Journal Article

Onchocerca jakutensis ocular infection in Poland: a new vector-borne human health risk?

Wesołowska, Maria, Pytrus, Wiktoria, Masny, Aleksander, Knysz, Brygida, Sałamatin, Rusłan, Zając-Pytrus, Hanna, Golab, Elzbieta

2020

Overview

Background Zoonotic onchocerciasis is a vector-borne disease, which involves many animal species, including large ungulates, boars, dogs, and sporadically, humans. So far, 39 cases of zoonotic onchocerciasis have been reported worldwide, 30 of which have been found in the last 20 years. Onchocerca nematodes are transmitted to humans by blood-sucking vectors during a blood meal. The following species have been responsible for zoonotic infections: Onchocerca cervicalis , O. dewittei japonica , O. gutturosa , O. jakutensis and O. lupi . In humans, the worms have usually been found in the subcutaneous tissues where they form subcutaneous nodules, induce inflammation of musculature, or penetrate the eye. Thirteen ocular zoonotic onchocerciasis cases have been reported so far. In the eye, nematodes were localized in the subconjunctival space, anterior chamber and within the vitreous body. Methods In a 39-year-old male patient, a writhing worm in the vitreous body of the left eye was detected and surgically removed. Laboratory identification of the worm was based on macroscopic and molecular identification, based on sequencing of the cytochrome c oxidase subunit 1 gene ( cox 1). Phylogenetic analysis of the first 250 nucleotide sequences showing the highest levels of similarity with the present isolate in a BLAST analysis was performed. Results Here, we report the first case worldwide of human ocular infection with O. jakutensis , a natural parasite of red deer. By exploiting a PCR assay, we detected the sequence almost identical to O. jakutensis (GenBank: KT001213.1; positions 1–650) with a single mismatch G/A at position 622. The sequence reported in this paper was deposited in the GenBank database under the accession number MK491767. Conclusions Our case together with the previous case reports indicate that zoonotic Onchocerca worms exhibit no tissue specificity and an eye infection has been described in over one third of human zoonotic onchocerciasis cases. In terms of the growing number of cases of zoonotic onchocerciasis in Europe, the USA and Japan, attention should be paid to the diagnosis of subcutaneous nodules and eye infestations.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adult / Animal diseases / Animal species / Animals / Anterior chamber / Biomedical and Life Sciences / Biomedicine / Blood / blood meal / Care and treatment / Case reports / Case studies / Cervus elaphus / Conjunctiva - parasitology / Cytochrome / Cytochrome c / Cytochrome oxidase / Cytochrome-c oxidase / Cytochromes / Deoxyribonucleic acid / Diagnosis / Disease transmission / Disease Vectors / Diseases / DNA / Entomology / Explosions / Eye / Eye diseases / Eye Infections - parasitology / Eyes / Filarioidea / Gene sequencing / Genes / Genes, Helminth / genetic databases / Health risks / hematophagy / Human / human health / Humans / Identification / Infections / Infectious Diseases / Inflammation / Japan / Laboratories / Male / Morphology / Nematodes / Nodules / Nucleotide sequence / nucleotide sequences / Nucleotides / Onchocerca - classification / Onchocerca cervicalis / Onchocerca gutturosa / Onchocerca jakutensis / Onchocerciasis / Onchocerciasis, Ocular - diagnosis / Onchocerciasis, Ocular - parasitology / Onchocercidae / Oxidases / Parasites / Parasitology / patients / PCR / Phylogenetics / Phylogeny / Poland / polymerase chain reaction / risk / Roundworms / Sequencing / Short Report / Specificity / Tissue / tissues / Tropical diseases / Tropical Medicine / Ungulates / Vector-borne diseases / Vector-borne helminths / Vectors / Vectors (Biology) / Veterinary Medicine/Veterinary Science / Virology / Vitreous humour / Worms / Zoonoses / Zoonoses - parasitology