A participatory Ecohealth study of smallholder pig

system in upland and lowland of Lao PDR

P. Inthavong, K. Blaszak, P. Durr, B. Khamlome, V. Somoulay, J. Allen, J. Gilbert, H. Holt and K. Graham

Purpose and background of the project

Research methodology

Results

Intervention options

Discussion and recommendation

To conduct baseline seroprevalence

surveys of key pig diseases and pig related zoonoses

To evaluate public health risks of pig-raising and pork consumption in one upland and one lowland province in Lao PDR

- Smallholder pigs owned by 50-70% of village households

- No prior epidemiological prevalence surveys and risk analysis

- Regional increase in zoonoses and increasing disease outbreaks

- Health and production risks

A cross-sectional data collection including blood sampling from HUMAN and PIGS with questionnaire survey for risk factors 3 sets of questionnaires Village head to get general village information Human Pig owners

Introduction of the principle of Ecohealth with participatory sessions in teams that included

Introduction of the project, diseases and known zoonoses risks

Conducting practice random sampling, questionnaire interviews

How to collect pig and human blood samples under ethical conditions

Study designs

2 provinces were selected 1 represent upland 1 represent lowland

30 villages from each province 15 persons and 15 pigs per village

Study designs Multistage random sampling random selection of village: PPP:Villages

are randomly sampled weighted by human population

random selection of HH random selection of individuals

Structuring sampling frames for humans and pigs ◦ Sampling based primarily on human population (not pig

population)

Ethical issues informed and signed consent forms for human participants

individual results within each village not identified by household names

Appropriate modest health practical gifts to participating households

Village level feedback of overall results

Humans

JEV

Hep E

Taenia/cysticercosis

Trichinella

Pigs

JEV, Hep E, Trichinella

CSF

PRRS

Erysipelas

FMD (Types O, A and Asia 1)

Data entry and manipulation using new web based program: SurVet

Data analysis on Stata program

Results

Number of pigs and people sampled

Study location People Pig

ILRI Luangprabang (north)

447 310

ILRI Savannakhet (south)

435 365

Total 882 675

Sample test

All tests carried out in Laos using commercial kits

Human samples were tested NCLE

Pig sample NAHC

Results: Crude seroprevalence

* Prevalence data reported above has not been adjusted for

population weighting factors

Disease Humans Pigs

JEV IgM 4.4% 8.5%

JEV IgG 75.2%

Hep E IgG 64% 61.4%

Trichinella 47.3% 13.7%

Taenia solium IgG 2.9%

Cysticercosis IgG 4.7%

Erysipelas 47.5%

CSF 10.3%

PRRS 8.2%

FMD (ABC non-structural ELISA) 2.1%

Antibody test Nth (n= 310) Crude

Seroprev

Sth (n= 365) Crude

Seroprev

JEV IgG 75.4% 81.8%

JEV IgM 12.2% 6.7%

HEV 81.9% 50.0%

Trich 13.5% 9.0%

CSF 7.4% 14.7%

PRRS 11.3% 9.6%

Erysipelas 63.5% 30.2%

FMD 2.0% 2.8%

Multivariate analysis of HEV in pigs

Factors OR (95% CI) p-value

Age 1.58 (1.26 to 1.99) <0.001

South 0.14 (0.08 to 0.24) <0.001

Sow catergories 1.55 (1.10 to 2.18) 0.01

Adjusted risk factors for human hepatitis E

Adjusted ORs were derived from a multivariate logistic analysis with random effects

Adj. OR (95% CI) P-value

Slaughter Pigs 1.64 (1.00, 2.70) 0.05

Southern vs. Northern Province 4.52 (2.93, 7.00) <0.001

Age of person 1.71 (1.42, 2.05) <0.001

Increased distance from pigs 0.82 (0.69, 0.98) 0.04

Female vs. male 0.67 (0.46, 0.99) 0.04

Investigation of risk factors for human cysticercosis or Taenia

Risk factors associated with higher cysticercosis or Taenia sero-positive

levels:

Odds Ratio (95% CI)

Non-use of toilets is clear risk factor 2.65 (1.37, 5.12)*

Investigation of risk factors for human JEV

Risk factors associated with higher JEV seropositive levels:

Odds Ratio (95% CI)

Age , > 20 years tended to be associated

with greater seropositive 6.50 (0.89, 47.66)

Nearly all people answered that they used mosquito nets – so no real

comparison of non-use as a risk factor

Data do not support that distance from pigs up to 150 metres is associated

with reduced risk

Combined Human Combined Pig Prev 61.4% Prev 64.0%

North – Upland South- Lowland

50.00% 81.9%

77.9% 50.00%

Information Communication and Education (ICE) materials development workshop

Result feedback meetings Village ICE pilot testing Human health risk reduction

options Village biosecurity for pigs

Modification and finalization of IEC materials for pig and human health ris reduction need to be done

Significant level of exposure of tested diseases were found in this atudy

Detailed risk related analysis have been done just only for HE

Detailed risk factor analysis and interpretation and report for all diseases need to be done

Using collected serums to test for other diseases

Risk reduction PA

Time constraints

Geographical/seasonal aspects

Multisectorial involment

Test validation

Data analysis skills

Blaszak, K1., Durr, P.2, Khamlome, B.3, Somoulay, V.4, Allen, J.2 and Gilbert, J.5 Holt, H.5

1 NAHC, Lao PDR; 2 AAHL, CSIRO Austria; 3 DHP, Lao PDR; 4 NCLE, Lao PDR; 5ILRI, Lao PDR