title: High susceptibility to repeated, low-dose, vaginal SHIV exposure late in the luteal phase of the menstrual cycle of pigtail macaques.
abstract: Fluctuations in susceptibility to HIV or SHIV during the menstrual cycle are currently not fully documented. To address this, the time point of infection was determined in 19 adult female pigtail macaques vaginally challenged during their undisturbed menstrual cycles with repeated, low-dose SHIV(SF162P3) exposures. Eighteen macaques (95%) first displayed viremia in the follicular phase, as compared with 1 macaque (5%) in the luteal phase (P < 0.0001). Due to a viral eclipse phase, we estimated a window of most frequent virus transmission between days 24 and 31 of the menstrual cycle, in the late luteal phase. Thus, susceptibility to vaginal SHIV infection is significantly elevated in the second half of the menstrual cycle when progesterone levels are high and when local immunity may be low. Such susceptibility windows have been postulated before but not definitively documented. Our data support the findings of higher susceptibility to HIV in women during progesterone-dominated periods including pregnancy and contraceptive use.
authors.affiliation: Division of HIV/AIDS Prevention, CDC, Atlanta, GA 30329, USA.
authors.forename: Sundaram A
authors.initials: SA
authors.lastname: Vishwanathan
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Guenthner
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Lin
authors.forename: Charles
authors.initials: C
authors.lastname: Dobard
authors.forename: Sunita
authors.initials: S
authors.lastname: Sharma
authors.forename: Debra R
authors.initials: DR
authors.lastname: Adams
authors.forename: Ron A
authors.initials: RA
authors.lastname: Otten
authors.forename: Walid
authors.initials: W
authors.lastname: Heneine
authors.forename: R Michael
authors.initials: RM
authors.lastname: Hendry
authors.forename: Janet M
authors.initials: JM
authors.lastname: McNicholl
authors.forename: Ellen N
authors.initials: EN
authors.lastname: Kersh
mesh_terms: D000818:Animals; D004198:Disease Susceptibility; D005260:Female; D015497:HIV-1; D008183:Luteal Phase / Q000502:physiology*; D008254:Macaca nemestrina; D011247:Pregnancy; D016097:Simian Acquired Immunodeficiency Syndrome / Q000635:transmission*; D015302:Simian Immunodeficiency Virus; D014621:Vagina / Q000821:virology*; D019562:Viral Load; D014766:Viremia