• blood of patients is infective for mosquitoes 3 to 5 days after onset of illness

TREATMENT

• supportive only

PREVENTION AND CONTROL

• a live viral vaccine prepared from chick embryos is safe and highly effective (more than 95 percent of those vaccinated will have immune response within 7 to 10 days; immunity lasts at least 10 years)

• mosquito control

FACTORS FACILITATING EMERGENCE

• lack of effective mosquito control

• lack of widespread vaccination

• urbanization in the tropics

• increased air travel

DISEASE(S) AND SYMPTOMS

• severe epigastric pain, nausea, vomiting, fever

• obstruction, ulceration, and bleeding in the gastrointestinal tract are possible

DIAGNOSIS

• recognition of the 2 to 3 cm. larva invading the oropharynx

• visualization of larvae through gastroscopic examination

INFECTIOUS AGENT

• larval nematodes of the Anisakidae family, common parasites of marine mammals and fish

MODE OF TRANSMISSION

• ingestion of larvae in raw or undercooked fish, squid, or octopus (larvae are colorless, tightly coiled, and not easily seen in fish flesh)

• not transmitted directly from person to person