Transcript Community health risks of agricultural antibiotic use

Poultry Production in
Maryland: Environmental
Impacts and Community
Health Issues
Ellen Silbergeld
EHS/BSPH
July 2006
Research at JHSPH on Poultry
Production
 EPIDEMIOLOGY
 EXPOSURE, HEALTH OUTCOMES
 PRODUCT MONITORING
 POULTRY PRODUCTS TESTING
 ENVIRONMENTAL STUDIES
 PATHWAYS AND ROUTES OF EXPOSURE
 AIR, WATER, DUSTS, SOILS
 BIOTIC TRANSFERS – WILDLIFE STUDIES
 MOLECULAR MICROBIOLOGY
 TRACKING PATHOGEN MOVEMENT
 TRACKING GENE TRANSFER
 MICROBIAL POPULATION GENETICS/DIVERSITY
 POLICY ANALYSIS
 ECONOMIC ANALYSES
 SCIENTIFIC BASIS for RISK ASSESSMENT
The CAFO (Concentrated Animal Feeding
Operation): Changes in Food Animal
Production since1930
 Factory farms –
integrated production
model
 Concentrated, high
volume housing and
processing
 Highly intensive
localization
 Broad integration of food
production and
distribution
THE GEOGRAPHIC CONCENTRATION
OF POULTRY PRODUCTION – 50 YEARS
in US
US poultry production, 1949
Each dot = 50,000 chickens
US poultry production 1991
Each dot = 740,000 chickens
DELMARVA POULTRY INDUSTRY
 600-800 million broiler
chickens produced annually.
 6000 broiler chicken houses
 2,500 chicken growers
 15,000 poultry employees
 Total annual gross income of
Delmarva broiler industry:
exceeds 1.3 billion dollars.
Many Nonfood Routes of Exposure
and Transfer
ENVIRONMENT
rivers and streams
Irrigation
Drinking water
Bay
Manure spreading
Swimming
Farm effluents
Sewage
Offal
FARMS
Animal
feeds
Slaughter
Handling
Harvesting
Preparation
Processing
Consumption
Contact
Adapted from Dr. Ruth Etzel USDA
HUMANS
Farmers,
workers,
communities
High Risk Populations
• Children
• Elderly
• Immunocompromised
THE OTHER PRODUCT OF CAFOs
The DelMarVa Penninsula:
The “other product” of poultry production
 >1,000,000 tons of “manure”
produced by ~800 million
chickens/yr
 Integrators own the birds
 Growers own the waste
 Management - largely land
applied
Why are we concerned?
 More biosolids applied
than land can handle
 Contributes to surface and
groundwater
contamination
 Increased nutrient runoff
into surface waters
 Detectable presence of
drugs and resistance
determinants in
groundwater
WHO IS AT RISK FOR EXPOSURE?
Workers and growers who work in broiler
houses
Workers who handle live chickens at
processing plants
Household members of these persons
Community residents
The Poultry Environment Health Study
HYPOTHESES
PERSONS WITH DIRECT EXPOSURE TO
THE POULTRY ENVIRONMENT ARE AT
INCREASED RISK OF EXPOSURE TO ABR
EXPOSED PERSONS ARE AT INCREASED
RISK OF BACTERIA-ASSOCIATED
OUTCOMES
THERE IS A GRADIENT OF EXPOSURE, AND
HEALTH RISK, AMONG WORKERS, THEIR
FAMILIES AND THE COMMUNITY
The Poultry Environment Health Study
SUBJECTS
POULTRY HOUSE WORKERS
“LIVE HANGERS”
GROWERS
HOUSEHOLD MEMBERS
COMMUNITY RESIDENTS
Working in the poultry industry
Living
near the
poultry
industry
The Poultry Environment Health Study
EXPOSURE RISKS
PATHOGENS
ANTIBIOTIC RESISTANCE
ANTIBIOTICS
ARSENIC
PATHWAYS
AIR, WATER, DUSTS, WILDLIFE, CAUGHT
FISH, FOOD PLANTS
110
Figure 2: Antibiotic-Resistant
Bacteria Present inIN
IndoorCAFOS
Air Samples Collected
AIRBORNE
BACTERIA
ARE
from a Swine CAFO
MULTI DRUG RESISTANT
100
100
100
100
100
100
Percentage of Tested Isolates Resistant
100
100
97
100
100
86
90
80
67
70
Coagulase-negative Staphylococcus
(n = 44)
Viridans Group Streptococcus
(n = 45)
Non-E. faecalis Enterococcus
(n = 29)
60
50
40
30
20
10
0
0
0
0
Multi-drug Resistant
(Resistant >=2 Classes
of Antibiotics)
MDR
Erythromycin
(Breakpoint >= 8 ug/ml)
ERYTH-R
Tetracycline
(Breakpoint >= 16 ug/ml)
TET-R
Antibiotic
Chapin et al (2005) EHP
Virginiamycin*
(Breakpoint >= 4 ug/ml)
VM-R
Vancomycin
(Breakpoint >= 32 ug/ml)
VAN-R
Air releases from CAFO ventilation
systems
The Poultry Environment Health Study
 OUTCOMES
BACTERIAL CARRIAGE
REPORTED DIARRHEAL DISEASE
RESPIRATORY FUNCTION TESTS
NEUROLOGICAL SYMPTOMS
 METHODS
ISOLATION OF BACTERIA FROM STOOL;
MEASUREMENT OF ANTIBODIES IN SERA
QUESTIONNAIRES
RESPIRATORY FUNCTION TESTING
Poultry Health Study: Health Status
in poultry workers– Preliminary
Results
 Self reported symptoms: PW and referents
PW report more frequent GI symptoms
OR 2-5
PW report much more frequent respiratory symptoms
OR 2.6-35
PW report much more frequent neuromuscular
symptoms, including paralysis, problems with vision
and speech
OR 5.4-13.8
Arsenic sources - US
ARSENIC – THE FORGOTTEN
ANTIBIOTIC
extensive use of arsenicals in broiler feeds
documented contamination of waste and
amended land
percolation into groundwater
arsenic is a human carcinogen and
associated with skin, liver, and
cardiovascular disease
ARSENIC and POULTRY
 Roxarsone, arsanilic acid used in poultry as
coccidiostats and growth promoters – 45 g/ton
feed
 GP – continuous lifelong exposure in feeds
 arsenicals excreted (>70%)
 100-200 mg/bird (900 million/yr)
 50,000-90,000 mt/year arsenic
 arsenicals
inorganic arsenic
 leach into groundwater
SHALLOW AQUIFERS IN DELMARVA
A SUGGESTIVE TRACE?
What does this tell us about avian flu?
?
?
?
Wild avians contact poultry houses
Photo courtesy of Dr Donald Burke
What are the risks of occupational
contact and AF exposure?
 Three papers
Koopmans et al (2004)
 National surveillance study in Netherlands; symptom
driven
 2003 H7N7 outbreak HPAI
 All farmers, workers, families, veterinarians in outbreak
regions
Bridges et al (2001)
 Outbreak investigation of poultry workers and govt
investigators
 Hong Kong 1997-8 H5N1
Myers et al (2006)
 Cross sectional study of Iowa pork farmers, meat
processing workers, veterinarians; Univ of Iowa referent
group
 Swine influenza transmission risks
Risks of Influenza A/ (H5/N1) infection in
poultry workers: Hong Kong 1997-8
Odds of antibody carriage:
 Farm/hatchery workers
 Work on farm >10% bird mortality
 Touching live poultry
 Feeding live poultry
 Butchering live poultry
[referents: government workers]
Occupational dose: response
observed
2.7
2.2
5.8
2.4
3.1
ACKNOWLEDGEMENTS
 STUDENTS
 Jon Furuno, Amy Chapin, Lance Price, Jay Graham, Amira
Roess, Meche Nweke, Keeve Nachman, Carter Erwin, Patrick
Butler, Redwan Huq,
 COLLEAGUES
 Carol Resnick, Rocio Vailes, Pat Charache, Kellogg Schwab,
Rolf Halden, Pat Breysse, Bill Spannhake, Kris Macri, Tim
Buckley, Pat Charache, John Griffin, Kazim Sheikh, Vasken
Aposhian, Tracy Hancock, Henrik Wegener
 Carole Morison, Patrick Harmon, Jim Lewis, Pilar Perez,
Jackie Nowell -- UFCW
 FUNDING
 CLF, Grace, HHMI, NIOSH, Winslow and Baker Foundations