Separate chapters were prepared on screening for gonorrhea (Chapter 59) and Chlamydial infection (Chapter 60).
In 1989 the Laboratory Centre for Disease Control, Ottawa, received reports of 55,186 cases of chlamydial infection across Canada (excluding British Columbia and the Yukon Territory). In 1989-90 women aged 15 to 39 years accounted for 34,802 of the cases of genital chlamydial infection (excluding British Columbia and the Northwest Territories). Although chlamydial infection became nationally notifiable in 1990, reporting practices may vary between provinces and territories. More than 4 million cases of chlamydial infection occur each year in the U.S., and 155,000 infants are born to women with cervical infection. At a community health centre in Montreal, 7.1% of women presenting for a routine gynecologic examination were found to have C. trachomatis infection. Chlamydial infection can cause pseudomembranous or membranous conjunctivitis in the newborn that may result in conjunctival scarring and corneal infiltrates. The recorded risk of conjunctivitis in infants born to women with C. trachomatis infection has varied from 18% to 50%.
In descending order of frequency, the infectious causes of ophthalmia neonatorum are C. trachomatis, Staphylococcus, N. gonorrhoeae, Streptococcus, Hemophilus and, rarely, herpes simplex virus, molluscum contagiosum virus and papilloma virus.
In a prospective controlled clinical trial Lund and associates<4> compared the effectiveness of 1% silver nitrate solution and 0.5% erythromycin ointment in the obstetric units of three hospitals in Capetown, South Africa. In the 13 months before the trial began, when ocular prophylaxis was not practised, the incidence of gonococcal ophthalmia neonatorum in the study area was 273 per 100,000 live births. Twenty-eight cases of gonococcal ophthalmia neonatorum were diagnosed among 24,575 births during the 13-month pretrial period, as compared with only five cases among 23,883 births during the 12 months after the prophylaxis was introduced (p<0.001). Four of the five infected infants had inadvertently not received prophylaxis. During the same two periods the incidence rates of gonococcal ophthalmia neonatorum in three midwife obstetric units that did not practise ocular prophylaxis were unchanged (39 cases in the pretrial period vs. 38 in the trial period).
In a prospective clinical trial,<5> the efficacy of prophylaxis with silver nitrate drops, tetracycline ointment and erythromycin ointment were compared among 12,431 infants born during the study period. Treatment was changed monthly. Gonococcal ophthalmia neonatorum occurred in one infant in the silver nitrate group, three in the tetracycline group and four in the erythromycin group; these differences were not statistically significant. Seven mothers of these eight infants had received no prenatal care, and five were drug abusers. The respective risks of gonococcal ophthalmia neonatorum after prophylactic treatment were 0.03%, 0.07% and 0.1%.
Laga and colleagues<2> compared the efficacy of 1% silver nitrate drops and 1% tetracycline ointment in a controlled trial involving 2,732 newborns in Kenya. The prevalence rate of intrapartum gonococcal infection was 6.4%; the frequency of multiresistant strains was high. The drugs were alternated every week for 15 months and were administered within 30 minutes after birth. To evaluate the protective efficacy of the two regimens mother-infant transmission rates were compared with those observed in a cohort study at the same hospital before prophylaxis was given at birth. After the silver nitrate and tetracycline prophylaxis the prevalence rates of gonococcal ophthalmia neonatorum were 0.4% and 0.1% respectively (difference not statistically significant). Attack rates in newborns exposed to N. gonorrhoeae at birth were 7.0% among those who received the silver nitrate and 3.0% among those who received the tetracycline (95% confidence interval: 3.4% to 11.4%). Thus, compared with the rates among the historical controls, the incidence of gonococcal ophthalmia neonatorum was 83% lower among infants treated with silver nitrate and 93% lower among those treated with tetracycline. Two factors may have contributed to the higher attack rates in the silver nitrate group. First, three of the five cases of infection occurred during the first week of the study, before nurses were fully familiar with the technique for applying the silver nitrate drops. Second, a substantial number of patients were lost to follow-up: 31% by day 7 and 57% by day 28.
In summary, the available evidence indicates that 1% silver nitrate solution, 1% tetracycline ointment and 0.5% erythromycin ointment have comparable efficacy in preventing gonococcal infection. On the basis of cost estimates and the attack rates reported in the Kenyan trial, tetracycline is more cost-effective than silver nitrate. Unfortunately, the only costs considered were those of the antibiotics used in prophylaxis and treatment. Given this limitation as well as the differences in 1) the price and availability of antibiotics or silver nitrate ampoules; and 2) the prevalence of gonococcal infection and PPNG strains, these results cannot be generalized to Canada.
In a randomized clinical trial Butterfield, Emde and Svejda<8> compared the effect on bonding of silver nitrate prophylaxis given immediately after birth and 1 hour after birth. Although mothers in the first group noted diminished eye openness it did not alter their baby-focused attention or prevent their pleasure and excitement in the initial encounter. For fathers the increased eye openness associated with delayed prophylaxis appeared to encourage more affectionate attention. These observations suggested that there might be some merit in delaying silver nitrate prophylaxis for a short time after birth but did not indicate any significant effect on ultimate parent-infant attachment.
The ideal prophylactic agent would be both nontoxic and highly effective in preventing gonococcal, chlamydial and nongonococcal, nonchlamydial ophthalmia neonatorum. Since gonococcal ophthalmia poses the greatest threat to a childs vision it is generally believed that the principal goal of ocular prophylaxis should be the prevention of gonococcal infection.
The U.S. Preventive Services Task Force has recommended that endocervical culture for gonorrhea be performed at the first prenatal visit in all pregnant women in high-risk categories.<9> Further, an ophthalmic antibiotic (erythromycin 0.5% or tetracycline 1% ophthalmic ointment) should be applied topically to the eyes of all newborns immediately after birth.
There is good evidence to support the use of universal ocular prophylaxis for gonococcal ophthalmia, at least in the absence of universal prenatal screening for gonorrhea. Prophylaxis should be administered as soon as possible (within 1 hour) after birth; 1% silver nitrate solution, 1% tetracycline ointment and 0.5% erythromycin ointment are approximately comparable in efficacy.
The occurrence of transient chemical conjunctivitis in some infants after silver nitrate prophylaxis is a minor disadvantage. The risk can be reduced to some degree through the use of single-dose ampoules. Alternatively, tetracycline or erythromycin ointment can be used. Additional considerations in choosing a prophylactic agent are individual preference, cost and the theoretic possibility that chemical conjunctivitis due to silver nitrate prophylaxis might adversely affect parent-infant bonding.
There is poor evidence to support the use of neonatal ocular prophylaxis with any agent for chlamydial ophthalmia neonatorum.
This review was initiated in March 1990 and recommendations were finalized by the Task Force in September 1990. A report with a full reference list was published in November 1992 (see reference #1).
Link to Structured Abstract of this review
Link to Summary Table of this review
Link to Selected References list of this review
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Task Force on Preventive Health Care
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© 1994 Minister of Supply and Services Canada.
Last modified March 30, 1998.