title: Diarrheagenic pathogens in adults attending a hospital in Singapore.
abstract: BACKGROUND
  Singapore's diarrhoeal notification system is based on specific pathogens. Official data may thus be skewed towards notifiable diseases. Limited information is available on the profiles of aetiological agents responsible for acute gastroenteritis (AGE) cases, especially among the adult population. To understand the frequency and distribution of potential causative agents of diarrheal disease in Singapore, we screened adults' stool samples collected from a large public hospital.
  
  
  METHODS
  The stool samples were screened for 18 diarrheagenic pathogens using a combination of commercial multiplex polymerase chain reaction (PCR), in-house singleplex PCR and immunochromatographic assays. One hundred adult faecal samples that were collected from October 2013 to January 2014 for routine diagnostic purposes and submitted for culture at Tan Tock Seng Hospital, Singapore were used.
  
  
  RESULTS
  Pathogens were detected in 32% of the samples. The predominant organisms encountered were norovirus genogroup II (11%), Aeromonas spp. (9%) and Campylobacter spp. (5%). One sample was positive for both verocytotoxigenic E. coli (VTEC) and E. coli O157:H7. Two other samples were positive for VTEC only, and one other sample was positive for E. coli O157:H7 only. Astrovirus, C. perfringens, Shigella spp. and toxigenic C. difficile were each detected in 2% of the samples. Cryptosporidium parvum, Giardia lamblia, group A rotavirus, Salmonella spp. and Vibrio spp. were each detected in 1% of the samples. No L. monocytogenes, Y. enterocolitica, enteric adenovirus, or norovirus genogroup I were detected.
  
  
  CONCLUSIONS
  Our preliminary findings suggest that pathogens causing non-notifiable diseases might have contributed considerably to the adult hospitalised AGE cases. However, as the samples were from an adult hospital, the data obtained may not be representative of the whole community. Thus, a larger study to collect clinical samples and risk exposure data from primary healthcare clinics and children hospital is planned for, to gain a more holistic perspective on the epidemiology of AGE in Singapore. A larger study may also offer valuable insights for improving the approach of microbiological surveillance of food, as well as strategizing inspection efforts along the food supply chain by public health authorities.
authors.affiliation: Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore. CHAU_Man_Ling@nea.gov.sg.
authors.forename: Man Ling
authors.initials: ML
authors.lastname: Chau
authors.affiliation: Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore. Sri_Harminda_HARTANTYO@nea.gov.sg.
authors.forename: Sri Harminda Pahm
authors.initials: SH
authors.lastname: Hartantyo
authors.affiliation: Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore. YAP_Min@nea.gov.sg.
authors.forename: Min
authors.initials: M
authors.lastname: Yap
authors.affiliation: Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore. Joanne_KANG@nea.gov.sg.
authors.forename: Joanne Su Lin
authors.initials: JS
authors.lastname: Kang
authors.affiliation: Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore. AUNG_Kyaw_Thu@nea.gov.sg.
authors.forename: Kyaw Thu
authors.initials: KT
authors.lastname: Aung
authors.affiliation: Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore. Ramona_GUTIERREZ@nea.gov.sg.
authors.forename: Ramona Alikiiteaga
authors.initials: RA
authors.lastname: Gutiérrez
authors.affiliation: Environmental Health Institute, National Environment Agency, 11 Biopolis Way, #04-03/04, Helios Block, Singapore, 138667, Singapore. NG_Lee_Ching@nea.gov.sg.
authors.forename: Lee Ching
authors.initials: LC
authors.lastname: Ng
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Tahir Foundation Building, 12 Science Drive 2, #10-01, Singapore, 117549, Singapore. clarence_tam@nuhs.edu.sg.|London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK. clarence_tam@nuhs.edu.sg.
authors.forename: Clarence C
authors.initials: CC
authors.lastname: Tam
authors.affiliation: Department of Laboratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore. timothy_barkham@ttsh.com.sg.
authors.forename: Timothy
authors.initials: T
authors.lastname: Barkham
mesh_terms: D000208:Acute Disease; D000328:Adult; D002167:Campylobacter / Q000235:genetics / Q000302:isolation & purification; D002846:Chromatography, Affinity; D004269:DNA, Bacterial / Q000032:analysis; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology*; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005759:Gastroenteritis / Q000453:epidemiology / Q000382:microbiology*; D006761:Hospitals; D006801:Humans; D060885:Multiplex Polymerase Chain Reaction; D029322:Norovirus / Q000235:genetics / Q000302:isolation & purification; D012367:RNA, Viral / Q000032:analysis; D012401:Rotavirus / Q000235:genetics / Q000302:isolation & purification; D012475:Salmonella / Q000235:genetics / Q000302:isolation & purification; D012846:Singapore / Q000453:epidemiology; D014734:Vibrio cholerae / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012367:RNA, Viral
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