[Investigation on Angiostrongylus cantonensis Infection in Rodents in Zhangzhou City, Fujian Province].

Objective: To investigate the Angiostrongylus cantonensis infection in rodents in Zhangzhou City and provide basis for control the disease. Methods: Eighteen villages in 4 counties, which located in coastal and mountain regions of rodent breeding, were selected between 2013-2015. Rodents were collected by cage trapping, and organs of heart and lungs were prepared for microscopic examination of A. cantonensis after identification of the species and age of the rodent. The infection rate was calculated and correlation between natural environment and the infection rate was analyzed. Results: A total of 1 551 rodents were collected and identified to be Rattus flavipectus, R. norvegicus, Sorex araneus, Mus musculus and R. lossea with a high-to-low ranking of R. flavipectus（41.8%）, R. norvegicus（28.4%） and S. araneus（20.9%）. The overall infection mice was 9.2%（142/1 551）. The infection rates of R. norvegicus and R. flavipectus were 13.2%（58/441） and 11.4%（74/649） respectively, both significantly higher than that of Sorex araneusï¼»1.5%（5/323）］, Mus musculusï¼»1.4%（1/74）］ and R. losseaï¼»6.3%（4/63）］ （P<0.05）. The infection rate in the costal regions was 12.4%（83/668）, significantly higher than that in the mountain regions（6.68%, 59/883）（χ2=15.083, P<0.05）. Moreover, in contrast with the significant difference in the infection rate between hilly（9.2%, 46/499） and mountainous areas（3.4%, 13/384）, there the infection rate showed no significant difference between coastal flatland（12.7%, 53/416） and coastal hilly areas（11.9%, 30/252） （χ2=2.264, P>0.05）. In addition, 696 adult worms were found in 142 infected rodents. These worms mainly located in the pulmonary artery（94.3%）, then and the heart （5.7%）. There was also no significant difference in infection rate between male（9.2%, 73/795） and female rodents（9.1%, 69/756） （P>0.05）. Conclusion: R. flavipectus and R. norvegicus are the important reservoir hosts for A. cantonensis in Zhangzhou. The infection rate in different species of rodents varies in different ecological environments.

[Data Integration and Information Sharing of Parasite Resources in Fujian Province].

Objective: To establish parasite library and database in Fujian Province by integrating information on human-animal coinfecting parasites, vectors and　intermediates, in the aim of resource sharing. Methods: According to the Standards and Technical Regulation for Preservation of Parasitic Germplasm Resources set by the Resource Sharing Platform for Parasitic and Tropical Diseases(referred to as Germplasm Resource Sharing Platform), the preserved and newly discovered parasitic germplasm resources in Fujian Center for Disease Control and Prevention were categorized, information described, preserved and displayed, and the information sharing was made through the Germplasm Resource Sharing Platform. Results: The library and database on parasites, medical vectors, and hosts were established. The library was comprised of 1 020 parasite specimens, vectors and hosts, including 100 （9.8%） adult worm specimens, 120（11.7%） eggs and larvae, and 800（78.4%） vectors and hosts. Information digitalization was achieved for 61 resources, including 9 species of nematodes, 16 species of trematodes, 7 species of tapeworms, 16 different medical mollusks, and 13 different medical arthropods, resulting in 3 150 pieces of information and 6 300 images. The database was integrated into the Germplasm Resource Sharing Platform for resource sharing. Conclusion: The library and database on parasite gemplasm resources in Fujian Province has been established. Information sharing is made available through the Germplasm Resource Sharing Platform.

Integrating Morphology, Breeding Ground and Mitochondrial COI Gene Analysis for Species Identification of Bellamya lithophaga (Gastropoda: Viviparidae) in China.

BACKGROUND: Angiostrongylus cantonensis is a zoonotic public health concern that causes human severe eosinophilic meningitis in Southeast Asia and China. As a medically important intermediate host of A. cantonensis, Bellamya lithophaga (Gastropoda: Viviparidae) is often confused with other morphologically similar sibling species of genus Bellamya, such as B. aeruginosa and B. purificata in the past. Hence, the aim of the present study was to investigate evidences to discriminate these equivocal Bellamya species. METHODS: This study was carried out by getting Bellamya snail samples from Fujian Province in the South-East of China. The snail morphological features, breeding grounds and phylogenetic relationship according to mitochondrial cytochrome c oxidase subunit I (COI) gene marker were analyzed. RESULTS: Based on external morphology, radular shape and cusp formula, as well as major breeding environment, B. lithophaga could be distinguished from B. aeruginosa, B. purificata. The phylogenetic tree also unconfirmed that B. lithophaga belongs to a different genetic clade from other morphologically similar species. CONCLUSION: Our findings demonstrate the significant differences in B. lithophaga and other sibling species, which supports the traditional species delimitation in the genus Bellamya.

[A new species of the genus Nanhaipotamon (Decapoda:Potamidae) serving as intermediate host of Paragonimus skrjabini].

OBJECTIVE: To describe a new species of the genus Nanhaipotamon. METHODS: Freshwater crabs were collected in the counties of Yongtai, Minqing, Youxi, Songxi, Zhenghe and Shouning, Fujian Province. The morphological characteristics of the crabs were described. The habitats were observed and crabs examined for the presence of Paragonimus metacerariae. RESULTS: A new species of freshwater crabs named as Nanhaipotamon fujianense sp. nov. was described: holotype (FJ6132-1): male, carapace length 18.44 mm, breadth 23.64 mm, thickness 12.61 mm; allotype (FJ6132-2): female, length 18.76 mm, breadth 25.25 mm, thicknes 14.31 mm, collected from Yongtai County in the middle of Fujian (N 25 degrees 44,778'; E118 degrees 32,278', and 232 m above sea lever). Distal segment of the first male pleopod with triangle convex inner-distal angle, and the axe-like expanded out-distal angle. The out-lateral border slightly sloped downwards. The segment length is 2.1 times as long as the subdistal segment. The crabs usually lived in the crevice of small stream. Paragonimus metacerariae were found in the crabs collected from Yongtai, Minqing, Youxi, Songxi and Zhenghe Counties. CONCLUSION: A new species of freshwater crab (Nanhaipotamon fujianense sp. nov.) has been recorded which serves as the intermediate hosts of Paragonimus skrjabini.

[Prevalent trend of the infection of soil-transmitted nematodes in Fujian Province].

OBJECTIVE: To understand the endemic situation of soil-transmitted nematodes in Fujian Province. METHODS: According to the national guidelines, the survey spots were determined by clustered random sampling in nine prefectures (cities) of Fujian Province from 2007 to 2009. Residents of 3 years old and above were investigated. The eggs of roundworm, hookworm and whipworm in feces were checked by Kato-Katz method. Eggs per gram (EPG) in feces were calculated. The gender, age and education status of the investigated subjects were recorded. The results were evaluated in comparison to those in 1992 and 2003. RESULTS: Altogether 93 833 residents in 610 villages of 184 towns from 49 counties were investigated. The overall infection rate of soil-transmitted nematodes was 10.14% (9 511/93 833), decreased by 86.88% and 71.84% compared to that in 1992 and 2003, respectively. The prevalence of roundworm, hookworm and whipworm was 1.32%(1 234/93 833), 7.31% (6 863/93 833) and 1.73% (1 622/93 833), respectively. The average EPG of roundworm, hookworm and whipworm was 9 556, 526 and 156, respectively. The prevalence in males and females was 9.48% (4 385/46 246) and 10.77% (5 126/47 587), respectively, with a statistical difference (chi2 = 42.84, P < 0.01). There was also a statistical difference among the age groups (chi2 = 1 626, P < 0.01). The higher education level of the people, the lower prevalence (chi2 = 1 107, P < 0.01). CONCLUSION: The prevalence of soil-transmitted nematodes is on a downward trend in Fujian Province, but remained high in the underdeveloped areas. The hookworm infection rate is higher than the average of the nation.

[A new species of the genus Nanhaipotamon (Decapoda: Potamidae) from China].

OBJECTIVE: To investigate the species of freshwater crabs in Fujian Province, China. METHODS: Fresh-water crabs were collected in Pingtan County of Fujian Province. The morphological characteristics of the crabs and the habitats were observed. The crab morphology was described and crabs examined for the presence of Paragonimus metacercariae. RESULTS: A new species of freshwater crabs named Nanhaipotamon pingtanense sp. nov. was obtained, holotype (FJ6133,1): male, carapace length 36.1 mm, breadth 46.8 mm, thickness 26.7 mm; allotype (FJ6133,2): female, carapace length 33.9 mm, breadth 42.7 mm, thickness 25.4 mm, collected from Pingtan County (N 26 degrees 52.958'; E 119 degrees 58.722', and 16-47 m above sea lever). Distal segment of the first male pleopod with squarish-rounded inner-distal angle, and the comparatively stout out-distal angle's end narrowed. The out-lateral border sloped downwards, concave situated in the middle. The segment length is 2.3 times as long as the subdistal segment. This species usually lived in the ditch and hid in mud hole. Paragonimus metacercariae were not found. CONCLUSION: A new species of Nanhaipotamon collected from Pingtan County of Fujian Province were described, and named as Nanhaipotamon pingtanense.

[Two new species of freshwater crabs (Decapoda: Potamidae) serving as intermediate hosts of Paragonimus in Fujian, China].

OBJECTIVE: To investigate the natural resources of the freshwater crab which can serve as the intermediate hosts of Paragonimus in Pinghe and Youxi of Fujian Province. METHODS: Freshwater crabs were collected. The morphological characteristics of the crabs and the habitats were observed. The crabs were dissected and examined for the presence of Paragonimus metacercariae. RESULTS: Two new species of crabs were described, named as Sinopotamon zhangzhouense sp. nov. and Bottapotamon youxiense sp. nov.. S. zhangzhouense sp. nov., holotype: male, carapace length 35.9 mm, breadth 42.8 mm, thickness 18.6 mm, collected from Pinghe County in southwest of Fujian. (24 degrees 14.206' N, 117 degrees 12.594' E). Distal segment of the first pleopod of male tended flattish, and showed palm nest-shaped concave, which divided into two point leafs, and longitudinal crack clearly identified in back. The end half of distal segment reversed to ventral outwardly. This species usually lived in the sluggish stream. The infection rate of Paragonimus westermani and P. cenocopiosus in S. zhangzhouense sp. nov. was 44.9% (35/78). B. youxiense sp. nov., holotype: male, carapace length 13.35 mm, breadth 16.63 mm, thickness 7.20 mm, collected from Youxi County in central Fujian (26 degrees 10.558' N, 118 degrees 22.012' E). The first pleopod of male was in slightly flat shape, ample and developed, as bow-like uplift. This species usually lived in the relatively flat terrain of stream. The infection rate of P. skrjabini metacercariae in B. youxiense sp. nov. was 92.1% (58/63). CONCLUSION: Two new species of freshwater crabs (S. zhangzhouense sp nov. and Ryouxiense sp. nov.) serving as the intermediate hosts of Paragonimus have been described.

[Survey on the foci of Paragonimus in Youxi, Yongtai and Pinghe Counties of Fujian Province].

OBJECTIVE: To investigate the natural foci of paragonimiasis in Youxi, Yongtai and Pinghe Counties of Fujian Province. METHODS: One village each from the three counties was selected according to reported paragonimiasis cases. Freshwater snails collected from fields were examined for cercariae. Freshwater crabs obtained in the fields were examined for metacercariae by washing filtration method or direct compression method. Feces of cats and dogs were collected for the detection of eggs by water precipitation. In order to identify the species of Paragonimus, 4 cats were orally fed with metacercariae. At the same time, the habitat of three survey sites was observed. RESULTS: Three fluke species, namely, P. skrjabini, P. westermani and P. cenocopiosus(Syn. Euparagonimus cenocopiosus) were found. In Banlin Village of Youxi County and Chishui Village of Yongtai County, the seropositive rate by IgG ELISA were 6.8% (21/309) and 6.8% (9/133), respectively. Four species of freshwater snails were found, two species of Tricula and one species of Pseudobythinella were newly identified first intermediate hosts of Paragonimus. Four species of freshwater carbs were found, one species of Nanhaipotamon served as a new second intermediate host of Paragonimus. In Youxi, the infection rate of P. skrjabini cercariae in snails and metacercariae in crabs was 2.1% (27/1 344) and 92.1% (58/63), respectively; the index of crab infection and the positive ratio of Paragonimus eggs in cat feces was 171.91 and 1/7, respectively. In Yongtai, the cercariae infection rate in Pseudobythinella and Tricula snails infected with P. skrjabini was 0.6% (4/690) and 0.1% (2/ 2330), respectively; the infection rate of P. skrjabini metacercariae in crabs was 18.2% (18/99); the index of crab infection was 9.12. In Pinghe, the infection rate of cercariae in Semisulcospira libertina and metacercariae in crabs was 03% (3/1092) and 44.9% (35/78), respectively; the index of crab infection was 616. CONCLUSION: Paragonimus skrjabini P. westermani and P. cenocopiosus have been found from the three counties of Fujian Province with different infection level in snails and crabs.

[A new species of the genus Nanhaipotamon (Decapoda: Potamidae) from Xiapu County, Fujian].

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. nonriense, and N. yongchunense.

[Survey on the current status of important human parasitic infections in Fujian province].

OBJECTIVE: To understand the prevalence of important human parasitic diseases in Fujian province. METHODS: According to the national guidelines, clustered random sampling was made for the survey. Modified Kato-Katz thick smear was applied to examine helminth eggs for soil-transmitted nematodes and Clonorchis sinensis. Cellophane and swab technique was applied for detecting Enterobius vermicularis eggs in children under 12. Questionnairing, skin test, serological test and eosinophil examination were carried out for Paragonimus infection. Questionnairing and serological test were used for Taenia infection and cysticercosis. Retrospective investigation was conducted with the data on outpatient and hospitalized cases with parasitic diseases. RESULTS: 45,736 people at 73 spots of 24 counties were investigated and 14 species of parasites were found. The overall infection rate of intestinal helminth infections was 36.15%. The prevalence of Ascaris lumbricoides, hookworms and Trichuris trichiura was 9.55%, 19.73% and 11.48% respectively. The infection rate of Enterobius vermicularis and Clonorchis sinensis was 22.06% and 0.60% respectively. The positive rate of skin test and serological test among skin test positives for Paragonimus infection was 7.07% and 9.23% respectively. The serology positive rate for cysticercosis was 2.28%, only 3 cases of taenia infection were found from 16371 persons investigated. Human infections with Angiostrongylus cantonensis, Diphyllobothrium latus, Taenia saginata, and Gnathostoma spinigerum were found for the first time in the Province. Metorchis orientalis and Echinostoma aegyptiaca infections in human were first recorded. CONCLUSION: The overall prevalence of soil-transmitted nematodes has decreased significantly in the province, although still highly prevalent in social-economically less developed areas. Meanwhile, attention should be paid to the food-borne parasitic infections in human population.

[Epidemiological study on group infection of Angiostrongylus cantonensis in Changle City].

OBJECTIVE: To make etiological and epidemiological investigation on the infection of Angiostrongylus cantonensis 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 hypodynamia(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.

[Morphological observation of Haplorchis pumilio].

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 x 16.7 microns with a smooth shell. Its aceromion is not evident. The average diameter of metacercariae is 168.5 microns. 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 x 95 microns, 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.