Detection of Toxolasma gondii in captive wild felids.

Toxoplasma gondii can infect all species of warm-blooded animals, including humans, and causes serious diseases in immunocompromized hosts. Live tachyzoites derived from serial passage in HeLa culture were used in the Sabin-Feldman dye test for detection of Toxoplasma gondii antibody in serum samples of 21 captive wild felids including one fishing cat (Prion nailurus viverrina), one leopard (Panthera pardus), two flat-headed cats (Prion nailurus planiceps), 6 tigers (Panthera tigris), two leopard cats (Felis bengalensis), two clouded leopards (Felis nebulosa), 3 pumas (Puma concolor), and 4 jungle cats (Felis chaus). Antibodies to Toxoplasma gondii were founded in 9 of 21 felids (42.8%). This study revealed that cell culture-derived tachyzoites can be used successfully as a source of live organisms in a gold standard Sabin-Feldman dye test, which is simpler, cheaper and less ethically sensitive than in vivo inoculation.

The effect of temperature and UV light on infectivity of avian influenza virus (H5N1, Thai field strain) in chicken fecal manure.

Normal chicken fecal manure (pH 8.23 and 13.7% moisture) was investigated for infectivity of the avian influenza virus (AIV; H5N1). The manure was divided into three groups; each group was inoculated with AIV at 2.38 x 10(5.25) ELD50. After viral inoculation, the first group was incubated at 25 degrees C. The second group was kept at 40 degrees C, and the last group was exposed to ultraviolet light at 4-5 microw/cm2 at room temperature. After incubation, a 20% suspension of manure was filtered and the filtrates were inoculated into 9-11 day-old embryonated chicken eggs per WHO protocol (2002). The results showed that at 25 degrees C the virus lost its infectivity within 24 hours, and at 40 degrees C within 15 minutes. UV light, however, could not destroy the infectivity of the virus even after exposure for 4 hours.