title: Availability of safe drinking-water: the answer to cholera outbreak? Nabua, Camarines Sur, Philippines, 2012.
abstract: BACKGROUND
  In May 2012, there were increasing diarrhoea cases and deaths reported from Nabua, Camarines Sur to the Philippines event-based surveillance system. An investigation was conducted to identify risk factors and determine transmission dynamics.
  
  
  METHODS
  A suspected case was defined as a resident of Nabua with at least three episodes of watery diarrhoea per day from 16 March to 22 June 2012. A confirmed case was defined as a suspected case positive for Vibrio cholerae. An environmental investigation was conducted and rectal swabs and water samples sent to the national reference laboratory for bacterial isolation. A 1:2 case-control study matching for age and sex was conducted. Data were analysed using Epi Info.
  
  
  RESULTS
  There were 309 suspected cases with two deaths, and the most affected age group was children under five years (45%). Eight cases were positive for Vibrio cholerae Ogawa El Tor and one for Non-01. Water samples were positive for faecal coliforms and Aeromonas caviae. The case-control study showed that cases had a higher odds than controls of using unchlorinated water sources (odds ratio [OR] = 3.6; 95% confidence interval [CI]:1.6-8.5) and having toilets located within 20 m of a septic tank (OR = 2.7; 95% CI: 1.4-5.3). In multivariate analysis, the only significant factor was drinking from piped water (OR = 0.21; 95% CI: 0.09-0.49).
  
  
  CONCLUSIONS
  In this cholera outbreak, drinking-water from unchlorinated wells was a significant risk factor. Future cholera control efforts should include not just improving water and sanitation systems but also intensified behaviour change campaigns.
authors.affiliation: Field Epidemiology Training Program, Epidemiology Bureau, Department of Health, Sta Cruz, Manila, Philippines . ; Department of Health, Sta Cruz, Manila, Philippines .
authors.forename: Alethea
authors.initials: A
authors.lastname: De Guzman
authors.affiliation: Department of Health, Sta Cruz, Manila, Philippines .
authors.forename: Vikki Carr
authors.initials: VC
authors.lastname: de los Reyes
authors.affiliation: Department of Health, Sta Cruz, Manila, Philippines .
authors.forename: Ma Nemia
authors.initials: MN
authors.lastname: Sucaldito
authors.affiliation: Department of Health, Sta Cruz, Manila, Philippines .
authors.forename: Enrique
authors.initials: E
authors.lastname: Tayag
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002771:Cholera / Q000453:epidemiology*; D004196:Disease Outbreaks; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010679:Philippines / Q000453:epidemiology; D012307:Risk Factors; D012499:Sanitation; D017678:Sex Distribution; D014871:Water Microbiology; D014881:Water Supply; D055815:Young Adult