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Parasitology Research Nov 2021Diverse Onchocerca species are present mostly parasitizing ungulates, with the exception of Onchocerca volvulus (O. volvulus) in humans and O. lupi in canids and cats....
Diverse Onchocerca species are present mostly parasitizing ungulates, with the exception of Onchocerca volvulus (O. volvulus) in humans and O. lupi in canids and cats. The human cases due to the O. lupi have been more highlighted during last years. So, the present review was performed to determine the detailed characteristics of confirmed human O. lupi case reports documented worldwide. Hence, a systematic search was done using English international databases (Scopus, PubMed, Web of Science, Embase, ProQuest, and Google Scholar). Totally, 14 confirmed human cases were documented during the last decade, mostly from the USA and Turkey with 7 and 3 cases, respectively. Most cases (7 individuals) were male with the age range of 22-month-old to 54-year-old. The parasite was frequently isolated from the right eye (5 cases), followed by the left eye (4 cases), cervical spinal canal (3 cases), scalp, and right forearm (one case each). Molecular identification of the isolated agent was the preferred way of diagnosis in most cases (9 records). In conclusion, human O. lupi cases have been more highlighted in recent years, whether due to the improved diagnostics and/or host-switching phenomenon, and both veterinarians and healthcare authorities should be alerted.
Topics: Animals; Eye; Humans; Male; Onchocerca; Onchocerciasis
PubMed: 34519871
DOI: 10.1007/s00436-021-07309-2 -
PLoS Neglected Tropical Diseases Oct 2021Molecular xenomonitoring (MX), the detection of parasite nucleic acid in the vector population, is recommended for onchocerciasis surveillance in elimination settings.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Molecular xenomonitoring (MX), the detection of parasite nucleic acid in the vector population, is recommended for onchocerciasis surveillance in elimination settings. However, the sensitivity of MX for detecting onchocerciasis-positive communities has not previously been evaluated. MX may have additional applications for control programmes but its utility is restricted by a limited understanding of the relationship between MX results and human prevalence.
METHODS
We conducted a systematic review of studies reporting the prevalence of Onchocerca volvulus DNA in wild-caught Simulium spp. flies (MX rate) and corresponding prevalence of microfilaria (mf) in humans. We evaluated the sensitivity of MX for detecting onchocerciasis-positive communities and describe the characteristics of studies with reduced sensitivity. We conducted a linear regression to evaluate the relationship between mf prevalence and MX rate.
RESULTS
We identified 15 relevant studies, with 13 studies comprising 34 study communities included in the quantitative analyses. Most communities were at advanced stages towards elimination and had no or extremely low human prevalence. MX detected positive flies in every study area with >1% mf prevalence, with the exception of one study conducted in the Venezuelan Amazonian focus. We identified a significant relationship between the two measurements, with mf prevalence accounting for half of the variation in MX rate (R2 0.50, p<0.001).
CONCLUSION
MX is sensitive to communities with ongoing onchocerciasis transmission. It has potential to predict human mf prevalence, but further data is required to understand this relationship, particularly from MX surveys conducted earlier in control programmes before transmission has been interrupted.
Topics: Animals; Diagnostic Tests, Routine; Humans; Insect Vectors; Microfilariae; Onchocerca volvulus; Onchocerciasis; Simuliidae
PubMed: 34637436
DOI: 10.1371/journal.pntd.0009812