A comparative study by complement-fixation of 17 virus strains, the isolation of which is described in an accompanying paper, has shown that they fall into three distinct serotypes designated as Quaranfil, Chenuda, and Nyamanini.
There was no antigenic crossing between the three selected prototypes of the three serotypes, but a low-grade, one-way crossing was observed between two of the strains classified as Nyamanini and one or both of the prototypes of Quaranfil and Chenuda. If this crossing can be verified among purified strains of the different serotypes, it would justify the creation of a group or complex under the name of Quaranfil, representing the initial isolate.
Among the several tissue culture systems tried, primary duck kidney monolayer cultures were found best for growth with the production of CPE and/or plaques of the three serotypes.
All of the three serotypes are sensitive to sodium deoxycholate and ether.
Present address: School of Public Health, Earl Warren Hall, University of California, Berkeley, California 94720.
Present address: Yale University, School of Medicine, Department of Epidemiology and Public Health, New Haven, Connecticut.