Scientists at Scripps Research 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 Kim Janda, PhD, the Ely R. Callaway Jr. Professor of Chemistry and member of the Skaggs Institute for Chemical Biology at Scripps Research.
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.
Janda 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 that only shows up when a human host has metabolized a worm neurotransmitter called tyramine. Humans then secrete this biomarker in urine.
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, Janda 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.
The Latest on: River blindness
via Google News
The Latest on: River blindness
- Africa: Poorer African Nations Rank High in Disease-Fighters' League Table on February 10, 2019 at 2:10 am
The five most common NTDs amenable to mass treatment are: blinding trachoma; intestinal worms; the mosquito-borne elephantiasis; snail-borne bilharzia; and river blindness. All five can be ... […]
- Poorest countries in Africa set to wipe out neglected diseases while richest fall behind on February 10, 2019 at 1:02 am
the leading cause of infectious blindness; intestinal worms that can stunt the growth of children; mosquito-borne elephantiasis; snail-borne bilharzia and river blindness. All of the diseases can be p... […]
- Ethiopia makes progress against neglected tropical diseases on February 9, 2019 at 7:52 am
The other three of the five most common NTDs are mosquito-borne elephantiasis (also known as lymphatic filariasis); snail-borne bilharzia; and river blindness. These five diseases affect 1.6 billion p... […]
- What causes river blindness? on February 1, 2019 at 3:35 am
River blindness is a disease that affects over 15 million people around the world. It is most common in sub-Saharan Africa, but it also occurs in the Middle East, as well as Central and South America. ... […]
- A new cure for river blindness and elephantiasis on January 28, 2019 at 4:00 pm
Onchocerciasis (river blindness) and lymphatic filariasis (elephantiasis) are neglected tropical diseases (NTDs) that cause severe disability and affect more than 106 million people, according to the ... […]
- Novel drug proves effective against neglected tropical diseases on January 14, 2019 at 4:13 am
Researchers have developed a novel drug with the potential to kill a bacterium causing two of the most neglected tropical diseases that lead to blindness and severe disability and affect over 157 mill... […]
- New antibiotic proves to be effective against river blindness in mice on January 8, 2019 at 6:19 am
A team of researchers from the U.K., the U.S., Japan and Germany has developed an antibiotic that kills a type of bacteria necessary for larval growth in the parasitic worm that causes river blindness ... […]
- From Fascinating to Disturbing — 10 things you should know about onchocerciasis on December 17, 2018 at 12:03 pm
1.Say what? Pronounced ohn-koe-ser-kye-ah-sess, you’ll more often hear the disease referred to as river blindness. The basis of this moniker is quite obvious: Oncho is spread by a type of blackfly tha... […]
- Eastern Sudan's Gallabat area declared free of river blindness on November 18, 2018 at 1:47 pm
KHARTOUM, Nov. 18 (Xinhua) -- Sudan's Federal Ministry of Health on Sunday declared Gallabat area in eastern Sudan's Qadarif State, on the border with Ethiopia, free of river blindness. "Sudan has man... […]
- Basic research in fruit flies leads to potential drug for diseases afflicting millions on July 12, 2018 at 11:37 am
Filarial nematodes, parasitic worms that cause river blindness and elephantiasis, are dependent on Wolbachia bacteria that infect the cells of the worms and are responsible for much of the pathology o... […]
via Bing News