What is the only effective control for viral hemorrhagic septicemia?

• A. Quarantine
• B. Culling
• C. Vaccination
• D. Limit spread

Answer: (D)

The key idea is that control of a viral disease hinges on preventing transmission, because there is no cure that reliably eliminates the virus once infection has occurred. For viral hemorrhagic septicemia, the most reliable way to protect uninfected fish populations is to prevent the virus from spreading. This means strict biosecurity measures: isolating and quarantining new and potentially exposed stock, restricting movements of fish and equipment between facilities, thorough disinfection of gear and water systems, regular testing to detect infections early, and rapid depopulation or segregation of infected or exposed fish to stop further transmission.

Vaccination may be used in some settings, but it isn’t universally protective against all VHSV strains and can’t replace the need to prevent spread. Because the virus can circulate in water and persist in the environment or in carriers, limiting spread remains the most dependable overarching control strategy.