Microbial quality of local and imported brands of bottled water in Trinidad [abstract]

A cross-sectional study was conducted to determine the microbial quality of local and imported brands of bottled water available in supermarkets, groceries, and parlours in Trinidad. A sample size of 344 bottles of water was determined by using a precision rate of 2 percent and a Type 1 error of 5 percent. These bottles were purchased from six geographical regions in Trinidad which represented the whole island. The membrane filter technique was used with cultures made on endo agar and Fc agar for total coliforms and faecal coliforms, respectively. Total aerobic plate count (TAPC) was determined on nutrient agar, Pseudomonas aeruginosa and Salmonella spp were assayed using standard methods. Of the 344 water samples tested, 239 (69.5 percent) and 105 (30.5 percent) were local brands and imported brands, respectively. Eighteen (5.2 percent) of 344 samples were contaminated by coliforms with a mean count of 0.88 2 ñ 6.38 coliforms per 100 ml while 5(1.5 percent) samples were contained Escherichia coli. The prevalence of total coliforms in local brands of bottled water was 7.5 percent (18 of 239) compared with 0.0 percent (0 of 105) detected in imported brands. The difference was statistically significant (p= 0.004). Similarly, the prevalence of aerobic bacteria in local brands of bottled water (34.7 percent) was significantly (p= 0.001) higher than that found in imported brands (17.1 percent). Among local brands, the prevalence of total coliforms ranged from 0.0 percent to 13.8 percent but the difference was not statistically significant (p= 0.121). However, the prevalence of aerobic bacteria among these local brands ranged from 5.0 percent to 88.5 percent and the difference was significant (p< 0.0001). All water samples tested were negative for faecal coliforms, Salmonella spp and P aeruginosa. It was concluded that based on the recommended zero tolerance for coliforms in potable water, 5 percent of bottled water sold in Trinidad could be considered unfit for human consumption. The need to implement national standards for bottled water in Trinidad cannot be over-emphasized. (AU)

Leptospirosis occurring in two children after fresh water immersion

Leptospirosis is relatively uncommon in children. Two cases of severe leptospirosis occurred in teenaged boys who shared a common exposure via immersion in fresh water. While both patients had laboratory-confirmed leptospirosis, their symptoms differed in many respects.(Au)

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)

Microbial quality of oysters sold in Western Trinidad and potential health risk to consumers

The prevalence and characteristics of Escherichia coli and Salmonella spp. as well as counts of E. coli in raw oysters, condiments/spices, and raw oyster cocktails sampled from 72 vendors across Western Trinidad were determined. The microbial quality of the water used in the preparation of raw oysters was also investigated. Of 200 samples each of raw oysters, condiments/spices and oyster cocktails tested, 154 (77.0 percent), 89 (44.5 percent) and 154 (77.0 percent) respectively yielded E. coli. The differences were statistically significant (P= <0.001; chi square = 62.91). The mean E. coli count per g in the ready-to-eat oyster cocktail ranged from 1.5 x 10(3) +/- 2.7 x 10(3) in Couva to 8.7 x 10(6) +/- 4.9 x 10(7) in San Fernando. One hundred and forty six (73.0 percent) oyster cocktails contaminated with E. coli had counts that exceeded the recommended standard of 16 per g. Of a total of 590 E. coli isolates from various sources tested, 24 (4.1 percent0, 20 (3.4 percent) and 69 (11.7 percent) were mucoid, haemolytic and non-sorbitol fermenters respectively. Twelve (2.0 percent) isolates of E. coli were O157 strains, while 92 (46.0 percent) of 200 E.coli isolates tested belonged to enteropathogenic serogroups. Ninety (45.0 percent) and 73 (36.5 percent) of 200 water samples contained total coliforms and faecal coliforms respectively, with counts that exceeded 2.2 coliforms per 100 ml. Salmonella spp. were isolated from 7 (3.5 percent), 1 (0.5 percent) and 2 (1.0 percent) of 200 samples each, of raw oysters, condiments/spices and oyster cocktails respectively. Oysters pose a health risk to consumers in Trinidad, particularly from colibacillosis and salmonellosis, and the need for increased public awareness of this hazard cannot be over-emphasized. (AU)

Public health aspects of halophilic vibrios in Jamaica

The occurrence of bacteria in oysters (Crassotrea rhizophorae) and seawater from Jamaican commercial oyster-culture sites was determined, using standard microbiological methods. Vibrio vulnificus, V. cholerae (non-01, non-toxigenic), V. parahaemolyticus and V. alginolyticus were identified in seawater samples, and the latter two mildly pathogenic species in oysters. The pathogenicity of halophilic vibrios is reviewed. The results suggest that correct selection of oyster-culture sites may significantly reduce the public health hazards associated with shellfish, and that more and precise information is required on the geographical and seasonal distribution of infection risk (AU)

Serological and ecological study of the genus Leptospira in Jamaica

In a serological and ecological study of the genus Leptospira in Jamaica, 535 sera from three species of livestock animals, bovine, porcine and caprine were serologically tested by the microscopic agglutination technique using live leptospiral antigens. Of the number tested, 316 (59.06 percent) were reactive with titers equalling or greater than 1:100. A total of six serotypes were identified and representative serovars were as follows:- jules (serogroup Hebdomadis) 257 (51.92 percent); icterohemorrhagiae (serogroup Ictero-hemorrhagiae) 140 (28.07 percent); autumnalis (serogroup Autumnalis) 41 (8.3 percent); canicola (serogroup Canicola) 30 (6.06 percent); pomona (serogroup Pomona) 25 (5.19 percent) and abramis (serogroup Pyrogenes) 2 (0.4 percent). The porcine species recorded the highest percentage of reactive sera (65.5 percent) and the caprine the lowest (38.9 percent). The widest distribution of serotypes occurred in pigs. A comparison of the parishes showed that the positive sera from Portland (80.9 percent) and Westmoreland (71.6 percent) topped others and St. Andrew had the lowest 11.0 percent. For the ecological study, 22 soil and 25 water samples collected from five selected livestock farms in the island were cultured initially in enrichment artificial medium (Ellinghausen and McCullough semi-solid), ESS, incorporating 5-fluorouracil, for the isolation of leptospires. A total of 23 (48.9 percent) isolates were obtained:- 16 (72.7 percent) from the soil samples and 7 (28 percent) from the water samples. One water isolate was lost and the 22 parent isolates were subsequently inoculated into weanling hamsters. The kidney tissues and heartblood of the inoculated hamsters on culture yielded 8 leptospiral isolates and the microscopic agglutination test of the sera of inoculated hamsters gave 9 reactive results. There was no positive results either from culture or serological test of the control (uninoculated) hamsters. The investigations revealed that the constituents of Jamaican soil, the heavy rainfall and the various environmental factors are ideal for the survival and distribution of leptospires in the island. Flooding helps to spark off epizootic outbreaks and the leptospiral serotypes mentioned earlier are enzootic and endemic in Jamaica. The predominant serotypes are jules and icterohemorrhagiae. People at high risk are the livestock attendants and milkers. The epidemiological importance of the serotypes identified and suggested means of dealing with their adverse effects are discussed (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)

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 field survey of molluscicide-degrading microorganisms in the Caribbean area

Employing a bacteriologic medium in which the sole nitrogen source was the organic molluscicide, Bayluscide, isolations were made of organisms from more than 40 field and laboratory sites in Puerto Rico, the Dominican Republic, St. Lucia, and Venezuela. Materials were subcultured four times, then selected strains isolated from the snail Biomphalaria glabrata were subjected to standard diagnostic procedures. In all, 6 different bacterial strains were identified as members of the genus Psuedomonas and 2 as members of the genus Aerobacter. Distribution of molluscicide-utilizing bacteria was practically universal, being found in water, sediment, and snail intestine contents. Bacteria were isolated with 15 species of mollusc tested for the presence of such organisms. The possible significance of molluscicide-degrading organisms, relative to snail control projects is discussed (Summary)