NIHE/KVL status Presentations: 1.Ww treatment capacity – microbiological quality 2.Microbiological quality of water spinach 3.Toxic metals in water spinach, fish and environment 4.Skin problmes among farmers engaged in ww-fed agri-aquaculture 5.Anthropologial study of farmers perceptions of ww use and associated health risks 6.Fishborne zoonotic parasites in ww-fed fish in Hanoi and Nam Dinh

Wastewater Treatment Capacity of Peri- Urban Aquatic Production System in Phnom Penh and Hanoi Vuong Tuan Anh 1, Phung Dac Cam 1, and Anders Dalsgaard 2 1 Division of Enteric Infection Diseases, National Institute of Hygiene and Epidemiology, Vietnam; 2 Department of Pathobiology, Royal Veterinary and Agricultural University, Denmark

Study objectives 1.Assessing the level of variation of numbers of thermotolerant coliforms and helminth eggs in wastewater (ww) at inlets and outlets of aquatic production system 2.Assessing microbiological water quality to which farmers are exposed during working

Phnom Penh Introduction of study sites l Urban Wastewater (ww) discharged to Boeng Cheung Ek (BCE) lake  BCE lake: 2 inlets (called Tumpun and Trabek pumping stations) and 1 outlet (STEUNG CHROV stream)  Aquatic production: water spinach l Control site: Boeng Samrong (Prek Phnov) lake  Aquatic production: fish raising

Phnom Penh Methodology l Sampling points: at 2 inlets, 1 outlet of BCE lake and the control site l Sample types: composite samples (mixed 8, 10, 12 am) l Schedule: once per week/12 consecutive weeks l Parameters: thermotolerant coliforms, E. coli and helminth eggs (Ascaris lumbricoides, Trichuris trichiura, hookworm) l Place of sample analysis: Cambodian Pasteur Instittute and NIHE l Lab methods: MPN and WHO manual 1996

Phnom Penh Results l Nos of thermotolerant coliforms lower in samples collected at the control and outlet sampling points l No of E. coli are lower in samples collected at the control and outlet sampling points l Few samples found to contain helminth eggs ( eggs/L)

Figure 1. Log number of thermotolerant coliforms/100ml

Figure 2. Log number of E. coli/100ml

Hanoi: Introduction of study site: Bang B village, Hoang Liet commune l Aquatic plant and fish raising l Major types of plants: water spinach, water mimosa, water dropwort and water cress l Use urban ww from To Lich river l ww is pumped directly (pumping station) l 2 aquatic plant production fields and 3 fishponds selected

Hanoi: methods l Composite sample collection (8,10,12 am) l Point-of-time sampling: when ww was pumped and later (a week or 2 weeks later after pumping ww) l Parameters: thermotolerant coliforms and helminth eggs l Laboratory analysis: MPN and WHO manual 1996 l Collaboration: RIA1

Hanoi results: vegetable fields

Hanoi results: fishpond with combined aquatic plant production

Hanoi results: fishponds

Hanoi results: Helminth eggs l Helminth eggs (vegetable fields) sample pos./total Sampling sites AscarisTrichurisHookwormAll types Inlet field A3/6 (50%) 0/61/6 (17%)4/6 (67%) Outlet/Inlet field A 3/7 (43%) 0/7 3/7 (43%) End field A1/4 (25%) 0/42/4 (50%)3/4 (75%) Inlet field L0/3 (0%) 0/31/3 (33%) End field L2/3 (66%) 0/31/3 (33%)2/3 (66%)

Hanoi results l Helminth eggs (fishponds) sample pos./total Sampling sitesAscarisTrichurisHookwormAll types Inlet fishpond T (1)1/3 (33%)0/3 1/3 (33%) Inlet fishpond T (2)1/1 (100%) 0/1 1/1 (100%) Outlet fishpond T (3)0/3 Outlet fishpond T (4)1/3 (33%)0/3 1/3 (33%) Inlet fishpond C (1)0/2 Outlet fishpond C (2)1/3 (33%)0/3 1/3 (33%) Inlet fishpond N (1)0/3 Outlet fishpond N (2)1/3 (33%)0/3 1/3 (33%)

Conclusion Phnom Penh: 3-4 log reduction in nos of thermotolerant coliforms between inlet/outlet Hanoi: 1-3 log reduction in nos of thermotolerant coliforms between inlet/outlet Few samples were found to contain helminth eggs No apparant reduction in nos of samples positive for helminth eggs between inlet/outlet

Future works Hanoi: continued water analyses until April 2006 Data analysis: on-going Preparation of manuscript (1 MS)

Acknowledgements EU for funding Mr Borin and his staff (RUA) Division of Enteric Infections, NIHE Mr Tuan and his staff (RIA1) Cambodian Pasteur Institute