WHOIPCS Epidemiology of Acute Pesticide Intoxication Project

1
WHO/IPCS Epidemiology of Acute Pesticide
Intoxication Project
Population Based Estimates of the Prevalence of
Pesticide Poisoning Stephen Corbett
2
Comparison of Countries with National Pesticide
Poisoning Data
3
OBJECTIVESIPCS Pesticide Poisoning Project

•  To estimate national prevalence of acute
  pesticide poisoning
•  
• Conduct community based surveys of acute
  pesticide intoxication to estimate the prevalence
  of API not captured by existing hospital based
  surveillance systems
•  
• Review existing sources of information relating
  to acute pesticide intoxication (e.g. Hospital
  records, surveillance systems, poison control
  data)
•  
• To identify risk factors most commonly associated
  with human pesticide exposure and intoxication
  and to utilise this information in the
  development of Pesticide Intoxication Prevention
  Programs

4
Comparison of Crude Hospital Admission Rate for
Pesticide Poisoning
5

• Community Surveys of API
• Literature Reviews
• Consistent under-estimate of pesticide poisonings
  in rural settings
• 10-20 0nly reported
• Under reporting can be minimised by availability
  of
• Cholinesterase testing
• Education of local health staff
• Information

6

• Community Surveys of API

Data Availability
Step 1
Step 2
Developing An Exposure Maitrix And Sampling Frame
Step 3
Develop a National Study Plan
7
Health Indices for Acute Pesticide Poisoning, by
Circumstance of Exposure
8

• Data Availability

• General Population Description
• Total population of province/nation by age and
  sex
• Total National/Provincial Rural population by
  age
• Total population of county/district by age and
  sex
• Village Population by age and sex
• Number of households

9
Data Availability

• Pesticide Use and Exposure
•  
• Pesticide manufacturing/formulation and
  consumption plants
• -         Agricultural crop production figures
• -         Forestry and Livestock
• -         Acreage by crop
• -         Amount of pesticide being used in
  public health campaigns
• -         Compare active ingredients and volumes
• -         Pesticide usage by chemical and
  functional class, and volume (Manufacture
  Import)
• -         National tends is pesticide use (IPM),
  by industry
• -         Characterise the dominant form of
  agriculture at a local level

10

• Data Availability

Exposed Populations -         Labour force data
(Landowning farmers/Agricultural
labourers) -         Number of pesticide
applicators/ mixer/loader -         Number of
public health officials(quarantine/vector
control) -         Proportion of population who
are agricultural workers -         Total numbers
of plantations and large farms. -        
Numbers of itinerant/migrant/seasonal
workers -         Growers associations
associated with crop types  
11

• Data Availability

12
Developing An Exposure Matrix And Sampling Frame
Example 1
Provincial Level
County/District Level
Assign counties to categories of agricultural
production
Cotton etc
Rice
Mixed
Scale up Prevalence Estimate to Provincial
level
Sample villages randomly within selected counties
Household survey of API prevalence
13
Developing An Exposure Matrix And Sampling Frame
Example 2
Provincial Level
County/District Level
Estimate agricultural product/activity specific
populations in each county
Cotton etc
Rice
Mixed
Scale up Prevalence Estimate to Provincial
level
Stratified sample weighted for each agricultural
product/activity population group
Survey households/workers within product specific
stratum
14
Definitions
A Case of Acute Pesticide Intoxication is a
person with an episode, within the last 12 months
, of an onset of acute symptoms (within 24 hours
after exposure). Symptoms can be ocular, dermal
and/or systemic symptoms which are consistent
with pesticide type.   An individual can have
more than one intoxication episode as long as all
the criteria for a case are met and the repeat
episode is not an exacerbation or continuation of
the original exposure. A Possible Case meets
above criteria but lacks sufficient detail on
pesticide type
A pesticide is defined as any substance or
mixture of substances intended for preventing,
destroying, repelling or mitigating any insects,
rodents, nematodes, fungi, weeds or any other
forms of life declared to be pests.
15
Tools

• Standard Questionnaire
• Poisoning Severity Score
• Symptom List

16
Poisoning Severity Score
17
MULTIPLIERS
c
b
a
Deaths
Thailand
33 Outpatients97 inpatients14 deaths 2.3
6.9 1
Hospital Admissions
Non hospitalised cases
18
CAPTURE RECAPTURE
n1known sample eg survey
n2 sample eg hospital admissions
n1
n2
n11
n11 cases in both lists
N
N total population
n2 /N n11/ n1
19
Timetable

• Complete Protocol October 2002
• Interest in conducting studies in Europe/
  SEARO/WPRO
• in 2003