No deaths occurred
during the pretransmission
experiments, but in addition to the one death that occurred early in the
infection prior to the occurrence of any weight loss or anemia (excluded from analyses), five occurred in the posttransmission
experiment, four of these in naïve mice (two in the N - lines, one in the I - lines, and one in the nontransmitted ancestral line, all derived from the preadapted line) and one in an immunized mouse (preadapted, nontransmitted ancestral line).