First report of Thelazia callipaeda Railliet & Henry, 1910 in a zoo lion (Panthera leo) (Linnaeus, 1758) from Romania

Thelaziasis in an urban woman in Beijing: a case report and literature review

BACKGROUND

Thelaziasis is a zoonotic disease mainly caused by Thelazia callipaeda (Spirurida, Thelaziidae, Thelazia), which can cause mild to severe signs and lesions, such as foreign body sensation, itching, tearing, eye pain, conjunctival bleeding, conjunctivitis, corneal ulcers, and even blindness. Thelaziasis cases have been reported mainly in agricultural areas and areas with high potential for contact with domestic animals [1].

CASE PRESENTATION

We report a case of Thelazia callipaeda infection in the right eye of a 41-year-old woman working in an office. The patient presented with persistent foreign body sensation, pruritus, and redness despite initial treatment with polyethylene glycol and levofloxacin eye drops. Subsequent examination revealed the presence of multiple Thelazia callipaeda worms, which were successfully removed. Postoperative treatment with gatifloxacin eye ointment resulted in significant symptom relief with no recurrence over two months.

CONCLUSIONS

This case highlights the thelaziasis in urban settings, emphasizing the need for ophthalmologists to consider parasitic infections in differential diagnosis even in well-maintained environments. Then, we provided an overview of human thelaziasis in China by mining publicly available databases from 2014 to 2023, suggesting a difference in regional distribution that warrants further epidemiological studies.

Population dynamics of sympatric Phortica spp. and first record of stable presence of Phortica oldenbergi in a Thelazia callipaeda-endemic area of Italy

BACKGROUND

Five species of the Phortica genus (Diptera: Drosophilidae) are known in Europe and the Middle East. Among these, Phortica variegata and Phortica okadai are better known for their role as vectors of the zoonotic eyeworm Thelazia callipaeda. Other species, such as Phortica semivirgo and Phortica oldenbergi, have been studied less. Given the paucity of data about these Phortica spp. vectors, we explored the population dynamics and ecology of Phortica spp. in an area highly endemic for T. callipeada (Manziana, Rome, Central Italy).

METHODS

Phortica spp. flies were collected over a 3-year period (2018-2020) during their active season (April-October) with a sweep net while hovering around fermenting fruits or a human operator acting as baits. Collected flies were morphologically identified and tested for a T. callipeada infection and for the presence of Wolbachia, by polymerase chain reaction (PCR). Population dynamics of species collected was associated to environmental drivers through generalized additive models.

RESULTS

Of the 5564 flies collected, 90.8% were P. variegata, 9.1% were P. oldenbergi, 0.05% were P. semivirgo, and one specimen was P. okadai. Only P. variegata scored molecularly infected with T. callipeada throughout the 3-year sampling period (1.8%). Phortica oldenbergi, observed consistently during the entire sampling period, exhibited a marked preference for fruit traps, contrasting with the lachryphagous activity of P. variegata. Analysis of environmental drivers of P. oldenbergi and P. variegata population dynamics indicated temperature, wind speed, and pressure as significant factors. In addition, Wolbachia pipientis endosymbiont was detected in P. oldenbergi and P. okadai.

CONCLUSIONS

For the first time, this study analysed several ecological aspects of Phortica species coexisting in a T. callipeada endemic area, highlighting different behaviors in the same environment and their vectorial role. Notably, this is also the first report of the presence of P. oldenbergi in Italy and P. okadai in Europe, underscoring the importance of extensive sampling for detecting potential vectors and alien species with direct implications for vector-borne disease epidemiology.

Update on infections with Thelazia callipaeda in European wildlife and a report in a red fox, Vulpes vulpes, in Portugal

Thelazia callipaeda, also known as the "oriental eye worm", is a zoonotic parasitic nematode with a wide range of hosts, particularly wild and domestic carnivores, but also lagomorphs and humans. Currently, ocular thelaziosis presents an expanding distribution range throughout Europe, including Portugal. This study provides an update on T. callipaeda infection reports (30 studies) in European wildlife comprising 54 host-locality records in 10 host species from nine European countries. The prevalence of T. callipaeda varied widely, with ranges from around 1% in red foxes and European hares to almost 50% in red foxes. The lowest mean intensity was 2.7 nematodes/host in European wildcats and the highest was 38.0 nematodes/host in wolves. In addition, a massive infection with T. callipaeda in a juvenile male red fox from eastern-central Portugal is also described, representing the southernmost report in a wild animal in this country. A total of 188 nematodes (139 females and 49 males) were collected from both eyes and were submitted to morphological and molecular characterization. Collected nematodes were morphologically identified as T. callipaeda. Given the endemicity of T. callipaeda in eastern-central Portugal, surveillance system should be implemented to monitor its presence among wild and domestic animals.

Wildlife parasitology: sample collection and processing, diagnostic constraints, and methodological challenges in terrestrial carnivores

Wild terrestrial carnivores play a crucial role as reservoir, maintenance, and spillover hosts for a wide parasite variety. They may harbor, shed, and transmit zoonotic parasites and parasites of veterinary importance for domestic hosts. Although wild carnivores are globally distributed and comprise many different species, some living in close proximity to human settlements, only a few studies have investigated parasites of wild terrestrial carnivores using non-specific techniques. Access to samples of wild carnivores may be challenging as some species are protected, and others are secretive, possibly explaining the data paucity. Considering the importance of wild carnivores' health and ecological role, combined with the lack of specific diagnostic methodologies, this review aims to offer an overview of the diagnostic methods for parasite investigation in wild terrestrial carnivores, providing the precise techniques for collection and analysis of fecal, blood, and tissue samples, the environmental impact on said samples, and the limitations researchers currently face in analyzing samples of wild terrestrial carnivores. In addition, this paper offers some crucial information on how different environmental factors affect parasite detection postmortem and how insects can be used to estimate the time of death with a specific highlight on insect larvae. The paper contains a literature review of available procedures and emphasizes the need for diagnostic method standardization in wild terrestrial carnivores.