CHINESE JOURNAL OF PARASITOLOGY AND PARASITIC DISEASES ›› 2017, Vol. 35 ›› Issue (3): 239-245.

• Original Articles • Previous Articles     Next Articles

Investigation of Pomacea canaliculata and rodent densities and their infection status with Angiostrongylus cantonensis in Nan′ao Island of Guangdong Province

HU Qiu-an, ZHANG Yi*(), GUO Yun-hai, LV Shan, XIA Shang, LIU He-xiang   

  1. National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention
    WHO Collaborating Centre for Tropical Diseases
    National Center for International Research on Tropical Diseases, Ministry of Science and Technology
    Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China
  • Received:2017-02-13 Online:2017-03-30 Published:2017-09-07
  • Contact: ZHANG Yi E-mail:zhang1972003@163.com

Abstract: Objective To investigate the densities of Pomacea canaliculata and rodents, as well as their infection status with Angiostronglyus cantonensis in Nanao Island of Guangdong Province, China. Methods Stratified random sampling was made in three villages(Gongqian village, Jinshan village and Liudu village) in Nanao Island from December 2015 to September 2016. P. canaliculata and rodents were collected and the sampling sites were mapped by GPS. For P. canaliculata, morphological observation was performed, followed by DNA extraction and PCR to double-check the species. Infection in P. canaliculata was examined by lung-microscopy, tissue homogenate and enzyme digestion. For rodents, morphological observation was first performed to identify species and sex, and the species was further confirmed by PCR on DNA from the liver tissue. The heart and lung were dissected to inspect A. cantonensis infection. Morphological examination and PCR were performed to determine the species of the collected samples of parasite. Data were analyzed by using SAS9.3 software. Results Totally 2 192 P. canaliculata were collected and 1 190 were selected for examination. Of them 72(6.1%) were positive for infection. 110 rodents were captured, consisting of the species of Rattus norvegicus, R. flavipectus, R. losea and Suncus murinus. Of them 32(29.1%) were positive for infection, consisting of 31 R. norvegicus and one R. flavipectus. The other two species showed negative results. As expected, the length of COⅠ amplification products was 670 bp and 706 bp, respectively, for P. canaliculata and rodents, while the length of ITS2 for A. cantonensis was 693 bp. There was a significant difference in density(H = 11.603 5, P < 0.01) and infection rate(χ2 = 65.144 1, P < 0.01) in P. canaliculata among different seasons. There was also a significant seasonal difference in the density of rats(H = 19.268 2, P < 0.01). P. canaliculata from rivers had the highest density (8.8/m2), while those from irrigation canals and ditches showed the highest infection rate(7.5%). There was no significant difference in the density of P. canaliculata inhabiting in different breeding environments (H = 3.909 3, P > 0.05). The infection rates for P. canaliculata and rodents were both closely related to the distance from breeding grounds to residential areas, the closer the distance, the higher the infection rate. Rats with heavier weight had higher infection rate(χ2 = 17.530 4, P < 0.01). Conclusion P. canaliculata as the intermediate host and rats as the definitive host of A. cantonensis are widely distributed in Nanao Island and harbor different degrees of infection.

Key words: Angiostronglyus cantonensis, Pomacea canaliculata, Rat, Density, Infection status, Nanao Island

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