ABSTRACT
@#Abstract：Objective To carry out serological analysis of varicella⁃zoster virus（VZV）IgG antibody level in healthy people aged 1 ~ 30 years in Liaoning Province. Methods In October 2020，3～5 mL venous blood samples were collected from 617 healthy people aged 1～30 years selected from six counties and districts in Shenyang，Fuxin and Dandong of Liaoning Province by stratified random sampling method，of which serum samples were collected and determined for VZV IgG antibody level by ELISA. The positive rate of serum antibody and geometric mean concentration（GMC）of antibody were calculated and compared. Results Among 617 serum samples，302 samples were positive for VZV IgG antibody，the positive rate was 48. 947%，and the GMC was 112. 772 mIU／mL. The positive rate of VZV IgG antibody was 29. 670%～75. 789% and the GMC was 45. 508～366. 559 mIU／mL in healthy people of various ages. Both of the antibody positive rate（χ2 = 67. 104， P < 0. 001）and GMC（F = 20. 685，P < 0. 001）showed significant differences. The positive rates of VZV IgG antibody in male and female were 44. 817% and 53. 633% respectively，which showed significant difference（χ2 = 4. 779，P = 0. 029）， while the GMCs were 96. 983 and 133. 829 mIU／mL respectively（t = -1. 958，P = 0. 051）with no significant difference. The positive rates of VZV IgG antibody of healthy people in Shenyang，Fuxin and Dandong of Liaoning Province were 55. 224%，40. 201% and 51. 152% respectively with significant differences（χ2 = 9. 683，P = 0. 008），of which the positive rate of FuxinwassignificantlylowerthanthoseofShenyangandDandong（χ2 =9. 046and5. 013，P =0. 003and0. 025，respectively）； While the GMCs were 133. 523，85. 953 and 123. 713 mIU／mL respectively with no significant difference（F = 0. 514， P = 0. 598）. Among 617 serum samples，54 sampleswere suspicious，which remained within the criticalrange afterre⁃examina⁃ tion，while the gap between positive rate and the total percentage of positive and suspicious results gradually decreased with the increase of age，indicating that the immunity to varicella gradually increased with the increase of age. Conclusion The VZV⁃IgG antibody level of healthy people aged 1～30 years in Liaoning Province increased gradually with age，while the overall level was low. To control the spread of varicella virus，it is recommended to increase varicella vaccine coverage in vulnerable areas and susceptible population to build VZV immune barrier.
ABSTRACT
Serum samples were tested for IgG antibodies using indirect immunofluorescence assays. We then analyzed associated risk factors. Serum samples were considered positive when reactive at a dilution of more than 1:320. Differences between groups and risk factors associated with exposure were statistically analyzed using Chi-square tests and the generalized linear model. 122 of 1,260 samples (9.68%) were positive for infection. The infection rate ranged from 0% to 30.43% and differed significantly among age groups ( < 0.01); infection rate in the 50-59 years group was significantly higher than that in other age groups. The seroprevalence of varied significantly among sites within the four provinces, and the infection rate of field workers was significantly higher than that of urban workers.
ABSTRACT
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 (P<0.005). 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.
ABSTRACT
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 (P<0.005). 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.