Prospective study of maternal and infantile infection with Chlamydia trachomatis.

We examined the prevalence of chlamydial infection in a population of pregnant women and observed their infants to determine the risk of development of ocular or respiratory infection. We examined endocervical and serum specimens from 322 pregnant women for Chlamydia trachomatis and chlamydial antibody. The cultures were obtained at the first prenatal visit. Six (2%) of the women were infected with C trachomatis. Chlamydial antibody was present in the genital secretions of 47% and 73% of the serum samples. The six infants born to infected women, 61 infants born to women who were culture-negative, but local antibody-positive, and 28 control infants born to culture-negative, antibody-negative women were followed for up to six months. Four of six infants born to infected women developed chlamydial infection: two developed culture-positive conjunctivitis, one had asymptomatic nasopharyngeal infection, and one infant developed pneumonitis. Three of 61 infants born to mothers who were culture-negative and local antibody-positive developed conjunctivitis due to C trachomatis. None of the 28 control infants developed chlamydial infection. Most (79%) of the infants had chamydial antibody in their serum at 2 to 4 weeks of age. The correlation between maternal and infant serum antibody titer was r=0.71 suggesting that antibody was placentally transferred.

Chlamydia trachomatis in women: antibody in cervical secretions as a possible indicator of genital infection.

One hundred eighty-five women college students were examined for genital infection with Chlamydia trachomatis. This organism was isolated from nine (5%) of the 185 women. Antibody was demonstrated in the genital secretions of 26 (14%) and in the serum of 70 (38%) of the women. None of the sexually inexperienced women was infected. Among those sexually experienced, the prevalence of isolation of C. trachomatis and of detection of local antibodies in cervical secretions and serum antibodies to C. trachomatis increased in relation to the number of life-time sexual partners. Local antibody appeared to be a more reliable indicator of infection with C. trachomatis than serum antibody in this college population.

Immunity to vaginal reinfection in female guinea pigs infected sexually with Chlamydia of guinea pig inclusion conjunctivitis.

Guinea pig boars were inoculated intraurethrally with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). At the heights of their urethral infections, they were caged with sows in estrus. Whereas some of the sows had not been previously exposed to GPIC agent, others had received an intravaginal inoculation 5 to 8 weeks earlier. Those sows for which infected boars provided the first exposure were challenged by intravaginal inoculation 5 to 8 weeks later. Vaginal and conjunctival scrapings were taken regularly and stained for chlamydial inclusions. Titers of serum anti-GPIC antibodies and of vaginal secretory IgA anti-GPIC antibodies were determined by immunofluorescence. Our results show for the first time that a sexually acquired vaginal GPIC infection induces immunity to manual reinfection of the vagina. Because of the high incidence of secondary conjunctival infections among the vaginally infected sows, we could not provide a sound statistical basis for our tentative conclusion that manual infection of the vagina induces immunity to sexual reinfection. The results of our antibody titrations confirm previous work showing that vaginal GPIC infection induces formation of both serum antibody and vaginal secretory immunoglobulin A antibody.