The coastal environment and human health : microbial indicators, pathogens, sentinels and reservoirs

© 2008 Author et al. This is an open access article distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Health 7 (2008): S3, doi:10.1186/1476-069X-7-S2-S3.Innovative research relating oceans and human health is advancing our understanding of disease-causing organisms in coastal ecosystems. Novel techniques are elucidating the loading, transport and fate of pathogens in coastal ecosystems, and identifying sources of contamination. This research is facilitating improved risk assessments for seafood consumers and those who use the oceans for recreation. A number of challenges still remain and define future directions of research and public policy. Sample processing and molecular detection techniques need to be advanced to allow rapid and specific identification of microbes of public health concern from complex environmental samples. Water quality standards need to be updated to more accurately reflect health risks and to provide managers with improved tools for decision-making. Greater discrimination of virulent versus harmless microbes is needed to identify environmental reservoirs of pathogens and factors leading to human infections. Investigations must include examination of microbial community dynamics that may be important from a human health perspective. Further research is needed to evaluate the ecology of non-enteric water-transmitted diseases. Sentinels should also be established and monitored, providing early warning of dangers to ecosystem health. Taken together, this effort will provide more reliable information about public health risks associated with beaches and seafood consumption, and how human activities can affect their exposure to disease-causing organisms from the oceans.The Oceans and Human Health Initiative research described within this paper is supported by the National Science Foundation, The National Institute for Environmental Health Sciences and the National Oceanic and Atmospheric Administration. Grant numbers are: NIEHS P50 ES012742 and NSF OCE- 043072 (RJG, LAA-Z, MFP), NSF OCE04-32479 and NIEHS P50 ES012740 (RSF), NSF OCE-0432368 and NIEHS P50 ES12736 (HMS-G), NIEHS P50 ES012762 and NSF OCE-0434087 (JSM)

Beach sand and the potential for infectious disease transmission: observations and recommendations

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

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

WRRCSR No. 1.29:82 The Significance of the Bactericidal Effect of Sunlight on Indicator and Pathogenic Bacteria in Marine Waters on Measurements and Interpretations of Water Quality

Natural streams collect runoff and discharges from many sources which alter the quality of stream water. To determine the hygienic quality of streams, water samples from streams are collected and assayed for two human enteric bacteria, fecal coliform (FC) and fecal streptococcus (FS). These bacteria are non-pathogenic to man and are normal inhabitants of the intestinal tract of man and warm blooded animals. The concentrations of these bacteria in natural waters are used as indicators of fecal pollution and as a probability factor that pathogenic microorganisms may be present in that polluted water.City and County of Honolulu, Department of Public Works (Contract No. F-365-80

WRRCTMR No.70 Stream Water Quality Assessment Based on Fecal, Coliform and Fecal Streptococcus Analysis

The quality of stream water in Hawaii was determined by carefully analyzing samples of unpolluted streams, streams polluted with sewage effluent, sewage effluent, cesspool wastes, and storm drain runoff for concentrations of fecal coliform (FC), fecal streptococcus (FS), and selected physical and chemical tests. High concentrations (10^3-10^4/100 ml) of FC and FS could be recovered from samples of stream waters obtained from unpolluted and polluted sites. Most of the stream-water samples collected in urbanized areas, but upstream from the sewage effluent discharge site (unpolluted stream), contained higher concentrations of FC than the 200 to 400 FC/100 ml considered by state and federal laws as being polluted with fecal matter and as a possible source of enteric pathogens. Only after analyzing stream samples for concentrations and the ratio of FC and FS, as well as concentrations of phosphates, was it possible to determine which stream samples did or did not contain sewage effluent. The results show that the impact of sewage effluent discharge into streams on Oahu, Hawaii, cannot be properly evaluated by analyzing the stream samples for only FC as mandated by law. Moreover, it should no longer be assumed that stream-water quality upstream of the sewage effluent discharge point is superior to that of the effluent entering the stream. Conclusions should not be made based solely on measurements of stream samples taken downstream of the sewage effluent discharge site. To properly assess the impact of sewage effluent discharge streams, samples of the sewage effluent - as well as stream samples taken upstream and downstream of the effluent discharge site - should be analyzed for FC, FS, phosphorus, and turbidity.City and County of Honolulu, Department of Public Works Grant/Contract No. F-365-8

Assessing the Impact of the Kapahulu Storm Drain System on the Quality of Water at Kuhio Beach and the Health of the Swimmers Using the Beach

Project Period: 1 April 1992-31 December 1993The primary goal of this study was to determine the concentrations of several types of fecal bacteria (fecal coliform, E. coli, enterococci, C. perfringens) in the Kapahulu storm drain system and its impact on the quality of water in Kuhio Beach. Another major goal of this study was to simultaneously conduct a pilot epidemiological study to determine whether there was a measurable increase in the illness rate of swimmers at the beach as the concentrations of indicator bacteria in the water increased. Additional goals to this study included the determination of the sources of indicator bacteria in the storm drain and to analyze the sediment and water samples from the storm drain for toxicity as well as for the presence of specific toxic chemicals using a new enzyme-immunoassay test.State of Hawaii Department of Health; contract number: ASO Log no. 92-61

WRRCPR No.94-05 Assessing The Impact of Mokapu Sewage Outfall on the Shoreline Water Quality of Kailua Bay (KB-2)

The discharge of secondary treated sewage effluent from the Mokapu Ocean Outfall into Kailua Bay, Oahu, Hawaii, represents a point source of pollution to the bay. Public health considerations are therefore of significant importance due to bodily contact and the possible ingestion of recreational water. The impact of the Mokapu outfall on the shoreline water quality at Kailua Bay was assessed in 1990 and 1991. The concentrations of fecal indicator bacteria (E. coli, enterococci, C. perfringens) were determined in sewage effluent samples and in water samples collected from the zone of mixing (ZOM) sites, offshore sites, nearshore sites, and shoreline sites of Kailua Bay. The indicator bacterial loads discharged from the outfall were on the orders of 106 E. coli/100 ml, 105 enterococci/100 ml, and 104 C. perfringens/ 100 ml. Within the ZOM, some of the sewage surfaced, however most of it was transported submerged and in a northerly direction. The sewage was also transported submerged to the two offshore sites located north and south of the ZOM but preferentially north. The nearshore data also suggested the movement of sewage in a direction north-northwest of the outfall. The absence or recoveries of only very low numbers of bacteria from the nearshore sites closest to the Kailua shoreline did not provide evidence that sewage from the outfall was possibly impacting the quality of the shoreline recreational waters. The geometric means of the seven true shoreline sites all met Hawaii's marine recreational water quality standard. The two other shoreline sites which equaled or exceeded the standard are actually the mouths of land-based fresh water sources which are known to contain high concentrations of indicator bacteria. The overall results suggested that the quality of shoreline water is more likely impacted by land-based sources such as rainfall events which increase surface runoff.City and County of Honolulu, Department of Wastewater Managemen

WRRCTR No.154 Clostridium perfringens as an Indicator of Stream Water Quality

The mCP medium devised by Bisson and Cabelli in 1979 was used to recover Clostridium perfringens from sewage and streams. This membrane filtration method proved to be uncomplicated and reliable. Of 98 presumptively positive colonies recovered from various stream samples. 89 or 91% were confirmed as C. perfringens by using biochemical tests, whereas only 1 of 29 (3%) of the presumptively negative colonies was subsequently confirmed as C. perfringens. The quality of streams receiving treated and chlorinated sewage effluent was determined by analyzing the effluent entering the stream as well as stream samples above and below the effluent discharge site for fecal coliform (FC), fecal streptococcus (FS. and C. perfringens (CP). Chlorination was shown to drastically reduce the concentrations of FC and FS, but not CP in the sewage effluent. As a result, the concentrations of FC and FS in the chlorinated effluent were less than the natural concentrations of these bacteria in the stream, whereas the same effluent contributed significantly more CP than was naturally present in the stream. Thus, analysis of stream water for CP, but not FC or FS, clearly indicated the input of effluent into the stream. Moreover, the FC:CP ratio was useful in determining the quality and distance of a major source of pollution within a stream.Office of Water Policy U.S. Department of the Interior Grant/Contract No. 14-34-0001-1113; A-087-H

Vulnerability to Pathogens: Water Quality Monitoring and Assessment Study

Honolulu Board of Water Supply; agreement number: contract no. C3381