Pattern and Predictors of Soil-Transmitted Helminth Reinfections - PowerPoint PPT Presentation

Pattern and Predictors of Soil-Transmitted Helminth Reinfections among Orang Asli (aborigine) Schoolchildren in Malaysia Hesham MS. Al-Mekhlafi , Atiya AS., Mohammed AK. Mahdy, WA Wan Ariffin, H Che Abdullah and Johari Surin 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 1 1 Bangkok- -Thailand Thailand Bangkok

INTRODUCTION INTRODUCTION � Intestinal parasitic infections are major health Intestinal parasitic infections are major health � � developing countries � rural problems worldwide � developing countries � rural problems worldwide communities. . communities � More than one billion of the world More than one billion of the world’ ’s population are s population are � infected either by one or more of STH STH, particularly , particularly infected either by one or more of Ascaris lumbricoides lumbricoides , , Trichuris Trichuris trichiura trichiura and and Ascaris hookworm (WHO 2002) . hookworm (WHO 2002) . � Neglected diseases Neglected diseases � 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 2 2 Bangkok- -Thailand Thailand Bangkok

Continued…… …… Continued ‘the cancers of developing nations’ according to according to Egger (1990) . . � et al. (1990) Egger et al. Complications Complications � � ● Retarded growth ( ● Retarded growth (Stoltzfus Stoltzfus et al. et al. 1997; Al 1997; Al- -Mekhlafi Mekhlafi et al. et al. 2005) 2005) ● ● Micronutrient deficiencies (IDA & VAD) ( Micronutrient deficiencies (IDA & VAD) (Dreyfuss Dreyfuss et al. et al. 2000; 2000; Congsbak Congsbak et al. et al. 2006) 2006) ● Impaired learning and school performance ( ● Impaired learning and school performance (Nokes Nokes & Bundy 1994; & Bundy 1994; Ezeamama Ezeamama et al. et al. 2005) 2005) � Shorten working life & reduce working capacity Adulthood � ● Shorten working life & reduce working capacity ● Adulthood Gilgen et al. et al. 2001) (Guyatt ( Guyatt 2000; 2000; Gilgen 2001) ● ● Increase the cost of health care Increase the cost of health care � (STH together with Death � ● ….. .. Death (STH together with schistosomiasis schistosomiasis represented more than 40% of represented more than 40% of ● … the disease burden caused by all tropical diseases, excluding malaria) laria) (WHO 1999) the disease burden caused by all tropical diseases, excluding ma (WHO 1999) 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 3 3 Bangkok- -Thailand Thailand Bangkok

Continued…… …… Continued � In Malaysia � In Malaysia � high prevalence Since 1970s � � Since 1970s � high prevalence � Highly prevalent in � Highly prevalent in Orang Orang Asli Asli communities. communities. � Prevalence of � Prevalence of ascariasis ascariasis, , trichuriasis trichuriasis and and hookworm infections in rural areas range between infections in rural areas range between hookworm 30.2– –69.0%, 15.8 69.0%, 15.8– –98% and 6 98% and 6– –51.0%, respectively 51.0%, respectively 30.2 ( (Norhayati Norhayati et al. 1997; et al. 1997; Zulkifli Zulkifli et al 2000; Al et al 2000; Al- -Mekhlafi Mekhlafi et al. 2006) et al. 2006) � Trichuriasis � Trichuriasis was the predominant infection. was the predominant infection. 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 4 4 Bangkok- -Thailand Thailand Bangkok

Continued…… …… Continued WEB OF CAUSATION WEB OF CAUSATION WEB OF CAUSATION Poverty (poor socioeconomic status) Poor health Contaminated Inadequate education Environment sanitation Geophagy (soil & water) Poor personal hygiene Flies and STH STH STH others arthropods Demography Inadequate Animals Health Care Resistant to anthelmintics 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 5 5 Bangkok- -Thailand Thailand Bangkok

PROBLEM STATEMENT PROBLEM STATEMENT � Despite: Despite: � great development in socioeconomic status great development in socioeconomic status several deworming deworming programs programs… …, , several Malaysia is still plagued with STH. Malaysia is still plagued with STH. STH continue to have significant impact on STH continue to have significant impact on public health particularly among rural children public health particularly among rural children 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 6 6 Bangkok- -Thailand Thailand Bangkok

OBJECTIVES OBJECTIVES � To determine the current prevalence of STH To determine the current prevalence of STH � among rural schoolchildren. among rural schoolchildren. � To investigate the pattern of STH To investigate the pattern of STH reinfections reinfections. . � � To investigate the possible risk factors of To investigate the possible risk factors of � reinfections reinfections 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 7 7 Bangkok- -Thailand Thailand Bangkok

METHODOLOGY METHODOLOGY � Study Area Study Area � Sekolah Kebangsaan Kebangsaan Betau Betau Sekolah . (200 km from Kuala Lumpur) , Malaysia . Pos Betau Betau, Kuala , Kuala Lipis Lipis, , Pahang Pahang, Malaysia Pos 18 Orang Asli villages � Subjects Subjects � 120 ) ( 120 ( ) Primary Schoolchildren Age: 7-12 years Male/Female: 60/60 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 8 8 Bangkok- -Thailand Thailand Bangkok

METHODOLOGY METHODOLOGY Faecal samples from Orang Asli schoolchildren Formol-ether sedimentation method Kato-Katz technique Harada Mori technique Complete Deworming 3-days course Albendazole 400mg Examined for efficacy Faecal samples � examined after 3 and 6 months Questionnaire Data Analysis 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 9 9 Bangkok- -Thailand Thailand Bangkok

RESULTS RESULTS Prevalence of STH among Orang Orang Asli Asli schoolchildren according to schoolchildren according to Prevalence of STH among severity of infection and gender severity of infection and gender Type of infections Ascariasis Trichuriasis Hookworm infection No. (%) No. (%) No. (%) Intensity of infection Negative 41 (34.2) 3 (2.5) 106 (88.3) Light infection 38 (31.7) 49 (40.8) 13 (10.8) Moderate infection 24 (20.0) 33 (27.5) 0 Heavy i avy infectio ion 17 (14 (14.2) 2) 35 (29 (29.2) 2) 0 Gender Male 39 (65.0) 58 (98.3) 9 (15.0) Female 40 (66.7) 141 (96.7) 4 (6.7) Total (%) Total (%) 65.8 65.8 97.5 97.5 10.8 10.8 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 10 10 Bangkok- -Thailand Thailand Bangkok

STH reinfection reinfection STH Reinfection rates and reinfection intensities of STH over a period of 6 months after deworming among Orang Asli schoolchildren in Pos Betau, Pahang (n=120) Ascaris Trichuris Hookworm Prevalence (%) 65.8 97.5 10.8 Baseline 18.9 38.7 3.6 3 months 48.1 65.7 5.6 6 months Reinfection rates (%) a 3 months 28.7 39.7 33.3 73.1 73.1 67.4 67.4 51.8 51.8 6 months Reinfection intensities b Baseline 2.58 2.58 3.30 3.30 0.28 0.28 3 months 0.68 1.16 0.07 2.10 2.10 2.37 2.37 0.12 0.12 6 months a Number of infected children after deworming/ number of infected children before deworming b Geometric mean counts of egg per gram faeces 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 11 11 Bangkok- -Thailand Thailand Bangkok

Total reinfection rates of STH after 3 and 6 months of deworming Ascaris Trichuris Hookworm Total 28.7 38.8 33.3 At 3 months % 48.9 48.9 73.1 66.5 51.9 At 6 months % 80.3 80.3 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 12 12 Bangkok- -Thailand Thailand Bangkok

Continued… ….. .. Continued Potential predictors of STH reinfection in rural Malaysian communities (Logistic regression) Variables Reinfection rates of STH At 3 months n (%) At 6 months n (%) Age: ≤ 10 years 40 (46.0) 67 (79.8) >10 years 15 (62.5) 19 (79.2) a Significant association ( P < 0.05) Gender: Male 17 (30.9) 37 (68.5) b Confirmed as significant predictors by Female 38 (67.9) a, b 49 (90.7) a, b logistic regression analysis Fathers’ educational levels: ≥ 6 years formal education 20 (48.8) 31 (77.5) No formal education 35 (50.0) 55 (80.9) Mothers’ educational levels: ≥ 6 years formal education 11 (50.0) 19 (90.5) 44 (49.4) 67 (77.0) No formal education Mothers’ employment status: Working 31 (57.1) 48 (90.5) a, b Not working 24 (44.9) 38 (72.7) Low household income: <RM450/month 38 (45.8) 63 (78.8) ≥ RM450/month 17 (60.7) 23 (82.1) Family siz e ≥ 8 members (large) 14 (56.0) 20 (80.0) < 8 members 41 (47.7) 66 (79.5) Toilet in house: Yes 10 (30.3) 23 (71.9) No 63 (82.9) 45 (57.7) a, b Source of drinking water: Piped 48 (50.0) 77 (81.1) Others (river, rain, well) 7 (46.7) 9 (69.2) Have animals in house: Yes 9 (37.5) 18 (78.3) No 46 (52.9) 68 (80.0) Nutritional status 13 13 Stunted children 42 (87.5) 30 (61.2) a Non-stunted children 25 (40.3) 44 (73.3)

Some potential source of infections in this area Some potential source of infections in this area 19 January 2008 19 January 2008 JITMM 2007 JITMM 2007 14 14 Bangkok- -Thailand Thailand Bangkok