In 1972, asevere outbi kofrespiratorydiseasewas observer! inafarn with 8(0 ducks at Tansui, Tairti county Taiwan. Severe rrespiratory signs were not! in ducks of 2-4-week-ok), and OX) of them were dead of the disease.
A hemagglutinating RNA vinis was isolat! by means of ernbryonat! duck eggs (DE) and duck kndney cell cultures (DK) inoculation, The isolate had a titer of 1O”ZO- 1(flS EII)5(nI in DE and 1(Yi.6 PFU/rnl in DK, and could cause CPE in both DK and chicken kidney cell cultures (CK), The isolate could also cause agglutination of EC of cattk pig, goat, she rabbit, guinea pig, rat, mouse, chicken, duck and goose. Growth cwve of the isolate was studier! in DKcultures. In liquid phase. vinis could Ire Summary deat!at4 hours pcGtincculation (P1) a dreachedjeak level (1(Y’6.l PFUkn1) at48hours P1, while in cellular phase, firstly detect! atE hours P1 and realt! 11 hours P1 with a titer of 1(Y’4.6 PFUhU1.
The physico-chemicral studies indicat! that the isolate was heat labile and sensitive to ether, sodium deoxycholate, solution of pH 3,0 and pH 9.0, but resistant to typsin treatment. Thesiofthevirus was ll0nmas measuxerlbyelctronrnicroscope.
Hemagglutinin and neuraminidase determinations confirmed that the isolate consist! of HavE and Ni antigens, which were similar to the strains A2uckft3ermany/i 868i68 isolated in Germany and AM.uckiPennsylvaniaM 86,69 isolat! in the Unit! Status.