Need for Improved Diagnostics to Screen for Soil-transmitted Helminths
Santosh George*
Alumni - Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, CT, USA
*Corresponding Author: Alumni - Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, CT, USA.
Received:
September 13, 2021; Published: September 23, 2021
Soil-transmitted helminths (STHs), namely Ascaris spp. (roundworm), Trichuris spp. (whipworm) and Ancylostoma spp. (hookworm) are parasitic worms that infect both animals and humans. Conventionally, the identification of STH species in animals have relied on coprological or post-mortem examination of the adult worms to identify morphological differences across various species. STH species have also been identified based on egg size (Trichuris spp. [1], Hookworm [2]). Misdiagnosis, on the other hand, might arise due to a mismatch in egg size across species. In recent years, the focus of diagnostics on the veterinary side has shifted from merely detecting the presence/absence of infection, to detecting its influence on productivity., in terms of reduced growth, cost of control (anthelminthics), increased risk of co-infection and potential interference with vaccination. An early sensitive and accurate diagnosis can therefore aid in targeted and accurate treatment, reducing economic losses.
References
- Yoshikawa H., et al. “Variations in egg size of Trichuris trichiura”. Parasitology Research8 (1989): 649-54.
- Stoll NR. “Necator americanus and Ancylostoma duodenale in Guam, Leyte, and Okinawa, with a note on hookworm egg sizes”. Journal of Parasitology5 (1946): 490-496.
- Guidelines for the evaluation of soil-transmitted helminthiasis and schistosomiasis at community level. A guide for control programme managers; World Health Organization, Geneva (1998).
- “Assessing the efficacy of anthelminth drugs against schistosomiasis and soil-transmitted helminthiases” (2013).
- Nikolay B., et al. “Sensitivity of diagnostic tests for human soil-transmitted helminth infections: a meta-analysis in the absence of a true gold standard”. International Journal of Parasitology11 (2014): 765-774.
- Bosch F., et al. “Diagnosis of soil-transmitted helminths using the Kato-Katz technique: What is the influence of stirring, storage time and storage temperature on stool sample egg counts?”. PLOS Neglected Tropical Diseases1 (2021): e0009032.
- Teesdale CH., et al. “Egg count variability and sensitivity of a thin smear technique for the diagnosis of Schistosoma mansoni”. Transactions of the Royal Society of Tropical Medicine and Hygiene3 (1985): 369-373.
- McCarthy JS., et al. “A research agenda for helminth diseases of humans: diagnostics for control and elimination programmes”. PLOS Neglected Tropical Diseases4 (2012): e1601.
- Chidambaram M., et al. “Evaluation of the utility of conventional polymerase chain reaction for detection and species differentiation in human hookworm infections”. Tropical Parasitology2 (2017): 111-116.
- George S., et al. “The molecular speciation of soil-transmitted helminth eggs collected from school children across six endemic countries”. Transactions of the Royal Society of Tropical Medicine and Hygiene11 (2016): 657-663.
- George S., et al. “Molecular Identification of Hookworm Isolates in Humans, Dogs and Soil in a Tribal Area in Tamil Nadu, India”. PLOS Neglected Tropical Diseases8 (2016): e0004891.
- Traub RJ., et al. “PCR-based coprodiagnostic tools reveal dogs as reservoirs of zoonotic ancylostomiasis caused by Ancylostoma ceylanicum in temple communities in Bangkok”. Veterinary Parasitology1-2 (2008): 67-73.
- George S., et al. “Identification of Ancylostoma ceylanicum in children from a tribal community in Tamil Nadu, India using a semi-nested PCR-RFLP tool”. Transactions of the Royal Society of Tropical Medicine and Hygiene4 (2015): 283-285.
- Demeler J., et al. “Phylogenetic characterization of beta-tubulins and development of pyrosequencing assays for benzimidazole resistance in cattle nematodes”. PLoS One 8 (2013): e70212.
- de Gruijter JM., et al. “Polymerase chain reaction-based differential diagnosis of Ancylostoma duodenale and Necator americanus infections in humans in northern Ghana”. Tropical Medicine and Internatonal Health6 (2005): 574-580.
- Leles D., et al. “Molecular paleoparasitological diagnosis of Ascaris sp. from coprolites: new scenery of ascariasis in pre-Colombian South America times”. Mem Inst Oswaldo Cruz.1 (2008): 106-108.
- Ngui R., et al. “Molecular identification of human hookworm infections in economically disadvantaged communities in Peninsular Malaysia”. American Society of Tropical Medicine and Hygiene5 (2012): 837-842.
- Betson M., et al. “Molecular epidemiology of ascariasis: a global perspective on the transmission dynamics of Ascaris in people and pigs”. Journal of Infectious Disease6 (2014): 932-941.
- Phosuk I., et al. “Molecular Identification of Trichuris suis and Trichuris trichiura Eggs in Human Populations from Thailand, Lao PDR, and Myanmar”. American Society of Tropical Medicine and Hygiene1 (2018): 39-44.
- Hii SF., et al. “Development and Evaluation of a Multiplex Quantitative Real-Time Polymerase Chain Reaction for Hookworm Species in Human Stool”. American Society of Tropical Medicine and Hygiene5 (2018): 1186-1193.
- Massetti L., et al. “High-throughput multiplex qPCRs for the surveillance of zoonotic species of canine hookworms”. PLOS Neglected Tropical Diseases 6 (2020): e0008392.
- Dunn JC., et al. “The increased sensitivity of qPCR in comparison to Kato-Katz is required for the accurate assessment of the prevalence of soil-transmitted helminth infection in settings that have received multiple rounds of mass drug administration”. Parasites and Vectors 1 (2020): 324.
- Traub RJ., et al. “Application of a species-specific PCR-RFLP to identify Ancylostoma eggs directly from canine faeces”. Veterinary Parasitology3-4 (2004): 245-255.
- Leles D., et al. “Molecular diagnosis of ascariasis from human feces and description of a new Ascaris sp. genotype in Brazil”. Veterinary Parasitology 1-2 (2009): 167-170.
- Carlsgart J., et al. “Multiplex PCR on single unembryonated Ascaris (roundworm) eggs”. Parasitology Research4 (2009): 939-943.
- Kaisar MMM., et al. “Improved diagnosis of Trichuris trichiura by using a bead-beating procedure on ethanol preserved stool samples prior to DNA isolation and the performance of multiplex real-time PCR for intestinal parasites”. Parasitology7 (2017): 965-974.
- Lamb HJ., et al. “The Future of Livestock Management: A Review of Real-Time Portable Sequencing Applied to Livestock”. Genes (Basel)12 (2020).
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