8/12/2019 exposure to goose droppings
1/1
091168LIS
VIRFvdB
RIVM National Institute for Public Health and the Environment, PO Box 1, 3720 BA Bilthoven, the Netherlands, www.rivm.com
Dr Sabine Dittrich(1,2)
, Dr Marion Koopmans(1)
, Dr Ana Maria de Roda Husman(1)
1 Centre for Infectious Disease Control Netherlands, National Institute for Public Health and the Environment (RIVM), The Netherlands
2 European Public Health Microbiology Training Program (EPIET/EUPHEM), European Centre for Disease Prevention and Control (ECDC),
Sweden
Questions and suggestions are welcome: [email protected]
Health risk assessment of exposure to geese
droppings in recreational waters in The NetherlandsBackgroundAdvice was sought from the RIVM by the Ministries of Agriculture and Health to assess the
possible health risk from exposure to goose droppings in recreational areas in the Netherlands.
A qualitative assessment of the health risk from exposure to goose droppings in recreational
water was done in order to assist the MoH in further policy decisions. This approach was chosen
since not enough accurate information are available for the Netherlands which would allow
quantative estimations and modeling. Data on all aspects of the contamination chain
(geese droppingsrecreational water public/swimmer) were collected and data gaps
identified.
Method Scientic literature (Pubmed) was screened for existing data on migration pattern, excreta
and existing water pollution data. Literature was included after assessing the relevance of the
article (abstract) in respect to the study question. Various combinations of keywords were used:
Geese/goose/waterfowls/birds, droppings/feces/fecal contamination, cryptosporidium/giradia/
avian influenza/contamination/pathogens. All relevant scientific publications before April 2009
were included.
Local experts on geese in the Netherlands were questioned on Dutch migration patterns.
Specic information on geese numbers, fecal contamination in the Netherlands were obtained
by using Dutch keywords like keutel, ganzen, nederlands on google.
ResultsGeese Droppings Recreational water Public
Geese in the Netherlands
Wintering geese (Sep-Feb):2 million/year on agricultural land
Breading geese (March-June):
~155000 / year by lakes/sea
Flock sizes: 10-10000 birds
Breading geese
main source of concern
Fecal Burdon
Amount: ~170 fecal pellets/geese/day
Dropping size: 0.42 g 25.4 g/dropping
Pathogen (prevalence)
C. parvum(81.8 - 90%)Giardia sp.(not available)
E. hellem(8.8%)
Campylobacter jejuni(50.2%)
Salmonella spp.(0.8%)
Fecal coliform bacteria (100%)
Avian influenza Virus
(1.8%; 0% highly pathogenic)
Routes of contamination
Two routes of contamination:1) Indirect contamination by fecal runoff from
agricultural land into canals/ recreational
sites
2) Direct contamination by defecation into
the water
Health consequences of pathogens
Gastroenteritis
Respiratory disease/Conjunctivities (AIV)
Survival time at 15-20C in fresh
water
C. parvum 3 - 12 months
Giardia sp. max. 2 months
E. hellemmin. 6 months
Campylobacter jejuni 30 min. (in sunlight)
Fecal coliform bacteria 12 - 30 days
Avian Influenza Virus 4 days
Infective dose (as available)
C. parvum 8 - 1000 cystsGiardia sp. 10 oocysts
Campylobacter jejuni 8*102bacteria
Dutch water quality
All recreational waters comply with EU
regulations
(tests for fecal contamination)
Exposure of swimmers (water intake)
Children: 37 ml per swim (in pools)
Adult: 16 ml per swim (in pools)
5.7 ml-13 ml per dive
(occupational diver)
SUMMARY of literature data Large numbers of geese large fecal burden
Breeding geese might be main source of contamination.
Large numbers of pathogens present (data not shown)
Long survival time of pathogens
Fecal contamination was linked to geese by molecular source tracking
MISSING data to perform detailed quantitative microbial risk assessment:
Detailed maps of geese numbers at specic sites no calculation using specific dilution factor
possible.
No data on long-lasting pathogens like Giardia sp.available for Dutch water sites.
Detailed data on feces produced by geese in the Dutch delta are not available and available
data are not consistent enough.
RecommendationLarge numbers of geese at a specific bathing site have the potential to be a public health threat.
No such risk can be scientifically proven with the data available for the Netherlands.
No outbreaks of gastroenteritis have so far been linked to contaminations through geese
anywhere in the world making the risk theoretical until otherwise proven. However, even if lakes
with high geese numbers result in higher contamination, proof of an association is very difcult.
It is recommended to monitor specific risk sites closely and perform a bathing water profile
as described by the EU water directive (2006/7/EC).
In addition a detailed evidence based Quantitative Microbial Risk Assessment is recommended
including laboratory studies of pathogen load and survival time in Dutch climate.
This would lead to a model taking run-off scenarios, varying amount of geese, meteorological
data, dilution factors and temperature changes into account and could lead to a tool to help
take decisions on possibly redefining recreational water sites.
ional Institute
Public Health
the Environment