SURVEILLANCE IN 2013 OF AVIAN INFLUENZA VIRUS FROM LIVE-BIRD MARKETS IN BANGKOK, THAILAND.

Live-bird markets have been implicated in transmission of avian influenza viruses, most recently of influenza A (H7N9) in China. Low pathogenic avian influenza (LPAI) viruses, such as H7N9, cause asymptomatic infections in poultry, and active surveillance is required to detect infection and to prevent transmission to humans. Although limited numbers of live birds for consumption are sold in Bangkok live bird markets (LBM), transmission of H7N9 in nearby China has prompted a program of active surveillance for avian influenza in Bangkok LBM to determine LPAI viruses. In November 2013, Bangkok One Health team organized avian influenza surveillance in all nine districts of Bangkok with LBMs. Oropharyngeal swabs (n = 834), sera (n = 375) and fresh feces (n = 420) were taken from 400 chickens, 20 ducks, 20 geese and 394 pet birds from 75/87 shops. Additionally, drinking water (n = 208) and waste water (n = 26) were collected. Samples were tested for influenza A viruses using RT-PCR. In addition, samples were inoculated in eggs and tested by hemagglutination (HA) and hemagglutination inhibition (HI) assays using H5N1- and H7N9-specific antigens. Sera were tested by HI assay using similar antigens. No sample was found positive for influenza A virus. These data provide evidence that avian influenza viruses, including LPAI viruses such as H7N9, were not circulating in Bangkok LBMs during the period surveyed.

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.

Cultivation of Giardia duodenalis in Mongolian gerbils.

The Mongolian gerbil (Meriones unguiculatus) is susceptible to infection with Giardia duodenalis trophozoites. Each animal was orally infected with 0.5 ml Diamond's TYIS-33 culture medium containing 10(6) trophozoites. Cysts were then collected and concentrated by sucrose gradient centrifugation. G. duodenalis cysts were first observed in feces on day 5 post-infection. The characteristic of G. duodenalis infection in gerbils was intermittent cyst release. The range in the number of cysts released per gerbil for a 4-hour collection period was 0-1.5 x 10(3).

In vivo culture of Cryptosporidium oocysts for laboratory use.

In the present study, we describe in vivo cultivation to produce oocysts. Seven-day-old mice were orally infected with 100,000-120,000 Cryptosporidium oocysts. On day 8 post-infection, the mice were killed by ether, and the small and large intestines collected. A simple extraction procedure was used and purified using Ficoll gradient centrifugation. After purification, the oocysts were preserved in phosphate buffered saline with antibiotic at 4 degrees C before use.