Volume 11, Number 10—October 2005
Emerging Foodborne Trematodiasis
|Foodborne trematodes||Species||Geographic distribution||Second intermediate hosts; habitats||Population at risk (× 106)|
|Liver flukes||Clonorchis sinensis||China (except for Inner Mongolia, Ningxia, Qinghai, Tibet, Xinjiang), Republic of Korea, Taiwan, Vietnam*||>100 species of freshwater fish; freshwater habitats with stagnant or slow-moving waters (ponds, river, aquaculture, swamps, rice fields)||601.0†|
|Opisthorchis felineus||Kazakhstan, Russian Federation, Siberia, Ukraine‡||>35 species of freshwater fish; freshwater habitats with stagnant or slow-moving waters (ponds, river, aquaculture, swamps, rice fields)||12.5§|
|Opisthorchis viverrini||Cambodia, Lao People's Democratic Republic, Thailand, Vietnam‡||67.3¶|
|Fasciola hepatica, Fasciola gigantica||Altiplano of Bolivia, Cuba, highlands of Ecuador and Peru, Nile delta of Egypt, northern Islamic Republic of Iran, Portugal, Spain‡||Watercress and other water plants (drinking water); irrigation channels, pastures, banks of rivers, ponds, pools||91.1#|
|Lung flukes||Paragonimus spp.||Southwestern Cameroon, China, Ecuador, eastern Nigeria, Peru, the Philippines, Republic of Korea**||>50 species of freshwater crab and crayfish; freshwater habitats with stagnant or slow-moving water (ponds, aquaculture)||292.8††|
|Intestinal flukes||Fasciolopsis buski||Bangladesh, China, India, Indonesia, Malaysia, Taiwan, Thailand‡‡||Water caltrop, water chestnut, water hyacinth, water bamboo, duckweed, water mimosa, water spinach; drainage systems of pig farms, freshwater habitats with stagnant or slow-moving waters||Not known|
|Echinostoma spp.||China, Indonesia, Malaysia, the Philippines, Republic of Korea, Taiwan, Thailand‡‡||Molluscs, fish, snails and tadpoles; freshwater or brackish habitats with stagnant or slow-moving waters||Not known|
|Heterophyes heterophyes||China, Egypt (Nile delta), India, Indonesia, Islamic Republic of Iran, Philippines, Sudan, Taiwan, Tunisia, Turkey‡‡||Brackish water fish (mullets, perches, gobies); brackish water habitats||Not known|
|Metagonimus yokogawai||The Balkans, China, Indonesia, Islamic Republic of Iran, Israel, Japan, Republic of Korea, Spain, Taiwan‡‡||Freshwater (Cyprinid) fish; freshwater habitats||Not known|
*References 1 and 18.
†Obtained by adding population at risk in China (including Taiwan) (1), Vietnam (10 million; JY Chai, pers. comm.), and Republic of Korea (44% of 2005 population (17,19).
§Obtained by adding 8% of 2005 population in Russian Federation, 1.3% in Kazakhstan, and 2% in Ukraine (17,19).
¶Obtained by adding 2005 population in the Lao People's Democratic Republic, population at risk in Vietnam (10 million; J.Y. Chai, pers. comm.), and 80% of 2005 population in Thailand (17,19).
#Obtained by adding 23% of 2005 population in Bolivia, 20.6% in Ecuador, 35.3% in Peru, 24.3% in Spain, 44.2% in Portugal, 50.7% in Egypt, 10.8% in the Islamic Republic of Iran, and total 2005 population in Cuba (17,19).
**References 4, 17, and 18.
††Obtained by adding 15.9% of 2005 population in China, 18.9% in Ecuador, 1.4% in Peru, and 14% in Republic of Korea (17,19). Population at risk in Cameroon estimated at 2.7 million (population of the South and Central province, known foci for paragonimiasis (20), estimated at 1.5 million in 1982 [http://www.absoluteastronomy.com/encyclopedia/C/Ce/Centre_Province,_Cameroon.htm]), which we standardized to 2005 (19). No estimate was provided for population at risk in eastern Nigeria.