Abstract
Background: Thelazia callipaeda is a zoonotic parasitic nematode of the family Thelaziidae, with Phortica okadai as the intermediate host and the only confirmed vector in China. China has the largest number of cases of thelaziosis in humans of the world. It is generally believed that domestic animals (dogs and cats) are the most important reservoir hosts of Thelazia callipaeda and directly threaten humans. At present, there is not much research and attention on the role of wildlife in the transmission cycle of thelaziosis in wildlife nature reserves.Methods: During 2016-2019, we selected four wildlife national nature reserve across the country as monitoring points for Phortica okadai and wildlife, and we chose to use fly-trap method for monitoring Phortica okadai density. Morphological analysis of the parasites collected from the conjunctival sac of the wildlife was taken as the first step, and a specific PCR was used for exact confirmation.Results: In 2019, the density of Phortica okadai in Foping National Nature Reserve of China, increased sharply and infected Phortica okadai were newly found in wildlife nature reserves. Wild giant panda, wild boar, leopard cat, and black bear were newly found to be infected by Thelazia callipaeda (one animal of each species). A total of four worms were collected and one worm was collected from each animals. The morphologic characteristics of the four worms led to their identification as Thelazia callipaeda, which was molecularly confirmed by a specific PCR amplification.Conclusions: This is the first report of Phortica okadai as well as a variety of wildlife including wild giant panda infected by Thelazia callipaeda in wildlife nature reserves in China. This indicates that there has been a transmission cycle of thelaziosis among wildlife in wildlife nature reserves. The increasing number of case reports in wildlife suggests the likely risk of infection of Thelazia callipaeda in villagers around wildlife nature reserves.
Habitat Suitability Evaluation for Giant panda in Liziping National Nature Reserve, Sichuan Province
