No. 223, Nkolbisson (NKO)

Strain: YM 31–65

Information from: J. J. Salaün, Institut Pasteur, P.O. Box 888, Yaoundé, Cameroun, 9 March 1968.

Antigenic group: Ungrouped.

Original source: Isolated by J. J. Salaün, H. Brottes, and A. Rickenbach, at Institut Pasteur, Yaoundé, Cameroun from adult (imago) female Eretmapodites leucopus collected from 28 December 1964 to 19 April 1965 by using human bait and netting at Nkolbisson, 8 kilometers from Yaoundé, Lat. 4° N, Long. 11° 30′ E. Habitat: Plateau 600 meters above sea level, tropical-rain, semi-deciduous forest. Storage: Specimens stored in -65° Revco until inoculated into mice.

Method of isolation in laboratory: Ground suspension in 0.75% bovalbumin solution. Inoculated 0.02 ml ic and 0.03 ml ip in 1-day-old suckling mice on 20 April 1965.

Validity of isolation: Virus not reisolated, but first isolation of the strain at Yaoundé.

Properties of virus: Physical: Filterable through Millipore 220 nm. Chemical: No data. Resistance to chemicals: Sensitive to 1:2 ether; control titer 107.6, after-treatment titer 104.4.