A comparison of newer tests for the diagnosis of onchocerciasis

Development and evaluation of an antigen detection dipstick assay for the diagnosis of human onchocerciasis

“…Given the high concordance value (87%) between the results obtained on urine and tears, urine would be the preferred sample for the dipstick assay, also because the test was marginally more sensitive on urine than on tears. Using ELISA, dot blot and transblot techniques, antigen detection in onchocerciasis is more sensitive in urine than in other body fluids such as tears and dermal fluids (Mbacham et al (1992); Ngu et al (1998); Vincent et al (2000)), perhaps because urine is the principal pathway by which soluble waste is eliminated from the body compared with tears. In tears the amount of antigens may only be detectable in heavily infected individuals or those who carry the parasite in their eyes.…”

“…Unfortunately, antibody detection assays, although sufficiently sensitive, are unable to distinguish between active and past infections (Lavebratt et al (1994); Chandrashekar et al (1996);Weil et al (2000)). On their part, developed antigen detection assays are either not sufficiently sensitive and specific, or are laborious and time consuming (Mbacham et al (1992); Ngu et al (1998);Vincent et al (2000)). Recently, the development of Polymerase Chain Reaction (PCR) based methods for the detection of parasite DNA in skin snips has greatly improved the diagnosis of onchocerciasis given its high sensitivity and specificity (Meredith et al (1991);Zimmerman et al (1994) depend on skin snipping procedures and require considerable laboratory skills and infrastructure (Pischke et al (2002)).…”

Nested PCR to detect and distinguish the sympatric filarial species Onchocerca volvulus, Mansonella ozzardi and Mansonella perstans in the Amazon Region

“…In order to overcome the limitations of conventional microscopic diagnosis for filarial species identification, other methods such as serodiagnosis and antigen detection have been used with varying levels of success (Vincent et al 2000, Ramzy 2002, Molyneux 2009). The use of an enzyme linked immunosorbent assay test for identifying O. volvulus failed in Brazil because of crossreactivity between this species and M. ozzardi .…”

Toward Molecular Parasitologic Diagnosis: Enhanced Diagnostic Sensitivity for Filarial Infections in Mobile Populations

“…Serological assays (a limited number of which are available commercially) are an alternative but suffer from poor specificity and an inability to distinguish between active and prior infection (1,20,27). An immunochromatographic card-type assay (Filariasis Now) detects circulating antigen of W. bancrofti but is not useful for any of the other pathogens (28) and is not available commercially in Europe or North America.…”