Microbial quality of water in rural communities of Trinidad

A cross-sectional study was conducted in four rural communities of northeastern Trinidad to determine the microbial quality of water supply to households and that quality's relationship to source and storage device. Of the 167 household water samples tested, total coliforms were detected in 132 of the samples (79.0 percent), fecal coliforms in 102 (61.1 percent), and E. coli in 111 (66.5 percent). There were significant differences among the towns in the proportions of the samples contaminated with coliforms (P <0.001) and E. coli (P <0.001). Of 253 strains of E. coli studied, 4 (1.6 percent) were mucoid, 9 (3.6 percent) were hemolytic, and 37 (14.6 percent) were nonsorbitol fermenters. Of 69 isolates of E. coli tested, 10 (14.5 percent) were verocytotoxigenic. Twenty-eight (14.0 percent) of 200 E. coli isolates tested belonged to enteropathogenic serogroups. Standpipe, the most common water source, was utilized by 57 (34.1 percent) of the 167 households. Treated water (pipeborne in homes, standpipes, or truckborne) was supplied to 119 households (71.3 percent) while 48 households (28.7 percent) used water from untreated sources (rain, river/stream, or well) as their primary water supply. The type of household storage device was associated with coliform contamination. Water stored in drums, barrels, or buckets was more likely to harbor fecal coliforms (74.2 percent of supplies) than was water stored in tanks (53.3 percent of samples), even after controlling for water source (P=0.04). Compared with water from other sources, water piped into homes was significantly less likely to be contaminated with total coliforms (56.9 percent versus 88.8 percent, P <0.001) and fecal coliforms (41.2 percent versus 69.8 percent, P <0.01), even when the type of storage device was taken into account. However, fecal contamination was not associated with whether the water came from a treated or untreated source. We concluded that the drinking water in rural communities in Trinidad was grossly unfit for human consumption, due both to contamination of various water sources and during household water storage (AU)

The water quality of the beaches of the Kingston Metropolitan area a public health concern

The recreational water of Jamaica with the exception of a few 'problem' spot are safe as prescribe by WHO standards. Continuous monitoring of the marine environment by various agencies, including environmental Control Division (ECD), Ministry of Health, National Resources and Conservation Authority (NRCA), Ministry of the Environment and Housing, National Water Commission (NWC) and the Underground Water Authority (UWA) Ministry of Public Utilities and Transport ensures early detection of adverse trends. The quality of the water of the beaches in Kingston and its environs, including the Portmore area of St. Catherine was studied to assess the extent of pollution by virtue of the waste water problems besetting these parishes. The study found that with the exception of two spots in Kingston - Victoria Pier and Rae Town the quality of the water was well within the guidelines set by the World Health Organisation. The results of analysis of the water from the different beaches show that if the beaches are divided into eastern - those in Portmore that is, Hellshire and Fort Clarence and Western - those in Kingston and Port Royal, there is not significant difference in nitrate level T = 1.1667, P = 0.005. There is however a significant difference in mean BOD between eastern and western beaches, T = 4.1569, P = 0.001, D.F = 28. This is also true for mean Faecal coliform count, T = 4.4397, P = 0.0005, D.F. = 28. Until now dilution has been 'a conditioner' of the beach waters, but with the rate of industrialization and residential development and the fact that all waste water eventually are discharged into the sea, there is the possibility that the time will come when the dilution factor will have it's effects. When this happen eutrophication will result. Every effort therefore must made to treat our waste water before discharge into the sea or better yet find alternative means of disposal (AU)

Investigation of an hepatitis A outbreak in a rural squatting community associated with a contaminated water-source in County St. George East, Trinidad - abstract

Following a report of a confirmed case of Hepatitis A in a child, a cross sectional epidemiological and an environmental survey were done on the total population ( about 90 households) of a village adjacent to the Arima river from April to September, 1989. The residents had no legal claim to the land and there was no pipe-bourne water supply or scavenging service to the area. Cases of Hepatitis A were identified based on clinical signs and symptoms, and a case control analysis was done using affected and non-affected households. Based on case definition criteria, the attack rate was 22 per cent and 30 cases were found. The age distribution was typical of Hepatitis A, and an epidemic curve had some features of both a common source and a propagated source epidemic. Highly significant were exposures related to using the river as a water source, using a spring and a household size > 4. It was concluded that there was an Hepatitis A outbreak, and the initial source was a river which collected waste from the nearby town and the effluent from a water treatment plant. This outbreak serves as a useful indicator of declining socio-economic conditions and deteriorating environmental standards (AU)

Developing alternative approaches to urban wastewater disposal in Latin America and the Caribbean

The explosive rate of urbanization and industrialization in Latin America and the Caribbean has aggravated serious wastewater disposal problems. To address those problems, sound pollution control programs are needed - programs that are founded on a firm legal base and supported by an institutional infrastructure suitable for their effective operation. Such programs should make a point of employing technologies that are appropriate for the climatic and economic conditions prevailing in the areas they serve. Promising methods for dealing with such problems include use of submarine outfalls with minimal pretreatment for cities along coasts and estuaries, maximum use of receiving waters' assimilative capacity (as determined through application of system management and water quality models), reuse of treated sewage effluent for irrigation, and the application of unconventional technology for urban slum sanitation. This article reviews those various approches and describes the ongoing collaboration between national governments and PAHO's Pan American Center for Sanitary Engineering and Environmental Sciences (CEPIS) in the areas of research, information exchange, human resources development, and institutional development for the purpose of establishing a viable strategy and framework through which these major problems can be confronted and perhaps ultimately over come.(AU)

Contaminated roof-collected water as a possible cause of an outbreak of salmonellosis

Roof-collected rainwater is a common source in subtropical regions and has not been associated with human illness. In Trinidad, the West Indies, a church group attending a rural camp, developed gastrointestional illness, caused by Salmonella arechevalata. This rare serotype was isolated from stool specimens of campers, food eaten at the camp, and a water tap, which was supplied by a storage tank of roof collected rainwater. The surface of the roof, used as water catchment, was covered with bird faeces. It is postulated that rainwater, falling on the roof, washed off animal excrement which contained S. archevalata and led to the outbreak of salmonellosis through camper ingestion of contaminated food and water.(Summary)

Predation on peridomestic mosquitoes by hylid tadpoles on Grand Bahamas Island

In order to determine whether tadpoles of Hyla septentrionalis are effective predators of larval peridomestic mosquitoes, larvae were exposed to tadpoles and the association between larvae and tadpoles in nature was recorded. Tadpoles were cannibalistic, eating egg masses of their own species, as well as a variety of material of both plant and animal origin. Tadpoles captured and ate more than 13 larval Culex pipiens per day. In natural breeding sites on Grand Bahamas Island, larval C. papiens were never abundant in sites that contained tadpoles and when tadpoles were introduced into vessels that contained mosquitoes, these containers soon became free of mosquitoes. The habitat of H. septentrionlis tadpoles in the study area seemed identical to that of larval C. papiens and more than half of apparently suitable sites contained tadpoles. Thus, the presence of these frogs appeared to limit the abundance of C. papiens.(AU)

Effect of seasonal effluent chlorination on coliforms in Jamaica Bay

Quite frequently, the need for chlorinating effluents discharged to receiving waters not used for recreational purposes is questioned. A study was undertaken to demonstrate that chlorination of wastewater treatment plant effluents that, by volume, represented less than 0.5 percent of the receiving water volume, would significantly improve the bacteriological quality of Jamaica Bay. This estuary was an ideal site for such an investigation because more than 99 percent of the treated effluents being discharged to the Bay are chlorinated on a seasonal basis only- May 15 to September 30. (AU)

A new medium for the differentiation of B. coli in water analysis

B. coli (lactose +, indol +) may be isolated by the standard method not only from faeces and polluted waters, but also from unpolluted soils and unpolluted waters. As a standard indicator of faecal contamination its value is therefore unquestionable. Local experience indicates that the utilisation of citrate by B. coli may be of value in differentiating faecal from non-faecal B. coli in water analysis (Summary)