Persistence of <it>Trichinella spiralis </it>in Rat Carcasses Experimentally Mixed in Different Feed

• Main Authors: Saloniemi H, Karhula H, Haltia L, Mikkonen T, Oivanen L, Sukura A
• Format: Article
• Language: English
• Published: BMC 2002-12-01
• Series: Acta Veterinaria Scandinavica
• Subjects: Trichinellosis; domestic cycle; exposure assessment; feed hazard; animal hygiene; zoonosis; disease control; rat; feed contamination; carrion
• Online Access: http://www.actavetscand.com/content/43/4/203

<p/> <p><it>Trichinella spiralis </it>infected rat carcasses were incubated for 6 weeks in several animal feeds to assess how long <it>Trichinella </it>can present a risk for an outbreak in contaminated feeds. In groups of 6, 24 infected target rats were placed in silage, grained barley, propionic acid-preserved feed, and also into simulated pasture conditions. Test environments were sampled after one-, 2-, 4-, and 6-week-incubations. <it>Trichinella </it>larvae were recovered by digestion, and their infectivity was evaluated in rats. A two-week incubation reduced the number of recovered larvae, but still after 6 weeks low numbers were isolated from all feeds except from the experimental group simulating pasture conditions. After 2 weeks storage, the larvae were infective in all storage environments. However, up to 4 weeks, they survived only in the propionic acid-fermented feed and there in small numbers with reduced reproductive capability. This indicates the possibility of farm animals to get infection from rats or other infected material being hazardously mixed with hay or other feed. If silage is stored for at least one month before use, however, the risk from this forage appears to be minimized.</p>