Ab. Rogers et Ea. Hoover, MATERNAL-FETAL FELINE IMMUNODEFICIENCY VIRUS TRANSMISSION - TIMING AND TISSUE TROPISMS, The Journal of infectious diseases, 178(4), 1998, pp. 960-967
The feline immunodeficiency virus (FIV) model of vertical human immuno
deficiency virus type 1 transmission was used to explore the timing an
d tissue tropisms associated with intrauterine lentivirus infection. C
ats chronically infected with FIV-B-2542 and their cesarean-derived fe
tuses and placentas were assayed by polymerase chain reaction and cocu
lture at defined gestational intervals. Prevalence of fetal FIV infect
ion was 0 at 3 weeks, 5% at 5 weeks, 38% at 7 weeks, and 60% at 9 week
s (term). Fetal tissues exhibiting the highest viral tropism were bloo
d mononuclear cells and brain (each containing virus in 60% of FIV-pos
itive fetuses) and thymus (47%). Maternal hematologic and virus load m
arkers did not vary substantially with gestational stage. Therefore, f
etal and/or placental maturation may determine the timing of lentiviru
s transmission. FIV infection prevalence in term fetuses was equivalen
t to that seen previously in vaginally delivered offspring, suggesting
that most vertical FIV transmission occurs late in utero rather than
intrapartum.