Possible Factors Influencing the Seroprevalence of Dengue among Residents of the Forest Fringe Areas of Peninsular Malaysia

Abstract

Dengue is an endemic mosquito-borne viral disease prevalent in many urban areas of the tropic, especially the Southeast Asia. Its presence among the indigenous population of Peninsular Malaysia (Orang Asli), however, has not been well described. The present study was performed to investigate the seroprevalence of dengue among the Orang Asli (OA) residing at the forest fringe areas of Peninsular Malaysia and determine the factors that could affect the transmission of dengue among the OA. Eight OA communities consisting of 491 individuals were recruited. From the study, at least 17% of the recruited study participants were positive for dengue IgG, indicating past exposure to dengue. Analysis on the demographic and socioeconomic variables suggested that high seroprevalence of dengue was significantly associated with those above 13 years old and a low household income of less than MYR500 (USD150). It was also associated with the vast presence of residential areas and the presence of a lake. Remote sensing analysis showed that higher land surface temperatures and lower land elevations also contributed to higher dengue seroprevalence. The present study suggested that both demographic and geographical factors contributed to the increasing risk of contracting dengue among the OA living at the forest fringe areas of Peninsular Malaysia. The OA, hence, remained vulnerable to dengue.

Socioeconomic risk markers of arthropod-borne virus (arbovirus) infections: a systematic literature review and meta-analysis

“…There were no studies examining YFV. Included studies consisted of 2 cohort studies,16 17 4 case–control studies,18–21 27 cross-sectional studies,22–48 1 nested cross-sectional study within a cohort,49 1 combined cross-sectional and cohort study50 and 1 longitudinal serosurvey 51. Studies were conducted in 23 countries: 4 in low-income countries (Burkina Faso,42 Laos35 and Sudan26 43), 14 in lower-middle-income countries (Ecuador,41 India,19 Jordan,33 37 Kenya,17 36 Nicaragua,16 50 Nigeria,27 31 40 Pakistan,39 Sri Lanka18 and Vietnam34), 13 in upper-middle income (Brazil,23 30 45–47 China,20 24 38 Colombia,49 51 Malaysia,25 Paraguay44 and Thailand29) and 5 in high-income countries/territories (Mayotte (France),28 French Guiana,21 Saudi Arabia,22 Sweden32 and USA48) according to the Development Assistance Committee List of Official Development Assistance Recipients (figure 2).…”

“…The association between education and arboviral infection was analysed in 1 cross-sectional study nested in a cohort, 2 case–control and 22 cross-sectional studies, spanning 18 countries and 6 arboviruses (CHIKV, DENV, JEV, RVFV, SINV and WNV). In these studies, education was classified in distinct ways depending on context, and included level of education,19 24 26 27 29 31–34 36 38–41 43 44 49 schooling age,23 parental education,20 the attainment of any formal education,25 37 42 length of education in years28 and illiteracy 30 45…”

“…Eleven of the 12 studies presented frequencies, 6 presented crude effect estimates and 2 presented adjusted effect estimates. The occupation-related variables analysed were employment status,25 26 30 location of work (inside or outside),23 earnings (above the country’s minimum wage or not),41 employment stability and occupation types 19 27–29 31 40 44. In a study conducted by Chiaravalloti-Neto et al in Brazil, there was a crude association between working outside and seropositivity for DENV, which was lost on adjusting for other socioeconomic and demographic covariates 23.…”

Urban Forest Research in Malaysia: A Systematic Review

“…Moreover, there was also a study on the potential of urban forests to be a form of preventive medicine via forest therapy [28,29]. Additionally, as mentioned previously, there was also a nationwide study on the role of urban forests in the spread of Dengue [15]. The study found that there was a positive correlation between the occurrence of dengue with the presence of a lake.…”

“…There were four articles that conducted their studies in multiple locations [11][12][13][14]. There was also a study conducted throughout Peninsular Malaysia, whereby the research was on the prevalence of dengue among residents residing on the fringe areas of urban forests [15].…”