ORAL ORAL PRESENTATIONPRESENTATION

Abdul MM, Azmi MT, Shamsul ASAbdul MM, Azmi MT, Shamsul AS

1616thth National Public Health Colloquium National Public Health Colloquium

2525thth Nov 2009 Nov 2009

THE INFLUENCE OF ENVIRONMENTAL RISK THE INFLUENCE OF ENVIRONMENTAL RISK FACTORS AND INDIVIDUAL BEHAVIOURS FACTORS AND INDIVIDUAL BEHAVIOURS

ON MALARIA OCCURRENCE IN LAHAD ON MALARIA OCCURRENCE IN LAHAD DATU DISTRICT OF SABAH: DATU DISTRICT OF SABAH: A CASE CONTROL STUDY.A CASE CONTROL STUDY.

RESEARCH TITLE :

CONTENTSCONTENTS

IntroductionIntroduction Literature ReviewLiterature Review Research JustificationResearch Justification ObjectivesObjectives HypothesisHypothesis MethodologyMethodology Results & DiscussionResults & Discussion Conclusion & Conclusion & RecommendationsRecommendations ReferencesReferences

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IntroductionIntroduction Recorded as early as 2700 BC in China (Cox 2002).“Mala aria” – bad airVector-borne disease caused by protozoan

parasitesCaused by Plasmodium spp.Transmitted by female Anopheles mosquitoes

Infection may results in wide variety of symptomsUncomplicated malariaSevere malaria

Curable disease ifDiagnosed and treated promptly and correctly

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Magnitude of problemMagnitude of problemWorldwide (WHO 2008)

Lived at high risk area – half of human population

300 millions infected1 million death

MalaysiaDecreasing trend since 1996IR (M’sia) 2.67/10 000 (2004)IR (Sabah) 9.56/ 10 000 (2004)IR (Lahad Datu) 20.4/10 000 (2008)

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Literature reviewLiterature reviewLansang et al. (1997) study showed that the risk

of malaria is higher in person worked in high risk occupation.

CHESTRAD (2000) study showed that low household income is associated with higher risk of malaria infection.

Tedros et al. (2000) and Koram et al. (1994) suggested that individual without car or refrigerator more likely to suffer from malaria.

Guthmann et al. (2001) showed individual with formal education more than primary level less likely to get malaria.

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Literature reviewLiterature reviewTedros et al. (2000) study showed low risk perception

towards malaria more likely to have high risk of malaria disease.

Usage of repellant, mosquito coil or aerosol spray found to reduced risk of severe malaria (Snow et al. 1998).

Several studies have suggested that the usage of insecticide-treated bednets able to reduce the incidence of malaria (Binka et al. 1996 & Alexander et al. 2005).

Konradsen et al. (2003) showed house sprayed with indoor residual spray was a protective factor for malaria infection.

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Literature reviewLiterature reviewIncardona et al. (2007) showed association

between history of movement to the jungle with malaria infection.

House located >500 m from forest fringe is protective factor towards malaria (Brooker et al. 2004)

Water bodies provide suitable habitat for malaria vector thus increase risk of infection (Guthmann et al. 2002)

Konradsen et al. (2003) suggest house built without good structure and design will increase risk of malaria.

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Research justificationResearch justification

Sabah highest malaria case contributor in Malaysia

Analytical study to determine the association between environmental & individual factors and malaria is rarely done lately (none in LD)

The incidence of malaria is high in Lahad Datu

Just

ificati

on

s

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Conceptual frameworkConceptual framework

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ObjectivesObjectives General

To identify the association between environmental risk factors, risk perception and individual behaviours with malaria infection in Lahad Datu district of Sabah.

SpecificTo determine the association between socioeconomic

status, risk perception, and individual movement and preventive behaviours with malaria infection in Lahad Datu.

To determine the association between environmental factors (presence of potential breeding sites and house’ structure and design) and malaria in Lahad Datu.

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MethodologyMethodology

Approved Study

Case (Vekpro

)

Control

Interviewed using a structured Q

Inclusion and

Exclusion

End

DESIGN STUDY TOOLS

Analysis

Results

No. of cases = 166

No. of controls = 166

Discussion &

Conclusion

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Area of study Area of study

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Sample sizeSample sizeBased on Hennekens et al. (1987)

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Questionnaires

Sociodemographic & Socioeconomic status

Individual behaviours•Preventive•Movement

Environmental risk factors•House location•House design &structure

Risk perception (12 Q)

Cut off point = 9 (75%)

Chronbach α = 0.73 Pretested in OPD LD (Dec

07)

BSMP status

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Data analysisData analysisAnalyzed using

SPSS version 12.0McNemar on-line calculator (Graphpad)

Statistical analysisDescriptive analysisBivariate analysisConditional logistic regression

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Results: Demographic Results: Demographic featuresfeaturesFactors Case n=166

N (%)Control n=166

N (%)

Age Minimum Maximum Median Interquartile range

Gender Male Female

Mukim Silam Silabukan Bandar Segama Tungku Felda

15702612

134 (80.7)32 (19.3)

59 (35.5)42 (25.3)37 (22.3)12 (7.2)10 (6.0)6 (3.6)

15702612

134 (80.7)32 (19.3)

59 (35.5)42 (25.3)37 (22.3)12 (7.2)10 (6.0)6 (3.6)

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Association of study Association of study variables with Malariavariables with Malaria1. Type of occupation

• Type of occupation was found to be associated with malaria.

• High risk occupation more likely to get malaria infection.

• Earlier studies support this association (Lansang, 1997; Chang 1997 ; Honrado & Fungladda 1994)

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Association of study Association of study variables with Malariavariables with Malaria2. Risk perception score

• Risk perception score was found associated with malaria infection.

• Consistent with the studies by Tedros et al. (2000) and Onwujekwe et al. (2000)

• Level of education associated with risk perception scores (OR 45; 95% CI 18-108)

• Risk perception influenced by many factors.

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Association of study Association of study variables with Malariavariables with Malaria3. Indoor residual spray

• Respondents lived in a house with no IRS done are at higher risk of malaria infection compared to those lived in a house sprayed with insecticide.

• Consistent with studies by Guthmann et al. (2001) and Konradsen et al. (2003)

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Association of study Association of study variables with Malariavariables with Malaria4. History of movement

• History of movement in the last two weeks was found to be associated with malaria.

• Consistent with studies by Honrado & Fungladda (1994) & Singhanetra-Renard (1986)

• Frequency, duration, place and purpose of movement were insignificant.

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ConclusionConclusion Type of occupation, risk perception, indoor

residual spray activity and history of movement in the last two weeks are risk factors for malaria infection in Lahad Datu district.

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Recommendations Recommendations Improve risk perception amongst communityStrengthen health education and promotion

Preventive measures when doing high risk jobs or moving into high risk area

IRS as method of choice in malaria control measures in oil palm plantations/estatesex; Hiring private company

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ReferencesReferences Cox 2002. History of human parasitology. Clinical Microbiology Review. 15(4); 595-612. Greenwood, B.M. 1989. The microepidemiology of malaria and its importance to malaria control. Transactions of the

Royal Society of Tropical Medicine and Hygiene: 83; 25-29. WHO. 2008. World Malaria Report 2008. World Health Organization Media Centre.

http://www.who.int/malaria/mediacentre/wmr2008/malaria2008.pdf JKN Sabah. 2004. Laporan Tahunan Unit Rancangan Kawalan Penyakit Bawaan Vektor (RKPBV) Pejabat Kesihatan

Kawasan Lahad Datu, Jabatan Kesihatan Negeri Sabah. Lansang, M.A.D., Belizario, V.Y., Bustos, M.D.G., Saul, A. & Aguirre, A. 1997. Risk factors for infection with malaria

in a low endemic community in Bataan, Phillipines. Acta Tropica: 63; 257-265. CHESTRAD. 2000. NetMark regional Africa programme briefing book. Insecticide treated materials in Nigeria.

NetMark. http://www.netmarkafrica.org/countries/nigeria/briefbook/nigeria_briefing_book.pdf Tedros, A.G., Haile, M., Witten, K.H., Getachew, A., Yohannes, M., Lindsay, S.W. & Byass, P. 2000. Household risk

factors for malaria among children in Ethiopia highlands. Transaction of the Royal Society of Tropical Medicine and Hygiene; 94: 17-21.

Koram, K.A., Bennett, S., Adiamah, J.H. & Greenwood, B.M. 1995. Socioeconomic risk factors for malaria in a peri-urban area Of Gambia. Transaction of the Royal Society of Tropical Medicine and Hygiene: 89; 146-150.

Alexander, N., Rodriguez, M., Perez, L., Caicedo, J.C., Cruz, J., Prieto, G., Arroyo, J.A., Cotacio, M.C., Suarez, M., De la Hoz F. & Hall A.J. 2005. Case-control study of mosquito nets against malaria in the Amazon region of Colombia. American Journal of Tropical Medicine and Hygiene: 73(1); 140-148.

Guthmann, J.P., Hall, A.J., Jaffar, S., Palacios, A., Lines, J. & Llanos-Cuentas, A. 2001. Environmental risk factors for clinical malaria: A case-control study in the Grau region of Peru. Transaction of The Royal Society of Tropical Medicine and Hygiene: 95; 577-583.

Snow, R.W., Peshu, N., Foster, D., Bomu, G., Mitsanze, E., Ngumbao, E., Chisengwa, R., Schellenberg, J.R., Hayes, R.J., Newbold, C.I. & Marsh, K. 1998. Environmental and entomological risk factors for the development of clinical malaria among children on the Kenyan Coast. Transactions of the Royal Society of Tropical Medicine and Hygiene: 92; 381-385.

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ReferencesReferences Binka, F.N., Kubaje, A., Adjuik, M., Williams, L.A., Lengeler, C., Maude, G.H., Armah, G.E., Kajihara, B.,

Adiamah, J.H. & Smith, P.G. 1996. Impact of permethrin impregnated bednets on child mortality in Kassena-Nankana district, Ghana: A randomized controlled trial. Tropical Medicine and International Health: 1; 147-154.

Konradsen, F., Amerasinghe, P., Van der Hoek, W., Amerasinghe, F., Perera, D. & Piyaratne, M. 2003. Strong Association between house characteristics and malaria vectors in Sri Lanka. American Journal of Tropical Medicine and Hygiene: 68(2); 177-181.

Incardona, S., Vong, S., Chiv, L., Lim, P., Nhem, S., Sem, R., Khim, N., Doung, S., Mercereau-Puijalon, O. & Fandeur, T. 2007. Large-scale malaria survey in Cambodia: Novel insights on species distribution and risk factors. Malaria Journal: 6; 37-48.

Brooker, S., Clark, S., Njagi, K.J., Polack, S., Mugo, B., Estambale, B., Muchiri, E., Magnussen, P. & Cox, J. 2004. Spatial clustering of malaria and associated risk factors during an epidemic in a highland area of western Kenya. Tropical Medicine and International Health: 9(7); 757-766.

Guthmann, J.P., Llanos-Cuentas, A., Palacios, A. & Hall, A.J. 2002. Environmental factors as determinants of malaria risk. A descriptive study on the northern coast of Peru. Tropical Medicine and Health: 7(6); 518-525.

Graphpad Software. 2008. McNemar’s test to analyze a matched case-control study. http://www.graphpad.com/quickcalcs/McNemar1.cfm

Chang, M.S., Hii, J., Buttner, P. & Mansoor, F. 1997. Changes in abundance and behaviour of vector mosquitoes induced by land use during the development of an oil palm plantation in Sarawak. Transaction of Royal Society of Tropical Medicine and Hygiene: 91; 382-386.

Honrado, E.R. & Fungladda, W. 1994. Social and behavioral risk factors related to malaria in Southeast Asian countries. Philippines Journal of Microbiological Infectious Disease: 23(2); 76-80.

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Thank YouThank You

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