8/12/2019 exposure to goose droppings

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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: sabine.dittrich@rivm.nl

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