OPHTHALMIA NEONATORUM

OPHTHALMIA NEONATORUM Neonatal conjunctivitis in the first month of life

OPHTHALMIA NEONATORUM The clinical presentation of conjunctivitis in the first 4 weeks of life is reported with widely varying frequencies in different parts of the world. For example, a large population receiving 1% silver nitrate prophylaxis in Los Angeles, California, had a frequency of 0.14%,whereas a population in Norway had a frequency of 18.9%,and another population in Kenya had a frequency of 17.8%.3 These studies are also examples of the variability of etiologic causations. It appears likely that Crede's important observations and the subsequent introduction of silver nitrate prophylaxis were in a population with predominantly gonococcal conjunctivitis with a frequency approaching 10%.

History At the turn of this century, many children admitted to schools for the blind in the United States had bilateral opacified corneas after gonococcal ophthalmia neonatorum. The widespread use of 1% silver nitrate prophylaxis after Crede's Credé's publication of his observations has made this cause of blindness rare. Many countries, including the United Kingdom and Sweden, have discontinued mandatory prophylaxis, as have many hospitals in the United States that are not required by state law to instill silver nitrate or another agent.

History A randomized, double-masked clinical trial comparing silver nitrate, erythromycin, and no eye prophylaxis in newborns not at risk for gonococcal infections demonstrated that both antimicrobial agents lower the rate of conjunctivitis but that any of the three choices are reasonable for infants born to women receiving prenatal care and who are screened for sexually transmitted diseases during pregnancy. Credé CSR: Die Verhutung der Augenentzundung der Neugeborenen. Acta Gyankol Gyänkol 18:367, 1881

OPHTHALMIA NEONATORUM Neonatal conjunctivitis in the first month of life PREDISPOSING FACTORS Organisms in vagina shed during delivery Premature rupture of membranes Long delivery Few tears and low levels of IgA Trauma to epithelial barrier Prophylaxis (antibiotics, silver nitrate)

AETIOLOGY OF NEONATAL CONJUNCTIVITIS The microbial causes of neonatal conjunctivitis that are probably acquired from the birth canal are N. gonorrhoeae, C. trachomatis, and herpes simplex virus. The organisms that cause the remaining cases of neonatal conjunctivitis are almost certainly acquired sometime after delivery and are not prevented by ocular prophylaxis. Most are bacterial and include Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Streptococcus group D, other Streptococcus sp, Pseudomonas sp, Serratia sp, Klebsiella sp, and Enterococcus sp. In many instances, an organism is not isolated. Infants who receive silver nitrate prophylaxis may develop a chemical conjunctivitis that is transient and distinguishable from infectious conjunctivitis.

Modern Prophylaxis The shedding of some microorganisms from the cervix during the third trimester is well documented. For example, 7% to 20% of women shed cytomegalovirus,7 and approximately 12% shed Chlamydia. Some women shed herpes simplex virus type 2 (HSV-2) during pregnancy even in the absence of typical genital lesions. If the screening of all pregnant women cannot be accomplished, the World Health Organization1has suggested screening women at high risk for delivering a baby who could develop neonatal conjunctivitis and the accompanying systemic involvements.

CHEMICAL CAUSES & TREATMENT:- Silver nitrate, antibiotics Onset in hours, lasts 24 hours

Chlamydia Chlamydia is a major sexually transmitted pathogen. The CDC estimates that there are 3 million new cases of chlamydial infection annually. The incidence of chlamydial infection seems to be directly related to the level of sexual activity and to geography. Handsfield and co-workers23 reported a prevalence approaching 25% in young, indigent, inner-city populations. Although the percentages of infection are higher in urban areas, chlamydial infections are widespread and cross all social strata, occurring in 4% to 10% of pregnant women nationwide. The direct and indirect costs of these infections approach $1 billion per year.

Chlamydia Infants whose mothers have untreated chlamydial infections antepartum have a 30% to 40% chance of developing chlamydial neonatal conjunctivitis postpartum. In addition, 10% to 20% of these children develop pneumonia related to Chlamydia. Perinatal chlamydial exposure may also cause localized infection in the nasopharynx, middle ear, vagina, and rectum.

CHLAMYDIA Is the commonest infectious cause 4-10% pregnant women infected Presents at 5-14 days 40% neonates infected :- watery conjunctivitis becoming purulent, papillary reaction (no follicles in newborn), +/- pseudomembranes, corneal scarring Complications: pneumonia, otitis media, rhinitis, GIT infection. DIAGNOSIS ELISA, Giemsa, culture, direct immunofluorescent antibodies (fastest). PCR TREATMENT Neonate- 50mg/kg erythromycin in 4 divided doses for 3 weeks, topical G tetracycline 1% Adults- 250mg QDS erythromycin for 3 weeks Prophylaxis- Oc tetracycline or Oc erythromycin within 1hr after birth

GONOCOCCAL CONJUNCTIVITIS N. gonorrhoeae is a gram-negative diplococcus. Humans are its only known reservoir. Gonococci have the ability to penetrate intact epithelial cells, and once inside the cell, they divide rapidly. Typically, the clinical picture of neonatal conjunctivitis related to N. gonorrhoeae includes the development of a hyperacute conjunctivitis associated with marked lid edema, chemosis, and purulent discharge, beginning 24 to 48 hours after birth. Conjunctival membranes may be present. With a delay in diagnosis, corneal ulceration may occur and can rapidly progress to perforation. Septicemia and meningitis are possible systemic involvements.

GONOCOCCAL Neisseria gonorrhoeae 75% bilateral Rare now due to antenatal screening (silver nitrate prophylaxis has been abandoned in the UK). Presents 1-2 days after birth Hyperacute purulent conjunctivitis +/- corneal ulceration and perforation DIAGNOSIS Gram stain (intracellular diplococci), culture TREATMENT 50,000u/kg penicillin in 2 divided doses for 7/7 or ceftriaxone 125mg stat IMI topical treatment unnecessary, but eyes should be kept clean

Gonococcal conjunctivitis It appears likely that Crede's important observations and the subsequent introduction of silver nitrate prophylaxis were in a population with predominantly gonococcal conjunctivitis with a frequency approaching 10%. Today, newborn gonococcal ocular infections are extremely uncommon in most populations. It has been estimated that there are perhaps a total of 2000 cases of gonococcal neonatal conjunctivitis annually in the United States

OTHER BACTERIAL Staphyloccus aureus, Strep. epidermidis, Streptococcus pneumoniae, E. coli, Pseudomonas, Haemophilus influenzae Usually at day 5 DIAGNOSIS By gram and culture. TREATMENT Neosporin ophthalmic covers most If Haemophilus:- need systemic ampicillin or cefuroxime as well

Bacterial conjunctivitis Classically, the onset of bacterial conjunctivitis is described as occurring on the fifth day. However, it is now recognized that it can occur anytime in the immediate postpartum period. The clinical picture is similar to those already described. Lid edema, chemosis, and conjunctival injection and discharge are variable and often indistinguishable from the same signs seen with other causes of neonatal conjunctivitis. In evaluation of an infant with suspected bacterial conjunctivitis, one should look for evidence of local trauma to the conjunctiva or cornea, because loss of the epithelial protective barrier often plays an important role in pathogenesis. Obstruction of the nasolacrimal duct secondary to infection must also be sought; if present and undetected, this may cause recalcitrant conjunctivitis.

Herpes simplex virus Although either herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2) can cause neonatal conjunctivitis, up to 70% of neonatal herpetic infections have been attributed to the genital strain, HSV Most neonatal HSV-1 infections seem to be related to contact with active infections ("fever blister" or "cold sores") in the immediate family during the perinatal period. HSV-2 is usually transmitted during passage through the birth canal or by transplacental mechanisms.

LABORATORY DIAGNOSIS The proper evaluation of neonatal conjunctivitis consists of immediate cytologic examination of conjunctival scrapings obtained with a metal spatula and appropriate microbial cultures. Gram-stained smears provide information regarding bacterial causes. Giemsa-stained smears provide information on possible causes on the basis of the inflammatory cell types present and the characteristics of any inclusion bodies . A Papanicolaou-stained smear provides evidence of herpes simplex virus infection.

Chlamydia The successful specific identification of C. trachomatis is based on cultures in special laboratories and identification with fluorescent monoclonal antibodies. However, the testing is not widely available, it is expensive, and the results are not available for 2 to 3 days. A number of tests have now become available that specifically identify Chlamydia on conjunctival smears with use of specific antibodies. These are more sensitive than examination of Giemsa-stained smears and are quite rapid, but they may require specific laboratory equipment. For example, a direct immunofluorescent monoclonal antibody stain for identification of chlamydial antigens on cells of conjunctival smears has a sensitivity of 100% and a specificity of 94%

Herpes Simplex type 2 Usually type II, within 2/52 Vesicular blepharitis +/- keratitis. Diagnosis Immunofluorescence, smears, culture. TREATMENT Topical / systemic acyclovir

Herpes Simplex type 2 Unless the patient has herpetic keratitis, there is no specific diagnostic clue. Findings include nonspecific lid edema, moderate injection of the bulbar conjunctiva, and usually nonpurulent, often serosanguineous, discharge. Microdendrites or geographic ulcers, rather than typical herpetic dendrites, are the most typical signs of corneal involvement in newborns. The exudate contains mononuclear cells or, if there is a conjunctival membrane, polymorphonuclear leukocytes. Clinical suspicion is enhanced by a maternal history of herpetic infection, the presence of a dendrite, or evidence of herpetic infection elsewhere on the body.

OPHTHALMIA NEONATORUM The treatment of herpes simplex virus infections in newborns should be based on the extent of involvement. Systemic and central nervous system infections with herpes simplex virus can be devastating. Therefore, the relative merits of combined topical and systemic antiviral therapy deserve special consideration. Most authorities believe all patients with any neonatal herpes infections require systemic therapy.