Lw. Sinton et al., FECAL STREPTOCOCCI AS FECAL POLLUTION INDICATORS - A REVIEW .2. SANITARY SIGNIFICANCE, SURVIVAL, AND USE, New Zealand Journal of Marine and Freshwater Research, 27(1), 1993, pp. 117-137
Some New Zealand regional councils are examining the use of faecal str
eptococci (or the subset, enterococci) to assist in identifying pollut
ion sources, or as better indicators of disease risk in bathing waters
than faecal coliforms. However, in spite of worldwide investigation,
faecal streptococci have largely failed to fulfil their potential as p
ollution source (human versus animal) indicators in receiving waters.
Many qualifications accompany the use of faecal coliform: faecal strep
tococci (FC:FS) ratios, and the species identification approach (using
biochemical and DNA-based methods) has produced inconclusive results.
Nevertheless, the FC:FS shift method (in which the ratio changes unde
r sample storage) may warrant further investigation. Although reported
results vary widely, most studies indicate that faecal streptococci o
utlive faecal coliforms in receiving waters and are more resistant to
sunlight-induced inactivation. USEPA epidemiological studies showed th
at enterococcus concentrations were better correlated than faecal coli
form concentrations with disease risk associated with bathing in sewag
e-polluted waters. These results, which implied that the enterococci b
etter represented viral hazard, led the USEPA to recommend the use of
enterococci (or Escherichia coli in freshwaters) as bathing water qual
ity indicators. These recommendations have largely been followed in pr
ovisional New Zealand Department of Health guidelines. However, adopti
on of the USEPA criteria should be approached cautiously, because of d
oubts about their epidemiological applicability in New Zealand, and a
lack of information about streptococcal concentrations and species pro
files in local effluents and receiving waters.