The prevalence of soil transmitted helminth infections in minority indigenous populations of South-East Asia and the Western Pacific Region: A systematic review and meta-analysis

Abstract

Introduction Soil transmitted helminth (STH) infections cause one of the most prevalent diseases in man. STHs disproportionately impact socio-economically disadvantaged communities including minority indigenous populations. This systematic review aimed to quantify the prevalence of STH infection within minority indigenous populations of the South-East Asia and Western Pacific Regions. Methods The systematic review was conducted in accordance with The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines following a published protocol. A random effects meta-analysis was used to estimate the pooled prevalence of STH infection, and meta-regression analysis was used to quantify associations with study characteristics. Where comparative data were available, sub-group analysis was conducted to evaluate the risk of STH infection in minority indigenous people relative to other population groups. The heterogeneity between studies was evaluated visually using Forest plots and was assessed quantitatively by the index of heterogeneity (I2) and Cochran Q-statistics. Results From 1,366 unique studies that were identified, 81 were included in the final analysis. The pooled prevalence of infection within minority indigenous populations was 61.4% (95% CI 50.8, 71.4) for overall STH infection; 32.3% (95% CI 25.7, 39.3) for Ascaris.lumbricoides; 43.6% (95% CI 32.6, 54.8) for Trichuris.trichiura; 19.9% (95% CI 15.7, 24.5) for hookworm and 6.3% (95% CI 3.2, 10.2) for Strongyloides.stercoralis. A significant increase in T. trichiura prevalence was observed over time. The stratified analysis showed that the prevalence of infection for STH overall and for each STH species were not significantly different in minority indigenous participants compared to other populations groups. Conclusion The prevalence of STH infection is high within minority indigenous populations across countries at very different levels of socio-economic development. The increasing prevalence of T. trichiura calls for the implementation of more effective therapies and control strategies.

Seroprevalence and associated risk factors of strongyloidiasis in indigenous communities and healthcare professionals from Brazil

“…stercoralis in indigenous populations and their correspondent assistance healthcare professionals with unknown seroprevalence. Indigenous populations are considered one of the most exposed populations to soil-transmitted helminths due to poverty and lack of sanitary conditions [ 35 , 36 ], particularly strongyloidiasis [ 37 ]. Brazilian indigenous populations were investigated for seroprevalence and associated risk factors, and we found a relatively high prevalence of strongyloidiasis (37.6%; 174/463; CI 95%: 33.3–42.1) using an ELISA test for anti-IgG against S .…”

“…stercoralis methods for detecting infection, with different sensitivities and specificities, resulting in a plausible prevalence underestimation [ 41 ]. Other metanalytic study has included 20 articles on strongyloidiasis prevalence of minority indigenous populations of South-East Asia and the Western Pacific Region, revealing an overall 16.8% of serological prevalence, significantly higher (p = 0.004) than 4.1% observed by microscopy [ 36 ]. Although the ELISA test has shown different diagnostic values (75.4–91.2% and 94.8–100%, sensitivity and specificity, respectively) depending on the assay [ 38 ], the in-house ELISA test for S .…”

“…Age and gender have also been described as risk factors for strongyloidiasis in indigenous populations [ 36 , 45 ] and people living in rural areas [ 16 , 44 , 46 ]. Herein, adults presented a significantly higher prevalence than young or children (<18 years).…”

Epidemiology of soil-transmitted helminths using quantitative PCR and risk factors for hookworm and Necator americanus infection in school children in Dak Lak province, Vietnam

“…An important finding in the risk factor analysis was the increased odds of infection with N. americanus associated with belonging to an ethnic minority group (Gia-rai, Hmong, Xo-dang, Êđê, Dao, Mnông, Nùng, Tày and other) compared to children from the ethnic majority group in Vietnam (Kinh), while some ethnic minorities (Gia-rai, Hmong, Xo-dang and Ede) were also associated with increased odds of moderate-to-heavy-intensity N. americanus infection. The burden of STH has been shown to be high amongst indigenous ethnic minority groups throughout the Western Pacific and neighbouring South-East Asia region, namely in the Philippines and Malaysia [ 4 , 55 , 56 ]. There has been one previous study comparing the prevalence of STH between ethnic groups in Vietnam, which found high prevalence in both Kinh and ethnic minority groups [ 57 ].…”

“…STHs are parasitic intestinal worms, and include hookworms ( Necator americanus , Ancylostoma duodenale and Ancylostoma ceylanicum) , Ascaris lumbricoides , Trichuris trichiura and Strongyloides stercoralis [ 2 , 3 ]. Like other NTDs, they disproportionately affect poorer, rural and indigenous communities in tropical and subtropical regions of the world [ 2 , 4 ]. High-intensity STH infections are associated with considerable morbidity including malnutrition, anaemia and impaired physical and cognitive development [ 5 – 7 ].…”