Search

Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk. [ABSTRACT FROM AUTHOR]

Standards based on fecal indicator bacteria (FIB) have traditionally been used by the U.S. Environmental Protection Agency to determine when recreational waters are contaminated by fecal and sewage inputs. Studies in tropical and subtropical areas, however, have shown that these same standards cannot reliably be used in these environments to determine when waters are contaminated by sewage. This is because soil, sediments, water, and plants have been shown to be significant indigenous sources of FIB in tropical/subtropical climates. In these climates, alternative fecal indicators, such as Clostridium perfringens and F+RNA coliphages, may be more reliable markers of sewage contamination, because these organisms are generally found in low concentrations in the environment. In the State of Hawaii, monitoring data relating to FIB (fecal coliform, Escherichia co/i, enterococci) and alternative indicator microorganisms (C. perfringens, F+RNA) in recreational waters has been obtained for the Island of Oahu, but similar data are lacking for other islands within the state. The major goal of this study was to monitor water samples obtained from the Nawiliwili watershed on the Island of Kauai for traditional FIB (fecal coliform and enterococci) as well as alternative fecal microbial indicators (C. perfringens, somatic coliphages, and F+RNA coliphages). Results for FIB concentrations on the Island of Kauai followed a similar trend as data obtained from the Island of Oahu. In addition, in areas like the Island of Kauai where cesspools are prevalent, monitoring for F+RNA and somatic coliphages may provide more reliable data in the detection of subsurface contamination of streams by cesspool waste, which can then lead to the pollution of coastal waters. Finally, genotyping of F+RNA phages obtained from the study sites provided additional evidence that human cesspool contamination was occurring within the Nawiliwili watershed. [ABSTRACT FROM AUTHOR]

Currently, the carriage rate for Community-Acquired Methicillin Resistant Staphylococcus aureus (CAMRSA) is unknown in Hawai'i. This survey focuses on a healthy population of 95 college students and 5 faculty who completed a survey related to possible risk factors for colonization of Staphylococcus aureus and were sampled for S. aureus from their anterior nares. Thirty-three (33%) subjects were carrying Staphylococcus aureus and of those, 3 (3%) carried MRSA. There was no significant association between Staphylococcus aureus carriage and ethnicity, gender, exposure to seawater, prior Staphylococcus aureus infections, recent antibiotic use, or pets. Additional testing of a larger group of healthy individuals would be beneficial in assessing factors associated with CA-MRSA and Methicillin-susceptible Staphylococcus aureus (MSSA ) carriage in Hawai'i. [ABSTRACT FROM AUTHOR]

The Fung Double Tube (FDT) and the newly developed CP AnaSelect Oxyplates methods can enumerate concentrations of Clostridium perfringens without need for external anaerobic generating systems. Because Clostridium perfringens is a reliable indicator of fecal contamination and it is one of the fastest growing fecal bacteria, these two methods were evaluated as feasible methods to screen recreational waters for sewage contamination. To increase the sensitivity and selectivity of these methods, three modifications were evaluated. The first modification was to pretreat the water samples using a microwave oven to attain high temperature (70C) for a short time (2.5 min) to reduce the interfering growth of non-C. perfringens colonies on the selective media. The second modification was the addition of phosphatase reaction, thus enumerated colonies could be confirmed as C. perfringens. The third modification was to increase the sample volume for the FDT test from 5 to 10 mL/tube. The data collected showed that these modifications improved the selectivity and sensitivity of these two methods to enumerate C. perfringens from sewage-contaminated water samples as well as environmental water samples such as streams, harbors, canals and coastal swimming beaches. The recovery efficiencies of the FDT and experimental CP AnaSelect Oxyplate for C. perfringens were similar to traditionally used membrane C. perfringens, tryptose sulfite cycloserine and Shahidi Ferguson perfringens agar media by membrane filtration technology, followed by incubation in anaerobic chambers. These results show that the modified FDT and CP AnaSelect Oxyplate methods are feasible and reliable methods to monitor environmental waters for C. perfringens. The FDT method is especially promising because it is simple, inexpensive and can produce results in 5–6 h. PRACTICAL APPLICATIONS Clostridium perfringens is currently being evaluated as a reliable indicator of sewage contamination in recreational waters. However, traditional methods to assay for C. perfringens are expensive and cumbersome because of the need for external anaerobic generating systems. In addition, target colonies must be confirmed by a second test. In this study, two methods are described, with capabilities to self-generate anaerobic conditions and to immediately confirm the target colonies as C. perfringens. Moreover, one of the methods meets the difficult criterion of obtaining results in 6 h so decision on closing the beach can be reached on the same day the beach water sample is tested. Since these two methods are feasible and reliable, it will encourage many laboratories to assay their recreational waters for C. perfringens and a national database to determine the quality of recreational waters based on concentrations of C. perfringens can be developed. [ABSTRACT FROM AUTHOR]