Human ocular onchocerciasis caused byOnchocerca lupi(Spirurida, Onchocercidae) in Iran

Abstract

Cases of canine onchocerciasis caused by Onchocerca lupi are increasingly reported from Europe and the western United States of America. The zoonotic role of this parasite had already been suspected in Europe as the clinical signs and histopathology seen in two ocular cases from Albania and the Crimean region were very similar to those of canine ocular onchocerciasis. In the most recent reports of human onchocerciasis, O. lupi has been morphologically and molecularly identified as the causative agent of ocular infestation in two patients from Turkey, and one patient from Tunisia. Here, we report an additional case of nodular lesions involving two, and possibly more, immature worms in a patient from Iran. The parasite was found to belong to the genus Onchocerca based on morphological features and the species was confirmed as O. lupi from a partial sequence analysis of 12S ribosomal DNA.

Human case of Onchocerca lupi infection, Germany, August 2014

“…Symptoms in humans and dogs are strikingly similar, involving the eye and its appendices. As demonstrated by our case and a previously reported one [8], also multiple O. lupi nodules can occur during human infection -either in parallel [8] or, as seen in our case, successively. In the patient described here, molecular methods unequivocally identified O. lupi as the causative agent.…”

“…The clinical picture in humans is characterised by the development of a bulbar subconjunctival nodule [5][6][7]10]. In one case also multiple eye nodules were observed [8]. An extradural infection with spinal cord compression was seen in a 22-month-old girl [9].…”

“…The zoonotic significance of O. lupi was first highlighted in 2002 in two suspected human cases from Albania and Russia [3] that had occurred close to regions where the parasite had been described in a wolf and dogs [4]. Only recently, further and definitive human infections have been described from 2011 onwards in Turkey [5][6][7], Iran [8], Tunisia [7], and the US Figure 2 Molecular phylogeny of various Onchocerca species and other filaria species pathogenic for humans based on partial sequences of parasite 12S rRNA genes…”

“…Only in two cases [9,10] additional anthelminthic drugs (ivermectin and/or albendazole) were administered. In one case dexamethasone was applied after surgery and cryotherapy because of generalised urticaria [8]. The incubation time of the disease is unknown.…”

Diagnostic challenges and the unwritten stories of dog and cat parasites

“…This infestation has been occasionally reported in symptomatic dogs from Hungary, Greece, Germany and Portugal (Széll et al, 2001;Komnenou et al, 2002;Faísca et al, 2010;Hermosilla et al, 2005;Sallo et al, 2005) and, more recently, in dogs and cats from Arizona and Colorado, the United States (Labelle et al, 2011(Labelle et al, , 2013. Since the first report of human ocular infestation in 2011 (Otranto et al, 2011b), within less than four years, up to 10 human cases of O. lupi have subsequently been described in patients from Germany (Bergua et al, 2015), Turkey (Otranto et al, 2011b;Ilhan et al, 2013), Tunisia , Iran (Mowlavi et al, 2013) and the United States (Eberhard et al, 2013;Dudley et al, 2015;Chen et al, 2015), which has stimulated the interest of the scientific community on this parasite. For example, in the United States, veterinarians must now report canine onchocercosis within seven days of the first identification (http://www.publichealth.lacounty.gov/vet/ docs/AnimalReportList2013.pdf).…”