Scientists have developed a urine diagnostic to detect the parasitic worms that cause river blindness, also called onchocerciasis, a tropical disease that afflicts 18 to 120 million people worldwide.
Described in the journal ACS Infectious Diseases, the new, non-invasive test may provide an inexpensive method of determining in real time whether a person has an infection, which would give public health officials and doctors critical information for tracking outbreaks and treating current infections.
"River blindness affects individuals both in Africa and Latin America, and because many of these endemic regions are difficult to access, what is needed in the field is an inexpensive point-of-care means to monitor the disease," says the senior author.
River blindness is a filarial disease, like elephantiasis, and occurs when the parasitic worm Onchocerca volvulus takes up residence in the skin. Adult worms pump out babies (microfilaria) at an alarming rate, which are ultimately re-spread by blackfly bites. The microfilariae can migrate to the eye and die, releasing toxins and causing inflammation. People with the disease will slowly go blind without medical intervention.
The senior author says onchocerciasis monitoring and evaluation are especially necessary steps for people leading elimination efforts. To know if these efforts are working, doctors need to be able to show when disease transmission has been interrupted. The current gold standard for detecting the parasitic worms is a "skin snip" biopsy. However, snips are generally insensitive indicators of infection, and the sensitivity of the skin snip decreases as the density of microfilaria in the skin decreases. Other tests cannot distinguish between past and current infections.
Currently, onchocerciasis elimination programs rely primarily on mass drug administration of the therapy Ivermectin to suppress and eventually eliminate transmission of Onchocerca volvulus. Yet, without a means to evaluate if an infection is ongoing, it's hard to assess if prevention efforts are working--and if it's safe for people to stop taking medication.
The new lateral flow assay took over 10 years to develop, but it is now ready for manufacturing and testing in the field. The key to the assay's success was in the making of designer antibodies to detect a unique biomarker NATOG (N-acetyl-tyramine-O-glucuronide) that only shows up when a human host has metabolized a worm neurotransmitter called tyramine. Humans then secrete this biomarker in urine. The ability of NATOG to distinguish between active and past infection overcomes the limitations of antibody biomarkers and PCR methodologies.
A negative on the "dipstick" test shows a colored line in the test. Got the parasite? The test would show no lines.
Unlike the skin snip biopsy, the author says this non-invasive test is the first to use a metabolite produced by adult worms. Moreover, the dipstick's inexpensive design, coupled with smartphone apps, would offer automatic image processing, which ultimately could translate to address critical gaps in the surveillance and treatment of river blindness.
https://www.scripps.edu/news-and-events/press-room/2018/20180827-river-blindness-diagnostic.html
https://pubs.acs.org/doi/10.1021/acsinfecdis.8b00163
New urine dipstick test to detect "River Blindness"
- 1,461 views
- Added
Edited
Latest News
How protein synthesis in de…
By newseditor
Posted 22 Apr
Atlas of mRNA variants in d…
By newseditor
Posted 22 Apr
Mapping microbiome in metas…
By newseditor
Posted 22 Apr
Full-length mRNA packaged i…
By newseditor
Posted 22 Apr
Glucose-sensing mechanism t…
By newseditor
Posted 21 Apr
Other Top Stories
Fusion of macrophages form multinucleated giant cells to eliminate…
Read more
Diverse physiological role of natural killer cells in different tis…
Read more
Mechanism of inflammation induced memory impairment
Read more
Connecting cholesterol metabolism with inflammatory circuit
Read more
Body tightly controls inflammatory response to pathogens
Read more
Protocols
A programmable targeted pro…
By newseditor
Posted 23 Apr
MemPrep, a new technology f…
By newseditor
Posted 08 Apr
A tangible method to assess…
By newseditor
Posted 08 Apr
Stem cell-derived vessels-o…
By newseditor
Posted 06 Apr
Single-cell biclustering fo…
By newseditor
Posted 01 Apr
Publications
Neuronal activity rapidly r…
By newseditor
Posted 22 Apr
A perspective on muscle phe…
By newseditor
Posted 22 Apr
Foxp1 suppresses cortical a…
By newseditor
Posted 22 Apr
Single-cell long-read seque…
By newseditor
Posted 22 Apr
Unlocking potential: the ro…
By newseditor
Posted 22 Apr
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar