On 2017 Sep 21, Margaret Hammerschlag commented:

The data reviewed here is not really new. The CDC's recommendations for screening and treating pregnant women in 1993 have resulted in a dramatic drop in perinatal chlamydia infection. We have seen only one case of chlamydial ophthalmia at my institution over the past 20 years and no cases of chlamydial pneumonia. We used to see 30-40 cases/year before screening. We have confirmed this by seroepidemiologc studies, one recently published online in Sex Transm Dis (Banniettis N, Thumu S, Weedon J, Szigeti A, Chotikanatis K, Hammerschlag MR, Kohlhoff SA. Seroprevalence of Chlamydia trachomatis in inner-city children and adolescents – implications for vaccine development. Sex Transm Dis, in press, 2017.). This is also confirmed by the observation that chlamydial ophthalmia is still very common in countries, like the Netherlands, that do not screen and treat pregnant women (Rours GIJG, Hammerschlag MR, De Faber JTHN, de Groot R, Verkooyen RP. Chlamydia trachomatis as a cause of neonatal conjunctivitis in Dutch infants. Pediatrics 121:e321-326, 2008.) Canada has discontinued neonatal ocular prophylaxis and will focus on expanded screening. Neonatal ocular prophylaxis in ineffective for prevention of perinatal chlamydial infection as we demonstrated in 1989 (Hammerschlag MR, Cummings CC, Roblin PM, Williams TH, Delke I. Efficacy of neonatal ocular prophylaxis for the prevention of chlamydial and gonococcal conjunctivitis. New Engl J Med 320:769-72, 1989.). At this point there is so little neonatal chlamydial infection in the US that treatment trials are not really possible.

On 2017 Sep 21, Margaret Hammerschlag commented:

The data reviewed here is not really new. The CDC's recommendations for screening and treating pregnant women in 1993 have resulted in a dramatic drop in perinatal chlamydia infection. We have seen only one case of chlamydial ophthalmia at my institution over the past 20 years and no cases of chlamydial pneumonia. We used to see 30-40 cases/year before screening. We have confirmed this by seroepidemiologc studies, one recently published online in Sex Transm Dis (Banniettis N, Thumu S, Weedon J, Szigeti A, Chotikanatis K, Hammerschlag MR, Kohlhoff SA. Seroprevalence of Chlamydia trachomatis in inner-city children and adolescents – implications for vaccine development. Sex Transm Dis, in press, 2017.). This is also confirmed by the observation that chlamydial ophthalmia is still very common in countries, like the Netherlands, that do not screen and treat pregnant women (Rours GIJG, Hammerschlag MR, De Faber JTHN, de Groot R, Verkooyen RP. Chlamydia trachomatis as a cause of neonatal conjunctivitis in Dutch infants. Pediatrics 121:e321-326, 2008.) Canada has discontinued neonatal ocular prophylaxis and will focus on expanded screening. Neonatal ocular prophylaxis in ineffective for prevention of perinatal chlamydial infection as we demonstrated in 1989 (Hammerschlag MR, Cummings CC, Roblin PM, Williams TH, Delke I. Efficacy of neonatal ocular prophylaxis for the prevention of chlamydial and gonococcal conjunctivitis. New Engl J Med 320:769-72, 1989.). At this point there is so little neonatal chlamydial infection in the US that treatment trials are not really possible.