Here are two links recently describe anisakiasis due to the consumption of raw fish, particularly salmon sashimi: http://www.cfs.gov.hk/tc_chi/multimedia/multimedia_pub/multimedia_pub_fsf_123_01.html  and http://skypost.ulifestyle.com.hk/article/1807725/魚生附寄生蟲%20日本病例10年增20倍. This disease is due to the ingestion of the larvae of a worm called Anisakis simplex.  

Anisakis is a type of Nematodes, common example includes roundworm, pinworm and whipworm which affect human causing abdominal discomfort, diarrhoeae or malnutrition. However, Anisakis larvae are not living in human gut like the mentioned examples. They rather live in the intestine of marine mammal (like whales) or birds. Once the larvae developed into adults, they produce eggs which are then shed into the sea water. Crustaceans like shrimps will eat the larvae and the shrimps containing the larvae are consumed by fish or squid. Marine mammals consuming these fish or squid may get infected and larvae develop into adult worm in their intestine to repeat the life cycle. When human ingest these fishes or squid the larvae can then invade the esophagus, stomach or intestine of the human leading to inflammation and other symptoms like vomiting, abdominal pain or diarrhoea. Larvae are not growing inside human and they will eventually die. However, surgical removal of these larvae is required for complete treatment. 

To prevent anisakiasis, cook seafood adequately would be the best option (internal meat temperature reaches 63 degree celsius). If seafood are to be served as sashimi, they should be pre processed to have the possible larvae killed by frozen at -20 degree celsius for 7 days or -35 degree celsius for 15 hours. Seafood product should also be purchased from reputable vendors who can provide hygiene certificate of their products and can indicate the seafood are raised in the aquatic farm free from Anisakis worm. Nevertheless, bacteria can still survive under low temperature and therefore risk of bacterial food poisoning and the spread of multidrug resistance bacteria through raw seafood product still exists.