Epidemiology and immunodiagnostics of Strongyloides stercoralis infections among migrant workers in Malaysia

Objective: To investigate the status of Strongyloides(S.) stercoralis infections among migrant workers in Malaysia for the first time and identify risk factors.Methods: Four diagnostic methods were employed for the detection of S. stercoralis including microscopy, enzyme-linked immunosorbent assay(ELISA) using a commercial kit, ELISA using the rSs1a antigen and polymerase chain reaction(PCR). Low and semi-skilled workers from five working sectors(i.e. manufacturing, food service, agriculture and plantation, construction and domestic service) were tested on a voluntary basis. Results: The overall seroprevalence of S. stercoralis from 483 workers employing the ELISA commercial kit for IgG was 35.8%(n=173; 95% CI: 31.5%-40.1%) whereas seroprevalence using the rSs1a-ELISA was 13.0%(n=63; 95% CI: 10.0%-16.0%). Cross tabulation between the ELISA commercial kit and rSs1a-ELISA showed that only 6.4%(n=31; 95% CI: 4.2%-8.6%) of the samples were positive in both tests. Microscopic examination of all 388 fecal samples were negative; however subsequent testing by a nested PCR against DNA from the same samples successfully amplified DNA from three male subjects(0.8%; 3/388). Male workers, India and Myanmar nationality, food service occupation and those living in the hostel were statistically significant with seroprevalence(P0.005). Conclusion: This is the first report on the epidemiology of S. stercoralis infections among the migrant workers in Malaysia. Our results highlight the importance of using appropriate diagnostic tools for detection. The presence of anti-S. stercoralis antibodies in the study population calls for improvements in personal hygiene and sanitation standards among migrant workers in Malaysia through control strategies including health education campaigns and programs aimed at increasing awareness and healthy behaviors.     

Lactococcus lactis Strain Plasma Intake Suppresses the Incidence of Dengue Fever-like Symptoms in Healthy Malaysians: A Randomized,Double-Blind,Placebo-Controlled Trial

Dengue fever (DF) is a mosquito-borne disease still with no effective treatment or vaccine available. A randomized, placebo-controlled, double-blinded, parallel-group trial was undertaken to evaluate the efficacy of oral intake of Lactococcus lactis strain plasma (LC-Plasma) on the presentation and severity of DF-like symptoms among healthy volunteers. Study participants (320) were assigned into two groups, and consumed either placebo or LC-Plasma tablets (approximately 100 billion cells/day) for 8 weeks. The clinical symptoms of DF were self-recorded through questionnaires, and exposure to DENV was determined by serum antibody and/or DENV antigen tests. No significant differences between groups were observed for exposure to DENV, or the symptomatic ratio. Results obtained showed that participants from the LC-Plasma group reported a significant reduction in the cumulative incidence days of DF-like symptoms, which include fever (p < 0.001), muscle pain (p < 0.005), joint pain (p < 0.001), and pain behind the eyes (p < 0.001), compared to that of the placebo group. Subgroup analysis revealed a significantly (p < 0.05) reduced severity score in the LC-Plasma group when study sites were separately analyzed. Overall, our findings suggest that LC-Plasma supplementation reduces the cumulative days with DF-like symptoms, and the severity of the symptoms. Daily oral intake of LC-Plasma, hence, is shown to mitigate the DF-like symptoms.