from hands of staff (16%); 6% of children had positive cultures. Contamination of hands and classroom objects is a potential source for the transmission of enteric diseases for children in day-care centers. A program directed at reducing contamination would be important in preventing the spread of diarrheal illness.

Pollution of ground water by nutrients and fecal coliforms from lakeshore septic tank systems

The fate of wastewater effluents discharged from 17 septic tank disposal systems located near the shores of eight lakes in northeastern and eastern New York State was investigated. Fecal coliforms chloride, conductivity, dissolved 02, phosphate and various forms of N in ground water samples were analyzed. Of 46 ground water samples, 23 were found to be highly contaminated and 16 slightly contaminated. Only 7 were not contaminated by the wastewater effluent. Seventeen of the 23 highly contaminated samples were collected within 30.5 m of the discharge point of the septic systems. Eleven of these were collected from ground water less than 122 cm below ground level. Eight of the 16 slightly contaminated samples and 3 of the 7 noncontaminated samples were collected at a distance greater than 30.5 m. The depth to the ground water from ground surface and the distance of the ground water from the discharge point of the sewage system are main factors influencing pattern and severity of ground water contamination. This survey indicated that significant nutrient and fecal coliform contamination of lakeshore ground waters was occurring.

Evaluation of Methods for Extraction of Enteric Virus from Louisiana Oysters

Six techniques were evaluated for recovery of poliovirus from Louisiana oysters. The methods were compared for percent recovery rates, toxicity, ease of extraction, bacterial contamination, and final volume of oyster concentrate. Oyster samples were contaminated with 30–40 plaque forming units of Poliovirus type 1 and processed by six variations of adsorption-elution-precipitation and elution-precipitation methods. The method developed by Ellender et al. (Natural enterovirus and fecal coliform contamination of gulf coast oysters. J. Food Prot. 43:105–110) was judged to be the preferred method for gulf coast oysters.

Natural Enterovirus and Fecal Coliform Contamination of Gulf Coast Oysters

The numbers of fecal coliforms and enteroviruses present in oysters and/or their growing waters of two Mississippi reefs were determined over a 12-month period. Bacterial and viral levels reflected the classification of the waters at each location as set by the Mississippi State Board of Health in compliance with the National Shellfish Sanitation Program, but statistically significant correlations between these levels were not observed. Twelve viral isolates were found at an approved oyster harvesting location, eight of which were identified as poliovirus type 1. At the prohibited site, 146 viruses were isolated including poliovirus types 1 and 2, echovirus type 24 and several isolates which remain to be identified. The number of virus isolates from samples from each location represented approximately 35% of the number of plaques observed; however, no consistent ratio of plaque to confirmed virus was demonstrated. The results suggest that the fecal coliform levels in oyster growing waters do not reflect the level of virus contaminaton in either approved or prohibited waters.