Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 14, Number 12—December 2008
Letter

Enzootic Angiostrongyliasis in Shenzhen, China

On This Page
Article Metrics
24
citations of this article
EID Journal Metrics on Scopus

Cite This Article

To the Editor: Angiostrongylus cantonensis is a zoonotic parasite that causes eosinophilic meningitis in humans after they ingest infective larvae in freshwater and terrestrial snails and slugs, paratenic hosts (such as freshwater fish, shrimps, frogs, and crabs), or contaminated vegetables. With the increase of income and living standards, and the pursuit of exotic and delicate foods, populations around the world have seen angiostrongyliasis become an important foodborne parasitic zoonosis (19).

Shenzhen municipality is situated in the most southern part of mainland People’s Republic of China between the northern latitudes of 22°27′ to 22°52′ and eastern longitudes of 113°46′ to 114°37′; it shares a border with the Hong Kong Special Administrative Region, China, in the south. The climate is subtropical, with an average annual temperature of 23.7°C. The city is 1,952.84 km2 and has a population of 10 million.

Since 2006, thirty-two sporadic cases of human eosinophilic meningitis caused by consumption of undercooked aquacultured snails have been documented in Shenzhen (Shenzhen Center for Disease Control and Prevention, unpub. data). To identify the source of these infections and assess the risk for an outbreak of eosinophilic meningitis, we conducted a survey to investigate whether A. cantonensis occurs in wild rats and snails in Shenzhen.

To examine A. cantonensis infection in intermediate host snails, 302 terrestrial snails (Achatina fulica) were collected from 10 investigation sites across Shenzhen, and 314 freshwater snails (Pomacea canaliculata)were sampled from 6 investigation sites. We examined the snails for A. cantonensis larvae by using pepsin digestion standardized procedures (3). To survey the prevalence of adult A. cantonensis in definitive host rats, we collected 187 Rattus norvegicus rats and 121 R. flavipectus rats collected from 4 sites where positive snails positive for A. cantonensis were found. These rats were examined for the presence of adult A. cantonensis in their cardiopulmonary systems.

A. cantonensis larvae were found in 96 (15.6%) of 616 examined snails. Of these, P. canaliculata had an average infection rate of 20.7% (65/314), significantly higher (p<0.01) than that of A. fulica (10.3%, 31/302), an indication that P. canaliculata may be the principal intermediate host for A. cantonensis in Shenzhen. A. cantonensis adults were recovered from the cardiopulmonary systems of 37 (12%) of 308 examined rats. Infection rate for R. norvegicus rats was 16.6% (31/187), significantly higher (p<0.01) than that for R. flavipectus (4.9%, 6/121), an indication that R. norvegicus may be the principal definitive host for A. cantonensis in Shenzhen, possibly due to the rat’s preference for eating snails. Infection rates were higher for female rats (25.6% for R. norvegicus and 7.8% for R. flavipectus) than for male rats (8.9% for R. norvegicus, 2.9% for R. flavipectus), possibly because female rats eat more snails to supply proteins for reproduction. This report of enzootic A. cantonensis infection in wild rats and snails in Shenzhen demonstrates the existence of natural origins of infection with A. cantonensis for humans in this city.

Persons in Shenzhen eat raw or undercooked freshwater and terrestrial snails and slugs. This practice provides opportunities for infection with A. cantonensis, particularly given that P. canaliculata has been aquacultured intensively for human consumption. The prevalence of A. cantonensis in wild rats and snails in Shenzhen poses substantial risk for future outbreaks of human eosinophilic meningitis. Moreover, public health officials, epidemiologists, researchers, clinical technicians, medical practitioners, parasitologists, and veterinarians, as well as the general public, should be aware of such risks, and integrated strategies should be taken to reduce or eliminate such risks.

Top

Acknowledgments

We thank Alasdair Nisbet for his assistance in improving the manuscript.

Project support was provided in part by a grant from Shenzhen Municipal Bureau of Science and Technology (grant no. 2007079) to R.-L.Z. and a grant from the Program for Changjiang Scholars and Innovative Research Team in University (grant no. IRT0723) to X.-Q.Z.

Top

Ren-Li Zhang, Mu-Xin Chen, Shi-Tong Gao, Yi-Jie Geng, Da-Na Huang, Jian-Ping Liu, Yuan-Liang Wu, and Xing-Quan ZhuComments to Author 
Author affiliations: Shenzhen Center for Disease Control and Prevention, Shenzhen, People’s Republic of China (R.-L. Zhang, M.-X. Chen, S.-T. Gao, Y.-J. Geng, D.-N. Huang, J.-P. Liu, Y.-L. Wu); South China Agricultural University, Guangzhou, People’s Republic of China (M.-X. Chen, X.-Q. Zhu)

Top

References

  1. Alicata  JE. The discovery of Angiostrongylus cantonensis as a cause of human eosinophilic meningitis. Parasitol Today. 1991;7:1513. DOIPubMedGoogle Scholar
  2. Hochberg  NS, Park  SY, Blackburn  BG, Sejvar  JJ, Gaynor  K, Chung  H, Distribution of eosinophilic meningitis cases attributable to Angiostrongylus cantonensis, Hawaii. Emerg Infect Dis. 2007;13:167580.PubMedGoogle Scholar
  3. Lindo  JF, Waugh  C, Hall  J, Cunningham-Myrie  C, Ashley  D, Eberhard  ML, Enzootic Angiostrongylus cantonensis in rats and snails after an outbreak of human eosinophilic meningitis, Jamaica. Emerg Infect Dis. 2002;8:3246.PubMedGoogle Scholar
  4. Slom  TJ, Cortese  MM, Gerber  SL, Jonse  RC, Holtz  TH, Lopez  AS, An outbreak of eosinophilic meningitis caused by Angiostrongylus cantonensis in travelers returning from the Caribbean. N Engl J Med. 2002;346:66875. DOIPubMedGoogle Scholar
  5. Leone  S, De Marco  M, Ghirga  P, Nicastri  E, Esposito  M, Narciso  P. Eosinophilic meningitis in a returned traveler from Santo Domingo: case report and review. J Travel Med. 2007;14:40710. DOIPubMedGoogle Scholar
  6. Tsai  HC, Liu  YC, Kunin  CM, Lai  PH, Lee  SS, Chen  YS, Eosinophilic meningitis caused by Angiostrongylus cantonensis associated with eating raw snails: correlation of brain magnetic resonance imaging scans with clinical findings. Am J Trop Med Hyg. 2003;68:2815.PubMedGoogle Scholar
  7. Waugh  CA, Shafir  S, Wise  M, Robinson  RD, Eberhard  ML, Lindo  JF. Human Angiostrongylus cantonensis, Jamaica. Emerg Infect Dis. 2005;11:19778.PubMedGoogle Scholar
  8. Lv  S, Zhang  Y, Steinmann  P, Zhou  XN. Emerging angiostrongyliasis in Mainland China. Emerg Infect Dis. 2008;14:1614. DOIPubMedGoogle Scholar
  9. Zhou  P, Chen  N, Zhang  RL, Lin  RQ, Zhu  XQ. Food-borne parasitic zoonoses in China: perspective for control. Trends Parasitol. 2008;24:1906. DOIPubMedGoogle Scholar

Top

Cite This Article

DOI: 10.3201/eid1412.080695

Related Links

Top

Table of Contents – Volume 14, Number 12—December 2008

EID Search Options
presentation_01 Advanced Article Search – Search articles by author and/or keyword.
presentation_01 Articles by Country Search – Search articles by the topic country.
presentation_01 Article Type Search – Search articles by article type and issue.

Top

Comments

Please use the form below to submit correspondence to the authors or contact them at the following address:

Xing-Quan Zhu, Laboratory of Parasitology, College of Veterinary Medicine, South China Agricultural University, 483 Wushan St, Tianhe District, Guangzhou, Guangdong Province 510642, People’s Republic of China

Send To

10000 character(s) remaining.

Top

Page created: July 22, 2010
Page updated: July 22, 2010
Page reviewed: July 22, 2010
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
file_external