Frequent perinatal transmission of feline immunodeficiency virus by chronically infected cats

Abstract

Vertical transmission of feline immunodeficiency virus (FIV) was studied in cats infected with either of two FIV clinical isolates (FIV-B-2542 or FIV-AB-2771) prior to breeding and conception. Queens infected 4 to 30 months (mean ‫؍‬ 14 months) prior to conception transmitted FIV to 59 of 83 (71%) kittens; 50.6% were virus positive on the day of birth. To examine potential routes of FIV transmission from mother to offspring, kittens were delivered via either vaginal or cesarean birth and nursed by either their virus-infected natural mothers or uninfected surrogate mothers. Comparison of FIV infection rates at birth with those at 6 months of age in kittens delivered by cesarean and surrogate raised demonstrated that late in utero transmission occurred in approximately 20% of kittens. Comparison of kittens nursed by FIV ؉ mothers with those by uninfected surrogate mothers demonstrated a 13.5% increase in infection rate of kittens exposed to milk-borne virus. Isolation of virus from 40% of maternal vaginal wash samples and the slightly greater infection rate in vaginally versus cesarean-delivered surrogate-nursed kittens suggested that intrapartum transmission may occur. In addition, we found that low maternal CD4 count (<200 cells per l), longer duration of maternal infection (>15 months), and maternal symptoms of clinical immunodeficiency correlated with increased rates of mother-to-kitten FIV transmission, paralleling observations in human immunodeficiency virus-infected women. We conclude that FIV infection provides a model in which to explore aspects of human immunodeficiency virus vertical transmission and intervention difficult to address in human patients.

Feline Immunodeficiency: ABCD Guidelines on Prevention and Management

“…If the seropositive queen is healthy, few kittens will be infected. 14,15 Although neither oronasal nor venereal spread has been documented in nature, cats can be infected experimentally by virus inoculation into the nose, mouth, vagina and rectum, and virus can be recovered from semen after natural and experimental infection. 16,17 Queens may be infected at mating if bitten by an infected tom cat.…”

Viral Reproductive Pathogens of Dogs and Cats

“…56,60 Although data concerning fetal viability differ, an increased number of nonviable kittens, either due to arrested development or fetal resorption, has been reported in experimentally infected queens compared with uninfected queens. 61,62 The average birth weights and postnatal weight gains of FIV-infected kittens were generally lower than those of kittens born to uninfected queens, even in the absence of vertical transmission. 61 A different FIV distribution in fetal tissues has been detected according to the viral strain.…”

“…61,62 The average birth weights and postnatal weight gains of FIV-infected kittens were generally lower than those of kittens born to uninfected queens, even in the absence of vertical transmission. 61 A different FIV distribution in fetal tissues has been detected according to the viral strain. 56,60 Diagnostic tests for FIV are based on the detection of antibodies against the structural proteins (capsid protein p24 or transmembrane peptides) by in-house ELISA or immunochromatographic tests.…”

Important mammalian veterinary viral immunodiseases and their control

“…Free ranging male cats that co-habit and interact aggressively with others are most commonly infected and form a source of FIV. Sexual contact does not appear to be a significant mode of virus transmission although the virus may be shed in semen; transmission via colostrum and milk can occur as well and also importantly FIV can be vertically transmitted in chronically infected cats [74]. FIV infection in cats has three stages, just like HIV infection in humans [75].…”