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Objective To investigate the population distribution of intermediate host snails and crabs of Paragonimus along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, so as to provide baseline data for researches on parasitic disease prevention and control and enlargement of samples in the parasitic resource bank. Methods A total of 23 villages in 8 counties (districts) along the Jiulong River, Zhangjiang River, and Dongxi River basins in Zhangzhou City, Fujian Province were selected as survey sites during the period from November 2020 through March 2023, and snail and freshwater crabs were sampled from 1 to 3 streams and ditches neighboring residential areas in each village. Morphological identification of snails was performed according to the external morphological characteristics of collected snail shells, and the unidentified snail species sampled from the natural foci of paragonimiasis in Yunxiao County were subjected to se-quence analysis of the mitochondrial cytochrome oxidase 1 (CO1) gene. The crab species was identified by observing the morphological characteristics of the terminal segment of the first pleopod of male crabs, and Paragonimus cercariae and metacercariae were detected in collected snails. Results The shells of the unidentified snails sampled from the natural foci of paragonimiasis in Yunxiao County were approximately 50 mm in height and 18 mm in width, thick and solid, long tower cone-shaped, and had 8 to 10 whorls. CO1 gene sequence analysis identified the snail species as Sulcospira hainanensis. A total of 6 freshwater snail species belonging to 5 genera within 3 families, identified 23 survey sites, including Semisulcospira libertina, Paludomus zhangchouensis and S. hainanensis that belonged to the Family Pleurceridae, Tricula fujianensis and T. huaanensis that belonged to the subfamily Triculinae, Family Pomatiopsidae, and Melanoides tuberculata (Family Thiaridae), and 11 species of freshwater crabs belonging to 5 genera within 2 families were identified, including Sinopotamon genus of S. jianglense, S. pinheense, and S. zhangzhouense, Huananpotamon genus of H. planopodum and H. zhangzhouense, Nanhaipotamon genus of N. huaanense and N. longhaiense, and Minpotamon genus of M. nasicum and M. auritum that belonged to the Family Potamidae, and Somanniathelphusa genus of S. huaanensis and S. zhangpuensis (Family Parathelphusidae). In addition, the prevalence of P. westermani cercariae infections was 0.08% (2/2 317) in P. zhangchouensis from Danyan Village in Changtai District and 0.09% (1/1 039) in S. hainanensis from Jinkeng Village in Yunxiao County, and the prevalence of P. westermani metacercariae infections was 25.81% (8/31) in S. jianglense from Danyan Village in Changtai District, and 26.31% (5/19) in S. zhangzhouense from Jinkeng Village in Yunxiao County, respectively. Conclusions There is a population diversity in the intermediate host snails and crabs along the Jiulongjiang River, Zhangjiang River, and Dongxi River basins in Bopingling Mountain, southern Fujian Province, and P. zhangzhouensis and S. hainanensis are, for the first time, confirmed as the first intermediate hosts of P. westermani.
ABSTRACT
The aim of the study was to investigate the population ecology of medical shellfish and the infection of An-giostrongylus cantonensis in Longhai ,Fujian Province ,China .Aquatic and terrestrial shellfish were collected in survey points according to different types of breeding grounds .Then ,lung-microscopy method was involved in the detection of the lung tis-sue in Ampullaria gigas .Other shellfishes were mashed to detect the third-stage larvae of Angiostrongylus cantonensis .Hom-ogenization and lung microscopy were compared in the detection of the larvae of A .cantonensis in Achatina snails .Factors re-lated to the environment and influence of shellfish hosts were also included .Results showed that 8 species of molluscans were found ,including Pila gigas ,Bellamya aeruginosa ,Bellamya lithophaga ,Melanoides tuberculata ,Achatina fulica ,Vag-inulus alte ,Philomycus bilineatus ,and Bradybaenasimilaris with 1 673 specimens in 27 survey points from 9 townships .The infectionratewas19.78% inaverage.TheinfectionrateinV.altewas56.63% (47/83);theinfectionratesforA.fulicaand P .gigas were 39 .32% (92/234) and 27 .14% (130/234) ,respectively .The infection rate of each survey point was closely re-lated to the distances from the residents living area .Morever ,A .cantonensis larvae were detected in M .tuberculata .Lung mi-croscopy and homogenization method detection rate was 87 .1%and 100 .0% ,respectively .The difference was statistically sig-nificant .In conclusion ,V .alte ,A . fulica and P .gigas were A . cantonensist infection dominant population . The infection rate was closely related to micro-ecological environment for all kinds of shellfish .M .tuberculata was the new host of A .can-tonensis .Lung microscopy method should not be used in the qualitative screening detection of A . f ulica infected with A .can-tonensist .
ABSTRACT
In order to understand the situation of schistosomiasis in Fujian Province, the surveillance and field survey data of 16 counties (cities or districts) were statistically analyzed from 2003 to 2008 according to the national and provincial surveillance protocols. The snail areas were 69 400 m~2 in 2003, and 506 700 m~2 in 2004, then decreased to 57 700 m~2 in 2008 after the snail control in 2005 and 2006. Serological examinations were conducted in 18 000 people, among which 5 412 people were the mobile population from schistosome-endemic areas, and 110 persons were positive, among which 8 persons had eggs and miracidia in their stools, among 7 885 appendix samples, Schistosoma japonicum eggs were found in 8 samples of the patients who came from the o-riginal endemic areas. By the stool examination, 2 709 head of farm cattle in the region with snails were not found infected with Schistosoma japonicum. It is suggested that the areas of residual snails are large and widespread, and the imported patients are found frequently, so the danger of schistosomisis transmission still remains.
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Objective To provide the basis for the differentiation with similar species of intestinal flukes through observing the figure of Haplorchis pumilio. Methods Adults of H. pumilio were collected from the intestine of the cat which was infected with the encysted cercariae of H.pumilio for 45 days. The worms were observed after staining. Eggs and metacercariae of H.pumilio were collected and examined for their shape, size and morphological characteristics. Pseudorasbora parva, the fish host, was examined for the parasitized sites of metacercariae. Results The principal characteristics of the adults is the acetabulum degradation. There are only the genital sucker with 44-48 hamuli. The average measurement of eggs is 31.2?16.7 ?m with a smooth shell. Its aceromion is not evident. The average diameter of metacercariae is 168.5 ?m. There are squamous spines on metacercaria. The metacercariae only parasitize in the muscle between the basis of the fin and the fish body. The average measurement of metacercaria cyst is 445?95?m, with squamous spines on the body surface. Hamuli are found on the genital sucker of metacercaria cyst. Conclusion The morphological figures and parasitic sites of metacercaria, the genital sucker of the adult, and the number and form of the hamulus on the genital sucker provide basis for distinguishing H. pumilio from other intestinal flukes.
ABSTRACT
A new species of Nanhaipotamon sp. Nov. was found from the west of Xiapu County, Fujian Province in April 2008. Holotype: male, carapace length 28.2 mm, breadth 35.6 mm, thickness 20.4 mm. Allotype, female, carapace length 22.6 mm, breadth 28.7 mm, thickness 20.4 mm. Male first pleopod reached beyond tubercle of abdominal lock, not reaching to suture of sternites 4/5. Subterminal segment was about 2.4 times as terminal segment, inner horn rounded to squarish, and its outer horn pointed to the upper part of abdomen. Morphologically, this new species is distinguishable to the similar species of freshwater crabs, such as N. formosanum, N. nanriense, and N. yongchunense.
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Objective To make etiological and epidemiological investigation on the infection of Angiostrongylus canto-nensis in 8 pupils in Changle City. Methods (1) CSF of patients was examined with the conventional method to detect pathogens and eosinophiles. (2) The fecal samples of wild rodents were collected from the spot and examined microscopically to discover the first stage larvae of A. cantonensis. (3) Snails (Pila gigas) were collected in the spot. The smashed head tissue was examined for the third stage larvae of A. cantonensis. (4) The patient's clinical symptoms and physical signs were recorded with an emphasis on central nervous system. Results (1) Two larvae of the third stage of A. cantonensis were found in CSF of one patient. Eosinophiles occupied 68% of the cell number in average (ranged from 47% to 83%) in CSF of the 8 patients. (2) The infection rate of the first stage larvae of A. cantonensis was 39.3% (44/112) in feces of the rodents. (3) The infection rate of the third stage larvae of A. cantonensis was 40. 0% (82/205) in the snails. (4) Major clinical manifestations in the 8 patients included: severe headache(8/8), dizziness(8/8), nausea(8/8), vomiting(8/8), lethargy(7/8), lower limb hypody-namia(7/8). Conclusion The confirmation of severe infection of A. cantonensis in 8 child patients demonstrated that a natural nidus of angiostrongyliasis is present in Chengle City.
