Comparison of ELISA and PCR of the 18S rRNA gene for detection of human strongyloidiasis using serum sample

Ivermectin and albendazole coadministration: opportunities for strongyloidiasis control

In 2020, WHO recognised the importance of strongyloidiasis alongside soil-transmitted helminths (STH) in their 2021-30 roadmap, which aspires to target Strongyloides stercoralis with preventive chemotherapy by use of ivermectin. Combination treatment with both albendazole, the primary drug used to treat STH, and ivermectin, would improve the efficiency of mass drug administration targeting both STH and S stercoralis. In this Personal View, we discuss the challenges and opportunities towards the development of an efficient control programme for strongyloidiasis, particularly if it is to run concurrently with STH control. We argue the need to define the prevalence threshold to implement preventive chemotherapy for S stercoralis, the target populations and optimal dosing schedules, and discuss the added benefits of a fixed-dose coformulation of ivermectin and albendazole. Implementation of an efficient control programme will require improvements to current diagnostics, and validation of new diagnostics, to target and monitor S stercoralis infections, and consideration of the challenges of multispecies diagnostics for S stercoralis and STH control. Finally, the evolution of ivermectin resistance represents a credible risk to control S stercoralis; we argue that genome-wide approaches, together with improved genome resources, are needed to characterise and prevent the emergence of resistance. Overcoming these challenges will help to reduce strongyloidiasis burden and enhance the feasibility of controlling it worldwide.

Liquid Biopsy for Promising Non-invasive Diagnostic Biomarkers in Parasitic Infections

BACKGROUND

Liquid biopsy refers to the sampling and molecular analysis of body fluids such as blood, saliva, and urine in contrast to conventional tissue biopsies. Liquid biopsy approach can offer powerful non-invasive biomarkers (circulating markers) for diagnosis and monitoring treatment response of a variety of diseases, including parasitic infections.

METHODS

In this review, we concentrate on cell-free DNA (cfDNA), microRNA (miRNA), and exosomes in the published literature.

RESULTS

Considering the high prevalence and severity of parasitic infections worldwide, circulating biomarkers can provide a new insight into the diagnosis and prognosis of parasites in the near future. Moreover, identifying and characterizing parasite- or host-derived circulating markers are important for a better understanding of the pathogenesis of parasite infection and host-parasite relationship at the molecular level. Profiling of biomarkers for parasitic diseases is a promising potential field, though further studies and optimization strategies are required, both in vitro and in vivo.

CONCLUSION

In this review, we discuss three approaches in the liquid biopsy including circulating cfDNA, miRNAs, and exosomes for diagnosis and evaluation of parasites and summarize circulating biomarkers in non-invasive samples during parasitic infections.

Seroprevalence of Strongyloides stercoralis among patients with leptospirosis in northern Iran: a descriptive cross-sectional study

Strongyloidiasis and leptospirosis are neglected tropical diseases that have affected many countries across the world. In this study, we evaluated the seroprevalence of Strongyloides stercoralis among patients with leptospirosis in northern Iran. We evaluated 156 laboratory- or clinically confirmed leptospirosis cases. The overall seroprevalence of S. stercoralis was 32.0% (95% confidence interval (CI): 27.4-36.5%, 50/156). Seropositivity was significantly associated with agricultural activities (odds ratio (OR): 2.84, 95% CI: 1.0-8.77) and gastrointestinal disorders (OR: 2.4, 95% CI: 1.1-4.9). Laboratory findings indicated that seropositivity of S. stercoralis was significantly associated with decreased levels of platelet and elevated levels of creatinine, alanine aminotransferase and aspartate aminotransferase (P < 0.05). Our findings suggested a higher exposure to S. stercoralis larvae among patients with leptospirosis. The public health and medical communities may benefit from this research through preventive measures to improve farmers' knowledge and awareness regarding strongyloidiasis and leptospirosis and the associated risk factors.

Serological assays for the diagnosis of Strongyloides stercoralis infection: a systematic review and meta-analysis of diagnostic test accuracy

The standard method for the diagnosis of Strongyloides stercoralis, stool examinations, is inconvenient and, therefore, serological methods have been proposed. This study aimed to evaluate the accuracy of serological assays for the diagnosis of strongyloidiasis using a systematic review and meta-analysis model. Four electronic databases were reviewed. We used a random effects model and 95% CIs to determine the overall sensitivity, specificity and diagnostic odds ratio (DOR). Heterogeneity was intended with Cochran Q χ2 test and I2 statistic. The accuracy of serological assays resulted in a sensitivity of 71.7% (95% CI: 56.07 to 83.4%), a specificity of 89.9% (95% CI: 80.8 to 94.9%) and a DOR of 22.5 (95% CI: 10.8 to 46.9). The forest plot showed high heterogeneity regarding sensitivity (I2=90.4%, 95% CI: 87.4 to 93.3%; Q=228.1, p=0.000) and specificity (I2=98.9%, 95% CI: 98.8 to 99.1%; Q=2066.4, p=0.000). Fagan's nomogram showed that the probability of someone having the infection and with a positive test result was 49%. Deeks' funnel plots showed no evidence of potential publication bias for the studies (p=0.26). The current review suggests that serological techniques have acceptable sensitivity and specificity and therefore can be recommended for the screening of S. stercoralis infection.

Molecular phylogenetic identification and morphological characteristics of Raillietina echinobothrida (Cestoda: Cyclophyllidea: Davaineidae) in commercial chickens in North China

Raillietina echinobothrida (R. echinobothrida) is one of the most pathogenic and prevalent tapeworms threat to the commercial chickens in China. However, there is a lack of research on their molecular identification and morphological characteristics. This study explored the molecular identification markers for R. echinobothrida in North China based on 18s ribosomal RNA (18s rRNA) gene and the ribosomal DNA second internal transcribed spacer (ITS-2) gene. The BLAST results of 18s rRNA (1643 bp) and ITS-2 (564 bp) gene sequences showed that the isolated intestinal tapeworms were R. echinobothrida. Phylogenetic trees obtained by maximum likelihood (ML) or neighbor-joining (NJ) method revealed that the R. echinobothrida in North China had the closest evolutionary relationship with the species found on the Qinghai-Tibet plateau, China. Morphological observations by hematoxylin staining and scanning electron microscope showed four round suckers and a retractable rostellum on the spherical scolex of R. echinobothrida. Two rows of alternately arranged hooks distributed around the rostellum. There were 30-40 testes in each mature segment. A well-developed cirrus pouch lied outside the excretory duct of mature segment. The gravid segment contained 200-400 eggs and there was a well-developed oncosphere in each egg. In addition, abundant ultrastructural features in mature proglottid of R. echinobothrida in North China were identified by transmission electron microscopy. In conclusion, the present study established ways of molecular phylogenetic identification for R. echinobothrida based on 18s rRNA and ITS-2 gene, and identified the morphological and ultrastructural characteristics of R. echinobothrida in North China.