| Literature DB >> 25058608 |
Mihály Sulyok1, Lajos Rózsa2, Imre Bodó3, Dennis Tappe4, Richard Hardi5.
Abstract
Ocular pentastomiasis is a rare infection caused by the larval stage of pentastomids, an unusual group of crustacean-related parasites. Zoonotic pentastomids have a distinct geographical distribution and utilize reptiles or canids as final hosts. Recently, an increasing number of human abdominal infections have been reported in Africa, where pentastomiasis is an emerging, though severely neglected, tropical disease. Here we describe four ocular infections caused by pentastomids from the Democratic Republic of the Congo. Two cases underwent surgery and an Armillifer grandis infection was detected by morphological and molecular approaches. Thus far, 15 other cases of ocular pentastomiasis have been reported worldwide. Twelve cases were caused by Armillifer sp., recorded almost exclusively in Africa, where such infections occur as a consequence of hunting and consuming snakes, their final hosts. Seven further cases were caused by Linguatula serrata, a cosmopolitan pentastomid whose final hosts are usually canids. Intraocular infections caused permanent visual damage in 69% and a total loss of vision in 31% of reported cases. In contrast, ocular adnexal cases had a benign clinical course. Further research is required to estimate the burden, therapeutic options and pathogenesis of this neglected disease.Entities:
Mesh:
Year: 2014 PMID: 25058608 PMCID: PMC4109912 DOI: 10.1371/journal.pntd.0003041
Source DB: PubMed Journal: PLoS Negl Trop Dis ISSN: 1935-2727
Figure 1Annulated foreign body in the anterior chamber of the left eye from Case 1.
A, lateral view. The eye shows marked conjunctival injections and the foreign body fills the whole pupil blocking the eyesight completely. B, frontal view. The high number of annulations of the parasite is clearly visible.
Figure 2Extracted pentastomid nymph from Case 1, morphologically and molecularly identified as Armillifer grandis.
The nymph is still surrounded by its shed translucent cuticle (exuvia), a characteristic feature of pentastomid larvae as they moult in the intermediate hosts' tissues. A. grandis is the smallest of the zoonotic African Armillifer species with the most body annulations (9–15 mm body length and >25 annulations; A. armillatus, the nearest geographical neighbour for comparison: 12–23 mm length and 18–22 annulations (2). A. grandis is the least often encountered zoonotic Armillifer species worldwide. Scale bar = 3 mm.
Figure 3Local villagers often find pentastomids in snakes sliced for consumption.
Adult Armillifer armillatus (confirmed by 18S rRNA gene PCR) in the lung of a young Ball Python (Python regius) before consumption in Sankuru district, Democratic Republic of the Congo. Sometimes local people do not clean and cook the snake properly just spit out the parasites while eating, so the eggs may accidentally be swallowed. The ova may also contaminate snake meat during butchering. Unless properly cooked, an egg may hatch in the intestine of an accidental human intermediate host. While most larvae migrate to visceral organs, a few will make their way to the eye [1].
Epidemiological and parasitological characteristics of patients with ocular pentastomiasis reported in the literature, including current cases.
| Case Nr.[Reference] | Year | Country | Age/sex | Diagnosis | Pentastomid Species |
| Case 1 | 1962 | USA | 8/F | Morphology |
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| Case 2 | 1987 | Israel | 12/M | Morphology |
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| Case 3 | 2011 | India | 5/M | Morphology |
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| Case 4 | 1960 | USA | 16/M | Morphology |
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| Case 5 | 2011 | Austria | 14/F | PCR |
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| Case 6 | 1951 | Congo | 10/M | Morphology |
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| Case 7 | 1967 | Liberia | 50/M | Morphology |
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| Case 8 | 1962 | Liberia | 9/M | Morphology |
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| Case 9 | 1957 | Liberia | 6/M | Morphology |
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| Case 10 | 1962 | Ghana | 25/M | Morphology |
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| Case 11 | 1962 | Uganda | 4/F | Morphology |
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| Case 12 | 1979 | Ghana | 15/M | Morphology |
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| Case 13 | 1972 | Brazil | 38/M | Morphology |
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| Case 14 | 1964 | Portugal | 9/ND | Morphology |
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| Case 15 | 1999 | Ecuador | 34/F | Morphology |
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| Current Case 1 | 2014 | DRC | 11/F | PCR |
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| Current Case 2 | 2014 | DRC | 36/M | Morphology | Unidentified pentastomid |
| Current Case 3 | 2014 | DRC | 63/F | Morphology | Unidentified pentastomid |
| Current Case 4 | 2013 | DRC | 25/M | Morphology |
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DRC, Democratic Republic of the Congo; ND, not described in publication;
*, year of publication;
formerly Belgian Congo;
patients originated from that country;
this case has currently been re-analyzed morphologically and by PCR by our group and is identified as A. grandis.
Clinical characteristics of patients with ocular pentastomiasis, including the current cases.
| Case Nr. [Reference] | Relevant history | Side | Localization | Symptom duration | Motile parasite | Therapy | Eye sight |
| Case 1 | Ocular trauma | Right | AC | 4 days | Yes | Surgical | Severely damaged |
| Case 2 | Ocular trauma | Right | AC | 1 week | Yes | Surgical | Severely damaged |
| Case 3 | Pet dog | Right | AC | 2 months | No | Surgical | Regained after surgery |
| Case 4 | Pet dog | Right | AC | 2–3 months | Yes | Surgical | Intact |
| Case 5 | Pet dog, cat, turtle | Right | AC | ND | Yes | Surgical | Regained after surgery |
| Case 6 | ND | Right | SC | ND | Yes | Surgical | Intact |
| Case 7 | Eating snakes | Right | AC | 6 months | No | Surgical | Severely damaged |
| Case 8 | ND | Left | Eyelid | 12 months | ND | Surgical | Intact |
| Case 9 | ND | Left | SC | Few weeks | ND | Surgical | Intact |
| Case 10 | ND | Right | PC | Several weeks | No | None | Severely damaged |
| Case 11 | ND | Left | SC | 4 months | Yes | Surgical | Intact |
| Case 12 | ND | Left | LC | ND | ND | Surgical | Intact |
| Case 13 | Eating snakes | Left | SC | 6 weeks | Yes | Surgical | Intact |
| Case 14 | ND | Left | PC | 6 months | Yes | Surgical | Severely damaged |
| Case 15 | None | Right | AC | 2 months | Yes | Surgical | ND |
| Current Case 1 | Eating snakes | Left | AC | 4 months | Yes | Surgical | Severely damaged |
| Current Case 2 | Eating snakes | Left | PC | 36 months | No | None | Severely damaged |
| Current Case 3 | Eating snakes | Right | PC | 36 months | No | None | Severely damaged |
| Current Case 4 | Eating snakes | Left | AC | ND | Yes | Surgical | Severely damaged |
ND, not described in publication; AC, anterior chamber; PC, posterior chamber; LC, lacrimal caruncule; SC, subconjunctival;
*, before surgery steroids and albendazole were administered;
ball hit his eye before symptom onset;
a fly hit his eye before symptom onset;
also had an eye-splash accident with the body fluids of a snake six months before symptom onset.