title: Usefulness of the hydrogen sulfide test for assessment of water quality in Bangladesh.
abstract: OBJECTIVE
  To evaluate the usefulness of the hydrogen sulfide (H(2)S) test for assessing water quality in Bangladesh.
  
  
  RESULTS
  We tested 382 water samples from a variety of sources using locally produced H(2)S test kits and laboratory-based membrane filtration for the detection of Escherichia coli. Compared with membrane filtration, H(2)S tests, when incubated for 24 h, had both a sensitivity and positive predictive value (PPV) of <40% when analysis was restricted to water samples with E. coli levels below 100 colony forming units (CFU) per 100 ml. In contrast, for E. coli levels from 1000 to 9999 CFU per 100 ml, sensitivity was 94% and PPV 88%; specificity was 97% and negative predictive value was 99%.
  
  
  CONCLUSIONS
  The hydrogen sulfide test, when incubated at 24 h, is a promising alternative for assessing water quality where E. coli levels may be high. An improved understanding of the incremental impact of contamination level on health is needed to better determine its usefulness.
  
  
  CONCLUSIONS
  The hydrogen sulfide test is inexpensive, easy to use and portable. Its use may allow rapid assessment of water quality in situations where cost or logistics prevent use of other testing methods, such as in remote areas or during flood and other natural disasters.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA 30333, USA. scg7@cdc.gov
authors.forename: S K
authors.initials: SK
authors.lastname: Gupta
authors.forename: M A
authors.initials: MA
authors.lastname: Sheikh
authors.forename: M S
authors.initials: MS
authors.lastname: Islam
authors.forename: K S
authors.initials: KS
authors.lastname: Rahman
authors.forename: N
authors.initials: N
authors.lastname: Jahan
authors.forename: M M
authors.initials: MM
authors.lastname: Rahman
authors.forename: R M
authors.initials: RM
authors.lastname: Hoekstra
authors.forename: R
authors.initials: R
authors.lastname: Johnston
authors.forename: P K
authors.initials: PK
authors.lastname: Ram
authors.forename: S
authors.initials: S
authors.lastname: Luby
mesh_terms: D001459:Bangladesh; D003906:Developing Countries; D004926:Escherichia coli / Q000302:isolation & purification* / Q000378:metabolism*; D006801:Humans; D006862:Hydrogen Sulfide / Q000032:analysis*; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D014871:Water Microbiology; D014881:Water Supply / Q000592:standards*
chemical_list: D011933:Reagent Kits, Diagnostic; D006862:Hydrogen Sulfide