Prevalence and associated risk factors of Strongyloides stercoralis infection in Lower Myanmar

Abstract

BackgroundStrongyloidiasis is prevalent in Southeast Asian regions along with other soil-transmitted helminthiases, but only limited present-day data was available for Myanmar.MethodsA prevalence survey for Strongyloides stercoralis infection was conducted among villagers in rural areas of three townships located in the Lower Myanmar during 2014–2016 by agar plate culture method in combination with specific identification by molecular assays. Risk factors associated with S. stercoralis infection were assessed by analyzing questionnaires obtained from study participants.ResultsStrongyloides stercoralis was identified in 40 out of 703 participants (5.7% overall prevalence). The highest prevalence (14.4%) was observed in Htantabin, while other two communities (Thabaung and Thanlyin) had much lower prevalence (2.2 and 2.5%, respectively). Infection was relatively rare (1.2%) in younger generations under 20 years compared to older generations (9.5%). Even in Htantabin, none of the female residents under age 40 (n = 33) had infection. In adult Htantabin residents, those who answered that they do not wear shoes regularly had an elevated risk of infection (odds ratio = 2.50, 95% confidence interval = 1.03–6.08).ConclusionsThis study showed that there is still an on-going transmission of strongyloidiasis in Lower Myanmar. It is highly desirable that the soil should be free of fecal contamination by improving the management of fecal waste. Meanwhile, health education to promote shoe-wearing would be beneficial to reduce the risk of transmission, especially for those who have frequent and intense contact with soil.

Prevalence and risk factors of Strongyloides stercoralis infection among Orang Asli schoolchildren: new insights into the epidemiology, transmission and diagnosis of strongyloidiasis in Malaysia

“…In neighbouring Southeast Asian countries, higher prevalence rates of S. stercoralis infection have been reported in Cambodia (Forrer et al ., 2018), Lao PDR (Vonghachack et al ., 2015) and Thailand (Laoraksawong et al ., 2018), while much lower prevalence rates were reported in Indonesia (Wiria et al ., 2013) and Myanmar (Aung et al ., 2018). Nevertheless, it is believed that strongyloidiasis is likely to have a much higher burden in Southeast Asia than currently indicated in the available literature (Schär et al ., 2016) not least because the region exhibits conditions that favour high transmission of strongyloidiasis, such as humid and wet climates, inadequate sanitary conditions and poverty (Al-Mekhlafi et al ., 2013; Schär et al ., 2013).…”

“…In the current study, the APC method showed superior sensitivity (174 cases) in detecting S. stercoralis larvae in fecal samples compared to direct smear (two cases), FES (15 cases) and conventional PCR (157 cases), with six samples found positive only by PCR. These results are consistent with those reported elsewhere (Requena-Méndez et al ., 2013; Amor et al ., 2016; Aung et al ., 2018; Tuyizere et al ., 2018). It is also interesting to note that the number of positive cases detected by the combined methods was not significantly different from using APC.…”

“…The age-related findings of the current study showed that children aged >10 years are generally at a higher risk of S. stercoralis infection compared to younger children, which is consistent with the general conclusion drawn in prior research (Schär et al ., 2013). This finding is also in agreement with many previous studies that have linked this infection to increasing age because S. stercoralis can be sustained in infected individuals for decades by means of autoinfection (Prendki et al ., 2011; Conlan et al ., 2012; Khieu et al ., 2014; Aung et al ., 2018). Hence, a higher prevalence of S. stercoralis infection is expected among adult individuals in Orang Asli communities.…”

“…With regards to the socioeconomic and behavioural risk factors of S. stercoralis infection, this study found that children who practised indiscriminate defecation used an unimproved water source for drinking water, and walked barefooted when outside the house were more likely to be infected than their counterparts. These findings are consistent with those of previous studies in other Asian countries (Khieu et al ., 2014; Senephansiri et al ., 2017; Aung et al ., 2018). Moreover, several studies have identified poor personal hygienic practices as significant predictors of IPIs among Orang Asli populations (Al-Mekhlafi et al ., 2006; Ahmed et al ., 2012; Anuar et al ., 2012; Elyana et al ., 2016; Muslim et al ., 2019).…”

“…Similarly, dogs in rural Cambodia have been found to carry two populations of S. stercoralis, one of which is shared with humans (Jaleta et al, 2017). In Malaysia, S. stercoralis larvae have been detected in fecal samples collected from dogs in rural Orang Asli communities and in soil samples collected from an urban area in Kuala Lumpur (Azian et al, 2008). Interestingly, larvae of Strongyloides spp.…”